Opthea Limited (OPT) 20-F 28 Sep 23 2023 FY Annual report (foreign) Financial data

Document and Entity Information

Document and Entity Information	12 Months Ended
	Jun. 30, 2023 shares
Document Information [Line Items]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Jun. 30, 2023
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Entity Registrant Name	OPTHEA LIMITED
Entity Central Index Key	0001815620
Current Fiscal Year End Date	--06-30
Entity File Number	001-39621
Entity Incorporation, State or Country Code	C3
Entity Address, Address Line One	Level 4
Entity Address, Address Line Two	650 Chapel Street
Entity Address, City or Town	South Yarra
Entity Address, Postal Zip Code	3141
Document Annual Report	true
Document Transition Report	false
Document Registration Statement	false
Document Shell Company Report	false
ICFR Auditor Attestation Flag	false
Document Accounting Standard	International Financial Reporting Standards
Entity Address, Country	AU
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Interactive Data Current	Yes
Auditor Firm ID	1070
Auditor Name	Deloitte Touche Tohmatsu
Auditor Location	Parramatta, Australia
Business Contact
Document Information [Line Items]
Entity Address, Address Line One	Level 4
Entity Address, Address Line Two	650 Chapel Street
Entity Address, City or Town	South Yarra
Entity Address, Postal Zip Code	3141
City Area Code	+61 3
Local Phone Number	9826 0399
Contact Personnel Name	Dr Megan Baldwin
Contact Personnel Email Address	info@opthea.com
Entity Address, Country	AU
American Depository Shares
Document Information [Line Items]
Trading Symbol	OPT
Title of 12(b) Security	American Depositary Shares, each representing eight ordinary shares
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding	11,613,763
Ordinary shares [member]
Document Information [Line Items]
No Trading Symbol Flag	true
Title of 12(b) Security	Ordinary shares, no par value
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding	467,159,374

Consolidated Statements of Prof

Consolidated Statements of Profit or Loss and Other Comprehensive Income - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Profit or loss [abstract]
Revenue	$ 108,406	$ 90,683	$ 68,613
Other income	276,869	108,322	26,950
Operating expenses:
Research and development	(122,128,314)	(78,654,217)	(25,891,851)
Patent and intellectual property expenses	(166,826)	(160,501)	(428,901)
Administration expenses	(28,115,929)	(17,922,419)	(13,418,193)
Interest expense on DFA	(13,462,160)
Finance income	3,227,496	235,468	372,001
Fair value adjustment gain on DFA	12,302,160
Net foreign exchange (loss)/gain	(489,137)	(2,813,993)	(11,011,961)
Loss before income tax	(148,447,435)	(99,116,657)	(50,283,342)
Income tax benefit	5,926,350	6,299,286	4,938,846
Loss for the year	(142,521,085)	(92,817,371)	(45,344,496)
Items that will not be reclassified subsequently to profit or loss:
Fair value gains on investments in financial assets			469,767
Other comprehensive income for the period, net of tax			469,767
Total comprehensive loss for the year	(142,521,085)	(92,817,371)	(44,874,729)
Loss for the year is attributable to:
Owners of the Company	(142,521,085)	(92,817,371)	(45,344,496)
Loss for the year	(142,521,085)	(92,817,371)	(45,344,496)
Total comprehensive loss for the year is attributable to:
Owners of the Company	(142,521,085)	(92,817,371)	(44,874,729)
Total comprehensive loss for the year	$ (142,521,085)	$ (92,817,371)	$ (44,874,729)
Loss per share attributable to the owners of the Company:
- Basic loss per share (cents)	$ (0.3220)	$ (0.2640)	$ (0.1415)
- Diluted loss per share (cents)	$ (0.3220)	$ (0.2640)	$ (0.1415)

Consolidated Statements of Fina

Consolidated Statements of Financial Position - USD ($)	Jun. 30, 2023	Jun. 30, 2022
Current assets:
Cash and cash equivalents	$ 89,188,713	$ 44,631,293
Current tax receivable	5,926,350	6,299,286
Receivables	636,564	257,668
Prepayments	2,634,671	8,720,195
Total current assets	98,386,298	59,908,442
Non-current assets:
Property and equipment, net	33,035	28,082
Right-of-use assets	168,451
Prepayments	53,535	110,295
Total non-current assets	255,021	138,377
Total assets	98,641,319	60,046,819
Current liabilities:
Payables (includes amounts to a related party of US$900,000)	17,891,854	11,445,498
Lease liabilities	97,485
Provisions	753,300	596,203
Total current liabilities	18,742,639	12,041,701
Non-current liabilities:
Lease liabilities	84,226
Financial liability due to a related party	85,660,000
Provisions	7,631	27,974
Total non-current liabilities	85,751,857	27,974
Total liabilities	104,494,497	12,069,675
Net Assets	(5,853,178)	47,977,144
Equity
Contributed equity	320,883,552	235,277,217
Accumulated Loss	(359,462,438)	(216,941,353)
Reserves	32,725,708	29,641,280
Total Equity	$ (5,853,178)	$ 47,977,144

Consolidated Statements of Fi_2

Consolidated Statements of Financial Position (Parenthetical) - USD ($)	Jun. 30, 2023	Jun. 30, 2022
Statement of financial position [abstract]
Amount Due To Related Party	$ 900,000	$ 900,000

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($)	Total	Contributed Equity	Pre-funded Warrants	Share-based Payment Reserve	Fair Value of Investment Reserve	FX Translation Reserve	Accumulated Deficit
Beginning balance at Jun. 30, 2020	$ 44,567,972	$ 113,852,364		$ 3,116,080	$ 551,409	$ 5,827,605	$ (78,779,486)
Fair value gains on investments in financial assets	469,767				469,767
Net loss for the year	(45,344,496)						(45,344,496)
Total Comprehensive income and expense for the period	(44,874,729)				469,767		(45,344,496)
Issuance of ordinary shares and pre-funded warrants on NASDAQ listing net of issuance cost $10,126,959	117,023,620	105,477,591	$ 11,546,029
Issuance of ordinary shares on exercise of pre-funded warrants net of issuance costs $1,099,412		11,546,029	$ (11,546,029)
Exercise of options granted under LTIP and NED plan		3,271,542		(3,271,542)
Recognition of share-based payment	3,897,638			3,897,638
Exchange on conversion	14,671,267			345,474	64,235	14,261,558
Ending balance at Jun. 30, 2021	135,285,768	234,147,526		4,087,650	1,085,411	20,089,163	(124,123,982)
Net loss for the year	(92,817,371)				(92,817,371)		(92,817,371)
Total Comprehensive income and expense for the period	(92,817,371)						(92,817,371)
Exercise of options granted under LTIP and NED plan	257,175	1,129,691		(872,516)
Recognition of share-based payment	5,251,572			5,251,572
Ending balance at Jun. 30, 2022	47,977,144	235,277,217		8,466,706	1,085,411	20,089,163	(216,941,353)
Net loss for the year	(142,521,085)				(142,521,085)		(142,521,085)
Total Comprehensive income and expense for the period	(142,521,085)						(142,521,085)
Issuance of ordinary shares net of issuance costs $4,531,040	81,815,357	81,815,357
Exercise of options granted under LTIP and NED plan	1,040,720	3,790,978		(2,750,258)
Recognition of share-based payment	5,834,686			5,834,686
Ending balance at Jun. 30, 2023	$ (5,853,178)	$ 320,883,552		$ 11,551,134	$ 1,085,411	$ 20,089,163	$ (359,462,438)

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2021
Issuance of ordinary shares and pre-funded warrants, net of issuance cost	$ 4,531,040
Ordinary shares [member]
Issuance of ordinary shares and pre-funded warrants, net of issuance cost	$ 4,531,040	$ 10,126,959
Pre-funded Warrants
Issuance of ordinary shares and pre-funded warrants, net of issuance cost		1,099,412
Exercise of Warrants
Issuance of ordinary shares and pre-funded warrants, net of issuance cost		$ 1,099,412

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Cashflow from operating activities
Interest received	$ 3,121,594	$ 216,422	$ 390,128
Royalty and license income received	3,826	90,683	103,031
Grant and other income	276,869	455,807	26,949
Payment of lease interest	(17,148)	(5,920)	(5,782)
Payments to suppliers, employees and for research & development and intellectual property costs (inclusive of GST)	(130,292,806)	(77,064,842)	(51,894,593)
Research and development tax incentive scheme credit received	6,299,286	4,972,898	5,834,100
Net cash flows used in operating activities	(120,608,379)	(71,334,952)	(45,546,167)
Cash flow from investing activities:
Purchase of plant and equipment	(21,954)	(16,910)	(12,702)
Proceeds from sale of financial assets			669,184
Net cash used in investing activities	(21,954)	(16,910)	656,482
Cash flows from financing activities:
Payment of lease liabilities	(70,966)	(85,578)	(87,373)
Net proceeds on issue of shares	81,815,358		105,477,591
Net proceeds on issue of pre-funded warrants			11,546,029
Net proceeds from DFA	84,500,000
Cash received for ordinary shares issued on exercise of options	1,040,718	257,175
Net cash provided by financing activities	167,285,110	171,597	116,936,247
Increase in cash and cash equivalents	46,654,777	(71,180,265)	72,046,562
Effects of exchange rate changes on the balance of cash held in foreign currencies	(2,097,357)	(2,381,619)	3,495,757
Cash and cash equivalents at beginning of period	44,631,293	118,193,177	42,650,858
Cash and cash equivalents at end of period	$ 89,188,713	$ 44,631,293	$ 118,193,177

Reporting Entity

Reporting Entity	12 Months Ended
	Jun. 30, 2023
Reporting Entity [Abstract]
Reporting Entity	Note 1 Reporting Entity Opthea Limited (the Company) is a listed public company incorporated in Australia. The address of its registered office and principal place of business is: Suite 0403, Level 4, 650 Chapel Street, South Yarra, VIC 3141, Australia. These consolidated financial statements comprise the Company and its subsidiaries (together referred to as the Group). The Group’s principal activity is the development of new drugs for the treatment of eye diseases.

Basis of Accounting

Basis of Accounting	12 Months Ended
	Jun. 30, 2022
Basis Of Accounting [Abstract]
Basis of Accounting	Note 2. Basis of Accounting These financial statements are general purpose financial statements which have been prepared in accordance with International Financial Reporting Standards (“or IFRS”) as issued by the International Accounting Standards Board (the “IASB”). The financial statements comprise the consolidated financial statements of the Group. For the purposes of preparing the consolidated financial statements, the Company is a for‑profit entity. The financial statements were authorized for issue by the directors on September 28, 2023. Going Concern For the year ended June 30, 2023, the Group incurred a loss after income tax of $ 142,521,085 (2022: $ 92,817,371 ) and had net cash outflows from operating activities of $ 120,608,379 (2022: $ 71,334,952 ). As at June 30, 2023, the Group had cash and cash equivalents of $ 89,188,713 (2022: $ 44,631,293 ), net current assets of $ 79,643,659 (2022: $ 47,866,741 ), and was in a negative net asset position of $ 5,853,178 (2022: positive $ 47,977,144 ). The consolidated financial statements have been prepared on a going concern basis, which contemplates continuity of normal activities and realization of assets and settlement of liabilities in the normal course of business. As the Group is still in the research and development phase, the ability of the Group to continue its development activities as a going concern is dependent upon it deriving sufficient cash from investors and from funding provided under the Development Funding Agreement (‘DFA or Agreement’) with Carlyle and Abingworth. Of the initial total funding of US$ 120 million, US$ 50 million was received by the Group in September 2022 and another US$ 35 million was received in December 2022. The Group expects to receive the remaining US$ 35 million no later than December 31, 2023. Subsequent to June 30, 2023, the Group was notified that a new co-investor of Carlyle and Abingworth intends to participate in a funding under the DFA of US$ 50 million to increase total DFA funding from US$ 120 million to US$ 170 million, which is subject to the co-investor’s final due diligence and receipt of regulatory and tax approvals, appropriate documentation and compliance with closing conditions. Upon completion of the final due diligence, receipt of approvals, execution of the appropriate documentation and satisfaction of the closing conditions, the Group expects to receive the additional US$ 50 million. While the Group anticipates that the due diligence will be completed to the satisfaction of the co-investor, the necessary approvals will be obtained, the appropriate documentation will be executed and that all closing conditions will be satisfied, there is no assurance that the Group will ultimately receive the additional US$ 50 million. If the additional US$ 50 million is not received by June 30, 2024, the Group will need to raise additional funds or reduce expenditures to continue as a going concern . Concurrently with the receipt of the notice from the co-investor to increase its investment, the Group entered into binding commitments for the private placement of ordinary shares and entitlement rights and accompanying options for aggregate gross proceeds of approximately A$ 90 million (approximately US$ 58 million) (the ‘Equity Offering’). The Equity Offering consists of two closings, of which the first closing of A$ 73 million (US$ 47 million) consisting of a placement offering and an acceleration portion of an Accelerated Non-Renounceable Entitlement Offer (“ANREO”) occurred on September 1, 2023. The second closing of A$ 17 million (US$ 11 million), representing the remaining institutional and retail portion of the ANREO, has been underwritten, occurred on September 20, 2023. The shares were issued and cash received on September 20, 2023. See Note 37, Events after the balance sheet date, for further information . While we expect that with our cash on hand at June 30, 2023 of $ 89 million, together with the net proceeds from the Equity Offering and the $ 85 million expected under the Funding Agreement, we will be able to fund our operations through the third calendar quarter of 2024, such proceeds will not be sufficient to fully fund all anticipated costs of th Phase 3 clinical trials to top-line data. We will need to raise significant additional funds to complete the efficacy and safety phase of both studies and to report top-line data. The Directors and management have considered the cash flow forecasts including the funding requirements of the business as well as the funding expected to be raised through the Agreement and Equity Offering. They have also considered the Group’s key risks and uncertainties affecting the likely development of the business, as well as the conditions set forth in the Agreement. Based on this assessment, the Directors and management believe that the conditions in the DFA can be met and that the Group has adequate resources to continue normal activities and realize its assets and settle its liabilities in the normal course of business. Accordingly, the directors have prepared the financial statements on the going concern basis. Should the Group not be able meet the conditions in the DFA to increase the total funding from US$ 120 million to US$ 170 million, the Group will need to raise additional funds or reduce expenditures to continue as a going concern. Based on that, substantial doubt exists as to whether the Group will continue as a going concern. The financial statements do not include any adjustments related to the recoverability and classification of recorded asset amounts or to the amounts and classification of liabilities that might be necessary should the Group not continue as a going concern.

Summary of Accounting Policies

Summary of Accounting Policies	12 Months Ended
	Jun. 30, 2023
Description Of Business And Summary Of Significant Accounting Policies [Abstract]
Summary of Accounting Policies	Note 3. Summary of Accounting Policies The consolidated financial statements have been prepared using the significant accounting policies and measurement bases summarized below. Basis of measurement The consolidated financial statements have been prepared on a historical cost basis, except for the investments classified as financial assets, which have been measured at fair value. All amounts are presented in United States dollars unless otherwise stated. Functional currency An entity’s functional currency is the currency of the primary economic environment in which the entity operates. During 2021, the Group’s operations continued to move further towards being US$ denominated and several other factors during the period have also contributed to the Group changing its functional currency during the year, such as the completion of U.S. initial public offering (IPO) and the Nasdaq listing in October 2020, opening a US subsidiary in May 2021 for a planned expansion into the US, and expanding the Board of Directors with the appointment of now five US based Directors. A significant element in the Group’s assessment to change the functional currency resulted from the significant increase in expenses denominated in US dollars relating to advanced clinical trials since the commencement of Phase 3 trials in March 2021. These changes, as well as the fact that the Group’s principal source of financing is now the U.S. capital market and all of the Group’s budgeting and planning is conducted solely in dollars led to the Company determining that the U.S. dollar (US$) best represents the currency of the primary economic environment in which the entity now operates. Accordingly, the Group changed its functional currency from Australian dollar (A$) to U.S. dollar (US$) effective January 1, 2021. Presentation Currency Following the change in functional currency, the Group changed its presentation currency from Australian dollars (A$) to US$. The change in presentation currency was made to better reflect the Group’s business activities and to enhance access to U.S. capital markets. Prior to the change, the Group reported its financial statements in Australian dollars (A$). A change in presentation currency is a change in accounting policy which is accounted for retrospectively during 2021. In making this change in presentation currency, the Group followed the requirements set out in IAS 21 The Effects of Changes in Foreign Exchange Rates . As required by IAS 21, the consolidated statement of profit or loss and other comprehensive income and the consolidated statement of cash flows for each period have been translated into the presentation currency using the average exchange rates prevailing during each reporting period. All assets and liabilities have been translated using the exchange rates prevailing at the consolidated statement of financial position dates. Shareholders’ equity transactions have been translated using the rates of exchange in effect as of the dates of various capital transactions. All resulting exchange differences arising from the translation are included as a separate component of other comprehensive income. All comparative financial information has been restated in fiscal year 2021 to reflect the Group’s results as if they had been historically reported in US$ and the effect on the consolidated financial statements resulted in an addition to the foreign currency translation reserve of US$ 14.3 million for financial year 2021. Change in Presentation of Other Income The Group changed its presentation of Other income by reclassifying interest income out of Other income and into Finance Income – interest income to better reflect the nature of the related amounts as finance income. This reclassification had no effect on the reported results of operations. Basis of consolidation The consolidated financial statements incorporate the financial statements of the Company and its subsidiaries. Control is achieved when the Company: • Has power over the investee; • Is exposed, or has rights, to variable returns from its involvement with the investee; and • Has the ability to use its power to affect its returns. Consolidation of a subsidiary begins when the Company obtains control over the subsidiary and ceases when the Company loses control of the subsidiary. All intragroup assets and liabilities, equity, income, expenses and cash flows relating to transactions between members of the Group are eliminated in full on consolidation. Foreign currency translation i. Functional and presentation currency As of January 1, 2021 the Group determined that its functional and presentation currency had changed from Australian Dollars to United States Dollars. Therefore, the functional and presentation currency of the Group is the United States dollars (US$). ii. Transactions and balances Transactions in foreign currencies are initially recorded in the functional currency by applying the exchange rates ruling in place at the date of the transaction. Monetary assets and liabilities denominated in foreign currencies are retranslated at the rate of exchange ruling in place at the reporting date. Non‑monetary items that are measured in terms of historical cost in a foreign currency are translated using the exchange rate as of the date of the initial transaction. Non‑monetary items measured at fair value in a foreign currency are translated using the exchange rates at the date when the fair value was determined. Financial assets and liabilities Recognition and derecognition of financial assets Purchases and sales of financial assets that require delivery of assets within the time frame generally established by regulation or convention in the marketplace are recognized on the trade date, i.e., the date that the Group commits to purchase the asset. Financial assets are derecognized when the right to receive cash flows from the financial assets has expired or when the entity transfers substantially all the risks and rewards of the financial assets. If the entity neither retains nor transfers substantially all of the risks and rewards, it derecognizes the asset if it has transferred control of the assets. When financial assets are recognized initially, they are measured at fair value, plus directly attributable transaction costs. Cash and cash equivalents Cash and cash equivalents in the statement of financial position comprise cash at bank and in hand and short‑term deposits with an original maturity of three months or less that are readily convertible to known amounts of cash and which are subject to an insignificant risk of changes in value. For the purposes of the statement of cash flows, cash and cash equivalents consist of cash and cash equivalents as defined above. Other receivables Other receivables generally comprise bank interest receivable, other receivables from external parties and Goods and Services Tax (GST) credits receivable and are recognized and carried at original invoice amount less an allowance for any uncollectible amounts. The amounts are usually received within 30 to 60 days of recognition. The Group measures the loss allowance for receivables at an amount equal to lifetime expected credit losses (ECL). The ECL on receivables are estimated under the simplified approach as permitted under IFRS 9 “Financial Instruments.” This uses a provision matrix by reference to past experience of the debtor and an analysis of the debtor’s current financial position, adjusted for factors that are specific to the debtors and general economic conditions of the industry in which the debtors operate. The Group writes off a receivable when there is information indicating that the debtor is in severe financial difficulty and there is no realistic prospect of recovery. Investments Investments in financial assets comprise of the Group’s non‑current investments in listed companies. On initial recognition, the Group may make an irrevocable election (on an instrument‑by‑instrument basis) to designate investments in equity instruments as fair value through other comprehensive income (FVTOCI). Designation at FVTOCI is not permitted if the equity instrument is held for trading. Investments in equity instruments at FVTOCI are initially measured at fair value plus transaction costs. Subsequently, they are measured at fair value with gains or losses arising from changes in the fair value recognized in other comprehensive income and accumulated in the fair value of investments reserve. The fair values of investments in financial assets that are actively traded in organized financial markets is determined by reference to quoted market bid prices at the close of business on the reporting date. The cumulative gain or loss is not reclassified to profit or loss on disposal of the equity instruments. Dividends on these investments in equity instruments are recognized in profit or loss in accordance with International Financial Reporting Standards. Finance income Almost all of the Group’s finance income is earned on short‑term bank deposits, and as such, finance income is recognized when the Group’s right to receive the payment is established. Payables Payables are carried at amortized cost and due to their short‑term nature, they are not discounted. They represent liabilities for goods and services provided to the Group prior to the end of the financial year that are unpaid and arise when the Group becomes obliged to make future payments in respect of the purchase of these goods and services. The amounts are unsecured and are usually paid within 30 days of recognition. Financial liabilitie s Financial liabilities are recognized in the Group’s statement of financial position when the Group becomes a party to the contractual provisions of the instrument. Financial liabilities are initially measured at fair value. Transaction costs that are directly attributable to the acquisitions or issue of financial liabilities (other than financial liabilities at fair value through profit or loss) are deducted from the fair value of the financial liabilities, as appropriate, on initial recognition. Subsequent measurement of the liability will be at its amortized cost, subject to any re-measurement of the obligation for changes in assumptions. Amortized cost and effective interest method The effective interest method is a method of calculating the amortized cost of an instrument and of allocating interest expense over the relevant period. The effective interest rate is the rate that exactly discounts estimated future cash payments through the expected life of the financial liability, or (where appropriate) a shorter period, to the amortized cost of the financial liability. Interest expense is recognized in profit and loss and is included in the “Interest expense on DFA” line item. Equipment Equipment is stated at historical cost less accumulated depreciation and any accumulated impairment losses. Depreciation is calculated on a straight‑line basis over their useful economic lives as follows: • Equipment and furniture – 3 to 10 years; and • Leasehold improvements – 8 years or the term of the lease if shorter. The assets’ residual values, useful lives and amortization methods are reviewed, and adjusted if appropriate, at each financial year end. An item of equipment is derecognized upon disposal or when no further economic benefits are expected from its use or disposal. Research and development costs Research costs are expensed as incurred. An intangible asset arising from the development expenditure on an internal project will only be recognized when the Group can demonstrate the technical feasibility of completing the intangible asset so that it will be available for use or sale, its intention to complete and its ability to use or sell the asset, how the asset will generate future economic benefits, the availability of resources to complete the development and the ability to measure reliably the expenditure attributable to the intangible asset during its development. As of June 30, 2023, 2022 and 2021, the Group is in the research phase and has not capitalized any development costs to date. Provisions and employee benefits i. Wages, salaries, annual leave and sick leave Liabilities for wages and salaries, including non‑monetary benefits and annual leave expected to be settled within 12 months of the reporting date are recognized in current provisions in respect of employees’ services up to the reporting date. They are measured at the amounts expected to be paid when the liabilities are settled. Expenses for non‑accumulating sick leave are recognized when the leave is taken and are measured at the rate paid or payable. ii. Long service leave The liability for long service leave is recognized in the provision for employee benefits and measured as the present value of expected future payments to be made in respect of services provided by employees up to the reporting date. Consideration is given to expected future wage and salary levels, experience of employee departures, and periods of service. Expected future payments are discounted using market yields at the reporting date on bonds with terms to maturity that match, as closely as possible, the estimated future cash outflows. Share‑based payment transactions The Group provides benefits to directors and employees (including key management personnel) of the Group in the form of share‑based payments, whereby employees render services in exchange for shares or rights over shares (equity‑settled transactions). The cost of these equity‑settled transactions with employees is measured by reference to the fair value at the date at which they are granted. Binomial models are used to value the options issued. The cost of the equity‑settled transactions is recognized, together with a corresponding increase in equity, over the period in which the performance conditions are fulfilled (the vesting period), ending on the date on which the relevant employees become fully entitled to the award (the vesting date). The charge to profit or loss for the period is the cumulative amount less the amounts already charged in previous periods. There is a corresponding credit to equity. Until an award has vested, any amounts recorded are contingent and will be adjusted if more or fewer awards vest than were originally anticipated to do so. Contributed equity Ordinary shares are classified as equity. Incremental costs directly attributable to the issue of new shares or options are shown in equity as a deduction, net of tax, from the proceeds. Revenue recognition License revenue in connection with licensing of the Group’s intellectual property (including patents) to customers is recognized as a right to use the Group’s intellectual property as it exists at the point in time in which the license is granted. This is because the contracts for the license of intellectual property are distinct and do not require, nor does the customer reasonably expect, that the Group will undertake further activities that significantly affect the intellectual property to which the customer has the rights. Although the Group is entitled to sales‑based royalties from the eventual sales of goods and services to third parties using the intellectual property licensed, these royalty arrangements do not in themselves indicate that the customer would reasonably expect the Group to undertake such activities, and no such activities are undertaken or contracted in practice. Accordingly, the promise to provide rights to the Group’s intellectual property is accounted for as a performance obligation satisfied at a point in time. The following consideration is received in exchange for licenses of intellectual property: • Up‑front license fees – these are fixed amounts and are recognized at the point in time when the Group transfers the intellectual property to the customer. • Sales‑based royalties – these are variable consideration amounts promised in exchange for the license of intellectual property and are recognized when the sales to third parties occur given the performance obligation to transfer the intellectual property to the customer is already satisfied. During the years ended June 30, 2023, 2022 and 2021, the Group’s only revenue related to sales‑based royalties. Income tax Current tax Current tax assets and liabilities for the current and prior periods are measured at the amount expected to be recovered from or paid to the taxation authorities based on the current period’s taxable income. The tax rates and tax laws used to compute the amount are those that are enacted or substantively enacted by the reporting date. Research and development tax incentive The Research and Development (R&D) Tax Incentive Scheme is an Australian Federal Government program under which eligible companies with annual aggregated revenue of less than A$ 20 million can receive cash amounts equal to 43.5 % of eligible research and development expenditures from the Australian Taxation Office (ATO). The R&D Tax Incentive Scheme incentive relates to eligible expenditure incurred in Australia and, under certain circumstances, overseas on the development of the Group’s lead candidate, OPT‑302. The R&D tax incentive is applied annually to eligible expenditure incurred during the Group’s financial year following annual application to AusIndustry, an Australian governmental agency, and subsequent filing of its Income Tax Return with the ATO after the financial year end. The Group estimates the amount of R&D tax incentive after the completion of the financial year based on eligible Australia and overseas expenditures incurred during that year. The Group has presented incentives in respect of the R&D Tax Incentive Scheme within income tax benefit in the Statements of Profit or Loss and Other Comprehensive Income by analogizing with IAS 12 “Income Taxes”. Deferred tax Deferred income tax is provided on all temporary differences at the reporting date between the tax bases of assets and liabilities and their carrying amounts for financial reporting purposes. Deferred income tax liabilities are recognized for all taxable temporary differences except when the deferred income tax liability arises from the initial recognition of goodwill or of an asset or liability in a transaction that is not a business combination and that, at the time of the transaction, affects neither the accounting profit nor taxable profit or loss. Deferred income tax assets are recognized for all deductible temporary differences, carry forward of unused tax assets (or credits) and unused tax losses, to the extent that it is probable that taxable profit will be available against which the deductible temporary differences, and the carry forward of unused tax credits and unused tax losses can be utilized, except when the deferred income tax asset relating to the deductible temporary differences arises from the initial recognition of an asset or liability in a transaction that is not a business combination and, at the time of the transaction, affects neither the accounting profit or taxable profit or loss. The carrying amount of deferred income tax assets is reviewed at each reporting date and reduced to the extent that it is no longer probable that sufficient taxable profit will be available to allow all or part of the deferred income tax asset to be utilized. Unrecognized deferred income tax assets are reassessed at each reporting date and are recognized to the extent that it has become probable that future taxable profit will allow the deferred tax asset to be recovered. Deferred income tax assets and liabilities are measured at the tax rates that are expected to apply to the year when the asset is realized or the liability is settled, based on tax rates (and tax laws) that have been enacted or substantively enacted at balance date. Income taxes relating to items recognized directly in equity are recognized directly in equity and not in profit or loss. Tax consolidation legislation Tax consolidation is a system adopted by the ATO that treats a group of entities as a single entity for tax purposes. Opthea Limited and its 100 % owned Australian domiciled subsidiary formed a tax consolidated group effective July 1, 2003. The head entity, Opthea Limited, and its controlled entity, Vegenics Pty Ltd, are current members of the tax consolidated group and account for their own current and deferred tax amounts. Members of the tax consolidated group have adopted the “separate taxpayer within group” method to allocate the current and deferred tax amounts to each entity within the Group. This method requires adjustments for transactions and events occurring within the tax consolidated group that do not give rise to a tax consequence for the Group or that have a different tax consequence at the level of the Group. This method requires adjustments for transactions and events occurring within the tax consolidated group that do not give rise to a tax consequence for the Group or that have a different tax consequence at the level of the Group. The head entity which is the parent entity, in assuming the net unused tax losses and unused relevant tax credits, has recognized reductions to investments in subsidiaries and where the amount of tax losses assumed is in excess of the carrying value of the investment, the parent has recognized the difference as a distribution from subsidiaries in profit or loss. Other taxes Revenues, expenses, assets and liabilities are recognized net of the amount of GST except: • When the GST incurred on a purchase of goods and services is not recoverable from the taxation authority, in which case the GST is recognized as part of the cost of acquisition of the asset or as part of the expense item as applicable; and • Receivables and payables are stated with the amount of GST included. The net amount of GST recoverable from, or payable to the taxation authority is included as part of receivables or payables in the statement of financial position. Cash flows are included in the statement of cash flows on a gross basis and the GST component of cash flows arising from investing and financing activities, which is recoverable from, or payable to, the taxation authority is classified as part of operating cash flows. Commitments and contingencies are disclosed net of the amount of GST recoverable from, or payable to, the taxation authority.

Critical Accounting Judgments a

Critical Accounting Judgments and Key Sources of Estimation Uncertainty	12 Months Ended
	Jun. 30, 2023
Disclosure of changes in accounting estimates [abstract]
Critical Accounting Judgments and Key Sources of Estimation Uncertainty	Note 4. Critical Accounting Judgments and Key Sources of Estimation Uncertainty In applying the Group’s accounting policies, management continually evaluates judgments, estimates and assumptions based on experience and other factors, including expectations of future events that may have an impact on the Group. All judgments, estimates and assumptions made are believed to be reasonable based on the most current set of circumstances available to management. Actual results may differ from the judgments, estimates and assumptions. Significant judgments, estimates and assumptions made by management in the preparation of these financial statements are outlined below: 4.1 Critical judgments in applying accounting policies Research and development costs The majority of Opthea’s expenditure is incurred as a result of clinical trials for OPT‑302. During the years ended June 30, 2020 2021 and 2022, Opthea completed its Phase 2b wet age‑related macular degeneration (wet AMD) and Phase 1b/2a diabetic macular edema (DME) trials and Phase 3 clinical trials for Sozinibercept (OPT-302) was initiated during 2021. A key measure of Opthea’s performance is the level of expenditure incurred on the research of OPT‑302 . Judgment is required in relation to: • The classification of expenses in the income statement between research and development costs and operating expenses; and • Whether costs relate to R&D, and consequently if they meet the capitalization criteria under IAS 138 “Intangible Assets.” The directors have determined that the Group is still in a research phase and accordingly, no development costs have been capitalized as of June 30, 2023, 2022 and 2021. Taxation Research and development tax incentive The Research and Development (R&D) Tax Incentive Scheme is an Australian Federal Government program under which eligible companies can receive cash refunds of 43.5 % of eligible R&D expenditure. Judgments are required as to the R&D tax incentive refundable offset eligibility in respect of: • The Group’s ability to make claims and its continued compliance under the scheme; • R&D and other supporting costs previously approved by Australian tax authorities; • Estimated amounts, timing and geographical location of future costs related to the projects for which applications have been approved to date; and • Assessment of whether expenditure on projects for which approval has been given by Australian tax authorities relate to Australian or overseas expenditure. For the years ended June 30, 2023, and 2022, the Group has recognized an R&D tax incentive receivable of US$ 6 million and US$ 6.3 million respectively within the consolidated statements of financial position, with a corresponding amount recognized within income tax benefit within the consolidated statements of profit or loss and other comprehensive income. The R&D tax incentive receivable as of June 30, 2023 and 2022 is based on the legislation as currently enacted as of June 30, 2023 and 2022, respectively. Any proposed changes to the legislation, such as rate changes and eligibility requirements, may have a retrospective impact if the legislation is passed. During the year, no such legislative changes have occurred. Investment tax credits such as the R&D tax incentive are outside of the scope of IAS 12 “ Income Taxes ” and IAS 20 “ Accounting for Government Grants and Disclosure of Government Assistance .” Based on the guidance in IAS 8 “Accounting Policies, Changes in Accounting Estimates and Errors,” companies need to make an accounting policy choice on how to present these incentives, which in practice is done by either analogizing with IAS 12 or with IAS 20. In the Group’s opinion, the R&D tax incentive should be presented by analogizing to IAS 12 because the nature of the incentive is considered to be more closely aligned to income taxes, based on the following considerations: • The R&D tax incentive is considered an income tax offset which will be offset against the Group’s tax obligation if and when the Group returns to a net tax payable position. In addition, whilst the Group is currently eligible to receive cash payments under the scheme since its consolidated revenue is currently below A$ 20 million, if and when the Group generates revenue in excess of A$ 20 million the R&D tax incentive will become non‑refundable and can only be offset against any future income tax payable by the Group. • The ATO, which is the tax authority in Australia, manages the annual claims process as the R&D tax incentive is included in the Group’s annual income tax return. • The ATO is also responsible for making the R&D tax incentive cash payment if a company is eligible for a cash refund under the program, oversees compliance with the requirements of the R&D tax incentive scheme and performs pre‑issuance reviews. Income tax The Group’s accounting policy for taxation requires judgments as to the differences between tax and accounting treatments of income and costs recognized in the consolidated statements of profit or loss and other comprehensive income. Judgment is also required in assessing whether deferred tax assets and liabilities are recognized in the statements of financial position and if accumulated income tax losses can be used to offset potential future tax profits. Functional currency Effective January 1, 2021 the Group’s functional and presentation currency changed from Australian dollars to U.S. dollars as disclosed in Note 3. The Group’s assets, liabilities and equity which were previously denominated in Australian dollars were translated into U.S. dollars on the date the functional currency changed. Significant judgment is required in determining the currency of the primary economic environment in which the Group operates, which requires an evaluation of various indicators related to the Group’s underlying transactions, events and conditions as they relate to generating and expending cash. 4.2 Key sources of estimation uncertainty Development funding - financial liability The Group evaluated the Financing Agreement and determined it to be a research and development funding arrangement with the characteristics of a debt instrument, as the transfer of financial risk to Launch Tx was not considered substantive and genuine. Accordingly, the Group has recorded payments received under the Financing Agreement as part of a development financing liability in its consolidated balance sheet. The Group measures the overall development financing liability at amortized cost based on the estimated timing of regulatory approval and attainment of certain sales milestones and the contractual success fee payments expected to be due therefrom, as discounted using an imputed interest rate. The development financing liability will be accreted as interest expense to its expected future repayment amount over the expected life of the agreement using the effective interest rate method. If the dates are delayed from those used at reporting date, it is expected that a fair value adjustment will result in a non-cash gain. If the timelines for approval and launch are accelerated, the Group would anticipate a fair value adjustment resulting in a non-cash charge to be recognized in the Consolidated Statements of Profit or Loss. Share‑based payment transactions The Group measures the cost of equity‑settled transactions with employees by reference to the fair value of the equity instruments at the date at which they are granted. Fair values are determined internally using Binomial models. The related assumptions are detailed in note 34. The accounting estimates and assumptions relating to equity‑settled share‑based payments have no impact on the carrying amounts of assets and liabilities in future reporting periods but may impact expenses and equity. Should one or more of the assumptions and estimates used in estimating the fair value of share‑based payments change, this could have a material impact on the amounts recognized in equity and employee‑related expenses.

Application of New and Revised

Application of New and Revised Accounting Standards	12 Months Ended
	Jun. 30, 2023
Disclosure of expected impact of initial application of new standards or interpretations [abstract]
Application of New and Revised Accounting Standards	Note 5. Application of New and Revised Accounting Standards New and amended Accounting Standards that are effective for the current year The Group has adopted all of the new and revised Standards and Interpretations issued by the International Accounting Standards Board (the IASB) that are relevant to its operations and effective for the current year. In the current year, the Group has applied a number of amendments to International Financial Reporting Standards and Interpretations issued by the International Accounting Standards Board (IASB) that are effective for an annual period that begins on or after July 1, 2022. Their adoption has not had any material impact on the disclosures or on the amounts reported in these financial statements. New and revised International Accounting Standards and Interpretations on issue but not yet effective At the date of authorization of the financial statements, the Group has not applied the new and revised International Accounting Standards, Interpretations and amendments that have been issued but are not yet effective. The new and revised Accounting Standards, Interpretations and amendments are not expected to have a material impact on the amounts recognized or disclosures included in the Group’s financial statements.

Segment Information

Segment Information	12 Months Ended
	Jun. 30, 2023
Disclosure of operating segments [abstract]
Segment Information	Note 6. Segment Information The Group operates in one industry and two geographical areas, those being the biotechnology and healthcare industry and Australia and United States, respectively. The Group is focused primarily on developing a novel therapy for the treatment of highly prevalent and progressive retinal diseases. The chief executive officer regularly reviews entity wide information that is compliant with International Financial Reporting Standards. There is only one segment for segment reporting purposes, and the information reviewed by the chief executive officer for the purpose of resources allocation and performance assessment is the same as the information presented in the consolidated financial statements. The Group’s only revenue stream in the current and previous financial year is royalty income generated from licenses granted in respect of the Group’s intellectual property that are unrelated to the Group’s core business and the development of OPT‑302 and that are not under development. These licenses are primarily used by third‑party licensees for research purposes. All of the royalty income of US$ 108,406 (2022: US$ 90,683 2021:US$ 68,613 ) was generated from customers based outside of Australia. The Group does not have any major customers. All equipment is located in Australia and United States.

Revenue

Revenue	12 Months Ended
	Jun. 30, 2023
Revenue [abstract]
Revenue	Note 7. Revenue 2023 2022 2021 US$ US$ US$ Sales-based royalties 108,406 90,683 68,613 Total Revenue 108,406 90,683 68,613

Other Income

Other Income	12 Months Ended
	Jun. 30, 2023
Analysis of income and expense [abstract]
Other Income	Note 8. Other Income 2023 2022 2021 US$ US$ US$ Grant and other income 276,869 108,322 26,950 Total other income 276,869 108,322 26,950

Research and Development Expens

Research and Development Expenses	12 Months Ended
	Jun. 30, 2023
Disclosure Of Research And Development Expenses [Abstract]
Research and Development Expenses	Note 9. Research and Development Expenses 2023 2022 2021 US$ US$ US$ Research project costs 122,128,314 78,654,217 25,891,851 Total research and development expenses 122,128,314 78,654,217 25,891,851 The research project costs relate to the research programs in respect to the treatment of eye diseases by Sozinibercept (OPT‑302).

Expenses

Expenses	12 Months Ended
	Jun. 30, 2023
Expense By Nature [Abstract]
Expenses	Note 10. Expenses 2023 2022 2021 US$ US$ US$ Administrative expenses Employee benefits expenses: Salaries and fees 6,274,560 2,931,243 1,794,840 Cash bonuses 1,265,944 376,649 479,501 Superannuation 287,396 171,899 188,543 Share-based payments expense 5,834,686 5,251,572 3,897,638 Total employee benefits expense 13,662,586 8,731,363 6,360,522 Other expenses: Insurance 2,551,768 4,205,106 4,419,433 Investor relations costs 451,378 328,026 285,071 Audit and accounting 337,038 496,652 647,549 Travel expenses 580,644 13,616 1,459 Payroll tax 340,003 172,884 18,766 Legal fees 1,330,054 1,252,014 83,605 Advisory fees 1 6,084,005 156,978 393,843 Consultancy costs 1,389,048 1,619,824 367,070 Other expenses 1,288,179 867,405 732,773 Total other expenses 14,352,117 9,112,505 6,949,569 Depreciation of: Equipment and furniture 17,000 11,917 15,012 Right-of-use assets 84,226 66,465 91,656 Total depreciation expense 101,226 78,382 106,668 Loss on disposal of non-current assets — 169 1,434 Total administrative expenses 28,115,929 17,922,419 13,418,193 1. Advisory fees relates to a market assessment of potential financing alternatives and solutions.

Finance Income

Finance Income	12 Months Ended
	Jun. 30, 2023
Material income and expense [abstract]
Finance Income	Note 11. Finance Income 2023 2022 2021 US$ US$ US$ Interest income 3,227,496 235,468 372,001 Total finance income 3,227,496 235,468 372,001

Interest Expense on DFA

Interest Expense on DFA	12 Months Ended
	Jun. 30, 2023
Material income and expense [abstract]
Interest Expense on DFA	Note 12. Interest expense on DFA 2023 2022 2021 US$ US$ US$ Interest expense on DFA 13,462,160 — — Total interest expense on DFA 13,462,160 — — The interest expense on DFA is non-cash interest at the imputed rate of 23.82 %.

Fair Value Adjustment Gain on D

Fair Value Adjustment Gain on DFA	12 Months Ended
	Jun. 30, 2023
Material income and expense [abstract]
Fair Value Adjustment Gain on DFA	Note 13. Fair value adjustment gain on DFA 2023 2022 2021 US$ US$ US$ Fair value adjustment gain on DFA 12,302,160 — — Total fair value adjustment gain on DFA 12,302,160 — — There are several factors that could affect the estimated timing of regulatory approval and attainment of sales milestones, some of which are not entirely within the Company’s control. Therefore, at each reporting date, the Company reassesses the estimated timing of regulatory approval and attainment of sales milestones and the expected contractual success fee payments due therefrom. If the timing and/or amount of such expected payments is materially different than original estimates, the Company will prospectively adjust the accretion of the development financing liability and the imputed interest rate. At June 30, 2023 the Company performed a fair value adjustment of the carrying amount of the Financial Liability. The expected timeline for approval and commercial launch have been delayed by twelve months, thus extending date of expected repayments. As the Company has more time to repay the amounts owed, the carrying value of the Financial Liability at June 30, 2023 was adjusted downward to reflect this delay. The fair value adjustment resulted in a non-cash gain on revaluation of $ 12.3 million. This change is recorded on the Profit and Loss statement as an unrealized fair value adjustment gain on the DFA. The Company will continue to accrete non-cash interest at the imputed rate of 23.82 %. Refer to Note 25. At every reporting period, the Company will review the expected approval and commercial launch dates. If the dates are delayed from those used at June 30, 2023, it is expected that a fair value adjustment will result in another non-cash gain. If the timelines for approval and launch are accelerated, the Company would anticipate a fair value adjustment resulting in a non-cash charge to be recognized on the Profit and Loss statement.

Net Foreign Exchange Loss

Net Foreign Exchange Loss	12 Months Ended
	Jun. 30, 2023
Net Foreign Exchange Loss Gain [Abstract]
Net Foreign Exchange Loss	Note 14. Net Foreign Exchange Loss 2023 2022 2021 US$ US$ US$ Net foreign exchange (loss)/gain ( 489,137 ) ( 2,813,993 ) ( 11,011,961 ) Total net foreign exchange (loss)/gain ( 489,137 ) ( 2,813,993 ) ( 11,011,961 ) Exchange differences arising on the translation of monetary items are recognized in the Statements of Profit and Loss and other Comprehensive Income. After the Company’s US IPO where the Company raised US$ 128 million, the Company entered into an Australian dollar denominated term deposit worth US$ 100 million (AUD 141.9 million) maturing on February 3, 2021 . The Company simultaneously entered into a foreign currency exchange contract under which the term deposit converted back to US dollars at effectively the same foreign exchange rate as when the term deposit was entered into. As the Group’s functional currency was the Australian dollar (A$) until December 31, 2020, the Group recorded a foreign exchange loss of US$ 9 milion in relation to this transaction.

Income Taxes

Income Taxes	12 Months Ended
	Jun. 30, 2023
Major components of tax expense (income) [abstract]
Income Taxes	Note 15. Income Taxes 2023 2022 2021 US$ US$ US$ (a) Income tax benefit The major components of income tax benefit are: Statement of Profit or Loss and Other Comprehensive Income Current tax Current income tax credit 5,926,350 6,299,286 4,938,846 5,926,350 6,299,286 4,938,846 Deferred tax In respect of the current year — — — Total income tax benefit recognized in the Statement of Comprehensive Income 5,926,350 6,299,286 4,938,846 (b) Current tax receivable US$ US$ US$ Research and Development Tax Incentive Credit receivable 5,926,350 6,299,286 4,972,898 (c) Numerical reconciliation between aggregate income tax benefit recognized in the Statement of Profit of Loss and Other Comprehensive Income and benefit calculated per the statutory income tax rate A reconciliation between income tax benefit and the product of accounting loss before income tax multiplied by the Group’s applicable income tax rate is as follows: 2023 2022 2021 US$ US$ US$ Accounting loss before tax ( 148,447,435 ) ( 99,116,657 ) ( 50,283,342 ) At the Company's statutory income tax rate of 30 % 44,534,230 29,734,997 15,085,003 R&D tax incentive on eligible expenses 5,926,350 6,299,286 4,938,846 Non-deductible R&D expenditure ( 4,087,138 ) ( 4,344,335 ) ( 3,420,951 ) Other non-deductible expenses - share-based payment expense ( 1,750,406 ) ( 1,575,472 ) ( 1,169,291 ) Amount of temporary differences and carried forward tax losses not recognized ( 38,696,687 ) ( 23,815,190 ) ( 10,494,761 ) 5,926,350 6,299,286 4,938,846 (d) Recognized deferred tax assets and liabilities in statement of financial position June 30, 2023 June 30,2022 June 30,2021 Deferred income tax at June 30 relates to the following: Deferred tax liabilities: Interest and royalty income receivable (future assessable income) ( 44,785 ) ( 17,085 ) ( 2,344,514 ) ( 44,785 ) ( 17,085 ) ( 2,344,514 ) Deferred tax assets related to temporary differences: Recognition of tax losses — — 1,508,764 Accrued expenses and other liabilities 200,536 198,607 205,458 Employee provisions 161,006 161,159 152,675 Other miscellaneous items 270,721 306,531 477,617 632,263 666,297 2,344,514 Net deferred tax assets 587,478 649,212 — Less: temporary differences not recognized ( 587,478 ) ( 649,212 ) — Net deferred tax recognized in the statement of financial position — — — (e) Unrecognized temporary differences Temporary differences with respect to deferred tax assets associated with intellectual property and other miscellaneous items which have a low probability of realization are unrecognized. These amounted to US$ 587,478 at year end (2022: $ 649,212 , 2021: nil). (f) Carry forward unrecognized tax losses The Group had income tax losses of US$ 67,878,759 and capital losses of US$ 412,122 at year end (2022: income tax losses of US$ 37,717,792 and capital losses of US$ 412,122 ) for which no deferred tax asset is recognized on the consolidated statement of financial position as they are currently not considered probable of realization. These tax losses are available indefinitely for offset against future assessable income subject to continuing to meet relevant statutory tests. (g) Franking credit balance Franking credits are a type of tax credit in Australia that is available to the Group’s shareholder to reduce double taxation on any dividends paid by the Group. The franking account balance at the end of the financial year at 30 % (2022: 30 %) is A$ 227,371 (2022: A$ 227,371 ), which represents the amount of franking credits available for the subsequent financial year. Franking credits are not recognized in the consolidated statement of financial position.

Earnings per Share

Earnings per Share	12 Months Ended
	Jun. 30, 2023
Earnings per share [abstract]
Earnings per Share	Note 16. Earnings per Share 2023 2022 2021 US$ US$ US$ The following reflects the income used in the basic and diluted earnings per share computations: (a) Earnings used in calculating earnings per share Net loss attributable to ordinary equity holders of the parent ( 142,521,085 ) ( 92,817,371 ) ( 45,344,496 ) (b) Weighted average number of shares Weighted average number of ordinary shares on issue for basic earnings per share 442,637,406 351,560,198 320,432,814 Effect of dilution: Share options — — Weighted average number of ordinary shares adjusted for the effect of dilution 442,637,406 351,560,198 320,432,814 Loss per share (basic and diluted in cents) (32.20 ) (26.40 ) (14.15 ) On August 24 and 28, 2023 the company announced a capital raising which has involved 195,647,457 ordinary shares and options that represent potential ordinary shares of 97,823,728 that would significantly change the number of ordinary shares or potential ordinary shares outstanding between the reporting date and the date of completion of this financial report. There is no impact on the current basic and diluted earnings per share. Diluted earnings per share is calculated as net loss divided by the weighted average number of ordinary shares and dilutive potential ordinary shares. Options granted under the Long Term Incentive (LTIP) and Non‑Executive Director Share and Option (NED Plan) plans would generally be included in the calculation due to the conditions of the issuance being satisfied. As the Group is in a loss position, the options are anti‑dilutive and, accordingly, the basic loss per share is the same as the diluted loss per share. A total number of 25,450,000 options/rights outstanding June 30, 2023 and 1,505,000 ADS options were anti‑dilutive and were therefore excluded from the weighted average number of ordinary shares for the purpose of diluted earnings per share. These options related to the following option plans. Fully paid ordinary shares have no par value, carry one vote per share and carry the right to dividends. No cash dividends have been paid, declared or recommended during or since the end of the financial year by the Company. Options 2023 2022 2021 NED Plan 16,500,000 14,000,000 10,000,000 LTIP 6,050,000 7,388,000 6,644,000 22,550,000 21,388,000 16,644,000 2023 2022 2021 Performance Rights NED Plan 650,000 — — LTIP 2,250,000 1,600,000 — 2,900,000 1,600,000 — 2023 2022 2021 ADS Options NED Plan — — LTIP 1,505,000 925,000 — 1,505,000 925,000 — As of June 30, 2023, 10,842,234 outstanding options and rights were exercisable as of that date (2022: 12,857,589 2021: 11,394,000 ). As at June 30, 2023 250,000 outstanding ADS options were exercisable as of that date (2022: nil , 2021: nil ).

Current Assets - Cash and Cash

Current Assets - Cash and Cash Equivalents	12 Months Ended
	Jun. 30, 2023
Current Assets Cash And Cash Equivalents [Abstract]
Current Assets - Cash and Cash Equivalents	Note 17. Current Assets – Cash and Cash Equivalents June 30, 2023 June 30, 2022 US$ US$ Cash at bank and in hand 12,067,158 11,853,883 Short-term deposits 77,121,555 32,777,410 Total cash and cash equivalents 89,188,713 44,631,293 Cash at bank earns interest at floating rates based on daily bank deposit rates. The carrying amounts of cash and cash equivalents represent fair value. Short term‑deposits are with two major Australian banks and are made for varying periods of between 30 and 90 days, depending on the immediate cash requirements of the Group, and earn interest at a fixed rate for the respective short‑term deposit periods. At year end, the average rate was 4.67 % (2022: 0.43 %, 2021: 0.24 %).

Current Assets - Receivables

Current Assets - Receivables	12 Months Ended
	Jun. 30, 2023
Current Assets Receivables [Abstract]
Current Assets - Receivables	Note 18. Current Assets - Receivables June 30, 2023 June 30, 2022 US$ US$ Interest receivable 162,853 56,952 GST receivable 1 325,474 157,060 Other receivable 1 148,237 43,656 Total current receivables 636,564 257,668 1 The GST and other receivables are non‑interest bearing. There were no receivables with a material expected credit loss recorded during the financial year (2022: nil , 2021: nil ).

Current Assets - Prepayments

Current Assets - Prepayments	12 Months Ended
	Jun. 30, 2023
Current prepayments [abstract]
Current Assets - Prepayments	Note 19. Current Assets - Prepayments June 30, 2023 June 30, 2022 US$ US$ R&D Contract Research Organization 1,693,964 7,428,599 Insurance 717,064 1,086,847 Other prepayments 223,643 204,749 Total current prepayments 2,634,671 8,720,195 The R&D Contract Research Organization prepayment consists of prepayments on the Phase 3 clinical trial for OPT‑302 in order to secure sites across the world and start patient recruitment. These prepayments covered the initial startup of the Phase 3 clinical trials and other key milestones and are expected to be consumed within the next 12 months. The insurance amount relates to specific Phase 3 clinical trial insurance in place for various sites around the world covering periods to 2024. The non‑current portion of the prepayments are recorded as non‑current assets. Refer Note 21.

Non-Current Assets - Right of U

Non-Current Assets - Right of Use Assets	12 Months Ended
	Jun. 30, 2023
Disclosure of quantitative information about right-of-use assets [abstract]
Non-Current Assets - Right of Use Assets	Note 20. Non-Current Assets - Right of Use Assets The Group has a three- year lease contract for its head office premises in Melbourne, Australia, which commenced on 15 July 2022. The agreement does not contain any extension options. The carrying amount of the lease at June 30, 2023 is as follows: June 30, 2023 June 30, 2022 US$ US$ Right-of-Use Asset Cost Opening balance as at July 1 281,554 281,554 Additions 252,677 — Exchange on translations — — 534,231 281,554 Right-of-Use-Asset Depreciation Opening balance as at July 1 ( 281,554 ) ( 187,702 ) Charge to the period ( 84,226 ) ( 93,852 ) Exchange on translation — — ( 365,780 ) ( 281,554 ) Net carrying amount at June 30 168,451 — 2023 2022 2021 US$ US$ US$ Amounts recognized in profit or loss: Depreciation expense on right-of-use asset 84,226 66,465 91,656 Lease finance costs 5,321 5,920 5,782 Expense relating to leases of low value assets 2,101 7,376 7,042 91,648 79,761 104,480 The Group did not have any short-term leases during the year ended June 30, 2023.

Non-Current Assets - Prepayment

Non-Current Assets - Prepayments	12 Months Ended
	Jun. 30, 2023
Disclosure Of Noncurrent Assets Prepayments [Abstract]
Non-Current Assets - Prepayments	Note 21. Non-Current Assets - Prepayments June 30, 2023 June 30, 2022 US$ US$ Insurance 53,535 110,295 Total non-current prepayments 53,535 110,295 The non‑current prepayment amount relates to specific Phase 3 Clinical trial insurance in place for various sites around the world covering periods to 2024.

Current Liabilities _ Payables

Current Liabilities – Payables	12 Months Ended
	Jun. 30, 2023
Current Liabilities Payables [Abstract]
Current Liabilities – Payables	Note 22. Current Liabilities – Payables June 30, 2023 June 30, 2022 US$ US$ Accounts Payable (unsecured) 1 17,842,981 11,402,164 Payroll related tax liability 48,873 43,334 Total current payables 17,891,854 11,445,498 1 Accounts Payable are non‑interest bearing and are normally settled on 30 day terms . Includes an amount of US$ 900,000 due to Launch Tx Service Agreement being a related party.

Current Liabilities - Provision

Current Liabilities - Provisions	12 Months Ended
	Jun. 30, 2023
Current provisions [abstract]
Current Liabilities - Provisions	Note 23. Current Liabilities - Provisions June 30, 2023 June 30, 2022 US$ US$ Annual leave 500,361 383,220 Long service leave 252,939 212,983 Total current provisions 753,300 596,203

Lease Liabilities

Lease Liabilities	12 Months Ended
	Jun. 30, 2023
Lease liabilities [abstract]
Lease Liabilities	Note 24. Lease Liabilities Lease liabilities are as indicated below. At the commencement date of the lease of its office premises, the Group recognizes lease liabilities measured at the present value of lease payments to be made over the lease term ending on July 14, 2024 using an incremental borrowing rate of 3 %. June 30, 2023 June 30, 2022 US$ US$ Carrying amount at July 1 112,965 New lease 252,677 — Payments ( 70,966 ) ( 112,965 ) Carrying amount at June 30 181,711 — Maturity analysis: Year 1 102,806 — Year 2 84,226 — 187,032 — Less: unearned interest ( 5,321 ) — 181,711 — Analyzed into: Current portion 97,485 — Non-current portion 84,226 — 181,711 —

Non-Current Liabilities - Finan

Non-Current Liabilities - Financial Liabilities	12 Months Ended
	Jun. 30, 2023
Categories of non-current financial liabilities [abstract]
Non-Current Liabilities - Financial Liabilities	Note 25. Non-Current Liabilities - Financial Liabilities June 30, 2023 June 30, 2022 US$ US$ Carrying amount at July 1 — — Funding at fair value 84,500,000 — Interest expense on DFA 13,462,160 Fair value adjustment gain on DFA ( 12,302,160 ) — Total financial liabilities 85,660,000 — Pursuant to the DFA, Launch Tx has committed to provide Opthea US$ 120 million in funding which may be increased up to US$ 170 million at their option, of which US$ 50 million (net of US$ 0.5 million of funding costs) was paid in September. Opthea received the proceeds from the first tranche of the DFA, with the remainder being funded in two additional tranches: one paid on December 31, 2022 and one to be paid on or before December 31, 2023 . Pursuant to the DFA, Opthea is required to use commercially reasonable efforts to develop Sozinibercept (OPT-302) for the treatment of wet AMD in accordance with the DFA, including pursuant to certain development timelines set forth therein. In return, Opthea will pay to Launch Tx (1) upon the first to occur of regulatory approval of Sozinibercept (OPT-302) for the treatment of wet AMD in the United States, United Kingdom or European Union (“Regulatory Approval”), fixed payments equal to a total of approximately two times the funding provided, consisting of seven payments, with the first payment due shortly after Regulatory Approval and the remaining six annual payments payable over a six-year period thereafter, and (2) variable payments equal to 7 % of net sales of Sozinibercept (OPT-302) for the treatment of wet AMD for each calendar quarter. The fixed and variable payment obligations discharge once Launch Tx has received a total of four times their investment. In certain instances, upon the termination of the Funding Agreement, we will be obligated to pay Investor several multiples of the amounts paid to us under the Funding Agreement. The Group remains in compliance with the DFA and no such instances has occurred. The Group evaluated the Financing Agreement and determined it to be a research and development funding arrangement with the characteristics of a debt instrument, as the transfer of financial risk to Launch Tx was not considered substantive and genuine. Accordingly, the Group has recorded payments received under the Financing Agreement as part of a development financing liability in its consolidated balance sheets. The Group accounts for the overall development financing liability at amortized cost based on the estimated timing of regulatory approval and attainment of certain sales milestones and the contractual success fee payments expected to be due therefrom, as discounted using an imputed interest rate. The development financing liability will be accreted as interest expense to its expected future repayment amount over the expected life of the agreement using the effective interest rate method. Certain legal and financial advisory fees incurred specifically to complete the Financing Agreement were capitalized and recorded as a reduction to the carrying amount of the development financing liability and will also be amortized to interest expense using the effective interest method. Pursuant to the Financing Agreement, the Opthea granted Launch Tx a security interest in all its assets (other than intellectual property not related to Sozinibercept (OPT-302)), provided that the Group is permitted to incur certain indebtedness. The security interest will terminate when the Group has paid Launch Tx the funding provided or upon certain terminations of the Financing Agreement. There are several factors that could affect the estimated timing of regulatory approval and attainment of sales milestones, some of which are not entirely within the Group’s control. Therefore, at each reporting date, the Group reassesses the estimated timing of regulatory approval and attainment of sales milestones and the expected contractual success fee payments due therefrom. If the timing and/or amount of such expected payments is materially different than original estimates, the Group will prospectively adjust the accretion of the development financing liability and the imputed interest rate. As of June 30, 2023, the development financing liability was classified as a long-term liability, as the Group expects the related repayments to take place between 2027 and 2032 for purposes of the model used to calculate its carrying value. The imputed interest rate on the unamortized portion of the development financing liability was approximately 23.82 %.

Non-Current Liabilities - Provi

Non-Current Liabilities - Provisions	12 Months Ended
	Jun. 30, 2022
Non-current provisions [abstract]
Non-Current Liabilities - Provisions	Note 26. Non-Current Liabilities - Provisions June 30, 2023 June 30, 2022 US$ US$ Long service leave 7,631 27,974 Total non-current provisions 7,631 27,974

Contributed Equity

Contributed Equity	12 Months Ended
	Jun. 30, 2023
Contributed Equity [Abstract]
Contributed Equity	Note 27. Contributed Equity June 30, 2023 June 30, 2022 June 30, 2021 US$ US$ US$ (a) Ordinary shares Issued and fully paid at June 30 320,883,552 235,277,217 234,147,526 Movement in ordinary shares: Opening balance 235,277,217 234,147,526 113,852,364 Issue of shares on exercise of options granted under the LTIP 3,790,978 1,129,691 3,271,542 Issue of shares on Nasdaq listing net of issuance cost $ 10,126,969 — — 105,477,591 Issue of shares on exercise of pre-funded warrants net of issuance cost $ 1,099,412 — — 11,546,029 Issue of shares net of issuance costs $ 4,531,040 81,815,357 — — 320,883,552 235,277,217 234,147,526 Ordinary shares on issue: No: No: No: Opening balance 352,152,542 351,003,541 269,157,769 Issue of shares on exercise of options granted under the LTIP 2,387,826 1,149,001 5,845,804 Issue of shares on Nasdaq listing — — 68,506,400 Issue of share on exercise of pre-funded warrants — — 7,493,568 Issue of shares on ASX 112,619,006 — — 467,159,374 352,152,542 351,003,541 Fully paid ordinary shares have no par value, carry one vote per share and carry the right to dividends. No cash dividends have been paid, declared or recommended during or since the end of the financial year by the Company. We have not declared or paid any dividends on our ordinary shares. We intend to retain any earnings for use in our business and do not currently intend to pay cash dividends on our ordinary shares. Dividends, if any, on our outstanding ordinary shares will be declared by and subject to the discretion of our board of directors, and subject to Australian law. Issued capital at June 30, 2023 amounted to US$ 320,883,552 ( 467,159,434 fully paid ordinary shares) net of share issue costs and tax. During the year ended June 30, 2023 the Company issued 112,619,066 ordinary shares on Nasdaq listing for net proceeds of US$ 81,815,357 1. During the year ended June 30, 2021 the Company issued 68,506,400 ordinary shares on Nasdaq listing for net proceeds of US$ 105,477,591 as well as issued 7,493,568 pre‑funded warrants for net proceeds of US$ 11,546,029 . At June 30, 2023, the company had 7,250,000 Non-Executive Director options that remain unexercised with expiry of October 2024 for 3,000,000 options, January 2025 for 2,250,000 options, October 2025 for 1,000,000 options and April 2026 for 1,000,000 options. At June 30, 2022, the company had 7,500,000 Non-Executive Director options that remain unexercised with expiry of November 2022 for 3,000,000 options, October 2024 for 2,000,000 options, January 2025 for 1,500,000 options, October 2025 for 500,000 options and April 2026 for 500,000 options. At June 30, 2021, the company had 4,750,000 Non‑Executive Director options that remain unexercised with expiry of November 2022 for 3,000,000 options, October 2024 for 1,000,000 options and January 2022 for 750,000 options. Options granted to directors and employees . The company has two share‑based payment schemes, the Long-Term Incentive Plan (LTIP) and Non‑Executive Director Share and Option Plan. Options to subscribe for the Company’s shares have been granted under these plans to certain employees and directors. The company granted 10,050,000 options/rights and 755,000 American Depository Shares (ADS) options over ordinary shares under these plans during the year ended June 30, 2023 (Note 34). These options/rights had a weighted average fair value at grant date of $ 1.62 per options and the ADS options had a weighted average fair value at grant date of $ 6.75 . During the year ended June 30, 2022, 6,613,000 options granted under the LTIP and NED Plan were exercised for $ 3,790,977 ($ 1,040,718 for cash and $ 2,750,258 via cashless conversion) The company granted 8,400,000 options/rights and 925,000 American Depository Shares (ADS) options over ordinary shares under these plans during the year ended June 30, 2022 (Note 34). These options/rights had a weighted average fair value at grant date of $ 0.781 per options and the ADS options had a weighted average fair value at grant date of $ 6.75 . During the year ended June 30, 2022, 2,056,000 options granted under the LTIP and NED Plan were exercised for $ 1,129,691 ($ 257,175 for cash and $ 872,516 via cashless conversion). The company granted 7,000,000 options over ordinary shares under these plans during the year ended June 30, 2021 (note 32). These options had a weighted average fair value at their grant date of US$ 1.03 per option. During June 30, 2021 8,400,000 options granted under the LTIP and NED Plan were exercised for US$ 3,271,542 . No options were granted under the Plans during the year ended June 30, 2020. (c) Capital management The Group is not subject to any externally imposed capital requirements. When managing share capital, management’s objective is to ensure the entity continues as a going concern as well as to provide benefits to shareholders and for other stakeholders. In order to maintain or achieve an appropriate capital structure, the Company may issue new shares or reduce its share capital, subject to the provisions of the Company’s constitution. The Group only commits to significant R&D expenditure when this is fully funded either by existing funds or further equity raises.

Accumulated Losses and Reserves

Accumulated Losses and Reserves	12 Months Ended
	Jun. 30, 2023
Disclosure of reserves within equity [abstract]
Accumulated Losses and Reserves	Note 28. Accumulated Losses and Reserves 2023 2022 US$ US$ (a) Movements in accumulated losses were as follows: Balance at July 1 ( 216,941,353 ) ( 124,123,982 ) Net loss for the period ( 142,521,085 ) ( 92,817,371 ) Balance at June 30 ( 359,462,438 ) ( 216,941,353 ) (b) Reserves Fair value of Investments reserve (i) 1,085,411 1,085,411 Share-based payments reserve (ii) 11,551,134 8,466,706 Foreign translation reserve (iii) 20,089,163 20,089,163 Total reserves 32,725,708 29,641,280 (i) Movement in fair value of investments reserve: Opening balance 1,085,411 1,085,411 Fair value on gains on investments in financial assets — — Exchange on translation — — Closing balance 1,085,411 1,085,411 (ii) Movement in share-based payments reserve: Opening balance 8,466,706 4,087,650 Share-based payments expense 5,834,686 5,251,572 Exercise of options ( 2,750,258 ) ( 872,516 ) Exchange on translation — — Closing balance 11,551,134 8,466,706 (iii) Movement in foreign translation reserve: Opening balance 20,089,163 20,089,163 (Gains)/loss on translation — — Closing balance 20,089,163 20,089,163 (c) Nature and purpose of reserves Fair value of investments reserve This reserve records fair value changes on listed investments. As at June 30, 2023 no remaining investments are held by the Group. Management's accounting policy is to not reclassify the realized fair value to accumulated loss upon disposal. Share‑based payment reserve This reserve is used to record the value of equity benefits provided to executives and employees as part of their remuneration. Foreign currency translation reserve The reserve records the value of foreign currency movements on the initial translation of financial statements from A$ to US$ that was completed in 2021.

Financial Risk Management Objec

Financial Risk Management Objectives and Policies	12 Months Ended
	Jun. 30, 2023
Disclosure of risk management strategy related to hedge accounting [abstract]
Financial Risk Management Objectives and Policies	Note 29. Financial Risk Management Objectives and Policies The Group’s principal financial assets comprise cash, receivables, short‑term deposits and investments in listed shares. The Group manages its exposure to key financial risks, including interest rate and currency risk in accordance with the Group’s financial risk management practices. The objective is to support the delivery of the Group’s financial targets whilst protecting future financial security. The Group’s other various financial assets and liabilities, such as receivables and payables, arise directly from its operations. The main risks arising from the Group’s financial assets and liabilities are interest rate risk, foreign currency risk, equity securities price risk and liquidity risk. The Group uses different methods to measure and manage different types of risks to which it is exposed. These include monitoring levels of exposure to interest rate and foreign exchange risk and assessments of market forecasts for interest rates and foreign exchange rates. Liquidity risk is monitored through future rolling cash flow forecasts. The board reviews and agrees policies for managing each of these risks as summarized below. Risk exposures and responses The Group has investigated the main financial risk areas which could impact on its financial assets and determined the impact on post tax (losses) or profits for a range of sensitivities. These can be seen in the post-tax (loss)/profit impact for each risk area. For each risk area, the equity impact relates solely to reserve movements and excludes movements in accumulated losses as the impact of these can be seen within the post-tax (loss)/profit impact. (i) Interest rate risk The Group’s exposure to market interest rates relates primarily to the short‑term deposits. The deposits are held with two of Australia’s largest banks. The objective of managing interest rate risk is to minimize the Group’s exposure to fluctuations in interest rates that might impact its interest income and cash flow. To manage interest rate risk, the Group invests the majority of its cash in short‑term deposits for varying periods of between 30 days and 90 days, depending on the short and long‑term cash requirements of the Group which is determined based on the Group’s cash flow forecast. This consideration also takes into account the costs associated with recalling a term deposit should early access to cash and cash equivalents be required. Cash is not locked into long‑term deposits at fixed rates so as to mitigate the risk of earning interest below the current floating rate. The Group currently has borrowings under the DFA with Ocelot (2022: nil ). The following sensitivity analysis (an annual effect) is based on the interest rate risk exposures at June 30, 2023 and 2022. At June 30, 2023, 2022 and 2021, if interest rates moved, with all variables held constant, post tax (loss)/profit and equity would have been affected as illustrated in the following table: Post tax (loss)/profit impact 2023 2022 2021 US$ US$ US$ Judgments of reasonably possible movements +0.50% (50 basis points) (2022:+ 0.50 %) 270,059 114,859 359,442 -0.50% (50 basis points) (2022:-0.50%) ( 270,059 ) ( 114,859 ) ( 359,442 ) The post-tax figures include an offset for unrecognized tax losses (bringing the tax effect to nil ) for the year ended June 30, 2023 (2022: nil ,2021: nil ). Significant assumptions used in the interest rate sensitivity analysis include: • The reasonably possible movement of 0.5% was calculated by taking the interest rates as of balance date, moving these by plus and minus 0.5% and then re‑calculating the interest on term deposits with the ‘new‑interest‑rate’. • The net exposure at balance date is representative of what the Group was and is expecting to be exposed to in the next twelve months from balance date . (ii) Foreign currency risk As a result of services provided by non‑related entities in Australia, Canada, United Kingdom and Europe, part of the Group’s monetary assets and liabilities are affected by movements in the exchange rate. The Group does not enter into any hedging transactions. At the reporting date, the Group has the following exposure to foreign currencies. : Consolidated 2023 AUD EURO GBP CAD Financial assets Cash 55,307,319 Receivables 6,290,086 Financial liabilities Payables ( 1,187,459 ) ( 53,332 ) ( 3,166 ) ( 136,689 ) Other financial liabilities Net exposure 60,409,946 ( 53,332 ) ( 3,166 ) ( 136,689 ) Consolidated 2022 AUD EURO GBP CAD Financial assets Cash 26,697,582 — — — Receivables 7,827,565 — — — Financial liabilities Payables ( 1,213,469 ) ( 435,698 ) ( 3,037 ) ( 13,419 ) Other financial liabilities — — — — Net exposure 33,311,678 ( 435,698 ) ( 3,037 ) ( 13,419 ) The following sensitivity is based on the foreign currency risk exposures in existence at June 30, 2023 and 2022. At June 30, 2023, 2022 and 2021, had the United States dollar moved with all other variables held constant, post tax (loss) profit and equity would have been affected as illustrated in the table below: Post tax (loss)/profit impact 2023 2022 2021 US$ US$ US$ Judgments of reasonably possible movements Consolidated AUD/USD +10% (2022:+ 10 %) ( 3,847,285 ) ( 2,119,834 ) ( 2,538,062 ) AUD/USD -10% (2022:-10%) 4,702,237 2,590,908 3,102,076 The reasonably possible movements at June 30, 2023 are higher than at June 30, 2022 and higher than June 30, 2021 due mainly to net exposure to the Australian dollar due to cash at bank deposits. There was minimum or insignificant exposure to the GBP, Euro and CAD during the current financial year. Significant assumptions used in the foreign currency exposure sensitivity analysis include: (a) The reasonably possible movement of 10% was calculated by taking the currency spot rates as of balance date, moving these by 10% and then re‑converting the currencies into US with the ‘new‑spot‑rate’. This methodology reflects the translation methodology undertaken by the Group. (b) The net exposure at balance date is representative of what the Group was and is expecting to be exposed to in the next twelve months from balance date. (c) Management believes the balance date risk exposures are representative of the risk exposure inherent in the financial instruments. (iii) Credit risk Credit risk is associated with those financial assets of the Group which comprise cash and cash equivalents, receivables and listed investments. The Group’s exposure to credit risk arises from default of the counter party, with a maximum exposure equal to the carrying amount of these investments. Credit risk is considered minimal as the Group transacts with reputable recognized Australian banks. (iv) Liquidity risk Liquidity risk arises from the financial liabilities of the Group and the Group’s subsequent ability to meet their obligations to repay their financial liabilities as and when they fall due. The Group manages liquidity risk by maintaining adequate reserves and by monitoring forecast and actual cash flows and by matching the maturity profiles of financial assets and liabilities. The financial liabilities of the Group relate to trade payables that are all expected to be paid within 12 months. With the funding agreement that was entered on August 12, 2022 the Group may incur a total payment equal to approximately four times the funding provided, consisting of seven payments, with the first payment due shortly after Regulatory Approval and the remaining six payments payable over a six-year period thereafter, and variable payments equal to 7 % of net sales of Sozinibercept (OPT-302) for the treatment of wet AMD for each calendar quarter . The Group’s objective is to maintain an appropriate cash asset balance to fund its operations.

Related Party Disclosures

Related Party Disclosures	12 Months Ended
	Jun. 30, 2023
Related party transactions [abstract]
Related Party Disclosures	Note 30. Related Party Disclosures (a) Subsidiarie s The consolidated financial statements include the financial statements of Opthea Limited and its subsidiaries in the following table: Parent entity % equity interest June 30, 2023 June 30, 2022 June 30, 2021 % % % Vegenics Pty Ltd 1 100 100 100 Opthea US Inc 2 100 100 100 (1) Opthea Limited is the ultimate parent entity. Vegenics Pty Ltd is incorporated in Australia and has the same financial year as Opthea Limited. (2) Opthea Limited is the ultimate parent entity. Opthea US Inc was incorporated in the United States in May 2021 and has the same financial year as Opthea Limited. (b) Transactions with related parties Balances and transactions between the Company and its subsidiaries, a related party of the Company, have been eliminated on consolidation and are not disclosed in this note. Transactions between the Group and its associates are disclosed below: With the appointment of Anshul Thakral (who is the CEO of Launch and Operation Executive of Carlyle) on June 7, 2023, as a Director of Opthea resulting in Launch, Ocelot and Carlyle being related parties of Opthea. Trading transactions During the year, group entities entered into the following transactions with related parties who are not members of the Group. Consolidated Purchase of Service 2023 2022 2021 Launch Tx - Ocelot — — — Launch 900,000 — — Purchase of services assisting Opthea with the management and oversight of trials under the Service Agreement with Launch Tx. Consolidated Amounts owed to related parties 2023 2022 2021 Launch Tx - Ocelot 85,660,000 — — Launch — — — Amounts owed to Ocelot relate to the Development Funding agreement and carry an effective rate of 23.82 % (refer to note 25).

Commitments

Commitments	12 Months Ended
	Jun. 30, 2023
Commitments [Abstract]
Commitments	Note 31. Commitments (i) Research projects and license commitments The Group has entered into research and development contracts and intellectual property license agreements with various third parties in respect of services for the Phase 3 wet AMD clinical trial and the clinical grade manufacture of OPT‑302. Expenditure commitments relating to these, and intellectual property license agreements are payable as follows: 2023 2022 2021 US$ US$ US$ Within one year 12,632,801 39,947,900 26,377,778 After one year but not more than five years 12,302,260 8,007,202 2,347,060 After more than five years 30,000 45,000 — 24,965,061 48,000,102 28,724,838 Currently, the biggest research contract has a 60 day termination clause and all commitments have been limited to a six month commitment. (ii) Commercial commitments 2023 2022 2021 US$ US$ US$ Within one year 47,415 507,874 — After one year but not more than five years — — — After more than five years — — — 47,415 507,874 — Currently, the biggest contract has a 60 day termination clause and all commitments have been limited to a twelve month commitment.

Contingencies

Contingencies	12 Months Ended
	Jun. 30, 2023
Disclosure of contingent liabilities [abstract]
Contingencies	Note 32. Contingencies The Group is party to various research agreements with respect to which a commitment to pay is contingent on the achievement of research milestones. Assuming all milestones are achieved within the time‑frames stipulated in the contracts, those which could become payable in less than one year total US$ nil (2022: US$ nil ) and those which could become payable in more than one year total US$ 1,086,244 (2022: US$ 11,512,675 ). Under these license/collaboration agreements, payments are to be made only if certain research and clinical development milestones are achieved and royalties may become payable on any eventual sales of products developed under these agreements. The group had a bank guarantee outstanding at June 30, 2023 in respect of a rental deposit for its office premises of US$ 38,036 (2021: US$ 39,478 ).

Cash Flow Statements Reconcilia

Cash Flow Statements Reconciliation	12 Months Ended
	Jun. 30, 2023
Cash Flow Statement Reconciliation [Abstract]
Cash Flow Statements Reconciliation	Note 33. Cash Flow Statements Reconciliation 2023 2022 2021 Restated US$ US$ US$ (a) Reconciliation to cash at the end of the year Cash at bank and in hand (note 17) 89,188,713 44,631,293 118,193,177 89,188,713 44,631,293 118,193,177 (b) Reconciliation of net loss after tax to net cash flows from operations Net loss for the year ( 142,521,085 ) ( 92,817,371 ) ( 45,344,496 ) Adjustments for: Income tax benefit recognized in profit or loss ( 5,926,350 ) ( 6,299,286 ) ( 4,938,846 ) Net loss of disposal of non-current assets — 169 — Depreciation of non-current assets 17,001 11,917 15,012 Depreciation of right-of-use assets 84,226 66,465 91,656 Interest expense on DFA 13,462,160 — — Fair value adjustment gain on DFA ( 12,302,160 ) — — Share-based payments 5,834,686 5,251,572 3,897,638 Net exchange differences 489,137 2,813,993 11,011,961 1,658,700 1,844,830 10,077,421 Changes in: Payables 7,296,785 8,511,607 ( 1,552,443 ) Receivables 378,896 307,618 ( 369,712 ) Prepayments 6,142,284 5,730,207 ( 14,231,546 ) Provisions 136,755 115,259 40,510 Net cash flows used in operating activities before tax ( 126,907,665 ) ( 76,307,850 ) ( 51,380,266 ) R&D tax incentive received 6,299,286 4,972,898 5,834,099 Net cash flows used in operating activities ( 120,608,379 ) ( 71,334,952 ) ( 45,546,167 )

Key Management Personnel

Key Management Personnel	12 Months Ended
	Jun. 30, 2023
Disclosure of transactions between related parties [abstract]
Key Management Personnel	Note 34. Key Management Personnel (a) Compensation of Key Management Personnel 2023 2022 2021 US$ US$ US$ Short-term employee benefits 2,898,544 1,555,658 1,099,081 Post-employment benefits 137,168 56,105 79,550 Share-based payments expense 4,221,472 4,664,767 3,897,638 7,257,184 6,276,530 5,076,269 (b) Other transactions and balances with director and key management personnel and their related parties There were no director and key management personnel related party transactions during the prior financial year for the current year refer to Note 30(b).

Share-Based Payments

Share-Based Payments	12 Months Ended
	Jun. 30, 2023
Disclosure of terms and conditions of share-based payment arrangement [abstract]
Share-Based Payments	Note 35. Share-Based Payments (a) Recognized share-based payment expenses The expense recognized for share‑based payments during the year is shown in the table below: 2023 2022 2021 US$ US$ US$ Expense arising from equity-settled share-based payment Director and employee services received 5,834,686 5,251,572 3,897,638 5,834,686 5,251,572 3,897,638 (b) Non‑executive director and employee share option plans During the 2015 financial year, the Group introduced an ownership‑based compensation scheme for non‑executive directors, executives and senior employees, the Long-Term Incentive Plan (LTIP) and Non‑Executive Directors Share and Option Plan (NED Plan). In accordance with the terms of the plans, as approved by shareholders at the 2014 annual general meeting, eligible non‑executive directors, executives and senior employees with the Group may be granted options to purchase ordinary shares. Each employee share option converts into one ordinary share of Opthea Limited on exercise. No amounts are paid or payable by the recipient on receipt of the option. The options carry neither rights to dividends nor voting rights and are not transferable. Options may be exercised at any time from the date of vesting to the date of their expiry. The number of options granted is subject to approval by the board and rewards executives and senior employees to the extent of the Group’s and the individual’s achievement judged against both qualitative and quantitative criteria as determined by the board on a case by case basis. The vesting condition of options granted under the LTIP and NED Plan is continuous service. Options/Rights services Grant date Grant date Exercise Expiry date Vesting date LTIP - director FY2019 November 29, 2018 0.150 0.625 November 29, 2022 November 29, 2019 LTIP - employees FY2018 August 23, 2017 0.260 0.920 January 1, 2023 June 30, 2018 LTIP - employees FY2019 April 3, 2019 0.180 0.608 April 3, 2023 April 3, 2021 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 October 19, 2021 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 October 19, 2022 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 October 19, 2023 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 January 31, 2023 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 November 30, 2022 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 April 30, 2023 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 April 30, 2023 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 September 30, 2024 LTIP - employees FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2021 LTIP - employees FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2022 LTIP - employees FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2023 LTIP - employees FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2024 LTIP - employees FY2022 June 6, 2022 0.553 1.460 June 5, 2032 June 6, 2022 LTIP - employees FY2022 June 6, 2022 0.553 1.460 June 5, 2032 June 6, 2023 LTIP - employees FY2022 June 6, 2022 June 5, 2032 LTIP - employees FY2022 June 6, 2022 0.553 1.460 June 5, 2032 June 6, 2024 LTIP - employees FY2023 November 16, 2022 0.471 0.658 November 16, 2032 November 16, 2025 LTIP - employees FY2023 November 16, 2022 0.672 0.000 November 16, 2032 November 16, 2025 LTIP - employees FY2023 December 13, 2022 0.459 0.644 December 13, 2032 December 13, 2023 LTIP - employees FY2023 December 13, 2022 0.459 0.644 December 13, 2032 December 13, 2024 LTIP - employees FY2023 December 13, 2022 0.459 0.644 December 13, 2032 December 13, 2025 LTIP - employees FY2023 December 13, 2022 0.459 0.644 December 13, 2032 December 13, 2026 NED Plan FY2016 March 7,2016 0.140 0.360 March 7, 2021 June 30, 2016 NED Plan FY2019 November 29, 2018 0.150 0.625 November 29, 2022 November 29, 2019 NED Plan FY2021 October 12, 2020 1.050 3.240 October 11, 2024 October 12, 2020 NED Plan FY2021 October 12, 2020 1.050 3.240 October 11, 2024 October 12, 2021 NED Plan FY2021 October 12, 2020 1.050 3.240 October 11, 2024 October 12, 2022 NED Plan FY2021 October 12, 2020 1.050 3.240 October 11, 2024 October 12, 2023 NED Plan FY2021 October 12, 2020 1.240 2.160 October 11, 2024 October 12, 2020 NED Plan FY2021 October 12, 2020 1.240 2.160 October 11, 2024 October 12, 2021 NED Plan FY2021 October 12, 2020 1.240 2.160 October 11, 2024 October 12, 2022 NED Plan FY2021 October 12, 2020 1.240 2.160 October 11, 2024 October 12, 2023 NED Plan FY2021 January 19, 2021 0.880 1.560 January 18, 2025 January 19, 2021 NED Plan FY2021 January 19, 2021 0.880 1.560 January 18, 2025 January 19, 2022 NED Plan FY2021 January 19, 2021 0.880 1.560 January 18, 2025 January 19, 2023 NED Plan FY2021 January 19, 2021 0.880 1.560 January 18, 2025 January 19, 2024 NED Plan FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2021 NED Plan FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2022 NED Plan FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2023 NED Plan FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2024 NED Plan FY2022 April 21, 2022 0.397 0.755 April 20, 2026 April 21, 2022 NED Plan FY2022 April 21, 2022 0.397 0.755 April 20, 2026 April 21, 2023 NED Plan FY2022 April 21, 2022 0.397 0.755 April 20, 2026 April 21, 2024 NED Plan FY2022 April 21, 2022 0.397 0.755 April 20, 2026 April 21, 2025 There has been no alteration of the terms and conditions of the above share‑based payment arrangements since the grant date. (c) Fair value of share options granted Where relevant, the expected life used in the model has been adjusted based on management’s best estimate for the effects of non‑transferability, exercise restrictions (including the probability of meeting conditions attached to the option), and behavioral considerations. Expected volatility is based on the historical share price volatility over the past 4 or 5 years. Options/Rights services Grant Exercise Fair Expected Option life Dividend Risk Model LTIP - director FY2019 0.420 0.625 0.150 58.00 % 4 years 0 % 2.04 % Binomial LTIP - employees FY2018 0.340 0.920 0.260 66.00 % 5 years 0 % 2.09 % Binomial LTIP - employees FY2019 0.480 0.608 0.180 57.00 % 4 years 0 % 2.04 % Binomial LTIP - employees FY2022 0.955 0.948 0.526 74.78 % 4 years 0 % 0.25 % Binomial LTIP - employees FY2022 0.955 nil 0.955 na 10 years 0 % n/a Binomial LTIP - employees FY2022 0.901 1.460 0.553 75.00 % 6.5 years 0 % 3.40 % Binomial LTIP - employees FY2023 0.672 0.658 0.471 75.00 % 6.5 years 0 % 3.60 % Binomial LTIP - employees FY2023 0.672 nil 0.672 75.00 % 10 years 0 % 3.70 % Binomial LTIP - employees FY2023 0.643 0.644 0.459 75.00 % 7 years 0 % 3.30 % Binomial NED Plan FY2016 0.280 0.360 0.140 65.00 % 5 years 0 % 2.09 % Binomial NED Plan FY2019 0.420 0.625 0.150 58.00 % 4 years 0 % 2.04 % Binomial NED Plan FY2021 2.190 2.160 1.240 77.25 % 4 years 0 % 0.25 % Binomial NED Play FY2021 2.190 3.240 1.050 77.25 % 4 years 0 % 0.25 % Binomial NED Plan FY2021 1.560 1.560 0.880 77.01 % 4 years 0 % 0.25 % Binomial NED Plan FY2022 0.955 0.945 0.526 74.78 % 4 years 0 % 0.25 % Binomial NED Plan FY2022 0.741 0.755 0.397 75.00 % 3.5 years 0 % 2.70 % Binomial Fair value of ADS options granted Where relevant, the expected life used in the model has been adjusted based on management’s best estimate for the effects of non‑transferability, exercise restrictions (including the probability of meeting conditions attached to the option), and behavioral considerations. Expected volatility is based on the historical share price volatility over the past 4 or 5 years. ADS Options Grant Exercise Fair Expected ADS Option life Dividend Risk Model LTIP - employee 2022 7.240 7.625 4.970 75.00 % 7 years 0 % 1.40 % Binomial LTIP - employee 2022 7.500 7.515 5.228 75.00 % 7 years 0 % 1.70 % Binomial LTIP - employee 2022 5.925 6.009 4.116 75.00 % 7 years 0 % 1.70 % Binomial LTIP - employee 2022 5.915 6.090 4.171 75.00 % 7 years 0 % 2.90 % Binomial LTIP - employee 2022 7.000 7.116 4.953 75.00 % 7 years 0 % 2.90 % Binomial LTIP - employee 2022 7.309 7.445 5.175 75.00 % 7 years 0 % 3.00 % Binomial LTIP - employee 2022 5.500 5.522 3.886 75.00 % 7 years 0 % 3.40 % Binomial LTIP - employee 2023 6.600 6.350 4.718 75.00 % 7 years 0 % 2.90 % Binomial LTIP - employee 2023 4.810 4.850 3.479 75.00 % 7 years 0 % 4.30 % Binomial LTIP - employee 2023 4.850 5.170 3.457 75.00 % 7 years 0 % 4.10 % Binomial LTIP - employee 2023 4.959 4.929 3.560 75.00 % 7 years 0 % 3.60 % Binomial LTIP - employee 2023 5.450 5.238 3.935 75.00 % 7 years 0 % 3.50 % Binomial LTIP - employee 2023 5.030 5.150 3.602 75.00 % 7 years 0 % 3.80 % Binomial LTIP - employee 2023 3.360 3.545 2.384 75.00 % 7 years 0 % 3.60 % Binomial (d) Movements in share options during the year The following reconciles the share/rights options outstanding at the beginning and end of the year: 2023 2022 2021 Number of Weighted Number of Weighted Number of Weighted Balance at beginning of year 22,988,000 1.16 16,644,000 1.28 18,044,000 0.50 Granted during the year: To employees and directors under the LTIP and NED Plan 10,050,000 0.58 8,400,000 0.77 7,000,000 2.21 Exercised during the year ( 6,613,000 ) 0.62 ( 2,056,000 ) 0.58 ( 8,400,000 ) 0.36 Expired during the year ( 975,000 ) 0.61 — — — — Balance at end of the year 25,450,000 1.04 22,988,000 1.16 16,644,000 1.28 Exercisable at end of year 10,842,234 1.48 12,857,589 0.97 11,394,000 0.86 The share options outstanding at the end of the year had a weighted average exercise price of US $ 1.04 (2022: US$ 1.16 , 2021: US$ 1.28 ) and a weighted average remaining contractual life of 555 days (2022: 567 days, 2021: 628 days). Movements in ADS options during the year The following reconciles the ADS options outstanding at the beginning and end of the year: 2023 2022 2021 Number of Weighted Number of Weighted Number of Weighted Balance at beginning of year 925,000 6.75 — — — — Granted during the year: To employees and directors under the LTIP and NED Plan 755,000 5.07 925,000 6.75 — — Exercised during the year — — — — — — Expired during the year ( 175,000 ) 7.62 — — — — Balance at end of the year 1,505,000 5.81 925,000 6.75 — — Exercisable at end of year 250,000 6.70 — — — —

Events After the Balance Sheet

Events After the Balance Sheet Date	12 Months Ended
	Jun. 30, 2023
Disclosure of non-adjusting events after reporting period [abstract]
Events After the Balance Sheet Date	Note 36. Events After the Balance Sheet Date On August 24 , 2023, Opthea announced a A$ 80 million capital raise consisting via a A$ 10 million private placement (“Placement”) and a A$ 70 million Accelerated Non‑Renounceable Entitlement Offer (“ANREO”). On August 28, 2023, Opthea announced an increase in the private placement by a further A$ 10 million to increase the overall raise to A$ 90 million. The proceeds from the Placement and Entitlement will be used to continue advancing the clinical development of OPT‑302 for the treatment of wet Age‑related Macular Degeneration (wet AMD) including to progress the Company’s Phase 3 clinical trials and for general corporate purposes. The Equity Financing of A$ 90 million (US$ 58 million) consists of two closings, of which the first closing of A$ 73 million (US$ 47 million) consisting of a placement offering and an acceleration portion of an Accelerated Non‑Renounceable Entitlement Offer (“ANREO”) occurred on September 1, 2023. The second closing of A$ 17 million (US$ 11 million), representing the remaining institutional and retail portion of the ANREO, has been underwritten, occurred on September 20, 2023. The shares were issued and cash received on September 20, 2023. Subsequent to June 30, 2023, the Group was notified that a new co‑investor of Carlyle and Abingworth intends to participate in a funding under the DFA of US$ 50 million to increase total DFA funding from US$ 120 million to US$ 170 million, which is subject to the co‑investor’s final due diligence and receipt of regulatory and tax approvals, appropriate documentation and compliance with closing conditions. Upon completion of the final due diligence, receipt of regulatory and tax approvals, execution of the appropriate documentation and satisfaction of the closing conditions, the Group expects to receive the additional US$ 50 million. While the Group anticipates that the due diligence will be completed to the satisfaction of the co‑investor, the necessary approvals will be obtained, the appropriate documentation will be executed and that all closing conditions will be satisfied, there is no assurance that the Group will ultimately receive the additional US$ 50 million. If the additional US$ 50 million is not received by June 30, 2024, the Group will need to raise additional funds or reduce expenditures to continue as a going concern. On August 28, 2023 Mr. Lawrence Gozlan, a director of the Company, and the Company have entered into a Consultancy Agreement of up to US$ 300,000 in respect of the provision of services associated with managing, overseeing and coordinating the conduct and implementation of the Capital Raising. The consultancy agreement is effective for the financial year June 30, 2024. In the opinion of the Directors, these duties are outside the scope of the ordinary duties of a Director. Besides the above-mentioned subsequent events, no matters or circumstances have arisen since the end of the reporting period, which significantly affected, or may significantly affect, the operations of the Group, the results of those operations, or the state of affairs of the Group in future financial years.

Summary of Accounting Policies

Summary of Accounting Policies (Policies)	12 Months Ended
	Jun. 30, 2023
Description Of Business And Summary Of Significant Accounting Policies [Abstract]
Basis of measurement	Basis of measurement The consolidated financial statements have been prepared on a historical cost basis, except for the investments classified as financial assets, which have been measured at fair value. All amounts are presented in United States dollars unless otherwise stated. Functional currency An entity’s functional currency is the currency of the primary economic environment in which the entity operates. During 2021, the Group’s operations continued to move further towards being US$ denominated and several other factors during the period have also contributed to the Group changing its functional currency during the year, such as the completion of U.S. initial public offering (IPO) and the Nasdaq listing in October 2020, opening a US subsidiary in May 2021 for a planned expansion into the US, and expanding the Board of Directors with the appointment of now five US based Directors. A significant element in the Group’s assessment to change the functional currency resulted from the significant increase in expenses denominated in US dollars relating to advanced clinical trials since the commencement of Phase 3 trials in March 2021. These changes, as well as the fact that the Group’s principal source of financing is now the U.S. capital market and all of the Group’s budgeting and planning is conducted solely in dollars led to the Company determining that the U.S. dollar (US$) best represents the currency of the primary economic environment in which the entity now operates. Accordingly, the Group changed its functional currency from Australian dollar (A$) to U.S. dollar (US$) effective January 1, 2021. Presentation Currency Following the change in functional currency, the Group changed its presentation currency from Australian dollars (A$) to US$. The change in presentation currency was made to better reflect the Group’s business activities and to enhance access to U.S. capital markets. Prior to the change, the Group reported its financial statements in Australian dollars (A$). A change in presentation currency is a change in accounting policy which is accounted for retrospectively during 2021. In making this change in presentation currency, the Group followed the requirements set out in IAS 21 The Effects of Changes in Foreign Exchange Rates . As required by IAS 21, the consolidated statement of profit or loss and other comprehensive income and the consolidated statement of cash flows for each period have been translated into the presentation currency using the average exchange rates prevailing during each reporting period. All assets and liabilities have been translated using the exchange rates prevailing at the consolidated statement of financial position dates. Shareholders’ equity transactions have been translated using the rates of exchange in effect as of the dates of various capital transactions. All resulting exchange differences arising from the translation are included as a separate component of other comprehensive income. All comparative financial information has been restated in fiscal year 2021 to reflect the Group’s results as if they had been historically reported in US$ and the effect on the consolidated financial statements resulted in an addition to the foreign currency translation reserve of US$ 14.3 million for financial year 2021. Change in Presentation of Other Income The Group changed its presentation of Other income by reclassifying interest income out of Other income and into Finance Income – interest income to better reflect the nature of the related amounts as finance income. This reclassification had no effect on the reported results of operations.
Basis of consolidation	Basis of consolidation The consolidated financial statements incorporate the financial statements of the Company and its subsidiaries. Control is achieved when the Company: • Has power over the investee; • Is exposed, or has rights, to variable returns from its involvement with the investee; and • Has the ability to use its power to affect its returns. Consolidation of a subsidiary begins when the Company obtains control over the subsidiary and ceases when the Company loses control of the subsidiary. All intragroup assets and liabilities, equity, income, expenses and cash flows relating to transactions between members of the Group are eliminated in full on consolidation.
Foreign currency translation	Foreign currency translation i. Functional and presentation currency As of January 1, 2021 the Group determined that its functional and presentation currency had changed from Australian Dollars to United States Dollars. Therefore, the functional and presentation currency of the Group is the United States dollars (US$). ii. Transactions and balances Transactions in foreign currencies are initially recorded in the functional currency by applying the exchange rates ruling in place at the date of the transaction. Monetary assets and liabilities denominated in foreign currencies are retranslated at the rate of exchange ruling in place at the reporting date. Non‑monetary items that are measured in terms of historical cost in a foreign currency are translated using the exchange rate as of the date of the initial transaction. Non‑monetary items measured at fair value in a foreign currency are translated using the exchange rates at the date when the fair value was determined.
Financial assets and liabilities	Financial assets and liabilities Recognition and derecognition of financial assets Purchases and sales of financial assets that require delivery of assets within the time frame generally established by regulation or convention in the marketplace are recognized on the trade date, i.e., the date that the Group commits to purchase the asset. Financial assets are derecognized when the right to receive cash flows from the financial assets has expired or when the entity transfers substantially all the risks and rewards of the financial assets. If the entity neither retains nor transfers substantially all of the risks and rewards, it derecognizes the asset if it has transferred control of the assets. When financial assets are recognized initially, they are measured at fair value, plus directly attributable transaction costs. Cash and cash equivalents Cash and cash equivalents in the statement of financial position comprise cash at bank and in hand and short‑term deposits with an original maturity of three months or less that are readily convertible to known amounts of cash and which are subject to an insignificant risk of changes in value. For the purposes of the statement of cash flows, cash and cash equivalents consist of cash and cash equivalents as defined above. Other receivables Other receivables generally comprise bank interest receivable, other receivables from external parties and Goods and Services Tax (GST) credits receivable and are recognized and carried at original invoice amount less an allowance for any uncollectible amounts. The amounts are usually received within 30 to 60 days of recognition. The Group measures the loss allowance for receivables at an amount equal to lifetime expected credit losses (ECL). The ECL on receivables are estimated under the simplified approach as permitted under IFRS 9 “Financial Instruments.” This uses a provision matrix by reference to past experience of the debtor and an analysis of the debtor’s current financial position, adjusted for factors that are specific to the debtors and general economic conditions of the industry in which the debtors operate. The Group writes off a receivable when there is information indicating that the debtor is in severe financial difficulty and there is no realistic prospect of recovery. Investments Investments in financial assets comprise of the Group’s non‑current investments in listed companies. On initial recognition, the Group may make an irrevocable election (on an instrument‑by‑instrument basis) to designate investments in equity instruments as fair value through other comprehensive income (FVTOCI). Designation at FVTOCI is not permitted if the equity instrument is held for trading. Investments in equity instruments at FVTOCI are initially measured at fair value plus transaction costs. Subsequently, they are measured at fair value with gains or losses arising from changes in the fair value recognized in other comprehensive income and accumulated in the fair value of investments reserve. The fair values of investments in financial assets that are actively traded in organized financial markets is determined by reference to quoted market bid prices at the close of business on the reporting date. The cumulative gain or loss is not reclassified to profit or loss on disposal of the equity instruments. Dividends on these investments in equity instruments are recognized in profit or loss in accordance with International Financial Reporting Standards. Finance income Almost all of the Group’s finance income is earned on short‑term bank deposits, and as such, finance income is recognized when the Group’s right to receive the payment is established. Payables Payables are carried at amortized cost and due to their short‑term nature, they are not discounted. They represent liabilities for goods and services provided to the Group prior to the end of the financial year that are unpaid and arise when the Group becomes obliged to make future payments in respect of the purchase of these goods and services. The amounts are unsecured and are usually paid within 30 days of recognition. Financial liabilitie s Financial liabilities are recognized in the Group’s statement of financial position when the Group becomes a party to the contractual provisions of the instrument. Financial liabilities are initially measured at fair value. Transaction costs that are directly attributable to the acquisitions or issue of financial liabilities (other than financial liabilities at fair value through profit or loss) are deducted from the fair value of the financial liabilities, as appropriate, on initial recognition. Subsequent measurement of the liability will be at its amortized cost, subject to any re-measurement of the obligation for changes in assumptions. Amortized cost and effective interest method The effective interest method is a method of calculating the amortized cost of an instrument and of allocating interest expense over the relevant period. The effective interest rate is the rate that exactly discounts estimated future cash payments through the expected life of the financial liability, or (where appropriate) a shorter period, to the amortized cost of the financial liability. Interest expense is recognized in profit and loss and is included in the “Interest expense on DFA” line item.
Equipment	Equipment Equipment is stated at historical cost less accumulated depreciation and any accumulated impairment losses. Depreciation is calculated on a straight‑line basis over their useful economic lives as follows: • Equipment and furniture – 3 to 10 years; and • Leasehold improvements – 8 years or the term of the lease if shorter. The assets’ residual values, useful lives and amortization methods are reviewed, and adjusted if appropriate, at each financial year end. An item of equipment is derecognized upon disposal or when no further economic benefits are expected from its use or disposal.
Research and development costs	Research and development costs Research costs are expensed as incurred. An intangible asset arising from the development expenditure on an internal project will only be recognized when the Group can demonstrate the technical feasibility of completing the intangible asset so that it will be available for use or sale, its intention to complete and its ability to use or sell the asset, how the asset will generate future economic benefits, the availability of resources to complete the development and the ability to measure reliably the expenditure attributable to the intangible asset during its development. As of June 30, 2023, 2022 and 2021, the Group is in the research phase and has not capitalized any development costs to date.
Provisions and employee benefits	Provisions and employee benefits i. Wages, salaries, annual leave and sick leave Liabilities for wages and salaries, including non‑monetary benefits and annual leave expected to be settled within 12 months of the reporting date are recognized in current provisions in respect of employees’ services up to the reporting date. They are measured at the amounts expected to be paid when the liabilities are settled. Expenses for non‑accumulating sick leave are recognized when the leave is taken and are measured at the rate paid or payable. ii. Long service leave The liability for long service leave is recognized in the provision for employee benefits and measured as the present value of expected future payments to be made in respect of services provided by employees up to the reporting date. Consideration is given to expected future wage and salary levels, experience of employee departures, and periods of service. Expected future payments are discounted using market yields at the reporting date on bonds with terms to maturity that match, as closely as possible, the estimated future cash outflows.
Share based payment transactions	Share‑based payment transactions The Group provides benefits to directors and employees (including key management personnel) of the Group in the form of share‑based payments, whereby employees render services in exchange for shares or rights over shares (equity‑settled transactions). The cost of these equity‑settled transactions with employees is measured by reference to the fair value at the date at which they are granted. Binomial models are used to value the options issued. The cost of the equity‑settled transactions is recognized, together with a corresponding increase in equity, over the period in which the performance conditions are fulfilled (the vesting period), ending on the date on which the relevant employees become fully entitled to the award (the vesting date). The charge to profit or loss for the period is the cumulative amount less the amounts already charged in previous periods. There is a corresponding credit to equity. Until an award has vested, any amounts recorded are contingent and will be adjusted if more or fewer awards vest than were originally anticipated to do so.
Contributed equity	Contributed equity Ordinary shares are classified as equity. Incremental costs directly attributable to the issue of new shares or options are shown in equity as a deduction, net of tax, from the proceeds.
Revenue recognition	Revenue recognition License revenue in connection with licensing of the Group’s intellectual property (including patents) to customers is recognized as a right to use the Group’s intellectual property as it exists at the point in time in which the license is granted. This is because the contracts for the license of intellectual property are distinct and do not require, nor does the customer reasonably expect, that the Group will undertake further activities that significantly affect the intellectual property to which the customer has the rights. Although the Group is entitled to sales‑based royalties from the eventual sales of goods and services to third parties using the intellectual property licensed, these royalty arrangements do not in themselves indicate that the customer would reasonably expect the Group to undertake such activities, and no such activities are undertaken or contracted in practice. Accordingly, the promise to provide rights to the Group’s intellectual property is accounted for as a performance obligation satisfied at a point in time. The following consideration is received in exchange for licenses of intellectual property: • Up‑front license fees – these are fixed amounts and are recognized at the point in time when the Group transfers the intellectual property to the customer. • Sales‑based royalties – these are variable consideration amounts promised in exchange for the license of intellectual property and are recognized when the sales to third parties occur given the performance obligation to transfer the intellectual property to the customer is already satisfied. During the years ended June 30, 2023, 2022 and 2021, the Group’s only revenue related to sales‑based royalties.
Income tax	Income tax Current tax Current tax assets and liabilities for the current and prior periods are measured at the amount expected to be recovered from or paid to the taxation authorities based on the current period’s taxable income. The tax rates and tax laws used to compute the amount are those that are enacted or substantively enacted by the reporting date. Research and development tax incentive The Research and Development (R&D) Tax Incentive Scheme is an Australian Federal Government program under which eligible companies with annual aggregated revenue of less than A$ 20 million can receive cash amounts equal to 43.5 % of eligible research and development expenditures from the Australian Taxation Office (ATO). The R&D Tax Incentive Scheme incentive relates to eligible expenditure incurred in Australia and, under certain circumstances, overseas on the development of the Group’s lead candidate, OPT‑302. The R&D tax incentive is applied annually to eligible expenditure incurred during the Group’s financial year following annual application to AusIndustry, an Australian governmental agency, and subsequent filing of its Income Tax Return with the ATO after the financial year end. The Group estimates the amount of R&D tax incentive after the completion of the financial year based on eligible Australia and overseas expenditures incurred during that year. The Group has presented incentives in respect of the R&D Tax Incentive Scheme within income tax benefit in the Statements of Profit or Loss and Other Comprehensive Income by analogizing with IAS 12 “Income Taxes”. Deferred tax Deferred income tax is provided on all temporary differences at the reporting date between the tax bases of assets and liabilities and their carrying amounts for financial reporting purposes. Deferred income tax liabilities are recognized for all taxable temporary differences except when the deferred income tax liability arises from the initial recognition of goodwill or of an asset or liability in a transaction that is not a business combination and that, at the time of the transaction, affects neither the accounting profit nor taxable profit or loss. Deferred income tax assets are recognized for all deductible temporary differences, carry forward of unused tax assets (or credits) and unused tax losses, to the extent that it is probable that taxable profit will be available against which the deductible temporary differences, and the carry forward of unused tax credits and unused tax losses can be utilized, except when the deferred income tax asset relating to the deductible temporary differences arises from the initial recognition of an asset or liability in a transaction that is not a business combination and, at the time of the transaction, affects neither the accounting profit or taxable profit or loss. The carrying amount of deferred income tax assets is reviewed at each reporting date and reduced to the extent that it is no longer probable that sufficient taxable profit will be available to allow all or part of the deferred income tax asset to be utilized. Unrecognized deferred income tax assets are reassessed at each reporting date and are recognized to the extent that it has become probable that future taxable profit will allow the deferred tax asset to be recovered. Deferred income tax assets and liabilities are measured at the tax rates that are expected to apply to the year when the asset is realized or the liability is settled, based on tax rates (and tax laws) that have been enacted or substantively enacted at balance date. Income taxes relating to items recognized directly in equity are recognized directly in equity and not in profit or loss.
Tax consolidation legislation	Tax consolidation legislation Tax consolidation is a system adopted by the ATO that treats a group of entities as a single entity for tax purposes. Opthea Limited and its 100 % owned Australian domiciled subsidiary formed a tax consolidated group effective July 1, 2003. The head entity, Opthea Limited, and its controlled entity, Vegenics Pty Ltd, are current members of the tax consolidated group and account for their own current and deferred tax amounts. Members of the tax consolidated group have adopted the “separate taxpayer within group” method to allocate the current and deferred tax amounts to each entity within the Group. This method requires adjustments for transactions and events occurring within the tax consolidated group that do not give rise to a tax consequence for the Group or that have a different tax consequence at the level of the Group. This method requires adjustments for transactions and events occurring within the tax consolidated group that do not give rise to a tax consequence for the Group or that have a different tax consequence at the level of the Group. The head entity which is the parent entity, in assuming the net unused tax losses and unused relevant tax credits, has recognized reductions to investments in subsidiaries and where the amount of tax losses assumed is in excess of the carrying value of the investment, the parent has recognized the difference as a distribution from subsidiaries in profit or loss.
Other taxes	Other taxes Revenues, expenses, assets and liabilities are recognized net of the amount of GST except: • When the GST incurred on a purchase of goods and services is not recoverable from the taxation authority, in which case the GST is recognized as part of the cost of acquisition of the asset or as part of the expense item as applicable; and • Receivables and payables are stated with the amount of GST included. The net amount of GST recoverable from, or payable to the taxation authority is included as part of receivables or payables in the statement of financial position. Cash flows are included in the statement of cash flows on a gross basis and the GST component of cash flows arising from investing and financing activities, which is recoverable from, or payable to, the taxation authority is classified as part of operating cash flows. Commitments and contingencies are disclosed net of the amount of GST recoverable from, or payable to, the taxation authority.

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Jun. 30, 2023
Revenue [abstract]
Summary of Revenue	2023 2022 2021 US$ US$ US$ Sales-based royalties 108,406 90,683 68,613 Total Revenue 108,406 90,683 68,613

Other Income (Tables)

Other Income (Tables)	12 Months Ended
	Jun. 30, 2023
Analysis of income and expense [abstract]
Schedule of Other Income	2023 2022 2021 US$ US$ US$ Grant and other income 276,869 108,322 26,950 Total other income 276,869 108,322 26,950

Research and Development Expe_2

Research and Development Expenses (Tables)	12 Months Ended
	Jun. 30, 2023
Disclosure Of Research And Development Expenses [Abstract]
Summary of Research and Development Expenses	2023 2022 2021 US$ US$ US$ Research project costs 122,128,314 78,654,217 25,891,851 Total research and development expenses 122,128,314 78,654,217 25,891,851

Expenses (Tables)

Expenses (Tables)	12 Months Ended
	Jun. 30, 2023
Expense By Nature [Abstract]
Summary of Expenses	2023 2022 2021 US$ US$ US$ Administrative expenses Employee benefits expenses: Salaries and fees 6,274,560 2,931,243 1,794,840 Cash bonuses 1,265,944 376,649 479,501 Superannuation 287,396 171,899 188,543 Share-based payments expense 5,834,686 5,251,572 3,897,638 Total employee benefits expense 13,662,586 8,731,363 6,360,522 Other expenses: Insurance 2,551,768 4,205,106 4,419,433 Investor relations costs 451,378 328,026 285,071 Audit and accounting 337,038 496,652 647,549 Travel expenses 580,644 13,616 1,459 Payroll tax 340,003 172,884 18,766 Legal fees 1,330,054 1,252,014 83,605 Advisory fees 1 6,084,005 156,978 393,843 Consultancy costs 1,389,048 1,619,824 367,070 Other expenses 1,288,179 867,405 732,773 Total other expenses 14,352,117 9,112,505 6,949,569 Depreciation of: Equipment and furniture 17,000 11,917 15,012 Right-of-use assets 84,226 66,465 91,656 Total depreciation expense 101,226 78,382 106,668 Loss on disposal of non-current assets — 169 1,434 Total administrative expenses 28,115,929 17,922,419 13,418,193 1. Advisory fees relates to a market assessment of potential financing alternatives and solutions.

Finance Income (Tables)

Finance Income (Tables)	12 Months Ended
	Jun. 30, 2023
Material income and expense [abstract]
Summary of Finance Income	2023 2022 2021 US$ US$ US$ Interest income 3,227,496 235,468 372,001 Total finance income 3,227,496 235,468 372,001

Interest Expense on DFA (Tables

Interest Expense on DFA (Tables)	12 Months Ended
	Jun. 30, 2023
Material income and expense [abstract]
Summary of Interest Expense on DFA	2023 2022 2021 US$ US$ US$ Interest expense on DFA 13,462,160 — — Total interest expense on DFA 13,462,160 — —

Fair Value Adjustment Gain on_2

Fair Value Adjustment Gain on DFA (Tables)	12 Months Ended
	Jun. 30, 2023
Material income and expense [abstract]
Summary of Fair Value Adjustment Gain on DFA	2023 2022 2021 US$ US$ US$ Fair value adjustment gain on DFA 12,302,160 — — Total fair value adjustment gain on DFA 12,302,160 — —

Net Foreign Exchange Loss (Tabl

Net Foreign Exchange Loss (Tables)	12 Months Ended
	Jun. 30, 2023
Net Foreign Exchange Loss Gain [Abstract]
Summary of Net Foreign Exchange Loss	2023 2022 2021 US$ US$ US$ Net foreign exchange (loss)/gain ( 489,137 ) ( 2,813,993 ) ( 11,011,961 ) Total net foreign exchange (loss)/gain ( 489,137 ) ( 2,813,993 ) ( 11,011,961 )

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Jun. 30, 2023
Major components of tax expense (income) [abstract]
Summary of Income Tax Benefit and Current Tax Receivable	2023 2022 2021 US$ US$ US$ (a) Income tax benefit The major components of income tax benefit are: Statement of Profit or Loss and Other Comprehensive Income Current tax Current income tax credit 5,926,350 6,299,286 4,938,846 5,926,350 6,299,286 4,938,846 Deferred tax In respect of the current year — — — Total income tax benefit recognized in the Statement of Comprehensive Income 5,926,350 6,299,286 4,938,846 (b) Current tax receivable US$ US$ US$ Research and Development Tax Incentive Credit receivable 5,926,350 6,299,286 4,972,898
Summary of Reconciliation Between Income Tax Benefit and the Product of Accounting Loss Before Income Tax Multiplied by the Groups Applicable Income Tax Rate	A reconciliation between income tax benefit and the product of accounting loss before income tax multiplied by the Group’s applicable income tax rate is as follows: 2023 2022 2021 US$ US$ US$ Accounting loss before tax ( 148,447,435 ) ( 99,116,657 ) ( 50,283,342 ) At the Company's statutory income tax rate of 30 % 44,534,230 29,734,997 15,085,003 R&D tax incentive on eligible expenses 5,926,350 6,299,286 4,938,846 Non-deductible R&D expenditure ( 4,087,138 ) ( 4,344,335 ) ( 3,420,951 ) Other non-deductible expenses - share-based payment expense ( 1,750,406 ) ( 1,575,472 ) ( 1,169,291 ) Amount of temporary differences and carried forward tax losses not recognized ( 38,696,687 ) ( 23,815,190 ) ( 10,494,761 ) 5,926,350 6,299,286 4,938,846
Summary of Recognized Deferred Tax Assets and Liabilities in Statement of Financial Position	(d) Recognized deferred tax assets and liabilities in statement of financial position June 30, 2023 June 30,2022 June 30,2021 Deferred income tax at June 30 relates to the following: Deferred tax liabilities: Interest and royalty income receivable (future assessable income) ( 44,785 ) ( 17,085 ) ( 2,344,514 ) ( 44,785 ) ( 17,085 ) ( 2,344,514 ) Deferred tax assets related to temporary differences: Recognition of tax losses — — 1,508,764 Accrued expenses and other liabilities 200,536 198,607 205,458 Employee provisions 161,006 161,159 152,675 Other miscellaneous items 270,721 306,531 477,617 632,263 666,297 2,344,514 Net deferred tax assets 587,478 649,212 — Less: temporary differences not recognized ( 587,478 ) ( 649,212 ) — Net deferred tax recognized in the statement of financial position — — —

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
	Jun. 30, 2023
Earnings Per Share [Line Items]
Summary of Income Used in Basic and Diluted Earnings Per Share Computation	2023 2022 2021 US$ US$ US$ The following reflects the income used in the basic and diluted earnings per share computations: (a) Earnings used in calculating earnings per share Net loss attributable to ordinary equity holders of the parent ( 142,521,085 ) ( 92,817,371 ) ( 45,344,496 ) (b) Weighted average number of shares Weighted average number of ordinary shares on issue for basic earnings per share 442,637,406 351,560,198 320,432,814 Effect of dilution: Share options — — Weighted average number of ordinary shares adjusted for the effect of dilution 442,637,406 351,560,198 320,432,814 Loss per share (basic and diluted in cents) (32.20 ) (26.40 ) (14.15 )
Options
Earnings Per Share [Line Items]
Summary of Option Plans	These options related to the following option plans. Options 2023 2022 2021 NED Plan 16,500,000 14,000,000 10,000,000 LTIP 6,050,000 7,388,000 6,644,000 22,550,000 21,388,000 16,644,000
Performance Rights
Earnings Per Share [Line Items]
Summary of Option Plans	2023 2022 2021 Performance Rights NED Plan 650,000 — — LTIP 2,250,000 1,600,000 — 2,900,000 1,600,000 —
A D S Options
Earnings Per Share [Line Items]
Summary of Option Plans	2023 2022 2021 ADS Options NED Plan — — LTIP 1,505,000 925,000 — 1,505,000 925,000 —

Current Assets - Cash and Cas_2

Current Assets - Cash and Cash Equivalents (Tables)	12 Months Ended
	Jun. 30, 2023
Current Assets Cash And Cash Equivalents [Abstract]
Summary of Cash and Cash Equivalents	June 30, 2023 June 30, 2022 US$ US$ Cash at bank and in hand 12,067,158 11,853,883 Short-term deposits 77,121,555 32,777,410 Total cash and cash equivalents 89,188,713 44,631,293

Current Assets - Receivables (T

Current Assets - Receivables (Tables)	12 Months Ended
	Jun. 30, 2023
Current Assets Receivables [Abstract]
Summary of Current Assets - Receivables	June 30, 2023 June 30, 2022 US$ US$ Interest receivable 162,853 56,952 GST receivable 1 325,474 157,060 Other receivable 1 148,237 43,656 Total current receivables 636,564 257,668 1 The GST and other receivables are non‑interest bearing. There were no receivables with a material expected credit loss recorded during the financial year (2022: nil , 2021: nil ).

Non-Current Assets - Right of_2

Non-Current Assets - Right of Use Assets (Tables)	12 Months Ended
	Jun. 30, 2023
Disclosure of quantitative information about right-of-use assets [abstract]
Summary of Carrying Amount of Lease	The carrying amount of the lease at June 30, 2023 is as follows: June 30, 2023 June 30, 2022 US$ US$ Right-of-Use Asset Cost Opening balance as at July 1 281,554 281,554 Additions 252,677 — Exchange on translations — — 534,231 281,554 Right-of-Use-Asset Depreciation Opening balance as at July 1 ( 281,554 ) ( 187,702 ) Charge to the period ( 84,226 ) ( 93,852 ) Exchange on translation — — ( 365,780 ) ( 281,554 ) Net carrying amount at June 30 168,451 —
Summary of Lease Amounts Recognized in Profit or Loss	2023 2022 2021 US$ US$ US$ Amounts recognized in profit or loss: Depreciation expense on right-of-use asset 84,226 66,465 91,656 Lease finance costs 5,321 5,920 5,782 Expense relating to leases of low value assets 2,101 7,376 7,042 91,648 79,761 104,480

Current Assets - Prepayments (T

Current Assets - Prepayments (Tables)	12 Months Ended
	Jun. 30, 2023
Current prepayments [abstract]
Summary of Current Assets Prepayments	June 30, 2023 June 30, 2022 US$ US$ R&D Contract Research Organization 1,693,964 7,428,599 Insurance 717,064 1,086,847 Other prepayments 223,643 204,749 Total current prepayments 2,634,671 8,720,195

Non-Current Assets - Prepayme_2

Non-Current Assets - Prepayments (Tables)	12 Months Ended
	Jun. 30, 2023
Disclosure Of Noncurrent Assets Prepayments [Abstract]
Summary of Non-Current Assets - Prepayments	June 30, 2023 June 30, 2022 US$ US$ Insurance 53,535 110,295 Total non-current prepayments 53,535 110,295

Current Liabilities _ Payables

Current Liabilities – Payables (Tables)	12 Months Ended
	Jun. 30, 2023
Current Liabilities Payables [Abstract]
Summary of Current Liabilities Payables	June 30, 2023 June 30, 2022 US$ US$ Accounts Payable (unsecured) 1 17,842,981 11,402,164 Payroll related tax liability 48,873 43,334 Total current payables 17,891,854 11,445,498 1 Accounts Payable are non‑interest bearing and are normally settled on 30 day terms .

Current Liabilities - Provisi_2

Current Liabilities - Provisions (Tables)	12 Months Ended
	Jun. 30, 2023
Current provisions [abstract]
Summary of Current Provisions	June 30, 2023 June 30, 2022 US$ US$ Annual leave 500,361 383,220 Long service leave 252,939 212,983 Total current provisions 753,300 596,203

Lease Liabilities (Tables)

Lease Liabilities (Tables)	12 Months Ended
	Jun. 30, 2023
Lease liabilities [abstract]
Summary of Lease Liabilities	June 30, 2023 June 30, 2022 US$ US$ Carrying amount at July 1 112,965 New lease 252,677 — Payments ( 70,966 ) ( 112,965 ) Carrying amount at June 30 181,711 — Maturity analysis: Year 1 102,806 — Year 2 84,226 — 187,032 — Less: unearned interest ( 5,321 ) — 181,711 — Analyzed into: Current portion 97,485 — Non-current portion 84,226 — 181,711 —

Non-Current Liabilities - Fin_2

Non-Current Liabilities - Financial Liabilities (Tables)	12 Months Ended
	Jun. 30, 2023
Categories of non-current financial liabilities [abstract]
Disclosure of Summary of Noncurrent Financial Liabilities	June 30, 2023 June 30, 2022 US$ US$ Carrying amount at July 1 — — Funding at fair value 84,500,000 — Interest expense on DFA 13,462,160 Fair value adjustment gain on DFA ( 12,302,160 ) — Total financial liabilities 85,660,000 —

Non-Current Liabilities - Pro_2

Non-Current Liabilities - Provisions (Tables)	12 Months Ended
	Jun. 30, 2022
Non-current provisions [abstract]
Summary of Non-Current Liabilities - Provisions	June 30, 2023 June 30, 2022 US$ US$ Long service leave 7,631 27,974 Total non-current provisions 7,631 27,974

Contributed Equity (Tables)

Contributed Equity (Tables)	12 Months Ended
	Jun. 30, 2023
Contributed Equity [Abstract]
Summary of Contributed Equity	June 30, 2023 June 30, 2022 June 30, 2021 US$ US$ US$ (a) Ordinary shares Issued and fully paid at June 30 320,883,552 235,277,217 234,147,526 Movement in ordinary shares: Opening balance 235,277,217 234,147,526 113,852,364 Issue of shares on exercise of options granted under the LTIP 3,790,978 1,129,691 3,271,542 Issue of shares on Nasdaq listing net of issuance cost $ 10,126,969 — — 105,477,591 Issue of shares on exercise of pre-funded warrants net of issuance cost $ 1,099,412 — — 11,546,029 Issue of shares net of issuance costs $ 4,531,040 81,815,357 — — 320,883,552 235,277,217 234,147,526 Ordinary shares on issue: No: No: No: Opening balance 352,152,542 351,003,541 269,157,769 Issue of shares on exercise of options granted under the LTIP 2,387,826 1,149,001 5,845,804 Issue of shares on Nasdaq listing — — 68,506,400 Issue of share on exercise of pre-funded warrants — — 7,493,568 Issue of shares on ASX 112,619,006 — — 467,159,374 352,152,542 351,003,541

Accumulated Losses and Reserv_2

Accumulated Losses and Reserves (Tables)	12 Months Ended
	Jun. 30, 2023
Disclosure of reserves within equity [abstract]
Summary of Accumulated Losses and Reserves	2023 2022 US$ US$ (a) Movements in accumulated losses were as follows: Balance at July 1 ( 216,941,353 ) ( 124,123,982 ) Net loss for the period ( 142,521,085 ) ( 92,817,371 ) Balance at June 30 ( 359,462,438 ) ( 216,941,353 ) (b) Reserves Fair value of Investments reserve (i) 1,085,411 1,085,411 Share-based payments reserve (ii) 11,551,134 8,466,706 Foreign translation reserve (iii) 20,089,163 20,089,163 Total reserves 32,725,708 29,641,280 (i) Movement in fair value of investments reserve: Opening balance 1,085,411 1,085,411 Fair value on gains on investments in financial assets — — Exchange on translation — — Closing balance 1,085,411 1,085,411 (ii) Movement in share-based payments reserve: Opening balance 8,466,706 4,087,650 Share-based payments expense 5,834,686 5,251,572 Exercise of options ( 2,750,258 ) ( 872,516 ) Exchange on translation — — Closing balance 11,551,134 8,466,706 (iii) Movement in foreign translation reserve: Opening balance 20,089,163 20,089,163 (Gains)/loss on translation — — Closing balance 20,089,163 20,089,163

Financial Risk Management Obj_2

Financial Risk Management Objectives and Policies (Tables)	12 Months Ended
	Jun. 30, 2023
Interest rate risk [member]
Disclosure Of Risk Management Strategy Related To Hedge Accounting [Line Items]
Summary of Judgments of Reasonably Possible Movements	At June 30, 2023, 2022 and 2021, if interest rates moved, with all variables held constant, post tax (loss)/profit and equity would have been affected as illustrated in the following table: Post tax (loss)/profit impact 2023 2022 2021 US$ US$ US$ Judgments of reasonably possible movements +0.50% (50 basis points) (2022:+ 0.50 %) 270,059 114,859 359,442 -0.50% (50 basis points) (2022:-0.50%) ( 270,059 ) ( 114,859 ) ( 359,442 )
Currency Risk
Disclosure Of Risk Management Strategy Related To Hedge Accounting [Line Items]
Summary of Judgments of Reasonably Possible Movements	At June 30, 2023, 2022 and 2021, had the United States dollar moved with all other variables held constant, post tax (loss) profit and equity would have been affected as illustrated in the table below: Post tax (loss)/profit impact 2023 2022 2021 US$ US$ US$ Judgments of reasonably possible movements Consolidated AUD/USD +10% (2022:+ 10 %) ( 3,847,285 ) ( 2,119,834 ) ( 2,538,062 ) AUD/USD -10% (2022:-10%) 4,702,237 2,590,908 3,102,076
Summary of Exposure to Foreign Currency Risk	At the reporting date, the Group has the following exposure to foreign currencies. : Consolidated 2023 AUD EURO GBP CAD Financial assets Cash 55,307,319 Receivables 6,290,086 Financial liabilities Payables ( 1,187,459 ) ( 53,332 ) ( 3,166 ) ( 136,689 ) Other financial liabilities Net exposure 60,409,946 ( 53,332 ) ( 3,166 ) ( 136,689 ) Consolidated 2022 AUD EURO GBP CAD Financial assets Cash 26,697,582 — — — Receivables 7,827,565 — — — Financial liabilities Payables ( 1,213,469 ) ( 435,698 ) ( 3,037 ) ( 13,419 ) Other financial liabilities — — — — Net exposure 33,311,678 ( 435,698 ) ( 3,037 ) ( 13,419 )

Related Party Disclosures (Tabl

Related Party Disclosures (Tables)	12 Months Ended
	Jun. 30, 2023
Related party transactions [abstract]
Summary of Consolidated Financial Statements Include Financial Statements of Opthea Limited and Subsidiaries	The consolidated financial statements include the financial statements of Opthea Limited and its subsidiaries in the following table: Parent entity % equity interest June 30, 2023 June 30, 2022 June 30, 2021 % % % Vegenics Pty Ltd 1 100 100 100 Opthea US Inc 2 100 100 100 (1) Opthea Limited is the ultimate parent entity. Vegenics Pty Ltd is incorporated in Australia and has the same financial year as Opthea Limited. (2) Opthea Limited is the ultimate parent entity. Opthea US Inc was incorporated in the United States in May 2021 and has the same financial year as Opthea Limited.
Summary of Trading Transactions with Related Parties	During the year, group entities entered into the following transactions with related parties who are not members of the Group. Consolidated Purchase of Service 2023 2022 2021 Launch Tx - Ocelot — — — Launch 900,000 — — Purchase of services assisting Opthea with the management and oversight of trials under the Service Agreement with Launch Tx. Consolidated Amounts owed to related parties 2023 2022 2021 Launch Tx - Ocelot 85,660,000 — — Launch — — —

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Jun. 30, 2023
Commitments [Abstract]
Summary of Expenditure Commitments Relating to Services for Clinical Trial and Intellectual Property License Agreements	Expenditure commitments relating to these, and intellectual property license agreements are payable as follows: 2023 2022 2021 US$ US$ US$ Within one year 12,632,801 39,947,900 26,377,778 After one year but not more than five years 12,302,260 8,007,202 2,347,060 After more than five years 30,000 45,000 — 24,965,061 48,000,102 28,724,838
Summary of Commercial Commitments	(ii) Commercial commitments 2023 2022 2021 US$ US$ US$ Within one year 47,415 507,874 — After one year but not more than five years — — — After more than five years — — — 47,415 507,874 —

Cash Flow Statements Reconcil_2

Cash Flow Statements Reconciliation (Tables)	12 Months Ended
	Jun. 30, 2023
Cash Flow Statement Reconciliation [Abstract]
Summary of Cash Flow Statements Reconciliation	2023 2022 2021 Restated US$ US$ US$ (a) Reconciliation to cash at the end of the year Cash at bank and in hand (note 17) 89,188,713 44,631,293 118,193,177 89,188,713 44,631,293 118,193,177 (b) Reconciliation of net loss after tax to net cash flows from operations Net loss for the year ( 142,521,085 ) ( 92,817,371 ) ( 45,344,496 ) Adjustments for: Income tax benefit recognized in profit or loss ( 5,926,350 ) ( 6,299,286 ) ( 4,938,846 ) Net loss of disposal of non-current assets — 169 — Depreciation of non-current assets 17,001 11,917 15,012 Depreciation of right-of-use assets 84,226 66,465 91,656 Interest expense on DFA 13,462,160 — — Fair value adjustment gain on DFA ( 12,302,160 ) — — Share-based payments 5,834,686 5,251,572 3,897,638 Net exchange differences 489,137 2,813,993 11,011,961 1,658,700 1,844,830 10,077,421 Changes in: Payables 7,296,785 8,511,607 ( 1,552,443 ) Receivables 378,896 307,618 ( 369,712 ) Prepayments 6,142,284 5,730,207 ( 14,231,546 ) Provisions 136,755 115,259 40,510 Net cash flows used in operating activities before tax ( 126,907,665 ) ( 76,307,850 ) ( 51,380,266 ) R&D tax incentive received 6,299,286 4,972,898 5,834,099 Net cash flows used in operating activities ( 120,608,379 ) ( 71,334,952 ) ( 45,546,167 )

Key Management Personnel (Table

Key Management Personnel (Tables)	12 Months Ended
	Jun. 30, 2023
Disclosure of transactions between related parties [abstract]
Schedule of Compensation of Key Management Personnel	(a) Compensation of Key Management Personnel 2023 2022 2021 US$ US$ US$ Short-term employee benefits 2,898,544 1,555,658 1,099,081 Post-employment benefits 137,168 56,105 79,550 Share-based payments expense 4,221,472 4,664,767 3,897,638 7,257,184 6,276,530 5,076,269

Share-Based Payments (Tables)

Share-Based Payments (Tables)	12 Months Ended
	Jun. 30, 2023
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Summary of Recognized Share Based Payment Expenses	The expense recognized for share‑based payments during the year is shown in the table below: 2023 2022 2021 US$ US$ US$ Expense arising from equity-settled share-based payment Director and employee services received 5,834,686 5,251,572 3,897,638 5,834,686 5,251,572 3,897,638
Summary of Fair Value of Share Options Granted	Options/Rights services Grant date Grant date Exercise Expiry date Vesting date LTIP - director FY2019 November 29, 2018 0.150 0.625 November 29, 2022 November 29, 2019 LTIP - employees FY2018 August 23, 2017 0.260 0.920 January 1, 2023 June 30, 2018 LTIP - employees FY2019 April 3, 2019 0.180 0.608 April 3, 2023 April 3, 2021 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 October 19, 2021 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 October 19, 2022 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 October 19, 2023 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 January 31, 2023 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 November 30, 2022 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 April 30, 2023 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 April 30, 2023 LTIP - employees FY2022 October 19, 2021 0.955 0.000 October 18, 2031 September 30, 2024 LTIP - employees FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2021 LTIP - employees FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2022 LTIP - employees FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2023 LTIP - employees FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2024 LTIP - employees FY2022 June 6, 2022 0.553 1.460 June 5, 2032 June 6, 2022 LTIP - employees FY2022 June 6, 2022 0.553 1.460 June 5, 2032 June 6, 2023 LTIP - employees FY2022 June 6, 2022 June 5, 2032 LTIP - employees FY2022 June 6, 2022 0.553 1.460 June 5, 2032 June 6, 2024 LTIP - employees FY2023 November 16, 2022 0.471 0.658 November 16, 2032 November 16, 2025 LTIP - employees FY2023 November 16, 2022 0.672 0.000 November 16, 2032 November 16, 2025 LTIP - employees FY2023 December 13, 2022 0.459 0.644 December 13, 2032 December 13, 2023 LTIP - employees FY2023 December 13, 2022 0.459 0.644 December 13, 2032 December 13, 2024 LTIP - employees FY2023 December 13, 2022 0.459 0.644 December 13, 2032 December 13, 2025 LTIP - employees FY2023 December 13, 2022 0.459 0.644 December 13, 2032 December 13, 2026 NED Plan FY2016 March 7,2016 0.140 0.360 March 7, 2021 June 30, 2016 NED Plan FY2019 November 29, 2018 0.150 0.625 November 29, 2022 November 29, 2019 NED Plan FY2021 October 12, 2020 1.050 3.240 October 11, 2024 October 12, 2020 NED Plan FY2021 October 12, 2020 1.050 3.240 October 11, 2024 October 12, 2021 NED Plan FY2021 October 12, 2020 1.050 3.240 October 11, 2024 October 12, 2022 NED Plan FY2021 October 12, 2020 1.050 3.240 October 11, 2024 October 12, 2023 NED Plan FY2021 October 12, 2020 1.240 2.160 October 11, 2024 October 12, 2020 NED Plan FY2021 October 12, 2020 1.240 2.160 October 11, 2024 October 12, 2021 NED Plan FY2021 October 12, 2020 1.240 2.160 October 11, 2024 October 12, 2022 NED Plan FY2021 October 12, 2020 1.240 2.160 October 11, 2024 October 12, 2023 NED Plan FY2021 January 19, 2021 0.880 1.560 January 18, 2025 January 19, 2021 NED Plan FY2021 January 19, 2021 0.880 1.560 January 18, 2025 January 19, 2022 NED Plan FY2021 January 19, 2021 0.880 1.560 January 18, 2025 January 19, 2023 NED Plan FY2021 January 19, 2021 0.880 1.560 January 18, 2025 January 19, 2024 NED Plan FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2021 NED Plan FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2022 NED Plan FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2023 NED Plan FY2022 October 19, 2021 0.526 0.948 October 18, 2025 October 19, 2024 NED Plan FY2022 April 21, 2022 0.397 0.755 April 20, 2026 April 21, 2022 NED Plan FY2022 April 21, 2022 0.397 0.755 April 20, 2026 April 21, 2023 NED Plan FY2022 April 21, 2022 0.397 0.755 April 20, 2026 April 21, 2024 NED Plan FY2022 April 21, 2022 0.397 0.755 April 20, 2026 April 21, 2025 Options/Rights services Grant Exercise Fair Expected Option life Dividend Risk Model LTIP - director FY2019 0.420 0.625 0.150 58.00 % 4 years 0 % 2.04 % Binomial LTIP - employees FY2018 0.340 0.920 0.260 66.00 % 5 years 0 % 2.09 % Binomial LTIP - employees FY2019 0.480 0.608 0.180 57.00 % 4 years 0 % 2.04 % Binomial LTIP - employees FY2022 0.955 0.948 0.526 74.78 % 4 years 0 % 0.25 % Binomial LTIP - employees FY2022 0.955 nil 0.955 na 10 years 0 % n/a Binomial LTIP - employees FY2022 0.901 1.460 0.553 75.00 % 6.5 years 0 % 3.40 % Binomial LTIP - employees FY2023 0.672 0.658 0.471 75.00 % 6.5 years 0 % 3.60 % Binomial LTIP - employees FY2023 0.672 nil 0.672 75.00 % 10 years 0 % 3.70 % Binomial LTIP - employees FY2023 0.643 0.644 0.459 75.00 % 7 years 0 % 3.30 % Binomial NED Plan FY2016 0.280 0.360 0.140 65.00 % 5 years 0 % 2.09 % Binomial NED Plan FY2019 0.420 0.625 0.150 58.00 % 4 years 0 % 2.04 % Binomial NED Plan FY2021 2.190 2.160 1.240 77.25 % 4 years 0 % 0.25 % Binomial NED Play FY2021 2.190 3.240 1.050 77.25 % 4 years 0 % 0.25 % Binomial NED Plan FY2021 1.560 1.560 0.880 77.01 % 4 years 0 % 0.25 % Binomial NED Plan FY2022 0.955 0.945 0.526 74.78 % 4 years 0 % 0.25 % Binomial NED Plan FY2022 0.741 0.755 0.397 75.00 % 3.5 years 0 % 2.70 % Binomial ADS Options Grant Exercise Fair Expected ADS Option life Dividend Risk Model LTIP - employee 2022 7.240 7.625 4.970 75.00 % 7 years 0 % 1.40 % Binomial LTIP - employee 2022 7.500 7.515 5.228 75.00 % 7 years 0 % 1.70 % Binomial LTIP - employee 2022 5.925 6.009 4.116 75.00 % 7 years 0 % 1.70 % Binomial LTIP - employee 2022 5.915 6.090 4.171 75.00 % 7 years 0 % 2.90 % Binomial LTIP - employee 2022 7.000 7.116 4.953 75.00 % 7 years 0 % 2.90 % Binomial LTIP - employee 2022 7.309 7.445 5.175 75.00 % 7 years 0 % 3.00 % Binomial LTIP - employee 2022 5.500 5.522 3.886 75.00 % 7 years 0 % 3.40 % Binomial LTIP - employee 2023 6.600 6.350 4.718 75.00 % 7 years 0 % 2.90 % Binomial LTIP - employee 2023 4.810 4.850 3.479 75.00 % 7 years 0 % 4.30 % Binomial LTIP - employee 2023 4.850 5.170 3.457 75.00 % 7 years 0 % 4.10 % Binomial LTIP - employee 2023 4.959 4.929 3.560 75.00 % 7 years 0 % 3.60 % Binomial LTIP - employee 2023 5.450 5.238 3.935 75.00 % 7 years 0 % 3.50 % Binomial LTIP - employee 2023 5.030 5.150 3.602 75.00 % 7 years 0 % 3.80 % Binomial LTIP - employee 2023 3.360 3.545 2.384 75.00 % 7 years 0 % 3.60 % Binomial
Summary of Share/Rights Options Outstanding	The following reconciles the share/rights options outstanding at the beginning and end of the year: 2023 2022 2021 Number of Weighted Number of Weighted Number of Weighted Balance at beginning of year 22,988,000 1.16 16,644,000 1.28 18,044,000 0.50 Granted during the year: To employees and directors under the LTIP and NED Plan 10,050,000 0.58 8,400,000 0.77 7,000,000 2.21 Exercised during the year ( 6,613,000 ) 0.62 ( 2,056,000 ) 0.58 ( 8,400,000 ) 0.36 Expired during the year ( 975,000 ) 0.61 — — — — Balance at end of the year 25,450,000 1.04 22,988,000 1.16 16,644,000 1.28 Exercisable at end of year 10,842,234 1.48 12,857,589 0.97 11,394,000 0.86
American Depository Shares
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Summary of Share/Rights Options Outstanding	The following reconciles the ADS options outstanding at the beginning and end of the year: 2023 2022 2021 Number of Weighted Number of Weighted Number of Weighted Balance at beginning of year 925,000 6.75 — — — — Granted during the year: To employees and directors under the LTIP and NED Plan 755,000 5.07 925,000 6.75 — — Exercised during the year — — — — — — Expired during the year ( 175,000 ) 7.62 — — — — Balance at end of the year 1,505,000 5.81 925,000 6.75 — — Exercisable at end of year 250,000 6.70 — — — —

Basis of Accounting - Additiona

Basis of Accounting - Additional Information (Details) $ in Millions				12 Months Ended
	Jul. 01, 2023 USD ($)	Jul. 01, 2023 AUD ($)	Aug. 12, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Loss after income tax				$ 142,521,085	$ 92,817,371	$ 45,344,496
Net cash outflows from operating activities				120,608,379	71,334,952	45,546,167
Cash and cash equivalents				89,188,713	44,631,293	118,193,177	$ 42,650,858
Current assets				98,386,298	59,908,442
Net current asset position				79,643,659	47,866,741
Net assets (liabilities)				(5,853,178)	$ 47,977,144
Aggregate proceeds from private placement of ordinary shares				81,815,358		$ 105,477,591
Cash on hand				89,000,000
Amount expected under funding agreement				$ 85,000,000
Development Funding Agreement
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Amount committed by investor			$ 120,000,000
Funding additional payment description	Upon completion of the final due diligence, receipt of approvals, execution of the appropriate documentation and satisfaction of the closing conditions, the Group expects to receive the additional US$50 million. While the Group anticipates that the due diligence will be completed to the satisfaction of the co-investor, the necessary approvals will be obtained, the appropriate documentation will be executed and that all closing conditions will be satisfied, there is no assurance that the Group will ultimately receive the additional US$50 million. If the additional US$50 million is not received by June 30, 2024, the Group will need to raise additional funds or reduce expenditures to continue as a going concern.	Upon completion of the final due diligence, receipt of approvals, execution of the appropriate documentation and satisfaction of the closing conditions, the Group expects to receive the additional US$50 million. While the Group anticipates that the due diligence will be completed to the satisfaction of the co-investor, the necessary approvals will be obtained, the appropriate documentation will be executed and that all closing conditions will be satisfied, there is no assurance that the Group will ultimately receive the additional US$50 million. If the additional US$50 million is not received by June 30, 2024, the Group will need to raise additional funds or reduce expenditures to continue as a going concern.
Funding payment			50,000,000
Development Funding Agreement | Second Tranche
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Funding payment			35,000,000
Development Funding Agreement | Third Tranche
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Funding payment			$ 35,000,000
Development Funding Agreement | Events after Reporting Period
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Funding initial payment	$ 50,000,000
Funding additional payment	50,000,000
Development Funding Agreement | Events after Reporting Period | Bottom of Range
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Amount committed by investor	120,000,000
Development Funding Agreement | Events after Reporting Period | Top of Range
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Amount committed by investor	170,000,000
Private Placement of Ordinary Shares (PIPE) | Events after Reporting Period
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Aggregate proceeds from private placement of ordinary shares	58,000,000	$ 90
Private Placement of Ordinary Shares (PIPE) | Events after Reporting Period | First Tranche
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Aggregate proceeds from private placement of ordinary shares	47,000,000	73
Private Placement of Ordinary Shares (PIPE) | Events after Reporting Period | Second Tranche
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Aggregate proceeds from private placement of ordinary shares	$ 11,000,000	$ 17

Summary of Accounting Policie_2

Summary of Accounting Policies - Additional Information (Details)	12 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2023 AUD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Effect on consolidated financial statements resulted in an addition to foreign currency translation reserve	$ 14,300,000
Unsecured amount payable payment period	30 days	30 days
Revenue	$ 108,406		$ 90,683	$ 68,613
Percentage of cash amount equal to eligible research and development expenditures	43.50%	43.50%
Australian Domiciled Subsidiary
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Ownership percentage in subsidiary	100%	100%
Leasehold Improvements
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful economic lives	8 years	8 years
Bottom of Range
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Other receivable collection period	30 days	30 days
Bottom of Range | Equipment and Furniture
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful economic lives	3 years	3 years
Top of Range
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Other receivable collection period	60 days	60 days
Top of Range | Research and Development Tax Incentive Scheme
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Revenue		$ 20,000,000
Top of Range | Equipment and Furniture
Description Of Business And Summary Of Significant Accounting Policies [Line Items]
Useful economic lives	10 years	10 years

Critical Accounting Judgements

Critical Accounting Judgements and Key Sources of Estimation Uncertainty - Additional Information (Details)	12 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2023 AUD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)
Critical Accounting Judgements And Key Sources Of Estimation Uncertainty [Line Items]
Research and development expense	$ 122,128,314		$ 78,654,217	$ 25,891,851
Percentage of cash amount equal to eligible research and development expenditures	43.50%	43.50%
Research and development tax incentive credit receivable	$ 5,926,350		6,299,286	4,972,898
Research and development tax incentive description	The R&D tax incentive is considered an income tax offset which will be offset against the Group’s tax obligation if and when the Group returns to a net tax payable position. In addition, whilst the Group is currently eligible to receive cash payments under the scheme since its consolidated revenue is currently below A$20 million, if and when the Group generates revenue in excess of A$20 million the R&D tax incentive will become non‑refundable and can only be offset against any future income tax payable by the Group.	The R&D tax incentive is considered an income tax offset which will be offset against the Group’s tax obligation if and when the Group returns to a net tax payable position. In addition, whilst the Group is currently eligible to receive cash payments under the scheme since its consolidated revenue is currently below A$20 million, if and when the Group generates revenue in excess of A$20 million the R&D tax incentive will become non‑refundable and can only be offset against any future income tax payable by the Group.
Revenue	$ 108,406		90,683	68,613
Research and Development Tax Incentive Scheme | Top of Range
Critical Accounting Judgements And Key Sources Of Estimation Uncertainty [Line Items]
Revenue		$ 20,000,000
Research and Development Tax Incentive Scheme | Bottom of Range | Non Refundable
Critical Accounting Judgements And Key Sources Of Estimation Uncertainty [Line Items]
Revenue		$ 20,000,000
Development Cost Capitalized
Critical Accounting Judgements And Key Sources Of Estimation Uncertainty [Line Items]
Research and development expense	$ 0		$ 0	$ 0

Segment Information - Additiona

Segment Information - Additional Information (Details)	12 Months Ended
	Jun. 30, 2023 USD ($) Segment Geographicalarea Industry	Jun. 30, 2022 USD ($)	Jun. 30, 2021 USD ($)
Disclosure of operating segments [abstract]
Number of operating segment | Industry	1
Number of geographical area | Geographicalarea	2
Number of reporting segment | Segment	1
Royalty income | $	$ 108,406	$ 90,683	$ 68,613

Revenue - Summary of Revenue (D

Revenue - Summary of Revenue (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Revenue [abstract]
Sales-based royalties	$ 108,406	$ 90,683	$ 68,613
Revenue	$ 108,406	$ 90,683	$ 68,613

Other Income - Schedule of Othe

Other Income - Schedule of Other Income (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Analysis of income and expense [abstract]
Grant and other income	$ 276,869	$ 108,322	$ 26,950
Total other income	$ 276,869	$ 108,322	$ 26,950

Research and Development Expe_3

Research and Development Expenses - Summary of Research and Development Expenses (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Disclosure Of Research And Development Expenses [Abstract]
Research project costs	$ 122,128,314	$ 78,654,217	$ 25,891,851
Total research and development expenses	$ 122,128,314	$ 78,654,217	$ 25,891,851

Expenses - Summary of Expenses

Expenses - Summary of Expenses (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Employee benefits expenses:
Salaries and fees	$ 6,274,560	$ 2,931,243	$ 1,794,840
Cash bonuses	1,265,944	376,649	479,501
Superannuation	287,396	171,899	188,543
Share-based payments expense	5,834,686	5,251,572	3,897,638
Total employee benefits expense	13,662,586	8,731,363	6,360,522
Other expenses:
Insurance	2,551,768	4,205,106	4,419,433
Investor relations costs	451,378	328,026	285,071
Audit and accounting	337,038	496,652	647,549
Travel expenses	580,644	13,616	1,459
Payroll tax	340,003	172,884	18,766
Legal fees	1,330,054	1,252,014	83,605
Advisory fees	6,084,005	156,978	393,843
Consultancy costs	1,389,048	1,619,824	367,070
Other expenses	1,288,179	867,405	732,773
Total other expenses	14,352,117	9,112,505	6,949,569
Depreciation of:
Equipment and furniture	17,000	11,917	15,012
Right-of-use assets	84,226	66,465	91,656
Total depreciation expense	101,226	78,382	106,668
Loss on disposal of non-current assets		169	1,434
Total administrative expenses	$ 28,115,929	$ 17,922,419	$ 13,418,193

Finance Income - Summary of Fin

Finance Income - Summary of Finance Income (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Material income and expense [abstract]
Interest income	$ 3,227,496	$ 235,468	$ 372,001
Total finance income	$ 3,227,496	$ 235,468	$ 372,001

Interest Expense on DFA - Summa

Interest Expense on DFA - Summary of Interest Expense on DFA (Details)	12 Months Ended
	Jun. 30, 2023 USD ($)
Material income and expense [abstract]
Interest expense on DFA	$ 13,462,160
Total interest expense on DFA	$ 13,462,160

Interest Expense on DFA - Addit

Interest Expense on DFA - Additinal Information (Details)	12 Months Ended
	Jun. 30, 2023
Material income and expense [abstract]
Non-cash interest at imputed rate	23.82%

Fair Value Adjustment Gain on_3

Fair Value Adjustment Gain on DFA - Summary of Fair Value Adjustment Gain on DFA (Details)	12 Months Ended
	Jun. 30, 2023 USD ($)
Material income and expense [abstract]
Fair value adjustment gain on DFA	$ 12,302,160

Fair Value Adjustment Gain on_4

Fair Value Adjustment Gain on DFA - Additional Information (Details) $ in Millions	12 Months Ended
	Jun. 30, 2023 USD ($)
Material income and expense [abstract]
Fair value adjustment, non-cash gain on revaluation	$ 12.3
Non-cash interest at imputed rate	23.82%

Net Foreign Exchange Loss - Sum

Net Foreign Exchange Loss - Summary of Net Foreign Exchange Loss (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Net Foreign Exchange Loss Gain [Abstract]
Net foreign exchange (loss)/gain	$ (489,137)	$ (2,813,993)	$ (11,011,961)
Total net foreign exhange (loss)/gain	$ (489,137)	$ (2,813,993)	$ (11,011,961)

Net Foreign Exchange Loss - Add

Net Foreign Exchange Loss - Additional Information (Details) - 12 months ended Jun. 30, 2023 $ in Millions, $ in Millions	USD ($)	AUD ($)
Net Foreign Exchange Loss Gain [Line Items]
Term deposit	$ 100	$ 141.9
Term deposit maturity date	Feb. 03, 2021
Foreign exchange loss	$ 9
US IPO
Net Foreign Exchange Loss Gain [Line Items]
Aggregate gross proceeds for IPO	$ 128

Income Taxes - Summary of Incom

Income Taxes - Summary of Income Tax Benefit and Current Tax Receivable (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Current tax
Current income tax credit	$ 5,926,350	$ 6,299,286	$ 4,938,846
Total	5,926,350	6,299,286	4,938,846
Deferred tax
Total income tax benefit recognized in the Statement of Comprehensive Income	5,926,350	6,299,286	4,938,846
(b) Current tax receivable
Research and development tax incentive credit receivable	$ 5,926,350	$ 6,299,286	$ 4,972,898

Income Taxes - Summary of Recon

Income Taxes - Summary of Reconciliation Between Income Tax Benefit and the Product of Accounting Loss Before Income Tax Multiplied by the Group's Applicable Income Tax Rate (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Reconciliation of accounting profit multiplied by applicable tax rates [abstract]
Accounting loss before tax	$ (148,447,435)	$ (99,116,657)	$ (50,283,342)
At the Company's statutory income tax rate of 30% (2020:27.5%)	44,534,230	29,734,997	15,085,003
R&D tax incentive on eligible expenses	5,926,350	6,299,286	4,938,846
Non-deductible R&D expenditure	(4,087,138)	(4,344,335)	(3,420,951)
Other non-deductible expenses - share-based payment expense	(1,750,406)	(1,575,472)	(1,169,291)
Amount of temporary differences and carried forward tax losses not recognized	(38,696,687)	(23,815,190)	(10,494,761)
Total income tax benefit recognized in the Statement of Comprehensive Income	$ 5,926,350	$ 6,299,286	$ 4,938,846

Income Taxes - Summary of Rec_2

Income Taxes - Summary of Reconciliation Between Income Tax Benefit and the Product of Accounting Loss Before Income Tax Multiplied by the Group's Applicable Income Tax Rate (Parenthetical) (Details)	12 Months Ended
	Jun. 30, 2023
Reconciliation of accounting profit multiplied by applicable tax rates [abstract]
Income tax rate	30%

Income Taxes - Summary of Recog

Income Taxes - Summary of Recognized Deferred Tax Assets and Liabilities in Statement of Financial Position (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Deferred tax liabilities:
Deferred tax liabilities	$ (44,785)	$ (17,085)	$ (2,344,514)
Deferred tax assets related to temporary differences:
Deferred tax assets related to temporary differences	632,263	666,297	2,344,514
Net deferred tax assets	587,478	649,212
Less: temporary differences not recognized	(587,478)	(649,212)
Net deferred tax recognized in the statement of financial position			0
Interest and Royalty Income Receivable Future Assessable Income
Deferred tax liabilities:
Deferred tax liabilities	(44,785)	(17,085)	(2,344,514)
Recognition of Tax Losses
Deferred tax assets related to temporary differences:
Deferred tax assets related to temporary differences			1,508,764
Accrued Expenses and Other Liabilities
Deferred tax assets related to temporary differences:
Deferred tax assets related to temporary differences	200,536	198,607	205,458
Employee Provisions
Deferred tax assets related to temporary differences:
Deferred tax assets related to temporary differences	161,006	161,159	152,675
Other Miscellaneous Items
Deferred tax assets related to temporary differences:
Deferred tax assets related to temporary differences	$ 270,721	$ 306,531	$ 477,617

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details)	12 Months Ended
	Jun. 30, 2023 USD ($)	Jun. 30, 2023 AUD ($)	Jun. 30, 2022 USD ($)	Jun. 30, 2022 AUD ($)	Jun. 30, 2021 USD ($)
Disclosure Of Temporary Difference Unused Tax Losses And Unused Tax Credits [Line Items]
Deferred tax assets related to temporary differences not recognized	$ (587,478)		$ (649,212)
Income tax losses	$ 67,878,759		37,717,792
Capital losses			$ 412,122
Net deferred tax recognized in the statement of financial position					$ 0
Franking account balance percentage	30%	30%	30%	30%
Franking account balance		$ 227,371		$ 227,371
Intellectual Property and Other Miscellaneous Items
Disclosure Of Temporary Difference Unused Tax Losses And Unused Tax Credits [Line Items]
Deferred tax assets related to temporary differences not recognized	$ 587,478		$ 649,212

Earnings Per Share - Summary of

Earnings Per Share - Summary of Income Used in Basic and Diluted Earnings Per Share Computation (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
(a) Earnings used in calculating earnings per share
Net loss attributable to ordinary equity holders of the parent	$ (142,521,085)	$ (92,817,371)	$ (45,344,496)
(b) Weighted average number of shares
Weighted average number of ordinary shares on issue for basic earnings per share	442,637,406	351,560,198	320,432,814
Effect of dilution:
Weighted average number of ordinary shares adjusted for the effect of dilution	442,637,406	351,560,198	320,432,814
Loss per share (basic in cents)	$ (0.3220)	$ (0.2640)	$ (0.1415)
Loss per share (diluted in cents)	$ (0.3220)	$ (0.2640)	$ (0.1415)

Earnings Per Share - Additional

Earnings Per Share - Additional Information (Details)	12 Months Ended
	Jun. 30, 2023 USD ($) shares Vote $ / shares	Aug. 28, 2023 shares	Aug. 24, 2023 shares	Jun. 30, 2022 shares	Jun. 30, 2021 shares	Jun. 30, 2020 shares
Earnings Per Share [Line Items]
Number of share options/rights outstanding in share-based payment arrangement	25,450,000			22,988,000	16,644,000	18,044,000
Outstanding options and rights exercisable	10,842,234			12,857,589	11,394,000
Disclosure - Earnings Per Share - Additional Information (Details) [Line Items]
Par value per share | $ / shares	$ 0
Voting right of ordinary shares carrying no par value | Vote	1
Dividends declared ordinary shares | $	$ 0
Dividends paid ordinary shares | $	$ 0
Major Ordinary Share Transactions
Earnings Per Share [Line Items]
Number of shares outstanding			195,647,457
Potential Ordinary Share Transactions
Earnings Per Share [Line Items]
Number of shares outstanding		97,823,728
ADS Options
Earnings Per Share [Line Items]
Anti-dilutive options outstanding excluded from the weighted average number of ordinary shares for the purpose of diluted earnings per share	1,505,000
Outstanding options and rights exercisable	250,000			0	0

Earnings Per Share - Summary _2

Earnings Per Share - Summary of Options Plans (Details) - shares	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Options
Earnings Per Share [Line Items]
Anti-dilutive options outstanding excluded from the weighted average number of ordinary shares for the purpose of diluted earnings per share	22,550,000	21,388,000	16,644,000
Performance Rights
Earnings Per Share [Line Items]
Anti-dilutive options outstanding excluded from the weighted average number of ordinary shares for the purpose of diluted earnings per share	2,900,000	1,600,000
A D S Options
Earnings Per Share [Line Items]
Anti-dilutive options outstanding excluded from the weighted average number of ordinary shares for the purpose of diluted earnings per share	1,505,000	925,000
NED Plan | Options
Earnings Per Share [Line Items]
Anti-dilutive options outstanding excluded from the weighted average number of ordinary shares for the purpose of diluted earnings per share	16,500,000	14,000,000	10,000,000
NED Plan | Performance Rights
Earnings Per Share [Line Items]
Anti-dilutive options outstanding excluded from the weighted average number of ordinary shares for the purpose of diluted earnings per share	650,000
LTIP | Options
Earnings Per Share [Line Items]
Anti-dilutive options outstanding excluded from the weighted average number of ordinary shares for the purpose of diluted earnings per share	6,050,000	7,388,000	6,644,000
LTIP | Performance Rights
Earnings Per Share [Line Items]
Anti-dilutive options outstanding excluded from the weighted average number of ordinary shares for the purpose of diluted earnings per share	2,250,000	1,600,000
LTIP | A D S Options
Earnings Per Share [Line Items]
Anti-dilutive options outstanding excluded from the weighted average number of ordinary shares for the purpose of diluted earnings per share	1,505,000	925,000

Current Assets - Cash and Cas_3

Current Assets - Cash and Cash Equivalents - Summary of Cash and Cash Equivalents (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020
Categories of current financial assets [abstract]
Cash at bank and in hand	$ 12,067,158	$ 11,853,883
Short-term deposits	77,121,555	32,777,410
Total cash and cash equivalents	$ 89,188,713	$ 44,631,293	$ 118,193,177	$ 42,650,858

Current Assets - Cash and Cas_4

Current Assets - Cash and Cash Equivalents - Additional Information (Details) - Deposit	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Current Assets Cash And Cash Equivalents [Line Items]
Number of Australian banks containing short term deposit	2
Average interest rate of short term deposits	4.67%	0.43%	0.24%
Bottom of Range
Current Assets Cash And Cash Equivalents [Line Items]
Short term deposit period	30 days
Top of Range
Current Assets Cash And Cash Equivalents [Line Items]
Short term deposit period	90 days

Current Assets - Receivables -

Current Assets - Receivables - Summary of Current Assets - Receivables (Details) - USD ($)		Jun. 30, 2023	Jun. 30, 2022
Current Assets Receivables [Abstract]
Interest receivable		$ 162,853	$ 56,952
GST receivable	[1]	325,474	157,060
Other receivable	[1]	148,237	43,656
Total current receivables		$ 636,564	$ 257,668
[1] The GST and other receivables are non‑interest bearing. There were no receivables with a material expected credit loss recorded during the financial year (2022: nil , 2021: nil ).

Current Assets - Receivables _2

Current Assets - Receivables - Summary of Current Assets - Receivables (Parenthetical) (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Current Assets Receivables [Abstract]
Receivables with material expected credit loss	$ 0	$ 0	$ 0

Current Assets - Prepayments -

Current Assets - Prepayments - Summary of Current Assets Prepayments (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022
Current prepayments [abstract]
R&D Contract Research Organization	$ 1,693,964	$ 7,428,599
Insurance	717,064	1,086,847
Other prepayments	223,643	204,749
Total current prepayments	$ 2,634,671	$ 8,720,195

Non-Current Assets - Prepayme_3

Non-Current Assets - Prepayments - Summary of Non-Current Assets - Prepayments (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022
Disclosure Of Noncurrent Assets Prepayments [Abstract]
Insurance	$ 53,535	$ 110,295
Total non-current prepayments	$ 53,535	$ 110,295

Non-Current Assets - Right of_3

Non-Current Assets - Right of Use Assets - Summary of Carrying Amount of Lease (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Disclosure of quantitative information about right-of-use assets [line items]
Net carrying amount	$ 168,451
Right-of-Use Asset Cost
Disclosure of quantitative information about right-of-use assets [line items]
Opening balance	281,554	$ 281,554
Additions	252,677
Net carrying amount	534,231	281,554
Right-of-Use-Asset Depreciation
Disclosure of quantitative information about right-of-use assets [line items]
Opening balance	(281,554)	(187,702)
Charge to the period	(84,226)	(93,852)
Net carrying amount	$ (365,780)	$ (281,554)

Non-Current Assets - Right of_4

Non-Current Assets - Right of Use Assets - Additional Information (Details)	12 Months Ended
	Jun. 30, 2023
Disclosure of quantitative information about right-of-use assets [abstract]
Lease contract term	3 years

Non-Current Assets - Right of_5

Non-Current Assets - Right of Use Assets - Summary of Lease Amounts Recognized in Profit or Loss (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Amounts recognized in profit or loss:
Depreciation expense on right-of-use asset	$ 84,226	$ 66,465	$ 91,656
Lease finance costs	5,321	5,920	5,782
Expense relating to leases of low value assets	2,101	7,376	7,042
Lease liability amounts recognized in profit and loss	$ 91,648	$ 79,761	$ 104,480

Current Liabilities - Payables

Current Liabilities - Payables - Summary of Current Liabilities Payables (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022
Current Liabilities Payables [Abstract]
Accounts Payable (unsecured)	$ 17,842,981	$ 11,402,164
Payroll related tax liability	48,873	43,334
Total current payables	$ 17,891,854	$ 11,445,498

Current Liabilities - Payable_2

Current Liabilities - Payables - Summary of Current Liabilities Payables (Parenthetical) (Details)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Current Liabilities Payables [Abstract]
Accounts payable settlement terms	30 day terms	30 day terms

Current Liabilities - Payable_3

Current Liabilities - Payables - Additional Information (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022
Disclosure of transactions between related parties [line items]
Amount due to related party	$ 900,000	$ 900,000
Launch Tx
Disclosure of transactions between related parties [line items]
Amount due to related party	$ 900,000

Current Liabilities - Provisi_3

Current Liabilities - Provisions - Summary of Current Provisions (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022
Current provisions [abstract]
Annual leave	$ 500,361	$ 383,220
Long service lave	252,939	212,983
Total current provisions	$ 753,300	$ 596,203

Lease Liabilities - Additional

Lease Liabilities - Additional Information (Details)	12 Months Ended
	Jun. 30, 2023
Lease liabilities [abstract]
Lease liabilities term	Jul. 14, 2024
Incremental borrowing rate	3%

Lease Liabilities - Summary of

Lease Liabilities - Summary of Lease Liabilities (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Lease liabilities [abstract]
Carrying amount at July 1		$ 112,965
New lease	$ 252,677
Payments	(70,966)	$ (112,965)
Carrying amount at June 30	181,711
Maturity analysis year 1	102,806
Maturity analysis year 2	84,226
Maturity analysis	187,032
Less: unearned interest	(5,321)
Lease liabilities maturity analysis, Net	181,711
Current portion	97,485
Non-current portion	84,226
Lease liabilities	$ 181,711

Non-Current Liabilities - Lease

Non-Current Liabilities - Lease Liabilities - Summary of Non-Current Liabilities - Lease Liabilities (Details)	Jun. 30, 2023 USD ($)
Non-current provisions [abstract]
Lease liabilities	$ 84,226
Total non-current provisions	$ 84,226

Non-Current Liabilities - Fin_3

Non-Current Liabilities - Financial Liabilities - Summary of Noncurrent Financial Liabilities (Details)	12 Months Ended
	Jun. 30, 2023 USD ($)
Categories of non-current financial liabilities [abstract]
Funding at fair value	$ 84,500,000
Interest expense on DFA	13,462,160
Fair value adjustment gain on DFA	(12,302,160)
Total financial liabilities	$ 85,660,000

Non-Current Liabilities - Fin_4

Non-Current Liabilities - Financial Liabilities - Additional Information (Details) $ in Millions			12 Months Ended
	Sep. 12, 2022	Aug. 12, 2022 USD ($)	Jun. 30, 2023 USD ($) Tranche
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Percentage of net sales			7%
Launch Tx
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Number of tranches | Tranche			2
Development Funding Agreement
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Amount committed by investor		$ 120
Percentage of net sales			7%
Imputed interest rate on unamortized development financing liability	23.82%
Development Funding Agreement | Launch Tx
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Funding initial payment			$ 50
Funding costs			$ 0.5
Tranche one payment date			Dec. 31, 2022
Tranche two payment date			Dec. 31, 2023
Development Funding Agreement | Bottom of Range
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Development financing liability repayment period			2027
Development Funding Agreement | Bottom of Range | Launch Tx
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Amount committed by investor			$ 120
Development Funding Agreement | Top of Range
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Development financing liability repayment period			2032
Development Funding Agreement | Top of Range | Launch Tx
Disclosure Of Reclassifications Or Changes In Presentation [Line Items]
Amount committed by investor			$ 170

Non-Current Liabilities - Pro_3

Non-Current Liabilities - Provisions - Summary of Non-Current Liabilities - Provisions (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022
Non-current provisions [abstract]
Long service leave	$ 7,631	$ 27,974
Total non-current provisions	$ 7,631	$ 27,974

Contributed Equity - Summary of

Contributed Equity - Summary of Contributed Equity (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Contributed Equity [Line Items]
Issued and fully paid at June 30	$ 320,883,552	$ 235,277,217
Movement in ordinary shares:
Beginning balance	47,977,144	135,285,768	$ 44,567,972
Ending balance	$ (5,853,178)	47,977,144	$ 135,285,768
Issues of shares on Nasdaq listing	112,619,066		68,506,400
Ordinary Shares
Contributed Equity [Line Items]
Issued and fully paid at June 30	$ 320,883,552	235,277,217	$ 234,147,526
Movement in ordinary shares:
Beginning balance	235,277,217	234,147,526	113,852,364
Issue of shares on exercise of options granted under the LTIP	3,790,978	1,129,691	3,271,542
Issue of shares net of issuance costs	$ 81,815,357
Issue of shares on Nasdaq listing net of issuance cost $10,126,959			105,477,591
Issue of shares on exercise of pre-funded warrants net of issuance cost $1,099,412			11,546,029
Ending balance		$ 235,277,217	$ 234,147,526
Opening balance	235,277,217	234,147,526
Ending balance	320,883,552	235,277,217	234,147,526
Ordinary Shares on Issue
Movement in ordinary shares:
Opening balance	352,152,542	351,003,541	269,157,769
Issue of shares on exercise of options granted under the LTIP	2,387,826	1,149,001	5,845,804
Issues of shares on Nasdaq listing			68,506,400
Issue of share on exercise of pre-funded warrants			7,493,568
Issue of shares on ASX	112,619,006
Ending balance	467,159,374	352,152,542	351,003,541

Contributed Equity - Summary _2

Contributed Equity - Summary of Contributed Equity (Parenthetical) (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2021
Contributed Equity [Line Items]
Shares issuance cost	$ 4,531,040
NASDAQ Listing
Contributed Equity [Line Items]
Shares issuance cost		$ 10,126,969
Exercise of Warrants
Contributed Equity [Line Items]
Shares issuance cost		$ 1,099,412

Contributed Equity - Additional

Contributed Equity - Additional Information (Details)	12 Months Ended
	Jun. 30, 2023 USD ($) shares Vote $ / shares	Jun. 30, 2022 USD ($) shares Scheme $ / shares	Jun. 30, 2021 USD ($) shares $ / shares	Jun. 30, 2020 shares
Contributed Equity [Line Items]
Par value per share | $ / shares	$ 0
Number of vote per share | Vote	1
Dividends paid ordinary shares | $	$ 0
Cash dividends declared | $	0
Issued capital | $	$ 320,883,552	$ 235,277,217
Fully paid ordinary shares	467,159,434
Shares issued on NASDAQ Listing	112,619,066		68,506,400
Net proceeds from issuance of ordinary shares on Nasdaq listing | $	$ 81,815,357		$ 105,477,591
Issuance of prefunded warrants			7,493,568
Net proceeds from issuance of prefunded warrants | $			$ 11,546,029
Number of non-executive director options unexercised	7,250,000	7,500,000	4,750,000
Number of share based payment schemes | Scheme		2
Number of options granted	10,050,000	8,400,000	7,000,000
Cash received for ordinary shares issued on exercise of options | $	$ 1,040,718	$ 257,175
Options Over Ordinary Shares
Contributed Equity [Line Items]
Number of options granted	10,050,000	8,400,000	7,000,000	0
Weighted average fair value per option at grant date | $ / shares	$ 1.62	$ 0.781	$ 1.03
Options Over Ordinary Shares | A D S Options
Contributed Equity [Line Items]
Number of options granted	755,000	925,000
Weighted average fair value per option at grant date | $ / shares	$ 6.75	$ 6.75
LTIP and NED Plan
Contributed Equity [Line Items]
Number of options granted	6,613,000	2,056,000	8,400,000	0
Cash received for ordinary shares issued on exercise of options | $	$ 3,790,977	$ 1,129,691	$ 3,271,542
LTIP and NED Plan | Cash Conversion
Contributed Equity [Line Items]
Cash received for ordinary shares issued on exercise of options | $	1,040,718	257,175
LTIP and NED Plan | Cashless Conversion
Contributed Equity [Line Items]
Cash received for ordinary shares issued on exercise of options | $	$ 2,750,258	$ 872,516
Expiry of November 2022
Contributed Equity [Line Items]
Number of non-executive director options unexercised		3,000,000	3,000,000
Expiry of October 2024
Contributed Equity [Line Items]
Number of non-executive director options unexercised	3,000,000	2,000,000	1,000,000
Expiry of January 2022
Contributed Equity [Line Items]
Number of non-executive director options unexercised			750,000
Expiry of January 2025
Contributed Equity [Line Items]
Number of non-executive director options unexercised	2,250,000	1,500,000
Expiry of October 2025
Contributed Equity [Line Items]
Number of non-executive director options unexercised	1,000,000	500,000
Expiry of April 2026
Contributed Equity [Line Items]
Number of non-executive director options unexercised	1,000,000	500,000

Accumulated Losses and Reserv_3

Accumulated Losses and Reserves - Summary of Accumulated Losses and Reserves (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Disclosure Of Reserves Within Equity [Line Items]
Net loss for the period	$ (142,521,085)	$ (92,817,371)	$ (45,344,496)
Total reserves	32,725,708	29,641,280
Movements in Accumulated Losses
Disclosure Of Reserves Within Equity [Line Items]
Beginning balance	(216,941,353)	(124,123,982)
Net loss for the period	(142,521,085)	(92,817,371)
Ending balance	(359,462,438)	(216,941,353)	(124,123,982)
Reserves
Disclosure Of Reserves Within Equity [Line Items]
Fair value of Investments reserve	1,085,411	1,085,411
Share-based payments reserve	11,551,134	8,466,706
Foreign translation reserve	20,089,163	20,089,163
Total reserves	32,725,708	29,641,280
Movement in Fair Value of Investments Reserve
Disclosure Of Reserves Within Equity [Line Items]
Opening balance	1,085,411	1,085,411
Closing balance	1,085,411	1,085,411	1,085,411
Movement in Share-Based Payments Reserve
Disclosure Of Reserves Within Equity [Line Items]
Opening balance	8,466,706	4,087,650
Share-based payments reserve	5,834,686	5,251,572
Exercise of options	(2,750,258)	(872,516)
Closing balance	11,551,134	8,466,706	4,087,650
FX Translation Reserve
Disclosure Of Reserves Within Equity [Line Items]
Opening balance	20,089,163	20,089,163
Closing balance	$ 20,089,163	$ 20,089,163	$ 20,089,163

Financial Risk Management Obj_3

Financial Risk Management Objectives and Policies - Summary of Judgments of Reasonably Possible Movements (Details) - Post tax (loss)/profit impact [Member] - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
+0.50% (50 basis points) (2022:+0.50%)
Disclosure Of Risk Management Strategy Related To Hedge Accounting [Line Items]
Judgments of reasonably possible movements	$ 270,059	$ 114,859	$ 359,442
-0.50% (50 basis points) (2022:-0.50%)
Disclosure Of Risk Management Strategy Related To Hedge Accounting [Line Items]
Judgments of reasonably possible movements	(270,059)	(114,859)	(359,442)
AUD/USD +10% (2022:+10%)
Disclosure Of Risk Management Strategy Related To Hedge Accounting [Line Items]
Judgments of reasonably possible movements	(3,847,285)	(2,119,834)	(2,538,062)
AUD/USD -10% (2022:-10%)
Disclosure Of Risk Management Strategy Related To Hedge Accounting [Line Items]
Judgments of reasonably possible movements	$ 4,702,237	$ 2,590,908	$ 3,102,076

Financial Risk Management Obj_4

Financial Risk Management Objectives and Policies - Summary of Judgments of Reasonably Possible Movements (Parenthetical) (Details)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Disclosure of risk management strategy related to hedge accounting [abstract]
Judgments of reasonably possible movements percentage	0.50%	0.50%	0.50%
Judgments of reasonably possible movements change in percentage	10%	10%	10%

Financial Risk Management Obj_5

Financial Risk Management Objectives and Policies - Additional Information (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Disclosure Of Risk Management Strategy Related To Hedge Accounting [Line Items]
Borrowings		$ 0
Tax effect	$ 0	$ 0	$ 0
Description of interest rate calculation due to reasonably possible movements	The reasonably possible movement of 0.5% was calculated by taking the interest rates as of balance date, moving these by plus and minus 0.5% and then re‑calculating the interest on term deposits with the ‘new‑interest‑rate’.
Description of calculation of reasonably possible movement related to currency risk	The reasonably possible movement of 10% was calculated by taking the currency spot rates as of balance date, moving these by 10% and then re‑converting the currencies into US with the ‘new‑spot‑rate’.
Percentage of net sales	7%
Liquidity risk description	The Group manages liquidity risk by maintaining adequate reserves and by monitoring forecast and actual cash flows and by matching the maturity profiles of financial assets and liabilities. The financial liabilities of the Group relate to trade payables that are all expected to be paid within 12 months. With the funding agreement that was entered on August 12, 2022 the Group may incur a total payment equal to approximately four times the funding provided, consisting of seven payments, with the first payment due shortly after Regulatory Approval and the remaining six payments payable over a six-year period thereafter, and variable payments equal to 7% of net sales of Sozinibercept (OPT-302) for the treatment of wet AMD for each calendar quarter
Bottom of Range
Disclosure Of Risk Management Strategy Related To Hedge Accounting [Line Items]
Short term deposit period	30 days
Top of Range
Disclosure Of Risk Management Strategy Related To Hedge Accounting [Line Items]
Short term deposit period	90 days

Financial Risk Management Obj_6

Financial Risk Management Objectives and Policies - Summary of Exposure to Foreign Currency Risk (Details) - Currency Risk - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
AUD
Financial liabilities
Net exposure	$ 60,409,946	$ 33,311,678
AUD | Cash
Financial assets
Changes in financial assets due to foreign currency risk exposure	55,307,319	26,697,582
AUD | Receivables
Financial assets
Changes in financial assets due to foreign currency risk exposure	6,290,086	7,827,565
AUD | Payables
Financial liabilities
Changes in financial liabilities due to foreign currency risk exposure	(1,187,459)	(1,213,469)
EUR
Financial liabilities
Net exposure	(53,332)	(435,698)
EUR | Payables
Financial liabilities
Changes in financial liabilities due to foreign currency risk exposure	(53,332)	(435,698)
GBP
Financial liabilities
Net exposure	(3,166)	(3,037)
GBP | Payables
Financial liabilities
Changes in financial liabilities due to foreign currency risk exposure	(3,166)	(3,037)
CAD
Financial liabilities
Net exposure	(136,689)	(13,419)
CAD | Payables
Financial liabilities
Changes in financial liabilities due to foreign currency risk exposure	$ (136,689)	$ (13,419)

Related Party Disclosures - Sum

Related Party Disclosures - Summary of Consolidated Financial Statements Include Financial Statements of Opthea Limited and Subsidiaries (Details)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Vegenics Pty Ltd
Disclosure Of Equity Interest In Subsidiaries [Line Items]
Ownership percentage in subsidiary	100%	100%	100%
Opthea US Inc
Disclosure Of Equity Interest In Subsidiaries [Line Items]
Ownership percentage in subsidiary	100%	100%	100%

Related Party Disclosures - S_2

Related Party Disclosures - Summary of Trading Transactions with Related Parties (Details)	12 Months Ended
	Jun. 30, 2023 USD ($)
Launch Tx - Ocelot
Disclosure of transactions between related parties [line items]
Amounts owed to related parties	$ 85,660,000
Launch
Disclosure of transactions between related parties [line items]
Purchase of Service	$ 900,000

Related Party Disclosures - Add

Related Party Disclosures - Additional Information (Details)	12 Months Ended
	Jun. 30, 2023
Launch Tx - Ocelot
Disclosure of transactions between related parties [line items]
Amounts owed to related party, effective rate	23.82%

Commitments - Summary of Expend

Commitments - Summary of Expenditure Commitments Relating to Services for Clinical Trial and Intellectual Property License Agreements (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Commitments [Line Items]
Expenditure commitments relating to services for clinical trial and intellectual property license agreements	$ 24,965,061	$ 48,000,102	$ 28,724,838
Within One Year
Commitments [Line Items]
Expenditure commitments relating to services for clinical trial and intellectual property license agreements	12,632,801	39,947,900	26,377,778
After One Year but not more than Five Years
Commitments [Line Items]
Expenditure commitments relating to services for clinical trial and intellectual property license agreements	12,302,260	8,007,202	$ 2,347,060
After more than Five Years
Commitments [Line Items]
Expenditure commitments relating to services for clinical trial and intellectual property license agreements	$ 30,000	$ 45,000

Commitments - Additional Inform

Commitments - Additional Information (Details)	12 Months Ended
	Jun. 30, 2023
Commitments [Abstract]
Termination clause of biggest research contract	60 days
Maximum commitment term	6 months
Termination clause of biggest contract	60 days
Maximum commercial commitment term	12 months

Commitments - Summary of Commer

Commitments - Summary of Commercial Commitments (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022
Commitments [Line Items]
Commercial commitments	$ 47,415	$ 507,874
Within One Year
Commitments [Line Items]
Commercial commitments	$ 47,415	$ 507,874

Contingencies - Additional Info

Contingencies - Additional Information (Details) - USD ($)	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Disclosure Of Contingent Liabilities [Line Items]
Bank guarantee outstanding in respect of rental deposit	$ 38,036		$ 39,478
Within One Year
Disclosure Of Contingent Liabilities [Line Items]
Amount payable	0	$ 0
More Than One Year
Disclosure Of Contingent Liabilities [Line Items]
Amount payable	$ 1,086,244	$ 11,512,675

Cash Flow Statements Reconcil_3

Cash Flow Statements Reconciliation - Summary of Cash Flow Statements Reconciliation (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020
(a) Reconciliation to cash at the end of the year
Cash at bank and in hand	$ 89,188,713	$ 44,631,293	$ 118,193,177
Cash and cash equivalents	89,188,713	44,631,293	118,193,177	$ 42,650,858
(b) Reconciliation of net loss after tax to net cash flows from operations
Net loss for the year	(142,521,085)	(92,817,371)	(45,344,496)
Adjustments for:
Income tax benefit recognized in profit or loss	(5,926,350)	(6,299,286)	(4,938,846)
Net loss of disposal of non-current assets		169	1,434
Depreciation of non-current assets	17,001	11,917	15,012
Depreciation of right-of-use assets	84,226	66,465	91,656
Total interest expense on DFA	13,462,160
Fair value adjustment gain on DFA	(12,302,160)
Share-based payments	5,834,686	5,251,572	3,897,638
Net exchange differences	489,137	2,813,993	11,011,961
Adjustments to reconcile profit (loss)	1,658,700	1,844,830	10,077,421
Changes in:
Payables	7,296,785	8,511,607	(1,552,443)
Receivables	378,896	307,618	(369,712)
Prepayments	6,142,284	5,730,207	(14,231,546)
Provisions	136,755	115,259	40,510
Net cash flows used in operating activities before tax	(126,907,665)	(76,307,850)	(51,380,266)
R&D tax incentive received	6,299,286	4,972,898	5,834,099
Net cash flows used in operating activities	$ (120,608,379)	$ (71,334,952)	$ (45,546,167)

Key Management Personnel - Sche

Key Management Personnel - Schedule of Compensation of Key Management Personnel (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Disclosure of transactions between related parties [abstract]
Short-term employee benefits	$ 2,898,544	$ 1,555,658	$ 1,099,081
Post-employment benefits	137,168	56,105	79,550
Share-based payments expense	4,221,472	4,664,767	3,897,638
Key management personnel compensation	$ 7,257,184	$ 6,276,530	$ 5,076,269

Key Management Personnel - Addi

Key Management Personnel - Additional Information (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Director and Key Management Personnel
Disclosure Of Transactions Between Related Parties [Line Items]
Related party transactions	$ 0	$ 0

Share-Based Payments - Summary

Share-Based Payments - Summary of Recognized Share Based Payment Expenses (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
Disclosure Of Detailed Information About Recognized Share Based Payment Expenses [Abstract]
Director and employee services received	$ 5,834,686	$ 5,251,572	$ 3,897,638

Share-Based Payments - Addition

Share-Based Payments - Additional Information (Details) - USD ($)	12 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2015
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Number of employee share converts into ordinary share on exercise				1
Amounts paid or payable by recipient on receipt of option				$ 0
Share options outstanding at end of year weighted average exercise price	$ 1.04	$ 1.16	$ 1.28
Weighted average remaining contractual life	555 days	567 days	628 days
Bottom of Range
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Historical share price volatility period	4 years
Bottom of Range | A D S Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Historical share price volatility period	4 years
Top of Range
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Historical share price volatility period	5 years
Top of Range | A D S Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Historical share price volatility period	5 years

Share-Based Payments - Summar_2

Share-Based Payments - Summary of Fair Value of Share Options Granted (Details)	12 Months Ended
	Jun. 30, 2023 $ / shares
LTIP - Director FY2019
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 0.625
Grant date share price	0.420
Fair value per option US	$ 0.150
Expected volatility	58%
Option life	4 years
Dividend yield	0%
Risk free interest rate	2.04%
Model used	Binomial
LTIP - Employees FY2018
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 0.920
Grant date share price	0.340
Fair value per option US	$ 0.260
Expected volatility	66%
Option life	5 years
Dividend yield	0%
Risk free interest rate	2.09%
Model used	Binomial
LTIP - Employees FY2019
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 0.608
Grant date share price	0.480
Fair value per option US	$ 0.180
Expected volatility	57%
Option life	4 years
Dividend yield	0%
Risk free interest rate	2.04%
Model used	Binomial
LTIP - Employees FY2022
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 0.948
Grant date share price	0.955
Fair value per option US	$ 0.526
Expected volatility	74.78%
Option life	4 years
Dividend yield	0%
Risk free interest rate	0.25%
Model used	Binomial
LTIP - Employees FY2022 Two
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date share price	$ 0.955
Fair value per option US	$ 0.955
Option life	10 years
Dividend yield	0%
Model used	Binomial
LTIP - Employees FY2022 Three
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 1.460
Grant date share price	0.901
Fair value per option US	$ 0.553
Expected volatility	75%
Option life	6 years 6 months
Dividend yield	0%
Risk free interest rate	3.40%
Model used	Binomial
NED Plan FY2022
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 0.945
Grant date share price	0.955
Fair value per option US	$ 0.526
Expected volatility	74.78%
Option life	4 years
Dividend yield	0%
Risk free interest rate	0.25%
Model used	Binomial
NED Plan FY2022 Two
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 0.755
Grant date share price	0.741
Fair value per option US	$ 0.397
Expected volatility	75%
Option life	3 years 6 months
Dividend yield	0%
Risk free interest rate	2.70%
Model used	Binomial
LTIP - Employees FY2023 One
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 0.658
Grant date share price	0.672
Fair value per option US	$ 0.471
Expected volatility	75%
Option life	6 years 6 months
Dividend yield	0%
Risk free interest rate	3.60%
Model used	Binomial
LTIP - Employees FY2023 Two
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date share price	$ 0.672
Fair value per option US	$ 0.672
Expected volatility	75%
Option life	10 years
Dividend yield	0%
Risk free interest rate	3.70%
Model used	Binomial
LTIP - Employees FY2023 Three
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 0.644
Grant date share price	0.643
Fair value per option US	$ 0.459
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	3.30%
Model used	Binomial
NED Plan FY2016
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 0.360
Grant date share price	0.280
Fair value per option US	$ 0.140
Expected volatility	65%
Option life	5 years
Dividend yield	0%
Risk free interest rate	2.09%
Model used	Binomial
NED Plan FY2019
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 0.625
Grant date share price	0.420
Fair value per option US	$ 0.150
Expected volatility	58%
Option life	4 years
Dividend yield	0%
Risk free interest rate	2.04%
Model used	Binomial
NED Plan FY2021
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 2.160
Grant date share price	2.190
Fair value per option US	$ 1.240
Expected volatility	77.25%
Option life	4 years
Dividend yield	0%
Risk free interest rate	0.25%
Model used	Binomial
NED Plan FY2021 Two
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 3.240
Grant date share price	2.190
Fair value per option US	$ 1.050
Expected volatility	77.25%
Option life	4 years
Dividend yield	0%
Risk free interest rate	0.25%
Model used	Binomial
NED Plan FY2021 Three
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 1.560
Grant date share price	1.560
Fair value per option US	$ 0.880
Expected volatility	77.01%
Option life	4 years
Dividend yield	0%
Risk free interest rate	0.25%
Model used	Binomial
LTIP - Employee 2022 | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 7.625
Grant date share price	7.240
Fair value per option US	$ 4.970
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	1.40%
Model used	Binomial
LTIP - Employee 2022 Two | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 7.515
Grant date share price	7.500
Fair value per option US	$ 5.228
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	1.70%
Model used	Binomial
LTIP - Employee 2022 Three | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 6.009
Grant date share price	5.925
Fair value per option US	$ 4.116
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	1.70%
Model used	Binomial
LTIP - Employee 2022 Four | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 6.090
Grant date share price	5.915
Fair value per option US	$ 4.171
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	2.90%
Model used	Binomial
LTIP - Employee 2022 Five | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 7.116
Grant date share price	7
Fair value per option US	$ 4.953
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	2.90%
Model used	Binomial
LTIP - Employee 2022 Six | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 7.445
Grant date share price	7.309
Fair value per option US	$ 5.175
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	3%
Model used	Binomial
LTIP - Employee 2022 Seven | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 5.522
Grant date share price	5.500
Fair value per option US	$ 3.886
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	3.40%
Model used	Binomial
LTIP - Employee 2023 | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 6.350
Grant date share price	6.600
Fair value per option US	$ 4.718
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	2.90%
Model used	Binomial
LTIP - Employee 2023 Two | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 4.850
Grant date share price	4.810
Fair value per option US	$ 3.479
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	4.30%
Model used	Binomial
LTIP - Employee 2023 Three | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 5.170
Grant date share price	4.850
Fair value per option US	$ 3.457
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	4.10%
Model used	Binomial
LTIP - Employee 2023 Four | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 4.929
Grant date share price	4.959
Fair value per option US	$ 3.560
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	3.60%
Model used	Binomial
LTIP - Employee 2023 Five | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 5.238
Grant date share price	5.450
Fair value per option US	$ 3.935
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	3.50%
Model used	Binomial
LTIP - Employee 2023 Six | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 5.150
Grant date share price	5.030
Fair value per option US	$ 3.602
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	3.80%
Model used	Binomial
LTIP - Employee 2023 Seven | ADS Options
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Exercise price	$ 3.545
Grant date share price	3.360
Fair value per option US	$ 2.384
Expected volatility	75%
Option life	7 years
Dividend yield	0%
Risk free interest rate	3.60%
Model used	Binomial
Non Executive Director and Employee Share Option Plans | LTIP - Director FY2019
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	November 29, 2018
Grant date fair value	$ 0.150
Exercise price	$ 0.625
Expiry date	Nov. 29, 2022
Vesting date	Nov. 29, 2019
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2018
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	August 23, 2017
Grant date fair value	$ 0.260
Exercise price	$ 0.920
Expiry date	Jan. 01, 2023
Vesting date	Jun. 30, 2018
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2019
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	April 3, 2019
Grant date fair value	$ 0.180
Exercise price	$ 0.608
Expiry date	Apr. 03, 2023
Vesting date	Apr. 03, 2021
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.955
Exercise price	$ 0
Expiry date	Oct. 18, 2031
Vesting date	Oct. 19, 2021
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Seven
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 12, 2020
Grant date fair value	$ 1.240
Exercise price	$ 2.160
Expiry date	Oct. 11, 2024
Vesting date	Oct. 12, 2022
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Two
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.955
Exercise price	$ 0
Expiry date	Oct. 18, 2031
Vesting date	Oct. 19, 2022
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Eight
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 12, 2020
Grant date fair value	$ 1.240
Exercise price	$ 2.160
Expiry date	Oct. 11, 2024
Vesting date	Oct. 12, 2023
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Three
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.955
Exercise price	$ 0
Expiry date	Oct. 18, 2031
Vesting date	Oct. 19, 2023
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Nine
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	January 19, 2021
Grant date fair value	$ 0.880
Exercise price	$ 1.560
Expiry date	Jan. 18, 2025
Vesting date	Jan. 19, 2021
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Four
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.955
Exercise price	$ 0
Expiry date	Oct. 18, 2031
Vesting date	Jan. 31, 2023
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Ten
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	January 19, 2021
Grant date fair value	$ 0.880
Exercise price	$ 1.560
Expiry date	Jan. 18, 2025
Vesting date	Jan. 19, 2022
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Five
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.955
Exercise price	$ 0
Expiry date	Oct. 18, 2031
Vesting date	Nov. 30, 2022
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Eleven
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	January 19, 2021
Grant date fair value	$ 0.880
Exercise price	$ 1.560
Expiry date	Jan. 18, 2025
Vesting date	Jan. 19, 2023
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Six
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.955
Exercise price	$ 0
Expiry date	Oct. 18, 2031
Vesting date	Apr. 30, 2023
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Twelve
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	January 19, 2021
Grant date fair value	$ 0.880
Exercise price	$ 1.560
Expiry date	Jan. 18, 2025
Vesting date	Jan. 19, 2024
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Seven
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.955
Exercise price	$ 0
Expiry date	Oct. 18, 2031
Vesting date	Apr. 30, 2023
Non Executive Director and Employee Share Option Plans | NED Plan FY2022
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.526
Exercise price	$ 0.948
Expiry date	Oct. 18, 2025
Vesting date	Oct. 19, 2021
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Eight
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.955
Exercise price	$ 0
Expiry date	Oct. 18, 2031
Vesting date	Sep. 30, 2024
Non Executive Director and Employee Share Option Plans | NED Plan FY2022 Two
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.526
Exercise price	$ 0.948
Expiry date	Oct. 18, 2025
Vesting date	Oct. 19, 2022
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Nine
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.526
Exercise price	$ 0.948
Expiry date	Oct. 18, 2025
Vesting date	Oct. 19, 2021
Non Executive Director and Employee Share Option Plans | NED Plan FY2022 Three
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.526
Exercise price	$ 0.948
Expiry date	Oct. 18, 2025
Vesting date	Oct. 19, 2023
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Ten
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.526
Exercise price	$ 0.948
Expiry date	Oct. 18, 2025
Vesting date	Oct. 19, 2022
Non Executive Director and Employee Share Option Plans | NED Plan FY2022 Four
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.526
Exercise price	$ 0.948
Expiry date	Oct. 18, 2025
Vesting date	Oct. 19, 2024
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Eleven
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.526
Exercise price	$ 0.948
Expiry date	Oct. 18, 2025
Vesting date	Oct. 19, 2023
Non Executive Director and Employee Share Option Plans | NED Plan FY2022 Five
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	April 21, 2022
Grant date fair value	$ 0.397
Exercise price	$ 0.755
Expiry date	Apr. 20, 2026
Vesting date	Apr. 21, 2022
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Twelve
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 19, 2021
Grant date fair value	$ 0.526
Exercise price	$ 0.948
Expiry date	Oct. 18, 2025
Vesting date	Oct. 19, 2024
Non Executive Director and Employee Share Option Plans | NED Plan FY2022 Six
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	April 21, 2022
Grant date fair value	$ 0.397
Exercise price	$ 0.755
Expiry date	Apr. 20, 2026
Vesting date	Apr. 21, 2023
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Thirteen
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	June 6, 2022
Grant date fair value	$ 0.553
Exercise price	$ 1.460
Expiry date	Jun. 05, 2032
Vesting date	Jun. 06, 2022
Non Executive Director and Employee Share Option Plans | NED Plan FY2022 Seven
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	April 21, 2022
Grant date fair value	$ 0.397
Exercise price	$ 0.755
Expiry date	Apr. 20, 2026
Vesting date	Apr. 21, 2024
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Fourteen
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	June 6, 2022
Grant date fair value	$ 0.553
Exercise price	$ 1.460
Expiry date	Jun. 05, 2032
Vesting date	Jun. 06, 2023
Non Executive Director and Employee Share Option Plans | NED Plan FY2022 Eight
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	April 21, 2022
Grant date fair value	$ 0.397
Exercise price	$ 0.755
Expiry date	Apr. 20, 2026
Vesting date	Apr. 21, 2025
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Fifteen
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	June 6, 2022
Expiry date	Jun. 05, 2032
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2022 Sixteen
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	June 6, 2022
Grant date fair value	$ 0.553
Exercise price	$ 1.460
Expiry date	Jun. 05, 2032
Vesting date	Jun. 06, 2024
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2023 One
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	November 16, 2022
Grant date fair value	$ 0.471
Exercise price	$ 0.658
Expiry date	Nov. 16, 2032
Vesting date	Nov. 16, 2025
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2023 Two
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	November 16, 2022
Grant date fair value	$ 0.672
Exercise price	$ 0
Expiry date	Nov. 16, 2032
Vesting date	Nov. 16, 2025
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2023 Three
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	December 13, 2022
Grant date fair value	$ 0.459
Exercise price	$ 0.644
Expiry date	Dec. 13, 2032
Vesting date	Dec. 13, 2023
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2023 Four
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	December 13, 2022
Grant date fair value	$ 0.459
Exercise price	$ 0.644
Expiry date	Dec. 13, 2032
Vesting date	Dec. 13, 2024
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2023 Five
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	December 13, 2022
Grant date fair value	$ 0.459
Exercise price	$ 0.644
Expiry date	Dec. 13, 2032
Vesting date	Dec. 13, 2025
Non Executive Director and Employee Share Option Plans | LTIP - Employees FY2023 Six
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	December 13, 2022
Grant date fair value	$ 0.459
Exercise price	$ 0.644
Expiry date	Dec. 13, 2032
Vesting date	Dec. 13, 2026
Non Executive Director and Employee Share Option Plans | NED Plan FY2016
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	March 7,2016
Grant date fair value	$ 0.140
Exercise price	$ 0.360
Expiry date	Mar. 07, 2021
Vesting date	Jun. 30, 2016
Non Executive Director and Employee Share Option Plans | NED Plan FY2019
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	November 29, 2018
Grant date fair value	$ 0.150
Exercise price	$ 0.625
Expiry date	Nov. 29, 2022
Vesting date	Nov. 29, 2019
Non Executive Director and Employee Share Option Plans | NED Plan FY2021
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 12, 2020
Grant date fair value	$ 1.050
Exercise price	$ 3.240
Expiry date	Oct. 11, 2024
Vesting date	Oct. 12, 2020
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Two
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 12, 2020
Grant date fair value	$ 1.050
Exercise price	$ 3.240
Expiry date	Oct. 11, 2024
Vesting date	Oct. 12, 2021
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Three
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 12, 2020
Grant date fair value	$ 1.050
Exercise price	$ 3.240
Expiry date	Oct. 11, 2024
Vesting date	Oct. 12, 2022
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Four
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 12, 2020
Grant date fair value	$ 1.050
Exercise price	$ 3.240
Expiry date	Oct. 11, 2024
Vesting date	Oct. 12, 2023
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Five
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 12, 2020
Grant date fair value	$ 1.240
Exercise price	$ 2.160
Expiry date	Oct. 11, 2024
Vesting date	Oct. 12, 2020
Non Executive Director and Employee Share Option Plans | NED Plan FY2021 Six
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Grant date	October 12, 2020
Grant date fair value	$ 1.240
Exercise price	$ 2.160
Expiry date	Oct. 11, 2024
Vesting date	Oct. 12, 2021

Share-Based Payments - Summar_3

Share-Based Payments - Summary of Share/Rights Options Outstanding (Details)	12 Months Ended
	Jun. 30, 2023 shares $ / shares	Jun. 30, 2022 shares $ / shares	Jun. 30, 2021 shares $ / shares
Disclosure of terms and conditions of share-based payment arrangement [abstract]
Balance, number of options and rights | shares	22,988,000	16,644,000	18,044,000
To employees and directors under the LTIP and NED Plan, number of options and rights | shares	10,050,000	8,400,000	7,000,000
Exercised during the year, number of options and rights | shares	(6,613,000)	(2,056,000)	(8,400,000)
Expired during the year, number of options and rights | shares	(975,000)
Balance, number of options and rights | shares	25,450,000	22,988,000	16,644,000
Exercisable at end of year, number of options and rights | shares	10,842,234	12,857,589	11,394,000
Balance, weighted average exercise price | $ / shares	$ 1.16	$ 1.28	$ 0.50
To employees and directors under the LTIP and NED Plan, weighted average exercise price | $ / shares	0.58	0.77	2.21
Exercised during the year, weighted average exercise price | $ / shares	0.62	0.58	0.36
Expired during the year, weighted average exercise price | $ / shares	0.61
Balance, weighted average exercise price | $ / shares	1.04	1.16	1.28
Exercisable at end of year, weighted average exercise price | $ / shares	$ 1.48	$ 0.97	$ 0.86

Share-Based Payments - Summar_4

Share-Based Payments - Summary of ADS Options Outstanding (Details)	12 Months Ended
	Jun. 30, 2023 shares $ / shares	Jun. 30, 2022 shares $ / shares	Jun. 30, 2021 shares $ / shares
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Balance, number of options and rights | shares	22,988,000	16,644,000	18,044,000
To employees and directors under the LTIP and NED Plan, number of options and rights | shares	10,050,000	8,400,000	7,000,000
Exercised during the year, number of options and rights | shares	(6,613,000)	(2,056,000)	(8,400,000)
Expired during the year, number of options and rights | shares	(975,000)
Balance, number of options and rights | shares	25,450,000	22,988,000	16,644,000
Outstanding options and rights exercisable | shares	10,842,234	12,857,589	11,394,000
Balance, weighted average exercise price | $ / shares	$ 1.16	$ 1.28	$ 0.50
To employees and directors under the LTIP and NED Plan, weighted average exercise price | $ / shares	0.58	0.77	2.21
Exercised during the year, weighted average exercise price | $ / shares	0.62	0.58	0.36
Expired during the year, weighted average exercise price | $ / shares	0.61
Balance, weighted average exercise price | $ / shares	1.04	1.16	1.28
Exercisable at end of year, weighted average exercise price | $ / shares	$ 1.48	$ 0.97	$ 0.86
American Depository Shares
Disclosure Of Terms And Conditions Of Sharebased Payment Arrangement [Line Items]
Balance, number of options and rights | shares	925,000
To employees and directors under the LTIP and NED Plan, number of options and rights | shares	755,000	925,000
Expired during the year, number of options and rights | shares	(175,000)
Balance, number of options and rights | shares	1,505,000	925,000
Outstanding options and rights exercisable | shares	250,000
Balance, weighted average exercise price | $ / shares	$ 6.75
To employees and directors under the LTIP and NED Plan, weighted average exercise price | $ / shares	5.07	$ 6.75
Expired during the year, weighted average exercise price | $ / shares	7.62
Balance, weighted average exercise price | $ / shares	5.81	$ 6.75
Exercisable at end of year, weighted average exercise price | $ / shares	$ 6.70

Events After The Balance Shee_2

Events After The Balance Sheet Date - Additional Information (Details) $ in Millions

12 Months Ended

Sep. 20, 2023 USD ($)

Sep. 20, 2023 AUD ($)

Sep. 01, 2023 USD ($)

Sep. 01, 2023 AUD ($)

Aug. 28, 2023 USD ($) Closing

Aug. 28, 2023 AUD ($) Closing

Jul. 01, 2023 USD ($)

Aug. 12, 2022 USD ($)

Jun. 30, 2023 USD ($)

Jun. 30, 2021 USD ($)

Aug. 24, 2023 AUD ($)

Jun. 30, 2022 USD ($)

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Issued capital

$ 320,883,552

$ 235,277,217

Percentage of net sales

7%

Net proceeds on issue of shares

$ 81,815,358

$ 105,477,591

Development Funding Agreement

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Amount committed by investor

$ 120,000,000

Percentage of net sales

7%

Events after Reporting Period

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Issued capital

$ 80

Equity financing

$ 58,000,000

$ 90

Number of equity financing closing | Closing

2

2

Events after Reporting Period | Private Placement [member]

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Issued capital

10

Events after Reporting Period | Development Funding Agreement

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Pipeline funding Initial payment

$ 50,000,000

Funding additional payment

50,000,000

Events after Reporting Period | Accelerated Non-Renounceable Entitlement Offer [member]

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Issued capital

$ 70

Events after Reporting Period | Placement Offering and Acceleration Portion of Accelerated Non-Renounceable Entitlement Offer [member]

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Equity financing first closing

$ 47,000,000

$ 73

Events after Reporting Period | Remaining Institutional and Retail Portion of Accelerated Non Renounceable Entitlement Offer [member]

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Equity financing second closing

$ 11,000,000

$ 17

Events after Reporting Period | Consultancy Agreement [member]

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Provision of services

$ 300,000

Events after Reporting Period | Bottom of Range | Private Placement [member]

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Increase in private placement

$ 10

Events after Reporting Period | Bottom of Range | Development Funding Agreement

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Amount committed by investor

120,000,000

Events after Reporting Period | Top of Range | Private Placement [member]

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Increase in private placement

$ 90

Events after Reporting Period | Top of Range | Development Funding Agreement

Disclosure Of Nonadjusting Events After Reporting Period [Line Items]

Amount committed by investor

$ 170,000,000