Tarsus Pharmaceuticals (TARS) 10-Q 24 Nov 20 2020 Q3 Quarterly report Financial data

Cover

Cover - shares	9 Months Ended
	Sep. 30, 2020	Nov. 23, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-39614
Entity Registrant Name	TARSUS PHARMACEUTICALS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-4717861
Entity Address, Address Line One	15440 Laguna Canyon Road, Suite 160
Entity Address, City or Town	Irvine
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92618
City Area Code	(949)
Local Phone Number	409-9820
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Trading Symbol	TARS
Security Exchange Name	NASDAQ
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Smaller Reporting Company	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		20,320,426
Amendment Flag	false
Entity Central Index Key	0001819790
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3

Condensed Balance Sheets

Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 86,329	$ 57,952
Restricted cash	20	20
Other receivables	1	36
Prepaid expenses and other current assets	2,722	22
Total current assets	89,072	58,030
Property and equipment, net of accumulated depreciation	604	154
Operating lease right-of-use asset	759	126
Other assets	1,750	6
Total assets	92,185	58,316
Current liabilities:
Accounts payable and other accrued liabilities	5,624	520
Accrued payroll and benefits	520	299
Total current liabilities	6,144	819
Other long-term liabilities	711	100
Total liabilities	6,855	919
Commitments and contingencies (Note 9)
Preferred stock	103,159	63,402
Stockholders’ (deficit) equity:
Common stock, $0.0001 par value; 17,502,288 shares authorized; 3,067,363 shares issued and 2,887,988 outstanding, which excludes 179,375 shares subject to repurchase at September 30, 2020 (unaudited); 2,650,919 shares issued and 2,646,619 outstanding, which excludes 4,300 shares subject to repurchase at December 31, 2019	2	2
Additional paid-in capital	3,548	27
Accumulated deficit	(21,379)	(6,034)
Total stockholders’ deficit	(17,829)	(6,005)
Total liabilities, preferred stock and stockholders’ deficit	92,185	58,316
Series A Preferred Stock, $0.0001 par value; 1,575,030 shares authorized, issued and outstanding at September 30, 2020 (unaudited) and December 31, 2019; liquidation preference of $3,650 at September 30, 2020 (unaudited) and December 31, 2019
Current liabilities:
Preferred stock	3,564	3,564
Series B Preferred Stock, $0.0001 par value; 6,731,649 shares authorized and 6,674,909 shares issued and outstanding at September 30, 2020 (unaudited) and December 31, 2019; liquidation preference of $60,010 at September 30, 2020 (unaudited) and December 31, 2019
Current liabilities:
Preferred stock	59,838	59,838
Series C Preferred Stock, $0.0001 par value; 2,857,084 shares authorized and 2,857,079 shares issued and outstanding at September 30, 2020 (unaudited) and zero shares authorized, issued or outstanding at December 31, 2019; liquidation preference of $40,000 at September 30, 2020 (unaudited) and $0 at December 31, 2019
Current liabilities:
Preferred stock	$ 39,757	$ 0

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Preferred stock, authorized (shares)	11,163,763	8,306,679
Preferred stock, outstanding (shares)	11,107,018	8,249,939
Preferred stock, liquidation preference	$ 103,660	$ 63,660
Common stock, par value (usd per share)	$ 0.0001	$ 0.0001
Common stock, authorized (shares)	17,502,288	17,502,288
Common stock, issued (shares)	3,067,363	2,650,919
Common stock, outstanding (shares)	2,887,988	2,646,619
Common stock, subject to repurchase (shares)	179,375	4,300
Series A Preferred Stock
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (shares)	1,575,030	1,575,030
Preferred stock, issued (shares)	1,575,030	1,575,030
Preferred stock, outstanding (shares)	1,575,030	1,575,030
Preferred stock, liquidation preference	$ 3,650	$ 3,650
Series B Preferred Stock
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (shares)	6,731,649	6,731,649
Preferred stock, issued (shares)	6,674,909	6,674,909
Preferred stock, outstanding (shares)	6,674,909	6,674,909
Preferred stock, liquidation preference	$ 60,010	$ 60,010
Series C Preferred Stock
Preferred stock, par value (usd per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (shares)	2,857,084	0
Preferred stock, issued (shares)	2,857,079	0
Preferred stock, outstanding (shares)	2,857,079	0
Preferred stock, liquidation preference	$ 40,000	$ 0

Condensed Statements of Operati

Condensed Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Operating expenses:
Research and development	$ 7,991	$ 399	$ 11,239	$ 2,465
General and administrative	2,150	234	4,282	749
Total operating expenses	10,141	633	15,521	3,214
Loss from operations before other income (expense) and income taxes	(10,141)	(633)	(15,521)	(3,214)
Other income (expense):
Interest income (expense), net	4	(21)	178	(16)
Change in fair value of derivative liabilities	0	(27)	0	(27)
Total other income (expense)	4	(48)	178	(43)
Provision for income taxes	(1)	0	(1)	(1)
Net loss	(10,138)	(681)	(15,344)	(3,258)
Comprehensive loss	$ (10,138)	$ (681)	$ (15,344)	$ (3,258)
Net loss attributable to common stockholders, basic and diluted (usd per share)	$ (3.71)	$ (0.28)	$ (5.73)	$ (1.41)
Weighted-average common shares outstanding, basic and diluted (shares)	2,729,685	2,471,237	2,677,315	2,311,788

Condensed Statements of Preferr

Condensed Statements of Preferred Stock and Stockholders' Deficit - USD ($) $ in Thousands	Total	Series C Preferred Stock	Common Stock	Additional Paid-In Capital	Accumulated Deficit
Beginning balance (shares) at Dec. 31, 2018	1,575,030
Beginning balance at Dec. 31, 2018	$ 3,564
Ending balance (shares) at Mar. 31, 2019	1,575,030
Ending balance at Mar. 31, 2019	$ 3,564
Beginning balance (shares) at Dec. 31, 2018			2,078,918
Beginning balance at Dec. 31, 2018	(1,354)		$ 1	$ 9	$ (1,364)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(1,745)				(1,745)
Recognition of stock-based compensation expense	4			4
Vesting of founder shares subject to repurchase (shares)			134,632
Lapse of repurchase rights related to common stock issued pursuant to early exercises (shares)			25,243
Ending balance (shares) at Mar. 31, 2019			2,238,793
Ending balance at Mar. 31, 2019	$ (3,095)		$ 1	13	(3,109)
Beginning balance (shares) at Dec. 31, 2018	1,575,030
Beginning balance at Dec. 31, 2018	$ 3,564
Ending balance (shares) at Sep. 30, 2019	1,575,030
Ending balance at Sep. 30, 2019	$ 3,564
Beginning balance (shares) at Dec. 31, 2018			2,078,918
Beginning balance at Dec. 31, 2018	(1,354)		$ 1	9	(1,364)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(3,258)
Ending balance (shares) at Sep. 30, 2019			2,545,079
Ending balance at Sep. 30, 2019	$ (4,596)		$ 2	23	(4,621)
Beginning balance (shares) at Mar. 31, 2019	1,575,030
Beginning balance at Mar. 31, 2019	$ 3,564
Ending balance (shares) at Jun. 30, 2019	1,575,030
Ending balance at Jun. 30, 2019	$ 3,564
Beginning balance (shares) at Mar. 31, 2019			2,238,793
Beginning balance at Mar. 31, 2019	(3,095)		$ 1	13	(3,109)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(831)				(831)
Recognition of stock-based compensation expense	5			5
Vesting of founder shares subject to repurchase (shares)			134,632
Vesting of founder shares subject to repurchase			$ 1
Lapse of repurchase rights related to common stock issued pursuant to early exercises (shares)			25,243
Ending balance (shares) at Jun. 30, 2019			2,398,668
Ending balance at Jun. 30, 2019	$ (3,920)		$ 2	18	(3,940)
Ending balance (shares) at Sep. 30, 2019	1,575,030
Ending balance at Sep. 30, 2019	$ 3,564
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(681)				(681)
Recognition of stock-based compensation expense	5			5
Vesting of founder shares subject to repurchase (shares)			134,632
Lapse of repurchase rights related to common stock issued pursuant to early exercises (shares)			11,779
Ending balance (shares) at Sep. 30, 2019			2,545,079
Ending balance at Sep. 30, 2019	$ (4,596)		$ 2	23	(4,621)
Beginning balance (shares) at Dec. 31, 2019	8,249,939	0
Beginning balance at Dec. 31, 2019	$ 63,402	$ 0
Ending balance (shares) at Mar. 31, 2020	8,249,939
Ending balance at Mar. 31, 2020	$ 63,402
Beginning balance (shares) at Dec. 31, 2019	2,646,619		2,646,619
Beginning balance at Dec. 31, 2019	$ (6,005)		$ 2	27	(6,034)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(1,957)				(1,957)
Recognition of stock-based compensation expense	4			4
Lapse of repurchase rights related to common stock issued pursuant to early exercises (shares)			4,300
Ending balance (shares) at Mar. 31, 2020			2,650,919
Ending balance at Mar. 31, 2020	$ (7,958)		$ 2	31	(7,991)
Beginning balance (shares) at Dec. 31, 2019	8,249,939	0
Beginning balance at Dec. 31, 2019	$ 63,402	$ 0
Ending balance (shares) at Sep. 30, 2020	11,107,018	2,857,079
Ending balance at Sep. 30, 2020	$ 103,159	$ 39,757
Beginning balance (shares) at Dec. 31, 2019	2,646,619		2,646,619
Beginning balance at Dec. 31, 2019	$ (6,005)		$ 2	27	(6,034)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (15,344)
Ending balance (shares) at Sep. 30, 2020	2,887,988		2,887,988
Ending balance at Sep. 30, 2020	$ (17,829)		$ 2	3,548	(21,379)
Beginning balance (shares) at Mar. 31, 2020	8,249,939
Beginning balance at Mar. 31, 2020	$ 63,402
Ending balance (shares) at Jun. 30, 2020	8,249,939
Ending balance at Jun. 30, 2020	$ 63,402
Beginning balance (shares) at Mar. 31, 2020			2,650,919
Beginning balance at Mar. 31, 2020	(7,958)		$ 2	31	(7,991)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(3,250)				(3,250)
Recognition of stock-based compensation expense	173			173
Exercise of vested stock options (shares)			1,077
Ending balance (shares) at Jun. 30, 2020			2,651,996
Ending balance at Jun. 30, 2020	$ (11,035)		$ 2	204	(11,241)
Increase (Decrease) in Temporary Equity [Roll Forward]
Issuance of Series C Preferred Stock (shares)		2,857,079
Issuance of Series C Preferred Stock in September 2020 at $14.0003 per share, net of issuance costs of $243		$ 39,757
Ending balance (shares) at Sep. 30, 2020	11,107,018	2,857,079
Ending balance at Sep. 30, 2020	$ 103,159	$ 39,757
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(10,138)				(10,138)
Recognition of stock-based compensation expense	223			223
Exercise of vested stock options (shares)			13,532
Exercise of vested stock options	6			6
Shares issued as consideration for in-license rights (Note 9 (b)) (shares)			222,460
Shares issued as consideration for in-license rights (Note 9 (b))	$ 3,115			3,115
Ending balance (shares) at Sep. 30, 2020	2,887,988		2,887,988
Ending balance at Sep. 30, 2020	$ (17,829)		$ 2	$ 3,548	$ (21,379)

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash Flows From Operating Activities:
Net loss	$ (15,344)	$ (3,258)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	56	18
Stock-based compensation (Note 5)	401	13
Amortization of operating lease right-of-use asset (Note 9(a))	94	26
Change in fair value of derivative liabilities (Note 8)	0	27
Non-cash related party interest expense	0	27
Issuance of common stock pursuant to in-license agreement (Note 9(b))	3,115	0
Changes in operating assets and liabilities:
Other receivables	34	4
Prepaid expenses and other current assets	(2,700)	(1)
Other non-current assets	(27)	(6)
Accounts payable and other accrued liabilities	3,025	256
Accrued payroll and benefits	221	27
Net cash used in operating activities	(11,125)	(2,867)
Cash Flows From Investing Activities:
Purchases of property and equipment	(506)	(151)
Cash used in investing activities	(506)	(151)
Cash Flows From Financing Activities:
Proceeds from issuance of convertible notes, net of issuance costs (Note 8)	0	1,000
Proceeds from exercise of vested stock options	6	0
Proceeds from early exercise of stock options	360	0
Net cash provided by financing activities	40,008	1,000
Net increase (decrease) in cash, cash equivalents and restricted cash	28,377	(2,018)
Cash, cash equivalents, and restricted cash — beginning of year	57,972	2,375
Cash, cash equivalents, and restricted cash — end of period	86,349	357
Reconciliation of cash, cash equivalents and restricted cash
Cash, cash equivalents and restricted cash	86,349	357
Supplemental Disclosures Noncash Investing and Financing Activities:
Operating lease right-of-use asset obtained in exchange for operating lease liability	726	163
Additions of property and equipment in accounts payable and other accrued liabilities (Note 3(b))	0	23
Series C Preferred Stock issuance costs in accounts payable and other accrued liabilities	243	0
Convertible notes issuance costs included in accounts payable and accrued liabilities	0	6
Deferred offering costs included in accounts payable and accrued liabilities	1,388	0
IPO
Cash Flows From Financing Activities:
Payments of issuance costs	(330)	0
Series B Preferred Stock
Cash Flows From Financing Activities:
Payments of issuance costs	(28)	0
Series C Preferred Stock
Cash Flows From Financing Activities:
Proceeds from issuance of Series C Preferred Stock, net of issuance costs (Note 4)	$ 40,000	$ 0

Condensed Statements of Prefe_2

Condensed Statements of Preferred Stock and Stockholders' Deficit - Parenthetical - Series C Preferred Stock $ in Thousands	1 Months Ended
	Sep. 30, 2020USD ($)$ / shares
Price per share (usd per share) | $ / shares	$ 14.0003
Stock issued, issuance costs | $	$ 243

Description of Business and Pre

Description of Business and Presentation of Financial Statements	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Presentation of Financial Statements	DESCRIPTION OF BUSINESS AND PRESENTATION OF FINANCIAL STATEMENTS (a) Description of Business Tarsus Pharmaceuticals, Inc. (“Tarsus” or the “Company”) is a late clinical-stage biopharmaceutical company focused on the development and commercialization of novel therapeutic candidates to address large market opportunities initially in ophthalmic conditions where there are limited treatment alternatives. (b) Initial Public Offering and Reverse Stock Split On October 20, 2020, the Company completed its initial public offering ("IPO") through an underwritten sale of 5,500,000 sh ares of its common stock at a price of $16.00 per share. The aggregate net proceeds from the offering, inclusive of an additional 825,000 common shares sold upon the full exercise of the underwriters’ purchase option, after deducting underwriting discounts and commissions and other offering expenses, were approximately $91.7 million. Concurrent with the IPO, all then-outstanding shares of the Company's convertible preferred stock outstanding (see Note 4 ) were automatically converted into an aggregate of 11,107,018 issued common shares and were reclassified into permanent equity. Following the IPO, there were no shares of Preferred Stock outstanding . In advance of the IPO, on October 8, 2020, the Tarsus Board of Directors approved a 1-for-7.4276 reverse stock split of the Company’s capital stock. The Company filed a certificate of amendment to its restated certificate of incorporation to reflect this reverse split, though the common stock par value was not affected by the reverse split. All share and per share information included in the accompanying financial statements has been adjusted to reflect this reverse stock split. The condensed financial statements as of September 30, 2020, including share and per share amounts, do not give effect to the IPO, the conversion of the preferred stock into common stock and related reclassification into permanent equity, as the IPO and such conversions and reclassifications into permanent equity were completed subsequent to September 30, 2020. (c) Liquidity Risks The Company has no revenue, and since inception, has accumulated losses and negative cash flows from operations. This has resulted in the Company's accumulated deficit of $21.4 million as of September 30, 2020 and $6.0 million as of December 31, 2019. The Company’s cash and cash equivalents was $86.3 million and $58.0 million as of September 30, 2020 and December 31, 2019, respectively. The Company has financed its operations to date primarily through equity capital raises. The Company believes that existing capital resources, including the net proceeds from the IPO in October 2020, will be sufficient to meet projected operating requirements for at least 12 months from the date of issuance of the accompanying condensed financial statements, though expects to continue to incur operating losses and negative cash flows. The Company will be required to raise additional capital to fund future operations, however, no assurance can be given as to whether additional needed financing will be available on terms acceptable to the Company, if at all. If sufficient funds on acceptable terms are not available when needed, the Company may be required to curtail planned activities to preserve cash resources. These factors may adversely impact the Company’s ability to achieve its business objectives and would likely have an adverse effect on its future business prospects, or even its ability to remain a going concern. As such, the condensed financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business. The condensed financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. Management expects to continue to incur additional substantial losses in the foreseeable future as a result of the Company’s research and development activities. (d) Operating Segment

Summary of Significant Accounti

Summary of Significant Accounting Policies and Use of Estimates	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies and Use of Estimates	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND USE OF ESTIMATES (i) Basis of Presentation The Company’s condensed financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“GAAP”) for interim financial information and pursuant to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (“SEC”). Accordingly, the accompanying condensed financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. The interim condensed balance sheet as of September 30, 2020, and the interim condensed statements of operations and comprehensive loss, changes in preferred stock and stockholders’ deficit and cash flows for the three and nine months ended September 30, 2020 and 2019 are unaudited. These unaudited interim financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, which consist of only normal and recurring adjustments, necessary for the fair statement of the Company’s financial information. The financial data and other information disclosed in these notes related to the three and nine-month periods are also unaudited. The condensed balance sheet as of December 31, 2019 has been derived from the audited financial statements at that date but does not include all information and footnotes required by GAAP for complete financial statements. The condensed interim operating results for the three and nine months ended September 30, 2020 are not necessarily indicative of results to be expected for the year ending December 31, 2020, any other interim periods or any future year or period. The accompanying interim unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2019, which are included in the Company’s prospectus related to the IPO, filed with the SEC on September 25, 2020 (the “Prospectus”), pursuant to Rule 424(b)(4) promulgated under the Securities Act of 1933, as amended (the “Securities Act”). The preparation of financial statements in conformity with GAAP and with the rules and regulations of the Securities and Exchange Commission (“SEC”) requires management to make informed estimates and assumptions that affect the amounts reported in these financial statements and accompanying notes. These amounts may materially differ from the amounts ultimately realized and reported due to the inherent uncertainty of any estimate or assumption. On an on-going basis, management evaluates its most critical estimates and assumptions, including those related to the (i) fair value of stock-based awards and periodic recognition of stock-based compensation, (ii) the realization of income tax assets and estimates of tax liabilities, (iii) expense accruals related to research and development activities, including clinical trials, and (iv) valuation of convertible notes, derivative instruments, and preferred stock. Accounting policies and estimates that most significantly impact the presented amounts within the accompanying financial statements are further described below: (ii) Cash and Cash Equivalents Cash and cash equivalents consist of bank deposits and highly liquid investments, including money market fund accounts, with original maturities of three months or less from the purchase date. (iii) Restricted Cash Restricted cash represents cash held as collateral for the Company’s corporate credit card program. Any cash that is legally or contractually restricted from immediate use is classified as restricted cash. (iv) Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents in deposits at financial institutions that exceed federally insured limits. In March 2020, the World Health Organization declared a pandemic related to the global novel coronavirus disease 2019 (“COVID-19”) outbreak. To date, the Company’s operations have not been significantly impacted by the COVID-19 pandemic, though the Company has been carefully monitoring the potential impact COVID-19 may have on its ongoing and planned clinical trials. However, the Company cannot at this time predict the specific extent, duration, or full impact that the COVID-19 outbreak will have on these activities or its financial condition. The Company’s results of operations involve numerous risks and uncertainties. Factors that could adversely impact the Company’s operating results and business objectives include, but are not limited to, (1) uncertainty of results of clinical trials, (2) uncertainty of regulatory approval of the Company’s potential product candidates, including TP-03 for ophthalmic conditions, TP-04 for treatment of skin conditions and TP-05 for prophylaxis of Lyme and community malaria reduction, (3) uncertainty of market acceptance of its product candidates, (4) competition from substitute products and larger companies, (5) securing and protecting proprietary technology and strategic relationships, and (6) and dependence on key individuals and sole source suppliers. The Company’s product candidates require approvals from the U.S. Food and Drug Administration (“FDA”) and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive these necessary approvals. If the Company is denied approval, approval is delayed, or is unable to maintain approval for any product candidate, it could have a materially adverse impact on its business. (v) Research and Development Costs The Company's research and development costs are expensed as incurred or as certain milestone payments become contractually due to the Company's licensors, as triggered by the achievement of clinical or regulatory events. (vi) Deferred Offering Costs Costs directly related to the Company’s IPO were deferred for expense recognition. These deferred offering costs are temporarily capitalized and consist of legal fees, accounting fees, and other applicable professional services. As of September 30, 2020, $1.7 million of these deferred offering costs are reported on the accompanying condensed Balance Sheets within “other assets.” There were no deferred offering costs capitalized as of December 31, 2019. With the Company's IPO on October 20, 2020, these deferred offering costs were concurrently reclassified to additional paid in capital and will be reported as such as of December 31, 2020. (vii) Stock-Based Compensation Stock-based awards issued to employees, consultants, and members of the Company's Board of Directors are valued as of the grant date. Corresponding compensation expense is recognized over the applicable vesting period. For awards with a service condition for vesting, the related expense is recognized on a straight-line basis over each award’s actual or implied vesting period. For awards that are subject to a performance condition for vesting, the Company recognizes compensation cost if and when it concludes that it is probable that the performance condition will be achieved and the related expense is recognized on an accelerated attribution method. As applicable, the Company reverses previously recognized expense for forfeitures of unvested awards in the period of occurrence. The Company uses the Black-Scholes option pricing model to estimate the fair value of stock-based awards as of the date of grant. This requires management assumptions that involve inherent uncertainties and the application of judgment, including (a) the fair value of the Company’s common stock on the date of the option grant, (b) the expected term of the stock option until its exercise by the recipient, (c) expected stock price volatility over the expected term, (d) the prevailing risk-free interest rate over the expected term, and (e) expected dividend payments over the expected term. Management estimates the expected term of awarded stock options utilizing the “simplified method” as the Company does not yet have sufficient exercise history since its November 2016 formation. Further, through September 30, 2020 the Company remained privately-held and therefore lacked company-specific historical and implied volatility information of its stock. Accordingly, management estimates this expected volatility using that of its designated peer-group of publicly-traded companies for a look-back period, as of the date of grant, that corresponds with the expected term of the awarded stock option. The Company estimates the risk-free interest rate based upon the U.S. Department of the Treasury yield curve in effect at award grant for time periods that correspond with the expected term of the awarded stock option. The Company’s expected dividend yield is zero because it has never paid cash dividends and does not expect to for the foreseeable future. Prior to the IPO, given the absence of a public trading market, the Company’s Board of Directors, with input from management, considered numerous objective and subjective factors to determine the fair value of its common stock. The factors included: (1) third-party valuations of the Company’s common stock; (2) the Company’s stage of development; (3) the status of research and development efforts; (4) the rights, preferences and privileges of the Company’s preferred stock relative to common stock; (5) the Company’s operating results and financial condition, including the Company’s levels of available capital resources; (6) equity market conditions affecting comparable public companies; (7) general U.S. market conditions; and (8) the lack of current marketability of the Company’s common stock. (viii) Preferred Stock The Company classifies preferred stock outside of stockholders’ deficit on the accompanying condensed balance sheets. The requirements of a deemed liquidation event, as defined within its amended and restated certificate of incorporation filed in September 2020 (the “2020 Amended and Restated Certificate of Incorporation”) were not entirely within the Company’s control. In the event of such a deemed liquidation event, the proceeds from the event are distributed in accordance with the liquidation preferences, provided that the holders of preferred stock have not converted their shares into common stock. The Company recorded the issuance of preferred stock at the issuance price less related issuance costs. The Company has not adjusted the carrying value of outstanding preferred stock to its liquidation preference because a deemed liquidation event is not probable of occurring as of the end of the reporting period. (ix) Net Loss per Share Attributable to Common Stockholders Basic net loss per share attributable to common stockholders is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding for the period, without the consideration for potential dilutive shares of common stock. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method and if-converted method, as applicable. Basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities. The Company’s participating securities include preferred stock, unvested common stock to founders, and unvested common stock awards issued upon early exercise of certain stock options. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Shares of common stock subject to repurchase by the Company are excluded from the weighted-average shares. Due to net losses in all periods presented, all otherwise potentially dilutive securities are antidilutive. Accordingly, basic net loss per share equals diluted net loss per share for all period presented in the accompanying financial statements. (x) Fair Value Measurements Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: • Level 1: Quoted prices (unadjusted) in active markets for identical assets or liabilities that are publicly accessible at the measurement date. • Level 2: Observable prices that are based on inputs not quoted on active markets, but that are corroborated by market data. These inputs may include quoted prices for similar assets or liabilities or quoted market prices in markets that are not active to the general public. • 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. The carrying amounts for financial instruments consisting of cash and cash equivalents, accounts payable and accrued liabilities approximate fair value due to their short maturities. Derivative instruments are carried at fair value based on unobservable market inputs. (xi) Comprehensive Loss Comprehensive loss represents all changes in stockholders’ deficit, except those resulting from distributions to stockholders. For all periods presented, comprehensive loss was the same as reported net loss. (xii) Recently Issued or Effective Accounting Standards Recently issued or effective accounting pronouncements that impact, or may have an impact, on the Company’s financial statements have been discussed within the footnote to which each relates. Other recent accounting pronouncements not disclosed in these condensed financial statements have been determined by the Company’s management to have no impact, or an immaterial impact, on its current and expected future financial position, results of operations, or cash flows.

Balance Sheet Account Detail

Balance Sheet Account Detail	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Account Detail	BALANCE SHEET ACCOUNT DETAIL The composition of selected financial statement captions that comprise the accompanying balance sheets are summarized below: (a) Prepaid Expenses and Other Current Assets “Prepaid expenses and other current assets” consists of the following: September 30, 2020 December 31, 2019 Prepaid expenses $ 412 $ 22 Clinical research organization service assets 2,310 — Prepaid expenses and other current assets $ 2,722 $ 22 (b) Property and Equipment, net of Accumulated Depreciation “Property and equipment, net of accumulated depreciation” consists of the following: September 30, 2020 December 31, 2019 Furniture and fixtures $ 295 $ 5 Office equipment 74 26 Lab equipment 138 92 Leasehold improvements 110 69 Software licenses 80 — Property and equipment, at cost 697 192 (Less): Accumulated depreciation 93 38 Property and equipment, net of accumulated depreciation $ 604 $ 154 Depreciation expense (included within “total operating expenses” in the accompanying Statements of Operations and Comprehensive Loss) for the three and nine months ended September 30, 2020 and 2019 was $24 thousand, $9 thousand, $56 thousand, and $18 thousand, respectively. (c) Accounts Payable and Other Accrued Liabilities “Accounts payable and other accrued liabilities” consists of the following: September 30, 2020 December 31, 2019 Trade accounts payable $ 4,706 $ 456 Operating lease liability, current portion 190 64 Accrued clinical studies 8 — Employee stock option early exercise liability, current portion 273 — Other accrued liabilities 447 — Accounts payable and other accrued liabilities $ 5,624 $ 520 (d) Other Long-Term Liabilities “Other long-term liabilities” consists of the following: September 30, 2020 December 31, 2019 Operating lease liability, non-current portion $ 625 $ 100 Employee stock option early exercise liability, non-current portion 86 — Other long-term liabilities $ 711 $ 100

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Stockholders' Equity	STOCKHOLDERS’ EQUITY Authorized Stock Under the September 2020 Amended and Restated Certificate of Incorporation, the Company is authorized to issue two classes of stock: common and preferred . The total number of shares authorized for issuance is 17.5 million of common shares and 11.2 million of preferred shares, of which 1.6 million shares are designated as Series A Preferred Stock, 6.7 million shares are designated as Series B Preferred Stock, and 2.9 million are designated as Series C Preferred Stock. Preferred Stock Overview Series A Preferred Stock Issuance In March and May 2018, the Company executed a private placement Series A Stock Purchase Agreement and issued 1.6 million shares of Series A Preferred Stock at $2.3174 per share for net proceeds of $3.6 million, after issuance costs of $0.1 million. Series B Preferred Stock Issuance In December 2019, the Company executed a private placement Series B Stock Purchase Agreement of 6.7 million shares of Series B Preferred Stock at $8.9904 per share for net proceeds of $57.4 million, after issuance costs of $0.2 million. Concurrently, convertible notes issued in May, August, and October 2019 for aggregate proceeds of $2.0 million were converted into preferred stock based on principal and accrued interest, and the Company issued 0.3 million shares of Series B Preferred Stock at its contractual conversion price (see Note 8 ). Series C Preferred Stock Issuance In September 2020, the Company executed a private placement Series C Stock Purchase agreement of 2.9 million shares of Series C Preferred Stock at a purchase price of $14.0003 per share for net proceeds of $39.8 million, after issuance costs of $0.2 million. The tables below include preferred stock details as of September 30, 2020 and December 31, 2019. As of September 30, 2020 Authorized Outstanding Net Liquidation Original Series A Preferred Stock 1,575,030 1,575,030 $ 3,564 $ 3,650 $ 2.3174 Series B Preferred Stock 6,731,649 6,674,909 59,838 60,010 8.9904 Series C Preferred Stock 2,857,084 2,857,079 39,757 40,000 14.0003 Total 11,163,763 11,107,018 $ 103,159 $ 103,660 As of December 31, 2019 Authorized Outstanding Net Liquidation Original Series A Preferred Stock 1,575,030 1,575,030 $ 3,564 $ 3,650 $ 2.3174 Series B Preferred Stock 6,731,649 6,674,909 59,838 60,010 8.9904 Total 8,306,679 8,249,939 $ 63,402 $ 63,660 Upon the completion of the IPO, all outstanding shares of convertible preferred stock converted into an aggregate of 11,107,018 shares of the Company’s common stock. Significant Provisions of Series A, Series B, and Series C Preferred Stock Conversion Rights and Mandatory Conversion Each share of Series A, Series B, and Series C Preferred Stock was convertible into common shares determined by dividing the original issuance price by the conversion price and at the sole option of the holder on a one-to-one basis. The conversion price will be adjusted for stock splits, distributions, dividends, noncash distributions, share purchase rights, and capital reorganizations. In addition, subject to customary exceptions, the conversion price for each series of preferred stock will be reduced upon the issuance or sale of common shares or instruments convertible or exercisable into common shares, for consideration or with an exercise price that is less than the conversion price applicable to such series. Such reduction may result in recognition of a deemed dividend to preferred stockholders if the resulting conversion price is less than the fair value per share of common stock as of the date preferred stock was issued. Mandatory conversion into common shares will occur upon either (i) the closing of a Qualified Public Offering, which is defined in the September 2020 Amended and Restated Certificate of Incorporation to include the sale of common stock in a firm commitment underwritten public offering on Form S-1, with a pre-money valuation of at least $260 million and that results in at least $75 million of proceeds, or (ii) by vote or written consent or agreement of the holders of a majority of the then-outstanding shares of Series A, Series B, and Series C Preferred Stock, voting together as a single class on an as-converted basis. Liquidation Preference In the event of any Liquidation Event (as defined in the September 2020 Amended and Restated Certificate of Incorporation), the holders of Series A, Series B, and Series C Preferred Stock are first entitled to proceeds or assets available for distribution that are in preference of any distribution to common stockholders (the “Liquidation Preference”); provided, however, that if the holders of Series A, Series B, and Series C Preferred Stock would receive greater proceeds in a Liquidation Event as a result of their conversion to common stock such shares of Series A, Series B, and/or Series C Preferred Stock shall be deemed to have automatically thus converted. This Liquidation Preference is equal to the sum of (i) the original issue price of Series A, Series B and Series C Preferred Stock ($2.3174, $8.9904, and $14.0003 per share, respectively) for each outstanding share of Series A, Series B, and Series C Preferred Stock and (ii) any declared but unpaid dividends for each outstanding share of Series A, Series B, and Series C Preferred Stock. If the proceeds from the Liquidation Event are less than the Liquidation Preference, then all available proceeds will be distributed ratably to the holders of Series A, Series B, and Series C Preferred Stock in proportion to the preferential amount each is otherwise entitled to receive. After the distributions described above have been paid in full, the remaining assets of the Company will be distributed among the holders of common stock pro rata based on the number of shares held by each holder. Voting Rights The holder of each share of preferred stock has the right to one vote for each share of common stock into which such preferred stock could then be converted, and with respect to such vote, such holder has full voting rights and powers equal to the voting rights and powers of the holders of common stock. So long as the majority of the Series A Preferred Stock originally issued remains outstanding, its holders are additionally entitled to elect one director (“Series A Director”). So long as at least 1.3 million shares of Series B or Series C Preferred Stock remain outstanding, the holders of the majority of such shares of Series B and Series C Preferred Stock (voting together as a single class) shall be entitled to elect two directors (each a “Series B/C Director”). The holders of outstanding common stock are entitled to elect three directors. The holders of preferred stock and common stock (voting together as a single class and on an as-converted basis) are entitled to elect any of the Company’s remaining directors. Dividend Rights The holders of Preferred Stock are entitled to receive dividends, when, as and if declared by the Board of Directors at the applicable dividend rate set forth in the September 2020 Amended and Restated Certificate of Incorporation ($0.19, $0.72, and $1.12 pe r annum for each share of Series A, Series B, and Series C Preferred Stock, respectively), prior and in preference to any declaration or payment of any cash dividend on the common stock. The Company cannot declare, pay, or set aside any dividends on shares of any class or series of capital stock unless the Series A, Series B, and Series C Preferred Stockholders first receive a dividend in an amount equal to the greater of (i) applicable dividend rate, or (ii) the dividend payable to such other class or series of capital stock. No cash dividends have been declared to date. Redemption Rights The Series A, Series B, and Series C Preferred Stock are not redeemable at the option of its holder under the terms of the September 2020 Amended and Restated Certificate of Incorporation. Upon certain change in control events that are outside of the Company’s control, including its liquidation, sale or transfer of control, the preferred stock is contingently redeemable. Common Stock Overview and Reserve for Future Issuance Common stockholders have one vote for each share of common stock held and are entitled to receive any dividends declared by the Company’s Board of Directors when legally available for distribution, then-subject to the dividend rights of the holders of Series A and Series B preferred stock discussed above. For the nine months ended September 30, 2020 and for the year ended December 31, 2019, no dividends were declared. As of September 30, 2020 and December 31, 2019, the Company had 3.1 million and 2.7 million common shares issued, respectively. At September 30, 2020 and December 31, 2019, the Company had 2.9 million, an d 2.6 million common shares outstanding, respectively. The following shares of common stock were reserved for issuance: September 30, 2020 December 31, 2019 Preferred Stock outstanding 11,107,018 8,249,939 Stock options issued and outstanding under the 2016 Plan 1,842,627 297,142 Stock options available for future grant under the 2016 Plan 411,397 2,150,867 Total shares of common stock reserved 13,361,042 10,697,948

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	STOCK-BASED COMPENSATION 2016 Stock Plan Through September 30, 2020, the Company had one active stockholder-approved stock-based compensation plan (the “2016 Plan”) that was adopted in December 2016 (see Note 10(b) for discussion of the adoption of a new plan in October 2020). The 2016 Plan permits the grant of incentive stock options, nonqualified stock options, stock awards and certain other awards to its employees, members of its Board of Directors, and consultants. The stated maximum availability of common stock under the 2016 Plan is 2.7 million shares. As of September 30, 2020 and December 31, 2019, the Company had 0.4 million an d 2.2 million share s of common stock available for issuance under the 2016 Plan, respectively. Stock-Based Compensation Summary Stock-based compensation expense is recorded in the accompanying condensed statements of operations and comprehensive loss based on the assigned department of the award recipient. Stock-based compensation expense for the three and nine months ended September 30, 2020 and 2019 was as follows: Three months ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Research and development $ 102 $ 2 $ 118 $ 4 General and administrative 121 3 283 9 Total stock-based compensation $ 223 $ 5 $ 401 $ 13 Early Exercise Feature of Certain Stock Options The 2016 Plan permits certain option holders to exercise awarded options prior to vesting. Upon this early exercise, the options become subject to a restricted stock agreement and remain subject to the same vesting provisions in the corresponding stock option award. These unvested options are subject to repurchase by the Company upon termination — at the same price previously exercised. These unvested shares are reported as issued (but not outstanding) on our accompanying Balance Sheets while subject to repurchase by the Company. These shares are also excluded from the basic and diluted net loss per share calculation until the repurchase right lapses upon vesting. The Company initially records a liability for these early exercises that is subsequently reclassified into stockholders’ equity on a pro rata basis as vesting occurs. There were no such repurchases during the nine months ended September 30, 2020 or 2019. As of September 30, 2020, the Company has recorded $0.4 million as a liability from these early exercise proceeds in the accompanying condensed Balance Sheets, reported within "accounts payable and other accrued liabilities" and "other long-term liabilities" (see Note 3(c) and (d) ).

Net Loss Per Share

Net Loss Per Share	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Loss Per Share	NET LOSS PER SHARE The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders (in thousands, except share and per share data): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net loss $ (10,138) $ (681) $ (15,344) $ (3,258) Weighted-average shares—basic and diluted 2,729,685 2,471,237 2,677,315 2,311,788 Net loss per share attributable to common stockholders—basic and diluted $ (3.71) $ (0.28) $ (5.73) $ (1.41) The following outstanding potentially dilutive securities were excluded from the calculation of diluted net loss per share attributable to common stockholders because their impact under the “treasury stock method” and “if-converted method” would have been anti-dilutive for the periods presented: Three months ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Stock options, unexercised—vested and unvested 1,842,627 297,142 1,842,627 297,142 Series A, Series B, and Series C Preferred Stock, outstanding 8,467,325 1,575,030 8,322,930 1,575,030 Shares subject to repurchase from its founders — 89,755 — 89,755 Stock options early-exercised and unvested 179,375 43,007 179,375 43,007 Convertible promissory notes — 124,857 — 55,958 Total 10,489,327 2,129,791 10,344,932 2,060,892

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The table below summarizes certain financial instruments measured at fair value that are included within the accompanying balance sheets, and their designation among the three fair value measurement categories (see Note 2(xiii) ): September 30, 2020 Fair Value Measurements Level 1 Level 2 Level 3 Total Assets: Money market funds $ 86,329 $ — $ — $ 86,329 Total assets measured at fair value $ 86,329 $ — $ — $ 86,329 December 31, 2019 Fair Value Measurements Level 1 Level 2 Level 3 Total Assets: Money market funds $ 57,952 — — $ 57,952 Total assets measured at fair value $ 57,952 — — $ 57,952 Money Market Funds Money market fund holdings are included in cash and cash equivalents on the accompanying balance sheets and are classified within Level 1 of the fair value hierarchy because of its readily-available market prices in active markets that are publicly accessible at the measurement date. These money market funds are invested in U.S. Treasury, bills, notes, and other obligations issued or guaranteed as to principal and interest by the U.S. Government or its agencies. Convertible Promissory Notes – Derivative Liabilities The following table sets forth a summary of the changes in fair value of the bifurcated derivative liability associated with the convertible promissory notes issued and settled during 2019 to certain related parties (see Note 8 ). The measurement of the derivative liabilities represents a Level 3 financial instrument: Derivative Fair value as of December 31, 2018 $ — Initial fair value of derivative liability upon issuance of May 2019 Notes 28 Initial fair value of derivative liability upon issuance of August 2019 Notes 50 Initial fair value of derivative liability upon issuance of October 2019 Notes 209 Revaluation of derivative liabilities included in other income (expense), net within the Statement of Operations for the year ended December 31, 2019 76 Settlement of derivative liabilities through conversion of all Notes (363) Fair value as of December 31, 2019 $ — Fair value as of September 30, 2020 $ — The fair values of the derivative liabilities presented above were estimated at the date of issuance and at subsequent balance sheet dates using a two-step approach to valuation. Management utilized a probability-weighted valuation method and then compared the instrument’s value with-and-without the derivative features in order to estimate their combined fair value, using unobservable inputs, which are classified as Level 3 within the fair value hierarchy. The significant inputs not included in the market and thus represents a Level 3 measurement in the valuation approach included the probability of achieving a settlement that provides the note holders the rights or the obligations to receive cash or a variable number of shares upon the completion of a then-future capital transaction. The convertible notes were issued and settled in full during the year ended December 31, 2019 (see Note 8 ).

Convertible Promissory Notes Pa

Convertible Promissory Notes Payable	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Convertible Promissory Notes Payable	CONVERTIBLE PROMISSORY NOTES PAYABLE Overview of Notes and Conversion in December 2019 In May 2019, the Company entered into a Note Purchase Agreement (the “May 2019 Purchase Agreement”) with its co-founders and certain other related parties (the “Note Holders”). Under the terms of the May 2019 Purchase Agreement, the Company received cash proceeds of $0.5 million and issued $0.5 million of convertible promissory notes (the “May 2019 Notes”) with a stated maturity of December 2020. These notes bore interest at a rate of 8.0% per annum, compounded annually, and payable at maturity. In the event of a qualified equity financing, the outstanding principal of the May 2019 Notes plus all accrued and previously unpaid interest would, at the option of the holder, either (i) automatically convert into shares of stock issued in the qualified equity financing based on a conversion price equal to 90% of the issuance price paid by these new investors, or (ii) be repaid in full. In August 2019, the Company amended and restated the May 2019 Purchase Agreement with the Note Holders and received an additional $0.5 million of proceeds and issued new $0.5 million convertible promissory notes to the same parties (the “August 2019 Notes”) with identical terms. In October 2019, the Company entered into a new Note Purchase Agreement (the “October 2019 Purchase Agreement”) with the Note Holders. Under the terms of the October 2019 Purchase Agreement, the Company received proceeds of $1.0 million and issued $1.0 million of convertible promissory notes (the “October 2019 Notes,” collectively with the May 2019 Notes and the August 2019 Notes, the “Notes”) with a conversion price equal to 80% of the issuance price in a qualified equity financing. In December 2019, the Company completed an issuance of Series B Preferred Stock (see Note 5 ). Upon this issuance, the $2.0 million of Note principal value, along with accrued interest, were converted into 0.3 million shares of Series B Preferred Stock under its contractual terms. The Company recorded “loss on extinguishment of convertible notes” (non-cash) of $0.3 million within “other income (expense)” in the accompanying Statements of Operations and Comprehensive Loss for the year ended December 31, 2019. Embedded Derivative and its Accounting These notes contained stock-settled redemption features that were required to be separately accounted for as a derivative liability until December 13, 2019, when the Company completed a "qualified equity financing" and these then-outstanding notes converted, at the option of the holder, into 2.0 million shares of Series B Preferred Stock. The fair value adjustments for this derivative liability consists of changes in the fair value of these stock-settled redemption features. The Company accounted for this derivative feature as an implied discount in presenting the carrying value of these Notes. This discount was accreted over the term to maturity of the Notes using the effective interest method, resulting in aggregate interest expense recognition (non-cash) of $22 thousand and $27 thousand for the three and nine months ended September 30, 2019, respectively. As the Notes were converted in December 2019, no interest expense was recorded for the nine months ended September 30, 2020. Changes in the embedded derivatives’ fair value at each reporting period were recognized in the accompanying statements of operations and comprehensive loss within “changes in fair value of derivative liabilities,” resulting in incremental “other expense” recognition (non-cash) of $27 thousand during the three and nine months ended September 30, 2019. As the Notes were converted in December 2019, no expense related to changes in fair value of derivative liabilities was recorded for the nine months ended September 30, 2020.

Commitment & Contingencies

Commitment & Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitment & Contingencies	COMMITMENTS & CONTINGENCIES (a) Facility Leases Overview In the ordinary course of business, the Company enters lease agreements with unaffiliated parties for the use of office and laboratory facilities and office equipment. As of December 31, 2019, the Company had one active facility lease in Irvine, California, that commenced on March 1, 2019 and expires April 30, 2022. This lease has a renewal option at the end of term, for which the Company was not reasonably certain to exercise at the lease commencement. As such, the renewal option was not included in the lease term used to calculate the right-of-use lease asset and lease liability. Prior to March 1, 2019, the Company did not have any material lease arrangements. The Company entered into two additional facility leases that commenced on June 1, 2020 for adjacent administrative and laboratory suites in Irvine, California. These leases expire on January 31, 2024. One of these leases included a renewal option at the end of its term, for which the Company was not reasonably certain to exercise at the lease commencement. As such, the renewal option was not included in the lease term used to calculate the right-of-use lease asset and lease liability. In connection with these two leases the Company capitalized right-of-use assets along with an accompanying lease liability of $0.7 million. All of the Company’s facility leases have minimum annual rent, payable monthly, and carry fixed annual rent increases. Under the arrangements, real estate taxes, certain operating expenses, and common area maintenance are reimbursable to the lessor. These amounts are expensed as incurred, as they are variable in nature and therefore excluded from the measurement of the reported right-of-use asset and liability discussed below. During the years ended December 31, 2019 and during the nine months ended September 30, 2020, the Company had no sublease arrangements with it as lessor. Components of Lease Expense The liability associated with each lease is amortized over the respective lease term using the effective interest rate method. The Company’s right-of-use asset is amortized over the lease term on a straight-line basis to lease expense, as reported on an allocated basis within “research and development” and “general and administrative” expenses on the accompanying Statements of Operations and Comprehensive Loss. For the three months ended September 30, 2020 and 2019, the Company recognized lease expense of $0.1 million and $16 thousand, respectively. For the nine months ended September 30, 2020 and 2019, the Company recognized lease expense of $0.1 million, and $36 thousand, respectively. There were no significant variable lease payments, including including non-lease components such as common area maintenance fees, recognized as lease expense for the three and nine months ended September 30, 2020 and 2019. Weighted-Average Remaining Lease Term and Applied Discount Rate The Company had one active lease for its Irvine office and laboratory facility, with a remaining lease term of 2 years, 4 months as of December 31, 2019 and a remaining lease ter m of 1 year, 7 months as of September 30, 2020. The Company h ad two add itional facility leases commence on June 1, 2020, with remaining lease term s of 3 years, 4 months as of September 30, 2020. The estimated incremental borrowing rate of 10% is utilized to present value future minimum lease payments since an implicit interest rate is not readily determinable each lease. The weighted average remaining lease term for the Company’s leases as of September 30, 2020 is 3 years, 1 month. Future Contractual Lease Payments as of September 30, 2020 The below table summarizes the (i) minimum lease payments over the next five years and thereafter, (ii) lease arrangement imputed interest, and (iii) present value of future lease payments: Operating Leases - future payments September 30, 2020 2020 (remaining three months) $ 5 2021 349 2022 298 2023 281 2024 25 Total future lease payments, undiscounted $ 958 (Less): Imputed interest (143) Present value of operating lease payments $ 815 (b) In-License Agreement for Lotilaner Skin and Eye Disease or Conditions in Humans In January 2019, the Company entered into a license agreement with Elanco Tiergesundheit AG (“Elanco”), granting it a worldwide license to certain intellectual property for the development and commercialization of lotilaner for the treatment or cure of any eye or skin disease or condition in humans (the "January 2019 Agreement"). The Company has sole responsibility for related development, regulatory, and commercialization activities. The Company made a $1.0 million upfront payment at execution of the January 2019 Agreement, which is reported within “research and development” expense within the accompanying unaudited Statements of Operations and Comprehensive Loss for the nine months ended September 30, 2019. The Company also made a required $1.0 million clinical milestone payment in the September 2020 as part of an achieved Phase 2b/3 clinical trial milestone for the treatment of Demodex blepharitis; this amount is reported within “research and development” expense within the accompanying Statements of Operations and Comprehensive Loss for the three and nine months ended September 30, 2020. The Company will make further payments to Elanco under the January 2019 Agreement upon achievement of various clinical milestones for an aggregate maximum of $5.0 million and various commercial and sales threshold milestones for an aggregate maximum of $79.0 million. In addition, the Company will be obligated to pay contractual royalties to Elanco in the single digits of its net sales. If the Company receives payments from any sublicensees, it will be obligated to pay Elanco a variable percentage in the low to mid double-digits of such proceeds, except for territories in which the Company achieved applicable regulatory approval prior to sublicense execution. All Other Disease or Conditions in Humans In September 2020, the Company executed an expanded license agreement with Elanco, granting it a worldwide license to certain intellectual property for the development and commercialization of lotilaner treatment or cure of all other diseases and conditions in humans – beyond that of the eye or skin (the “September 2020 Agreement”). The Company issued Elanco 222,460 shares of its common stock at the execution of the September 2020 Agreement. The value of these shares was then-determined to equate to $3.1 million (at $14.0003 per share, approximating the Company's Series C preferred stock issuance price – see Note 4 ) and is reported within “research and development” expense within the accompanying Statements of Operations and Comprehensive Loss for the three and nine months ended September 30, 2020. In addition, upon the 18-month anniversary of contract execution, if not terminated by the Company prior to the anniversary, it is obligated to grant Elanco additional shares that aggregate to $3.0 million (valued as of the Company’s IPO price of $16.00 per share - see Note 10(a) ), amounting to a fixed 187,500 shares. The Company accounted for the transaction as an asset acquisition as substantially all of the fair value of the gross assets acquired were concentrated in a group of similar identifiable assets thus satisfying the requirements of the screen test in ASU 2017-01. The assets acquired in the transaction were measured based on the upfront payment to Elanco and the fair value of the common stock shares issued to Elanco, as the fair value of the consideration given was more readily determinable than the fair value of the assets received. Because the assets had not yet received regulatory approval and have no alternative future use, the fair value attributable to these assets were initially recorded as in process research and development expenses. The Company will make further payments to Elanco under the September 2020 Agreement upon achievement of various clinical milestones for an aggregate maximum of $4.5 million, and various commercial and sales threshold milestones for an aggregate maximum of $77.0 million. In addition, the Company will be obligated to pay contractual royalties to Elanco in the single digits of its net sales. If the Company receives payments from any sublicensees, it will be obligated to pay Elanco a variable percentage in the low to mid double-digits of such proceeds, except for territories in which the Company achieved applicable regulatory approval prior to sublicense execution. (c) Employment Agreements The Company has entered into employment agreements with four of its named executive officers. These agreements provide for the payment of certain benefits upon separation of employment under specified circumstances, such as termination without cause, or termination in connection with a change in control event. (d) Contingencies From time to time, the Company may be subject to various litigation and related matters arising in the ordinary course of business. The Company is currently not aware of any such matters where there is at least a reasonable probability that a material loss has been or will be incurred for financial statement recognition. (e) Indemnities and Guarantees The Company has certain indemnity commitments, under which it may be required to make payments to its officers and directors in relation to certain transactions to the maximum extent permitted under applicable laws. The duration of these indemnities varies, and in certain cases, is indefinite and does not provide for any limitation of maximum payments. The Company has not been obligated to make any such payments to date and no liabilities have been recorded for this contingency in the accompanying condensed balance sheets.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	SUBSEQUENT EVENTS (a) Completion of Initial Public Offering On October 20, 2020, the Company completed its IPO selling 5,500,000 shares of common stock at a price to the public o f $16.00 pe r share. An incremental 825,000 common shares were also sold upon the full exercise of the underwriters’ purchase option. The aggregate net proceeds f rom the offering, after deducting underwriting discounts and commissions and other related expenses, were approximately $91.7 million . In addition, upon closing the IPO, all outstanding shares of convertible preferred stock outstanding (see Note 4 ) converted into an aggregate of 11,107,018 shar es of the Company’s common stock. (b) 2020 Equity Incentive Plan Adoption The Company's Board of Directors and stockholders adopted and approved the Company's 2020 Equity Incentive Plan (“2020 Plan”) on October 8, 2020. The 2020 Plan replaces the 2016 Plan (see Note 5 ), however, awards outstanding under the 2016 Plan will continue to be governed by their existing terms. The number of shares of the Company's common stock available for issuance under the 2020 Plan will equal the sum of 9,000,000 shares plus up to 2,433,395 shares remaining available for issuance under the 2016 Plan, or issued pursuant to or subject to awards granted under the 2016 Plan. The 2020 Plan provides for the following types of awards: incentive and non-statutory stock options, stock appreciation rights, restricted shares, and restricted stock units.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies and Use of Estimates (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Operating Segment	Operating SegmentTo date, the Company has operated and managed its business and financial information on an aggregate basis for the purposes of evaluating financial performance and the allocation of resources. Accordingly, the Company’s management determined that it operates in one reportable operating segment that is focused exclusively on developing pharmaceutical products for eventual commercialization.
Basis of Presentation	Basis of Presentation The Company’s condensed financial statements have been prepared in conformity with accounting principles generally accepted in the United States (“GAAP”) for interim financial information and pursuant to Form 10-Q and Article 10 of Regulation S-X of the Securities and Exchange Commission (“SEC”). Accordingly, the accompanying condensed financial statements do not include all of the information and footnotes required by GAAP for complete financial statements. The interim condensed balance sheet as of September 30, 2020, and the interim condensed statements of operations and comprehensive loss, changes in preferred stock and stockholders’ deficit and cash flows for the three and nine months ended September 30, 2020 and 2019 are unaudited. These unaudited interim financial statements have been prepared on the same basis as the Company’s annual financial statements and, in the opinion of management, reflect all adjustments, which consist of only normal and recurring adjustments, necessary for the fair statement of the Company’s financial information. The financial data and other information disclosed in these notes related to the three and nine-month periods are also unaudited. The condensed balance sheet as of December 31, 2019 has been derived from the audited financial statements at that date but does not include all information and footnotes required by GAAP for complete financial statements. The condensed interim operating results for the three and nine months ended September 30, 2020 are not necessarily indicative of results to be expected for the year ending December 31, 2020, any other interim periods or any future year or period. The accompanying interim unaudited condensed financial statements should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2019, which are included in the Company’s prospectus related to the IPO, filed with the SEC on September 25, 2020 (the “Prospectus”), pursuant to Rule 424(b)(4) promulgated under the Securities Act of 1933, as amended (the “Securities Act”). The preparation of financial statements in conformity with GAAP and with the rules and regulations of the Securities and Exchange Commission (“SEC”) requires management to make informed estimates and assumptions that affect the amounts reported in these financial statements and accompanying notes. These amounts may materially differ from the amounts ultimately realized and reported due to the inherent uncertainty of any estimate or assumption. On an on-going basis, management evaluates its most critical estimates and assumptions, including those related to the (i) fair value of stock-based awards and periodic recognition of stock-based compensation, (ii) the realization of income tax assets and estimates of tax liabilities, (iii) expense accruals related to research and development activities, including clinical trials, and (iv) valuation of convertible notes, derivative instruments, and preferred stock.
Cash and Cash Equivalents	Cash and Cash EquivalentsCash and cash equivalents consist of bank deposits and highly liquid investments, including money market fund accounts, with original maturities of three months or less from the purchase date.
Restricted Cash	Restricted CashRestricted cash represents cash held as collateral for the Company’s corporate credit card program. Any cash that is legally or contractually restricted from immediate use is classified as restricted cash.
Concentration of Credit Risk and Other Risks and Uncertainties	Concentration of Credit Risk and Other Risks and Uncertainties Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents in deposits at financial institutions that exceed federally insured limits. In March 2020, the World Health Organization declared a pandemic related to the global novel coronavirus disease 2019 (“COVID-19”) outbreak. To date, the Company’s operations have not been significantly impacted by the COVID-19 pandemic, though the Company has been carefully monitoring the potential impact COVID-19 may have on its ongoing and planned clinical trials. However, the Company cannot at this time predict the specific extent, duration, or full impact that the COVID-19 outbreak will have on these activities or its financial condition. The Company’s results of operations involve numerous risks and uncertainties. Factors that could adversely impact the Company’s operating results and business objectives include, but are not limited to, (1) uncertainty of results of clinical trials, (2) uncertainty of regulatory approval of the Company’s potential product candidates, including TP-03 for ophthalmic conditions, TP-04 for treatment of skin conditions and TP-05 for prophylaxis of Lyme and community malaria reduction, (3) uncertainty of market acceptance of its product candidates, (4) competition from substitute products and larger companies, (5) securing and protecting proprietary technology and strategic relationships, and (6) and dependence on key individuals and sole source suppliers. The Company’s product candidates require approvals from the U.S. Food and Drug Administration (“FDA”) and comparable foreign regulatory agencies prior to commercial sales in their respective jurisdictions. There can be no assurance that any product candidates will receive these necessary approvals. If the Company is denied approval, approval is delayed, or is unable to maintain approval for any product candidate, it could have a materially adverse impact on its business.
Research and Development Costs	Research and Development CostsThe Company's research and development costs are expensed as incurred or as certain milestone payments become contractually due to the Company's licensors, as triggered by the achievement of clinical or regulatory events.
Deferred Offering Costs	Deferred Offering CostsCosts directly related to the Company’s IPO were deferred for expense recognition. These deferred offering costs are temporarily capitalized and consist of legal fees, accounting fees, and other applicable professional services. As of September 30, 2020, $1.7 million of these deferred offering costs are reported on the accompanying condensed Balance Sheets within “other assets.” There were no deferred offering costs capitalized as of December 31, 2019. With the Company's IPO on October 20, 2020, these deferred offering costs were concurrently reclassified to additional paid in capital and will be reported as such as of December 31, 2020.
Stock-Based Compensation	Stock-Based Compensation Stock-based awards issued to employees, consultants, and members of the Company's Board of Directors are valued as of the grant date. Corresponding compensation expense is recognized over the applicable vesting period. For awards with a service condition for vesting, the related expense is recognized on a straight-line basis over each award’s actual or implied vesting period. For awards that are subject to a performance condition for vesting, the Company recognizes compensation cost if and when it concludes that it is probable that the performance condition will be achieved and the related expense is recognized on an accelerated attribution method. As applicable, the Company reverses previously recognized expense for forfeitures of unvested awards in the period of occurrence. The Company uses the Black-Scholes option pricing model to estimate the fair value of stock-based awards as of the date of grant. This requires management assumptions that involve inherent uncertainties and the application of judgment, including (a) the fair value of the Company’s common stock on the date of the option grant, (b) the expected term of the stock option until its exercise by the recipient, (c) expected stock price volatility over the expected term, (d) the prevailing risk-free interest rate over the expected term, and (e) expected dividend payments over the expected term. Management estimates the expected term of awarded stock options utilizing the “simplified method” as the Company does not yet have sufficient exercise history since its November 2016 formation. Further, through September 30, 2020 the Company remained privately-held and therefore lacked company-specific historical and implied volatility information of its stock. Accordingly, management estimates this expected volatility using that of its designated peer-group of publicly-traded companies for a look-back period, as of the date of grant, that corresponds with the expected term of the awarded stock option. The Company estimates the risk-free interest rate based upon the U.S. Department of the Treasury yield curve in effect at award grant for time periods that correspond with the expected term of the awarded stock option. The Company’s expected dividend yield is zero because it has never paid cash dividends and does not expect to for the foreseeable future. Prior to the IPO, given the absence of a public trading market, the Company’s Board of Directors, with input from management, considered numerous objective and subjective factors to determine the fair value of its common stock. The factors included: (1) third-party valuations of the Company’s common stock; (2) the Company’s stage of development; (3) the status of research and development efforts; (4) the rights, preferences and privileges of the Company’s preferred stock relative to common stock; (5) the Company’s operating results and financial condition, including the Company’s levels of available capital resources; (6) equity market conditions affecting comparable public companies; (7) general U.S. market conditions; and (8) the lack of current marketability of the Company’s common stock.
Preferred Stock	Preferred StockThe Company classifies preferred stock outside of stockholders’ deficit on the accompanying condensed balance sheets. The requirements of a deemed liquidation event, as defined within its amended and restated certificate of incorporation filed in September 2020 (the “2020 Amended and Restated Certificate of Incorporation”) were not entirely within the Company’s control. In the event of such a deemed liquidation event, the proceeds from the event are distributed in accordance with the liquidation preferences, provided that the holders of preferred stock have not converted their shares into common stock. The Company recorded the issuance of preferred stock at the issuance price less related issuance costs. The Company has not adjusted the carrying value of outstanding preferred stock to its liquidation preference because a deemed liquidation event is not probable of occurring as of the end of the reporting period.
Net Loss per Share Attributable to Common Stockholders	Net Loss per Share Attributable to Common StockholdersBasic net loss per share attributable to common stockholders is calculated by dividing the net loss by the weighted-average number of shares of common stock outstanding for the period, without the consideration for potential dilutive shares of common stock. Diluted net loss per share is computed by dividing the net loss by the weighted-average number of common share equivalents outstanding for the period determined using the treasury-stock method and if-converted method, as applicable. Basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities. The Company’s participating securities include preferred stock, unvested common stock to founders, and unvested common stock awards issued upon early exercise of certain stock options. The Company’s participating securities do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Shares of common stock subject to repurchase by the Company are excluded from the weighted-average shares. Due to net losses in all periods presented, all otherwise potentially dilutive securities are antidilutive. Accordingly, basic net loss per share equals diluted net loss per share for all period presented in the accompanying financial statements.
Fair Value Measurements	Fair Value Measurements Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or an exit price that would be paid to transfer a liability in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The authoritative guidance on fair value measurements establishes a three-tier fair value hierarchy for disclosure of fair value measurements as follows: • Level 1: Quoted prices (unadjusted) in active markets for identical assets or liabilities that are publicly accessible at the measurement date. • Level 2: Observable prices that are based on inputs not quoted on active markets, but that are corroborated by market data. These inputs may include quoted prices for similar assets or liabilities or quoted market prices in markets that are not active to the general public. • 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. The carrying amounts for financial instruments consisting of cash and cash equivalents, accounts payable and accrued liabilities approximate fair value due to their short maturities. Derivative instruments are carried at fair value based on unobservable market inputs.
Comprehensive Loss	Comprehensive LossComprehensive loss represents all changes in stockholders’ deficit, except those resulting from distributions to stockholders. For all periods presented, comprehensive loss was the same as reported net loss.
Recently Issued or Effective Accounting Standards	Recently Issued or Effective Accounting StandardsRecently issued or effective accounting pronouncements that impact, or may have an impact, on the Company’s financial statements have been discussed within the footnote to which each relates. Other recent accounting pronouncements not disclosed in these condensed financial statements have been determined by the Company’s management to have no impact, or an immaterial impact, on its current and expected future financial position, results of operations, or cash flows.

Balance Sheet Account Detail (T

Balance Sheet Account Detail (Tables)	9 Months Ended
	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Prepaid expenses and other current assets	“Prepaid expenses and other current assets” consists of the following: September 30, 2020 December 31, 2019 Prepaid expenses $ 412 $ 22 Clinical research organization service assets 2,310 — Prepaid expenses and other current assets $ 2,722 $ 22
Property and equipment, net of accumulated depreciation	“Property and equipment, net of accumulated depreciation” consists of the following: September 30, 2020 December 31, 2019 Furniture and fixtures $ 295 $ 5 Office equipment 74 26 Lab equipment 138 92 Leasehold improvements 110 69 Software licenses 80 — Property and equipment, at cost 697 192 (Less): Accumulated depreciation 93 38 Property and equipment, net of accumulated depreciation $ 604 $ 154
Accounts payable and accrued liabilities	“Accounts payable and other accrued liabilities” consists of the following: September 30, 2020 December 31, 2019 Trade accounts payable $ 4,706 $ 456 Operating lease liability, current portion 190 64 Accrued clinical studies 8 — Employee stock option early exercise liability, current portion 273 — Other accrued liabilities 447 — Accounts payable and other accrued liabilities $ 5,624 $ 520
Other long-term liabilities	“Other long-term liabilities” consists of the following: September 30, 2020 December 31, 2019 Operating lease liability, non-current portion $ 625 $ 100 Employee stock option early exercise liability, non-current portion 86 — Other long-term liabilities $ 711 $ 100

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Stock details	The tables below include preferred stock details as of September 30, 2020 and December 31, 2019. As of September 30, 2020 Authorized Outstanding Net Liquidation Original Series A Preferred Stock 1,575,030 1,575,030 $ 3,564 $ 3,650 $ 2.3174 Series B Preferred Stock 6,731,649 6,674,909 59,838 60,010 8.9904 Series C Preferred Stock 2,857,084 2,857,079 39,757 40,000 14.0003 Total 11,163,763 11,107,018 $ 103,159 $ 103,660 As of December 31, 2019 Authorized Outstanding Net Liquidation Original Series A Preferred Stock 1,575,030 1,575,030 $ 3,564 $ 3,650 $ 2.3174 Series B Preferred Stock 6,731,649 6,674,909 59,838 60,010 8.9904 Total 8,306,679 8,249,939 $ 63,402 $ 63,660 September 30, 2020 December 31, 2019 Preferred Stock outstanding 11,107,018 8,249,939 Stock options issued and outstanding under the 2016 Plan 1,842,627 297,142 Stock options available for future grant under the 2016 Plan 411,397 2,150,867 Total shares of common stock reserved 13,361,042 10,697,948

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Stock-based compensation	Stock-based compensation expense for the three and nine months ended September 30, 2020 and 2019 was as follows: Three months ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Research and development $ 102 $ 2 $ 118 $ 4 General and administrative 121 3 283 9 Total stock-based compensation $ 223 $ 5 $ 401 $ 13

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net loss per share, basis and diluted	The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders (in thousands, except share and per share data): Three Months Ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Net loss $ (10,138) $ (681) $ (15,344) $ (3,258) Weighted-average shares—basic and diluted 2,729,685 2,471,237 2,677,315 2,311,788 Net loss per share attributable to common stockholders—basic and diluted $ (3.71) $ (0.28) $ (5.73) $ (1.41)
Outstanding potentially dilutive securities	The following outstanding potentially dilutive securities were excluded from the calculation of diluted net loss per share attributable to common stockholders because their impact under the “treasury stock method” and “if-converted method” would have been anti-dilutive for the periods presented: Three months ended September 30, Nine Months Ended September 30, 2020 2019 2020 2019 Stock options, unexercised—vested and unvested 1,842,627 297,142 1,842,627 297,142 Series A, Series B, and Series C Preferred Stock, outstanding 8,467,325 1,575,030 8,322,930 1,575,030 Shares subject to repurchase from its founders — 89,755 — 89,755 Stock options early-exercised and unvested 179,375 43,007 179,375 43,007 Convertible promissory notes — 124,857 — 55,958 Total 10,489,327 2,129,791 10,344,932 2,060,892

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Financial instruments measured at fair value	The table below summarizes certain financial instruments measured at fair value that are included within the accompanying balance sheets, and their designation among the three fair value measurement categories (see Note 2(xiii) ): September 30, 2020 Fair Value Measurements Level 1 Level 2 Level 3 Total Assets: Money market funds $ 86,329 $ — $ — $ 86,329 Total assets measured at fair value $ 86,329 $ — $ — $ 86,329 December 31, 2019 Fair Value Measurements Level 1 Level 2 Level 3 Total Assets: Money market funds $ 57,952 — — $ 57,952 Total assets measured at fair value $ 57,952 — — $ 57,952
Changes in fair value of derivative liability	The following table sets forth a summary of the changes in fair value of the bifurcated derivative liability associated with the convertible promissory notes issued and settled during 2019 to certain related parties (see Note 8 ). The measurement of the derivative liabilities represents a Level 3 financial instrument: Derivative Fair value as of December 31, 2018 $ — Initial fair value of derivative liability upon issuance of May 2019 Notes 28 Initial fair value of derivative liability upon issuance of August 2019 Notes 50 Initial fair value of derivative liability upon issuance of October 2019 Notes 209 Revaluation of derivative liabilities included in other income (expense), net within the Statement of Operations for the year ended December 31, 2019 76 Settlement of derivative liabilities through conversion of all Notes (363) Fair value as of December 31, 2019 $ — Fair value as of September 30, 2020 $ —

Commitment & Contingencies (Tab

Commitment & Contingencies (Tables)	9 Months Ended
	Sep. 30, 2020
Commitments and Contingencies Disclosure [Abstract]
Future contractual lease payments	The below table summarizes the (i) minimum lease payments over the next five years and thereafter, (ii) lease arrangement imputed interest, and (iii) present value of future lease payments: Operating Leases - future payments September 30, 2020 2020 (remaining three months) $ 5 2021 349 2022 298 2023 281 2024 25 Total future lease payments, undiscounted $ 958 (Less): Imputed interest (143) Present value of operating lease payments $ 815

Description of Business and P_2

Description of Business and Presentation of Financial Statements (Details) $ / shares in Units, $ in Thousands	Oct. 20, 2020USD ($)$ / sharesshares	Oct. 08, 2020	Sep. 30, 2020USD ($)segment	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)
Subsequent Event [Line Items]
Accumulated deficit | $			$ 21,379	$ 6,034
Cash and cash equivalents | $			$ 86,329	$ 57,952	$ 337
Number of reportable segments | segment			1
Subsequent Event
Subsequent Event [Line Items]
Reverse stock split, conversion ratio		0.1346
Subsequent Event | IPO
Subsequent Event [Line Items]
Stock issued (shares) | shares	5,500,000
Price per share (usd per share) | $ / shares	$ 16
Stock issued, net proceeds | $	$ 91,700
Common stock issued upon conversion of preferred stock (shares) | shares	11,107,018
Subsequent Event | Underwriters' option
Subsequent Event [Line Items]
Stock issued (shares) | shares	825,000

Summary of Significant Accoun_3

Summary of Significant Accounting Policies and Use of Estimates (Details)	9 Months Ended
	Sep. 30, 2020USD ($)segment	Dec. 31, 2019USD ($)
Accounting Policies [Abstract]
Deferred offering costs | $	$ 1,700,000	$ 0
Expected dividend yield	0.00%
Number of reportable segments | segment	1

Balance Sheet Account Detail -

Balance Sheet Account Detail - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Prepaid expenses	$ 412	$ 22
Clinical research organization service assets	2,310	0
Prepaid expenses and other current assets	$ 2,722	$ 22

Balance Sheet Account Detail _2

Balance Sheet Account Detail - Property and Equipment, Net of Accumulated Depreciation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 697		$ 697		$ 192
(Less): Accumulated depreciation	93		93		38
Property and equipment, net of accumulated depreciation	604		604		154
Depreciation	24	$ 9	56	$ 18
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	295		295		5
Office equipment
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	74		74		26
Lab equipment
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	138		138		92
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	110		110		69
Software licenses
Property, Plant and Equipment [Line Items]
Property and equipment, at cost	$ 80		$ 80		$ 0

Balance Sheet Account Detail _3

Balance Sheet Account Detail - Accounts Payable and Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Trade accounts payable	$ 4,706	$ 456
Operating lease liability, current portion	190	64
Accrued clinical studies	8	0
Employee stock option early exercise liability, current portion	273	0
Other accrued liabilities	447	0
Accounts payable and other accrued liabilities	$ 5,624	$ 520

Balance Sheet Account Detail _4

Balance Sheet Account Detail - Other Long-Term Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Operating lease liability, non-current portion	$ 625	$ 100
Employee stock option early exercise liability, non-current portion	86	0
Other long-term liabilities	$ 711	$ 100

Stockholders' Equity - Addition

Stockholders' Equity - Additional Information (Details)	Oct. 20, 2020USD ($)shares	Sep. 30, 2020USD ($)directorvote$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares	May 31, 2018USD ($)$ / sharesshares	Sep. 30, 2020USD ($)directorvote$ / sharesshares	Sep. 30, 2019USD ($)	Dec. 31, 2019$ / sharesshares
Class of Stock [Line Items]
Common stock, authorized (shares)		17,502,288	17,502,288		17,502,288		17,502,288
Preferred stock, authorized (shares)		11,163,763	8,306,679		11,163,763		8,306,679
Preferred stock, conversion ratio					1
Preferred stock, mandatory conversion to common shares, minimum public offering value | $		$ 260,000,000
Preferred stock, mandatory conversion to common shares, minimum public offering proceeds | $		$ 75,000,000
Preferred stock voting rights, number of votes | vote		1			1
Common stock voting rights, number of directors | director		3			3
Preferred stock dividends declared (usd per share) | $ / shares					$ 0		$ 0
Common stock voting rights, number of votes | vote		1			1
Common stock dividends declared (usd per share) | $ / shares					$ 0		$ 0
Common stock, issued (shares)		3,067,363	2,650,919		3,067,363		2,650,919
Common stock, outstanding (shares)		2,887,988	2,646,619		2,887,988		2,646,619
IPO
Class of Stock [Line Items]
Stock issued, issuance costs | $					$ 330,000	$ 0
Subsequent Event | IPO
Class of Stock [Line Items]
Stock issued (shares)	5,500,000
Stock issued, net proceeds | $	$ 91,700,000
Common stock issued upon conversion of preferred stock (shares)	11,107,018
Convertible notes payable
Class of Stock [Line Items]
Convertible notes converted | $			$ 2,000,000
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, authorized (shares)		1,575,030	1,575,030		1,575,030		1,575,030
Price per share (usd per share) | $ / shares		$ 2.3174	$ 2.3174		$ 2.3174		$ 2.3174
Preferred stock voting rights, number of directors | director		1			1
Preferred stock dividend rate (usd per share) | $ / shares		$ 0.19
Series A Preferred Stock | Private placement
Class of Stock [Line Items]
Stock issued (shares)				1,600,000
Price per share (usd per share) | $ / shares				$ 2.3174
Stock issued, net proceeds | $				$ 3,600,000
Stock issued, issuance costs | $				$ 100,000
Series B and C Preferred Stock
Class of Stock [Line Items]
Preferred stock voting rights, number of directors | director		2			2
Preferred stock voting rights, minimum shares outstanding for election of directors (shares)		1,300,000			1,300,000
Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock, authorized (shares)		6,731,649	6,731,649		6,731,649		6,731,649
Price per share (usd per share) | $ / shares		$ 8.9904	$ 8.9904		$ 8.9904		$ 8.9904
Stock issued, issuance costs | $					$ 28,000	$ 0
Preferred stock dividend rate (usd per share) | $ / shares		$ 0.72
Series B Preferred Stock | Private placement
Class of Stock [Line Items]
Stock issued (shares)			6,700,000
Price per share (usd per share) | $ / shares			$ 8.9904				$ 8.9904
Stock issued, net proceeds | $			$ 57,400,000
Stock issued, issuance costs | $			$ 200,000
Series B Preferred Stock | Convertible notes payable
Class of Stock [Line Items]
Conversion of notes, preferred stock issued (shares)			300,000
Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock, authorized (shares)		2,857,084	0		2,857,084		0
Price per share (usd per share) | $ / shares		$ 14.0003			$ 14.0003
Stock issued, issuance costs | $		$ 243,000
Preferred stock dividend rate (usd per share) | $ / shares		$ 1.12
Series C Preferred Stock | Private placement
Class of Stock [Line Items]
Stock issued (shares)		2,900,000
Price per share (usd per share) | $ / shares		$ 14.0003			$ 14.0003
Stock issued, net proceeds | $		$ 39,800,000
Stock issued, issuance costs | $		$ 200,000

Stockholders' Equity - Preferre

Stockholders' Equity - Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Preferred stock, authorized (shares)	11,163,763			8,306,679
Preferred stock, outstanding (shares)	11,107,018	8,249,939	8,249,939	8,249,939	1,575,030	1,575,030	1,575,030	1,575,030
Preferred stock, net carrying value	$ 103,159	$ 63,402	$ 63,402	$ 63,402	$ 3,564	$ 3,564	$ 3,564	$ 3,564
Preferred stock, liquidation preference	$ 103,660			$ 63,660
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, authorized (shares)	1,575,030			1,575,030
Preferred stock, outstanding (shares)	1,575,030			1,575,030
Preferred stock, net carrying value	$ 3,564			$ 3,564
Preferred stock, liquidation preference	$ 3,650			$ 3,650
Original issue price (usd per share)	$ 2.3174			$ 2.3174
Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock, authorized (shares)	6,731,649			6,731,649
Preferred stock, outstanding (shares)	6,674,909			6,674,909
Preferred stock, net carrying value	$ 59,838			$ 59,838
Preferred stock, liquidation preference	$ 60,010			$ 60,010
Original issue price (usd per share)	$ 8.9904			$ 8.9904
Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock, authorized (shares)	2,857,084			0
Preferred stock, outstanding (shares)	2,857,079			0
Preferred stock, net carrying value	$ 39,757			$ 0
Preferred stock, liquidation preference	$ 40,000			$ 0
Original issue price (usd per share)	$ 14.0003

Stockholders' Equity - Shares R

Stockholders' Equity - Shares Reserved for Issuance (Details) - shares	Sep. 30, 2020	Dec. 31, 2019
Equity [Abstract]
Preferred stock outstanding (shares)	11,107,018	8,249,939
Stock options issued and outstanding under the 2016 Plan (shares)	1,842,627	297,142
Stock options available for future grant under the 2016 Plan (shares)	411,397	2,150,867
Total shares of common stock reserved (shares)	13,361,042	10,697,948

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Details) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2020USD ($)planshares	Dec. 31, 2018shares	Dec. 31, 2019shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plans | plan	1
Repurchase of stock options (shares)	0	0
Liability for early exercise of stock options | $	$ 0.4
2016 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum availability of common stock (shares)	2,700,000
Common stock available for issuance (shares)	400,000		2,200,000

Stock-Based Compensation - Expe

Stock-Based Compensation - Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 223	$ 5	$ 401	$ 13
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	102	2	118	4
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 121	$ 3	$ 283	$ 9

Net Loss Per Share (Details)

Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Net loss	$ (10,138)	$ (3,250)	$ (1,957)	$ (681)	$ (831)	$ (1,745)	$ (15,344)	$ (3,258)
Weighted-average shares—basic and diluted (shares)	2,729,685			2,471,237			2,677,315	2,311,788
Net loss per share attributable to common stockholders—basic and diluted (usd per share)	$ (3.71)			$ (0.28)			$ (5.73)	$ (1.41)

Net Loss Per Share - Outstandin

Net Loss Per Share - Outstanding Potentially Dilutive Securities (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	10,489,327,000	2,129,791,000	10,344,932,000	2,060,892,000
Stock options, unexercised—vested and unvested
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	1,842,627,000	297,142,000	1,842,627,000	297,142,000
Series A, Series B, and Series C Preferred Stock, outstanding
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	8,467,325,000	1,575,030,000	8,322,930,000	1,575,030,000
Shares subject to repurchase from its founders
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	0	89,755,000	0	89,755,000
Stock options early-exercised and unvested
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	179,375,000	43,007,000	179,375,000	43,007,000
Convertible promissory notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total	0	124,857,000	0	55,958,000

Fair Value Measurements - Finan

Fair Value Measurements - Financial Instruments Measured at Fair Value (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Assets:
Total assets measured at fair value	$ 86,329	$ 57,952
Money market funds
Assets:
Money market funds	86,329	57,952
Level 1
Assets:
Total assets measured at fair value	86,329	57,952
Level 1 | Money market funds
Assets:
Money market funds	86,329	57,952
Level 2
Assets:
Total assets measured at fair value	0	0
Level 2 | Money market funds
Assets:
Money market funds	0	0
Level 3
Assets:
Total assets measured at fair value	0	0
Level 3 | Money market funds
Assets:
Money market funds	$ 0	$ 0

Fair Value Measurements - Chang

Fair Value Measurements - Changes in Fair Value of Derivative Liability (Details) - Derivative Liabilities - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2020
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Fair value, beginning of period	$ 0
Revaluation of derivative liabilities included in other income (expense), net within the Statement of Operations	76
Settlement of derivative liabilities through conversion of all Notes	(363)
Fair value, end of period	0
Fair value	0	$ 0
May 2019 Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Initial fair value of derivative liability upon issuance of notes	28
August 2019 Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Initial fair value of derivative liability upon issuance of notes	50
October 2019 Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Initial fair value of derivative liability upon issuance of notes	$ 209

Convertible Promissory Notes _2

Convertible Promissory Notes Payable (Details) - USD ($) shares in Millions	1 Months Ended				3 Months Ended		9 Months Ended		12 Months Ended
	Dec. 31, 2019	Oct. 31, 2019	Aug. 31, 2019	May 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Debt Instrument [Line Items]
Change in fair value of derivative liabilities					$ 0	$ (27,000)	$ 0	$ (27,000)
Convertible notes payable
Debt Instrument [Line Items]
Convertible notes converted	$ 2,000,000
Loss on extinguishment of convertible notes									$ 300,000
Interest expense						22,000	0	27,000
Change in fair value of derivative liabilities						$ (27,000)	$ 0	$ (27,000)
Convertible notes payable | Series B Preferred Stock
Debt Instrument [Line Items]
Conversion of notes, preferred stock issued (shares)	0.3
Convertible notes payable | Series B Preferred Stock | Embedded derivative
Debt Instrument [Line Items]
Conversion of notes, preferred stock issued (shares)	2
Convertible notes payable | Founders and other related parties | May 2019 Notes
Debt Instrument [Line Items]
Cash proceeds from debt issuance				$ 500,000
Face amount of debt issued				$ 500,000
Interest rate				8.00%
Conversion price, percentage of issuance price				90.00%
Convertible notes payable | Founders and other related parties | August 2019 Notes
Debt Instrument [Line Items]
Cash proceeds from debt issuance			$ 500,000
Face amount of debt issued			$ 500,000
Convertible notes payable | Founders and other related parties | October 2019 Notes
Debt Instrument [Line Items]
Cash proceeds from debt issuance		$ 1,000,000
Face amount of debt issued		$ 1,000,000
Conversion price, percentage of issuance price		80.00%

Commitment & Contingencies - Fa

Commitment & Contingencies - Facility Leases (Details) $ in Thousands	Jun. 01, 2020USD ($)contract	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Dec. 31, 2019contract
Lessee, Lease, Description [Line Items]
Operating lease right-of-use asset obtained in exchange for operating lease liability	$ 700			$ 726	$ 163
Lease expense		$ 100	$ 16	$ 100	$ 36
Estimated incremental borrowing rate		10.00%		10.00%
Weighted average remaining lease term		3 years 1 month		3 years 1 month
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2020 (remaining three months)		$ 5		$ 5
2021		349		349
2022		298		298
2023		281		281
2024		25		25
Total future lease payments, undiscounted		958		958
(Less): Imputed interest		(143)		(143)
Present value of operating lease payments		$ 815		$ 815
Irvine office and laboratory facility
Lessee, Lease, Description [Line Items]
Number of leases | contract						1
Remaining lease term		1 year 7 months		1 year 7 months		2 years 4 months
Other facility leases
Lessee, Lease, Description [Line Items]
Number of leases entered during period | contract	2
Remaining lease term		3 years 4 months		3 years 4 months

Commitment & Contingencies - In

Commitment & Contingencies - In-License Agreement for Lotilaner (Details) - USD ($)	Sep. 03, 2020	Sep. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jan. 31, 2019
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Research and development			$ 7,991,000	$ 399,000	$ 11,239,000	$ 2,465,000
Common stock issued for license agreement, value			$ 3,115,000
License agreement with Elanco
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Research and development					$ 1,000,000	$ 1,000,000
Common stock issued for license agreement (shares)		222,460
Common stock issued for license agreement, value		$ 3,100,000
Common stock issued for license agreement, share price (usd per share)		$ 14.0003	$ 14.0003		$ 14.0003
Additional shares to be issued upon 18-month anniversary of contract execution, value	$ 3,000,000
Additional shares to be issued upon 18-month anniversary of contract execution (shares)		187,500
Additional shares to be issued upon 18-month anniversary of contract execution, share price (usd per share)		$ 16
License agreement with Elanco | Clinical milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Maximum milestone payments		$ 4,500,000	$ 4,500,000		$ 4,500,000		$ 5,000,000
License agreement with Elanco | Commercial and sales milestones
Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]
Maximum milestone payments		$ 77,000,000	$ 77,000,000		$ 77,000,000		$ 79,000,000

Commitment & Contingencies - Em

Commitment & Contingencies - Employment Arrangements (Details)	Sep. 30, 2020arrangement
Commitments and Contingencies Disclosure [Abstract]
Number of employment arrangements with executive officers	4

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	Oct. 20, 2020	Oct. 08, 2020	Sep. 30, 2020	Dec. 31, 2019
2016 Plan
Subsequent Event [Line Items]
Common stock available for issuance (shares)			400,000	2,200,000
Subsequent Event | 2020 Plan
Subsequent Event [Line Items]
Common stock available for issuance (shares)		9,000,000
Common stock reserved for issuance, increase percentage on first business day of each of next ten fiscal years		4.00%
Subsequent Event | 2016 Plan
Subsequent Event [Line Items]
Common stock available for issuance (shares)		2,433,395
Subsequent Event | IPO
Subsequent Event [Line Items]
Stock issued (shares)	5,500,000
Price per share (usd per share)	$ 16
Stock issued, net proceeds	$ 91.7
Common stock issued upon conversion of preferred stock (shares)	11,107,018
Subsequent Event | Underwriters' option
Subsequent Event [Line Items]
Stock issued (shares)	825,000

Uncategorized Items - tars-2020

Label	Element	Value
Restricted Cash and Cash Equivalents	us-gaap_RestrictedCashAndCashEquivalents	$ 20,000
Restricted Cash and Cash Equivalents	us-gaap_RestrictedCashAndCashEquivalents	$ 20,000