KalVista Pharmaceuticals (KALV) 10-Q 7 Sep 23 2024 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Jul. 31, 2023	Aug. 31, 2023
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jul. 31, 2023
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Trading Symbol	KALV
Entity Registrant Name	KALVISTA PHARMACEUTICALS, INC.
Entity Central Index Key	0001348911
Current Fiscal Year End Date	--04-30
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Shell Company	false
Document Quarterly Report	true
Title of 12(b) Security	Common Stock, $0.001 par value per share
Security Exchange Name	NASDAQ
Document Transition Report	false
Entity File Number	001-36830
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-0915291
Entity Address, Address Line One	55 Cambridge Parkway
Entity Address, Address Line Two	Suite 901E
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02142
City Area Code	857
Local Phone Number	999-0075
Entity Common Stock, Shares Outstanding		34,403,458

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jul. 31, 2023	Apr. 30, 2023
Current assets:
Cash and cash equivalents	$ 49,409	$ 56,238
Marketable securities	73,848	93,137
Research and development tax credit receivable	19,057	16,568
Prepaid expenses and other current assets	7,528	6,383
Total current assets	149,842	172,326
Property and equipment, net	2,813	2,948
Right of use assets	7,571	7,822
Other assets	106	106
Total assets	160,332	183,202
Current liabilities:
Accounts payable	5,060	4,817
Accrued expenses	7,950	9,128
Lease liability - current portion	1,122	1,087
Total current liabilities	14,132	15,032
Long-term liabilities:
Lease liability - net of current portion	6,865	7,145
Total long-term liabilities	6,865	7,145
Commitments and contingencies (Note 6)
Stockholders’ equity
Common stock, $0.001 par value, 100,000,000 authorized Shares issued and outstanding: 34,266,595 at July 31, 2023 and 34,171,138 at April 30, 2023	34	34
Additional paid-in capital	510,591	507,133
Accumulated deficit	(368,399)	(343,082)
Accumulated other comprehensive loss	(2,891)	(3,060)
Total stockholders’ equity	139,335	161,025
Total liabilities and stockholders’ equity	$ 160,332	$ 183,202

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - $ / shares	Jul. 31, 2023	Apr. 30, 2023
Statement of Financial Position [Abstract]
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	34,266,595	34,171,138
Common stock, shares outstanding	34,266,595	34,171,138

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2023	Jul. 31, 2022
Operating expenses:
Research and development	$ 19,307	$ 18,186
General and administrative	9,786	8,130
Total operating expenses	29,093	26,316
Operating loss	(29,093)	(26,316)
Other income:
Interest income	923	242
Foreign currency exchange gain (loss)	456	(517)
Other income	2,397	3,549
Total other income	3,776	3,274
Net loss	(25,317)	(23,042)
Other comprehensive (loss) income:
Foreign currency translation gain (loss)	91	(403)
Unrealized holding gain on marketable securities	392	98
Reclassification adjustment for realized (gain) loss on marketable securities included in net loss	(314)	16
Other comprehensive income (loss)	169	(289)
Comprehensive (loss)	$ (25,148)	$ (23,331)
Net loss per share to common stockholders, basic	$ (0.74)	$ (0.94)
Net loss per share to common stockholders, diluted	$ (0.74)	$ (0.94)
Weighted average common shares outstanding, basic	34,414,226	24,557,615
Weighted average common shares outstanding, diluted	34,414,226	24,557,615

Condensed Consolidated Statem_2

Condensed Consolidated Statement of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Apr. 30, 2022	$ 185,093	$ 25	$ 439,104	$ (250,175)	$ (3,861)
Balance, shares at Apr. 30, 2022		24,550,748
Issuance of common stock from equity incentive plans	168		168
Issuance of common stock from equity incentive plans, shares		20,124
Stock-based compensation expense	2,642		2,642
Net loss	(23,042)			(23,042)
Foreign currency translation gain (loss)	(403)				(403)
Unrealized holding (loss) gain from marketable securities	98				98
Reclassification adjustment for realized (gain) loss on marketable securities included in net loss	16				16
Balance at Jul. 31, 2022	164,572	$ 25	441,914	(273,217)	(4,150)
Balance, shares at Jul. 31, 2022		24,570,872
Balance at Apr. 30, 2023	161,025	$ 34	507,133	(343,082)	(3,060)
Balance, shares at Apr. 30, 2023		34,171,138
Issuance of common stock from equity incentive plans	204		204
Issuance of common stock from equity incentive plans, shares		35,313
Release of restricted stock units, shares		60,144
Stock-based compensation expense	3,254		3,254
Net loss	(25,317)			(25,317)
Foreign currency translation gain (loss)	91				91
Unrealized holding (loss) gain from marketable securities	392				392
Reclassification adjustment for realized (gain) loss on marketable securities included in net loss	(314)				(314)
Balance at Jul. 31, 2023	$ 139,335	$ 34	$ 510,591	$ (368,399)	$ (2,891)
Balance, shares at Jul. 31, 2023		34,266,595

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Jul. 31, 2023	Jul. 31, 2022
Cash flows from operating activities
Net loss	$ (25,317)	$ (23,042)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	193	158
Stock-based compensation expense	3,254	2,642
Realized (gain) loss from sale of marketable securities	(314)	16
Non-cash operating lease expense	6	23
Amortization of premium on marketable securities	62	391
Foreign currency exchange (gain) loss	(395)	426
Changes in operating assets and liabilities:
Research and development tax credit receivable	(2,084)	(3,570)
Prepaid expenses and other assets	(1,003)	1,935
Accounts payable	108	(678)
Accrued expenses	(1,240)	(1,043)
Net cash used in operating activities	(26,730)	(22,742)
Cash flows from investing activities
Purchases of marketable securities	(25,767)	(10,102)
Sales and maturities of marketable securities	45,386	41,066
Acquisition of property and equipment	(6)	(920)
Net cash provided by investing activities	19,613	30,044
Cash flows from financing activities
Issuance of common stock from equity incentive plans	204	168
Net cash provided by financing activities	204	168
Effect of exchange rate changes on cash and cash equivalents	84	(339)
Net (decrease) increase in cash and cash equivalents	(6,829)	7,131
Cash and cash equivalents at beginning of period	56,238	30,732
Cash and cash equivalents at end of period	$ 49,409	37,863
Supplemental disclosures of non-cash activities:
Right of use assets obtained in exchange for operating lease liabilities		1,192
Property and equipment included in accounts payable and accrued expenses:		$ 144

The Company

The Company	3 Months Ended
	Jul. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	1. The Company Company Background KalVista Pharmaceuticals, Inc. (“KalVista” or the “Company”) is a clinical stage pharmaceutical company focused on the discovery, development, and commercialization of small molecule protease inhibitors for diseases with significant unmet need. The Company applies its insights into the chemistry and biology of proteases to develop orally delivered, small molecule inhibitors with high selectivity, potency, and bioavailability that it believes will make them successful treatments for disease. The Company’s initial focus is on developing novel, oral therapeutics targeting hereditary angioedema (HAE). The Company has advanced its candidate, sebetralstat, into the Phase 3 KONFIDENT clinical trial to evaluate the safety and efficacy of sebetralstat as the first potential oral, on-demand therapy for HAE attacks. This worldwide, double-blind, placebo-controlled crossover trial will evaluate the response of adolescents and adults experiencing acute HAE attacks with two different doses of sebetralstat and placebo. Sebetralstat is the most advanced potential oral therapy for acute HAE attacks in clinical development and is intended to provide a substantial improvement over the current on-demand standard of care for HAE attacks, which currently are only treated with injectable or infused therapies. In July 2023, KalVista announced that it achieved its enrollment target of 114 patients in the study and as a result, expects data from KONFIDENT in the fourth quarter of 2023. If the trial is successful, the Company anticipates submitting an NDA to the FDA in the first half of 2024. The Company is also conducting preclinical development on a novel, oral Factor XIIa (“Factor XIIa”) inhibitor program, which KalVista initially is advancing to provide a next generation of HAE therapeutics and which also offers the opportunity for expansion into other high unmet need indications in the future. The Company’s headquarters is located in Cambridge, Massachusetts, with additional offices located in Porton Down, United Kingdom, and Salt Lake City, Utah. Liquidity The Company has devoted substantially all of its efforts to research and development, including preclinical and clinical trials of sebetralstat. The Company has not completed the development of any product candidates or commenced commercial operations. Pharmaceutical drug product candidates, like those being developed by the Company, require approvals from the FDA or foreign regulatory agencies prior to commercial sales. There can be no assurance that any product candidates will receive the necessary approvals and any failure to receive approval or delay in approval may have a material adverse impact on the Company’s business and financial results. The Company is subject to a number of risks and uncertainties similar to those of other life science companies developing new products, including, among others, the risks related to the necessity to obtain adequate additional financing, to successfully develop product candidates, to obtain regulatory approval of product candidates, to comply with government regulations, to successfully commercialize its potential products, to the protection of proprietary technology and to the dependence on key individuals. To date, the Company has not generated any product sales revenues and does not have any products that have been approved for commercialization. As of July 31, 2023, the Company had an accumulated deficit of $ 368.4 million and $ 123.3 million of cash, cash equivalents and marketable securities. The Company does not expect to generate significant revenue unless and until it obtains regulatory approval for, and commercializes, one of its current or future product candidates. The Company anticipates that it will continue to incur losses for the foreseeable future, and it expects those losses to increase as it continues the development of, and seeks regulatory approvals for, product candidates, and begins to commercialize any approved products. The Company is subject to all of the risks inherent in the development of new therapeutic products, and it may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect its business. The Company currently anticipates that, based upon its operating plans and existing capital resources, it has sufficient funding to operate for at least the next twelve months. The Company will need to expend substantial resources for research and development, including costs associated with the clinical testing of its product candidates and will need to obtain additional financing to fund its operations and to conduct trials for its product candidates. KalVista will seek to finance future cash needs through equity offerings, future grants, corporate partnerships and product sales. The Company has never been profitable and has incurred significant operating losses in each year since its inception. Cash requirements may vary materially from those now planned because of changes in KalVista’s focus and direction of its research and development programs, competitive and technical advances, patent developments, regulatory changes or other developments. Additional financing will be required to continue operations after KalVista exhausts its current cash resources and to continue its long-term plans for clinical trials and new product development. There can be no assurance that any such financing can be obtained by the Company, or if obtained, what the terms thereof may be, or that any amount that the Company is able to raise will be adequate to support KalVista’s working capital requirements until it achieves profitable operations. If adequate additional working capital is not secured when needed, KalVista may be required to make reductions in spending, extend payment terms with suppliers, liquidate assets where possible and/or suspend or curtail planned research programs. Any of these actions could materially harm the Company’s business and prospects.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Jul. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies Principles of Consolidation: The accompanying unaudited interim condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and in accordance with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. Such financial statements reflect all adjustments that are, in management’s opinion, necessary to present fairly, in all material respects, the Company’s consolidated financial position, results of operations, and cash flows. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the annual financial statements. There were no adjustments other than normal recurring adjustments. These unaudited interim condensed consolidated financial results are not necessarily indicative of the results to be expected for the year ending April 30, 2024, or for any other future annual or interim period. The accompanying unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements as of and for the year ended April 30, 2023 in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on July 10, 2023. Segment Reporting: The chief operating decision maker, the CEO, manages the Company’s operations as a single operating segment for the purposes of assessing performance and making operating decisions. Recent Accounting Pronouncements: In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which amends the impairment model by requiring entities to use a forward-looking approach on expected losses to estimate credit losses on certain financial instruments, including trade receivables and available-for-sale debt securities. This guidance became effective on May 1, 2023 and did not have a material impact to the consolidated financial statements. As the Company has never recorded any other-than-temporary-impairment adjustments to its available-for-sale debt securities prior to the effective date, no transition provisions were applicable to the Company. Net Loss per Share: Basic net loss per share is computed by dividing the net loss by the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing net loss by the sum of the weighted average number of common shares and the number of potential dilutive common share equivalents outstanding during the period. Potential dilutive common share equivalents consist of the incremental common shares issuable upon the exercise of share options and awards. Potential dilutive common share equivalents consist of: July 31, 2023 2022 Stock options and awards 5,909,619 4,697,733 In computing diluted earnings per share, common share equivalents are not considered in periods in which a net loss is reported, as the inclusion of the common share equivalents would be anti-dilutive. As a result, there is no difference between the Company’s basic and diluted loss per share for the periods presented. The weighted average number of common shares used in the basic and diluted net loss per common share calculations includes the weighted-average pre-funded warrants outstanding during the period as they are exercisable at any time for nominal cash consideration. Fair Value Measurement: The Company classifies fair value measurements using a three-level hierarchy that prioritizes the inputs used to measure fair value. This hierarchy requires entities to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: Level 1, quoted market prices in active markets for identical assets or liabilities; Level 2, observable inputs other than quoted market prices included in Level 1, such as quoted market prices for markets that are not active or other inputs that are observable or can be corroborated by observable market data; and Level 3, unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities, including certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. These fair values are obtained from independent pricing services which utilize Level 1 and Level 2 inputs. The following tables summarize the cash equivalents and marketable securities measured at fair value on a recurring basis as of July 31, 2023 and April 30, 2023 (in thousands): Balance at Level 1 Level 2 Level 3 July 31, 2023 Cash equivalents $ 34,212 $ — $ — $ 34,212 Marketable securities: Corporate debt securities — 58,513 — 58,513 U.S. government agency securities — 15,335 — 15,335 $ 34,212 $ 73,848 $ — $ 108,060 Balance at Level 1 Level 2 Level 3 April 30, 2023 Cash equivalents $ 31,507 $ — $ — $ 31,507 Marketable securities: Corporate debt securities — 77,967 — 77,967 U.S. government agency securities — 15,170 — 15,170 $ 31,507 $ 93,137 $ — $ 124,644

Marketable Securities

Marketable Securities	3 Months Ended
	Jul. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Marketable Securities	3. Marketable Securities The objectives of the Company’s investment policy are to ensure the safety and preservation of invested funds, as well as to maintain liquidity sufficient to meet cash flow requirements. The Company invests its excess cash in securities issued by financial institutions, commercial companies, and government agencies that management believes to be of high credit quality in order to limit the amount of its credit exposure. The Company has not realized any material losses from its investments. The Company classifies all of its debt securities as available-for-sale. Unrealized gains and losses on investments are recognized in accumulated comprehensive loss, unless an unrealized loss is considered to be other than temporary, in which case the unrealized loss is charged to operations. The Company periodically reviews its investments for other than temporary declines in fair value below cost basis and whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. The Company believes the individual unrealized losses represent temporary declines primarily resulting from interest rate changes. Realized gains and losses are included in other income in the consolidated statements of operations and comprehensive loss and are determined using the specific identification method with transactions recorded on a trade date basis. The following tables summarize the fair values of the Company’s investments by type as of July 31, 2023 and April 30, 2023 (in thousands): July 31, 2023 Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value Corporate debt securities $ 58,307 $ 303 $ ( 97 ) $ 58,513 Obligations of the U.S. Government and its agencies 15,094 241 — 15,335 Total $ 73,401 $ 544 $ ( 97 ) $ 73,848 April 30, 2023 Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value Corporate debt securities $ 77,768 $ 367 $ ( 168 ) $ 77,967 Obligations of the U.S. Government and its agencies 15,094 76 15,170 Total $ 92,862 $ 443 $ ( 168 ) $ 93,137 The Company has classified all of its available-for-sale investment securities, including those with maturities beyond one year, as current assets on its condensed consolidated balance sheets based on the highly liquid nature of the investment securities and because these investment securities are considered available for use in current operations. As of July 31, 2023, unrealized losses related to individual securities that had been in a continuous loss position for 12 months or longer were insignificant. The following table summarizes the scheduled maturity for the Company’s marketable securities at July 31, 2023 (in thousands): July 31, 2023 Maturing in one year or less $ 50,347 Maturing after one year through two years 12,188 Maturing after two years through four years 11,313 Total $ 73,848

Accrued Expenses

Accrued Expenses	3 Months Ended
	Jul. 31, 2023
Payables and Accruals [Abstract]
Accrued Expenses	4. Accrued Expenses Accrued expenses consisted of the following as of July 31, 2023 and April 30, 2023 (in thousands): July 31, April 30, 2023 2023 Accrued compensation $ 2,501 $ 4,207 Accrued research expense 3,925 3,817 Accured professional fees 1,376 906 Other accrued expenses 148 198 $ 7,950 $ 9,128

Prepaid Expenses and Other Curr

Prepaid Expenses and Other Current Assets	3 Months Ended
	Jul. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid Expenses and Other Current Assets	5. Prepaid Expenses and Other Current Assets Prepaid expenses and other current assets consisted of the following as of July 31, 2023 and April 30, 2023 (in thousands): July 31, April 30, 2023 2023 Prepaid clinical expenses $ 3,175 $ 1,724 Other prepaid expenses 2,840 2,583 Interest and other receivables 469 654 VAT receivable 1,044 1,422 Total prepaid expenses and other current assets $ 7,528 $ 6,383

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Jul. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. Commitments and Contingencies Clinical Studies: The Company enters into contractual agreements with contract research organizations in connection with preclinical and toxicology studies and clinical trials. Amounts due under these agreements are invoiced to the Company on predetermined schedules during the course of the studies and clinical trials and are not refundable regardless of the outcome. The Company has contractual obligations related to the expected future costs to be incurred to complete the ongoing preclinical studies and clinical trials. The remaining commitments, which have cancellation provisions, total $ 26.2 million at July 31, 2023. Indemnification: In the normal course of business, the Company enters into contracts and agreements that contain a variety of representations and warranties and provide for general indemnification. The Company’s exposure under these agreements is unknown because it involves future claims that may be made against the Company but have not yet been made. To date, the Company has not paid any claims or been required to defend any action related to its indemnification obligations. However, the Company may record charges in the future as a result of these indemnification obligations. No amounts associated with such indemnifications have been recorded to date. Contingencies: From time to time, the Company may have certain contingent liabilities that arise in the ordinary course of business activities. The Company accrues a liability for such matters when it is probable that future expenditures will be made and such expenditures can be reasonably estimated. There were no contingent liabilities requiring accrual at July 31, 2023 .

Leases

Leases	3 Months Ended
	Jul. 31, 2023
Leases [Abstract]
Leases	7. Leases The Company has a lease agreement for approximately 8,300 square feet of space for its headquarters located in Cambridge, Massachusetts that runs through September 2028. The Company has lease agreements for approximately 13,400 square feet of office and research laboratory space located in Porton Down, United Kingdom that run through April 2028. The Company has a lease agreement in Salt Lake City, Utah for approximately 6,200 square feet of office space that runs through February 2032. The Company has a lease agreement for approximately 500 square feet of research laboratory space in Cambridge, Massachusetts that commenced in July 2022 with an option to renew annually. Total rent expense was approximately $ 0.5 million and $ 0.5 million for the three months ended July 31, 2023 and 2022, respectively and is reflected in general and administrative expenses and research and development expenses as determined by the underlying activities. The following table summarizes the maturity of undiscounted payments due under lease liabilities and the present value of those liabilities as of July 31, 2023 (in thousands): Years ending April 30, Operating 2024 $ 1,308 2025 1,777 2026 1,814 2027 1,853 2028 1,848 Thereafter 1,537 Total minimum lease payments 10,137 Less amounts representing interest 2,150 Present value of minimum payments 7,987 Current portion 1,122 Long-term portion $ 6,865

Subsequent Event

Subsequent Event	3 Months Ended
	Jul. 31, 2023
Subsequent Events [Abstract]
Subsequent Event	8. Subsequent Event In August 2023, the Company signed a new lease for office space in Zug, Switzerland. The one -year lease, commencing in September 2023, requires monthly payments of approximately $ 10,000 .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Jul. 31, 2023
Accounting Policies [Abstract]
Principles of Consolidation	Principles of Consolidation: The accompanying unaudited interim condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. The accompanying unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) for interim financial information and in accordance with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. Such financial statements reflect all adjustments that are, in management’s opinion, necessary to present fairly, in all material respects, the Company’s consolidated financial position, results of operations, and cash flows. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the annual financial statements. There were no adjustments other than normal recurring adjustments. These unaudited interim condensed consolidated financial results are not necessarily indicative of the results to be expected for the year ending April 30, 2024, or for any other future annual or interim period. The accompanying unaudited interim condensed consolidated financial statements should be read in conjunction with the audited financial statements as of and for the year ended April 30, 2023 in the Company’s Annual Report on Form 10-K filed with the Securities and Exchange Commission (“SEC”) on July 10, 2023.
Segment Reporting	Segment Reporting: The chief operating decision maker, the CEO, manages the Company’s operations as a single operating segment for the purposes of assessing performance and making operating decisions.
Recent Accounting Pronouncements	Recent Accounting Pronouncements: In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , which amends the impairment model by requiring entities to use a forward-looking approach on expected losses to estimate credit losses on certain financial instruments, including trade receivables and available-for-sale debt securities. This guidance became effective on May 1, 2023 and did not have a material impact to the consolidated financial statements. As the Company has never recorded any other-than-temporary-impairment adjustments to its available-for-sale debt securities prior to the effective date, no transition provisions were applicable to the Company.
Net Loss per Share	Net Loss per Share: Basic net loss per share is computed by dividing the net loss by the weighted average number of common shares outstanding during the period. Diluted net loss per share is computed by dividing net loss by the sum of the weighted average number of common shares and the number of potential dilutive common share equivalents outstanding during the period. Potential dilutive common share equivalents consist of the incremental common shares issuable upon the exercise of share options and awards. Potential dilutive common share equivalents consist of: July 31, 2023 2022 Stock options and awards 5,909,619 4,697,733 In computing diluted earnings per share, common share equivalents are not considered in periods in which a net loss is reported, as the inclusion of the common share equivalents would be anti-dilutive. As a result, there is no difference between the Company’s basic and diluted loss per share for the periods presented. The weighted average number of common shares used in the basic and diluted net loss per common share calculations includes the weighted-average pre-funded warrants outstanding during the period as they are exercisable at any time for nominal cash consideration.
Fair Value Measurement	Fair Value Measurement: The Company classifies fair value measurements using a three-level hierarchy that prioritizes the inputs used to measure fair value. This hierarchy requires entities to maximize the use of observable inputs and minimize the use of unobservable inputs. The three levels of inputs used to measure fair value are as follows: Level 1, quoted market prices in active markets for identical assets or liabilities; Level 2, observable inputs other than quoted market prices included in Level 1, such as quoted market prices for markets that are not active or other inputs that are observable or can be corroborated by observable market data; and Level 3, unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities, including certain pricing models, discounted cash flow methodologies and similar techniques that use significant unobservable inputs. These fair values are obtained from independent pricing services which utilize Level 1 and Level 2 inputs. The following tables summarize the cash equivalents and marketable securities measured at fair value on a recurring basis as of July 31, 2023 and April 30, 2023 (in thousands): Balance at Level 1 Level 2 Level 3 July 31, 2023 Cash equivalents $ 34,212 $ — $ — $ 34,212 Marketable securities: Corporate debt securities — 58,513 — 58,513 U.S. government agency securities — 15,335 — 15,335 $ 34,212 $ 73,848 $ — $ 108,060 Balance at Level 1 Level 2 Level 3 April 30, 2023 Cash equivalents $ 31,507 $ — $ — $ 31,507 Marketable securities: Corporate debt securities — 77,967 — 77,967 U.S. government agency securities — 15,170 — 15,170 $ 31,507 $ 93,137 $ — $ 124,644

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Jul. 31, 2023
Accounting Policies [Abstract]
Schedule of Potential Dilutive Common Share Equivalents	Potential dilutive common share equivalents consist of: July 31, 2023 2022 Stock options and awards 5,909,619 4,697,733
Schedule of Cash Equivalents and Marketable Securities Measured at Fair Value	The following tables summarize the cash equivalents and marketable securities measured at fair value on a recurring basis as of July 31, 2023 and April 30, 2023 (in thousands): Balance at Level 1 Level 2 Level 3 July 31, 2023 Cash equivalents $ 34,212 $ — $ — $ 34,212 Marketable securities: Corporate debt securities — 58,513 — 58,513 U.S. government agency securities — 15,335 — 15,335 $ 34,212 $ 73,848 $ — $ 108,060 Balance at Level 1 Level 2 Level 3 April 30, 2023 Cash equivalents $ 31,507 $ — $ — $ 31,507 Marketable securities: Corporate debt securities — 77,967 — 77,967 U.S. government agency securities — 15,170 — 15,170 $ 31,507 $ 93,137 $ — $ 124,644

Marketable Securities (Tables)

Marketable Securities (Tables)	3 Months Ended
	Jul. 31, 2023
Investments, Debt and Equity Securities [Abstract]
Summary of Fair Values of Company's Investments By Type	The following tables summarize the fair values of the Company’s investments by type as of July 31, 2023 and April 30, 2023 (in thousands): July 31, 2023 Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value Corporate debt securities $ 58,307 $ 303 $ ( 97 ) $ 58,513 Obligations of the U.S. Government and its agencies 15,094 241 — 15,335 Total $ 73,401 $ 544 $ ( 97 ) $ 73,848 April 30, 2023 Amortized Unrealized Unrealized Estimated Cost Gains Losses Fair Value Corporate debt securities $ 77,768 $ 367 $ ( 168 ) $ 77,967 Obligations of the U.S. Government and its agencies 15,094 76 15,170 Total $ 92,862 $ 443 $ ( 168 ) $ 93,137
Summary of Scheduled Maturity for Marketable Securities	The following table summarizes the scheduled maturity for the Company’s marketable securities at July 31, 2023 (in thousands): July 31, 2023 Maturing in one year or less $ 50,347 Maturing after one year through two years 12,188 Maturing after two years through four years 11,313 Total $ 73,848

Accrued Expenses (Tables)

Accrued Expenses (Tables)	3 Months Ended
	Jul. 31, 2023
Payables and Accruals [Abstract]
Schedule of Accrued Expenses	Accrued expenses consisted of the following as of July 31, 2023 and April 30, 2023 (in thousands): July 31, April 30, 2023 2023 Accrued compensation $ 2,501 $ 4,207 Accrued research expense 3,925 3,817 Accured professional fees 1,376 906 Other accrued expenses 148 198 $ 7,950 $ 9,128

Prepaid Expenses and Other Cu_2

Prepaid Expenses and Other Current Assets (Tables)	3 Months Ended
	Jul. 31, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Current Assets	Prepaid expenses and other current assets consisted of the following as of July 31, 2023 and April 30, 2023 (in thousands): July 31, April 30, 2023 2023 Prepaid clinical expenses $ 3,175 $ 1,724 Other prepaid expenses 2,840 2,583 Interest and other receivables 469 654 VAT receivable 1,044 1,422 Total prepaid expenses and other current assets $ 7,528 $ 6,383

Leases (Tables)

Leases (Tables)	3 Months Ended
	Jul. 31, 2023
Leases [Abstract]
Summary of Maturity of Undiscounted Payments and Future Minimum Payments Due Under Lease Liabilities and Present Value of Liabilities	The following table summarizes the maturity of undiscounted payments due under lease liabilities and the present value of those liabilities as of July 31, 2023 (in thousands): Years ending April 30, Operating 2024 $ 1,308 2025 1,777 2026 1,814 2027 1,853 2028 1,848 Thereafter 1,537 Total minimum lease payments 10,137 Less amounts representing interest 2,150 Present value of minimum payments 7,987 Current portion 1,122 Long-term portion $ 6,865

The Company - Additional Inform

The Company - Additional Information (Detail) $ in Thousands	Jul. 07, 2023 Patient	Jul. 31, 2023 USD ($)	Apr. 30, 2023 USD ($)
Number of patients reached in targeted enrollment | Patient	114
Accumulated deficit		$ 368,399	$ 343,082
Cash, cash equivalents and marketable securities		$ 123,300

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Schedule of Potential Dilutive Common Share Equivalents (Detail) - shares	3 Months Ended
	Jul. 31, 2023	Jul. 31, 2022
Stock Options and Awards [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Number of anti-dilutive potential common share equivalents outstanding	5,909,619	4,697,733

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Cash Equivalents and Marketable Securities Measured at Fair Value (Detail) - USD ($) $ in Thousands	Jul. 31, 2023	Apr. 30, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 34,212	$ 31,507
Marketable securities	73,848	93,137
Cash equivalents and marketable securities	108,060	124,644
Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	34,212	31,507
Cash equivalents and marketable securities	34,212	31,507
Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents and marketable securities	73,848	93,137
Corporate Debt Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	58,513	77,967
Corporate Debt Securities [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	58,513	77,967
U.S. Government Agency Securities [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	15,335	15,170
U.S. Government Agency Securities [Member] | Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Marketable securities	$ 15,335	$ 15,170

Marketable Securities - Summary

Marketable Securities - Summary of Fair Values of Company's Investments By Type (Detail) - USD ($) $ in Thousands	Jul. 31, 2023	Apr. 30, 2023
Marketable Securities [Line Items]
Amortized Cost	$ 73,401	$ 92,862
Unrealized Gains	544	443
Unrealized Losses	(97)	(168)
Estimated Fair Value	73,848	93,137
Corporate Debt Securities [Member]
Marketable Securities [Line Items]
Amortized Cost	58,307	77,768
Unrealized Gains	303	367
Unrealized Losses	(97)	(168)
Estimated Fair Value	58,513	77,967
Obligations of U.S. Government and Its Agencies [Member]
Marketable Securities [Line Items]
Amortized Cost	15,094	15,094
Unrealized Gains	241	76
Estimated Fair Value	$ 15,335	$ 15,170

Marketable Securities - Summa_2

Marketable Securities - Summary of Scheduled Maturity for Marketable Securities (Detail) - USD ($) $ in Thousands	Jul. 31, 2023	Apr. 30, 2023
Investments, Debt and Equity Securities [Abstract]
Maturing in one year or less	$ 50,347
Maturing after one year through two years	12,188
Maturing after two years through four years	11,313
Total	$ 73,848	$ 93,137

Accrued Expenses - Schedule of

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Jul. 31, 2023	Apr. 30, 2023
Payables and Accruals [Abstract]
Accrued compensation	$ 2,501	$ 4,207
Accrued research expense	3,925	3,817
Accured professional fees	1,376	906
Other accrued expenses	148	198
Total accrued expenses	$ 7,950	$ 9,128

Prepaid Expenses and Other Cu_3

Prepaid Expenses and Other Current Assets - Schedule of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Jul. 31, 2023	Apr. 30, 2023
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Prepaid clinical expenses	$ 3,175	$ 1,724
Other prepaid expenses	2,840	2,583
Interest and other receivables	469	654
VAT receivable	1,044	1,422
Total prepaid expenses and other current assets	$ 7,528	$ 6,383

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail)	3 Months Ended
	Jul. 31, 2023 USD ($)
Other Commitments [Line Items]
Contractual obligations remaining commitments including cancellation provisions	$ 26,200,000
Amounts associated with indemnifications	0
Indemnification Guarantee [Member]
Other Commitments [Line Items]
Contingent liabilities	$ 0

Leases - Additional Information

Leases - Additional Information (Detail) $ in Millions	3 Months Ended
	Jul. 31, 2023 USD ($) ft²	Jul. 31, 2022 USD ($)
General and Administrative Expenses and Research and Development Expenses [Member]
Lessee Lease Description [Line Items]
Rent expense | $	$ 0.5	$ 0.5
Massachusetts [Member]
Lessee Lease Description [Line Items]
Lease agreement square feet	8,300
Massachusetts [Member] | Research Laboratory [Member]
Lessee Lease Description [Line Items]
Lease agreement square feet	500
United Kingdom [Member]
Lessee Lease Description [Line Items]
Lease agreement square feet	13,400
Utah [Member]
Lessee Lease Description [Line Items]
Lease agreement square feet	6,200

Leases - Summary of Maturity of

Leases - Summary of Maturity of Undiscounted Payments Due Under Lease Liabilities and Present Value of Liabilities (Detail) - USD ($) $ in Thousands	Jul. 31, 2023	Apr. 30, 2023
Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]
2024	$ 1,308
2025	1,777
2026	1,814
2027	1,853
2028	1,848
Thereafter	1,537
Total minimum lease payments	10,137
Less amounts representing interest	2,150
Present value of minimum payments	7,987
Current portion	1,122	$ 1,087
Long-term portion	$ 6,865	$ 7,145

Subsequent Event - Additional I

Subsequent Event - Additional Information (Detail) - Subsequent Event [Member]	1 Months Ended
	Aug. 31, 2023 USD ($)
Subsequent Event [Line Items]
Lease term	1 year
Monthly lease payments	$ 10,000