Stockholders' Equity - Additional Information (Detail) - USD ($)				1 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 02, 2023	Sep. 26, 2023	Dec. 16, 2022	Nov. 07, 2023	Oct. 31, 2023	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022	May 25, 2023	Mar. 23, 2023	Feb. 17, 2023	Aug. 26, 2022	Jul. 31, 2021
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Common Warrant Shares					44,299,909		22,388,909		22,388,909		5,323,110
Proceeds from warrant exercise									$ 19,445,000
Weighted average grant date fair value per option granted (in dollars per share)									$ 3.80	$ 2.62
Number of shares available for issuance under the plan on the first day of each year							15,467,229		15,467,229		8,159,382
Convertible preferred stock, shares authorized							10,000,000		10,000,000		10,000,000				10,000,000
Pre-funded warrants issued		2,420,394
Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Public offering price per pre-funded warrant	$ 19.99
Number of shares available for issuance under the plan on the first day of each year					30,499,352
Pre-funded warrants issued				2,341,167
Tranche A [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock (shares)		3,310,568
Sale and issuance of warrants to purchase common stock		$ 15,000,000
Number of Common Warrant Shares			8,598,870
Proceeds from warrant exercise									$ 15,000,000
Warrants and rights immediately exercisable term			30 days
Weighted Average Exercise Price per Share			$ 1.75
Exercisable warrants maximum aggregate exercise price			$ 15,000,000
Tranche A [Member] | Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock (shares)				526,741
Tranche B [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Common Warrant Shares			14,000,000
Warrants expire term prior to anniversary date of issuance			3 years 6 months
Warrants and rights exercisable term from following receipt of U.S. Food and drug administration approval			30 days
Weighted Average Exercise Price per Share			$ 2.5
Exercisable warrants maximum aggregate exercise price			$ 35,000,000
Tranche B [Member] | Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from warrant exercise					$ 17,500,000
Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Ownership interest of voting rights of all classes of stock (percent)							10.00%		10.00%
2020 Inducement Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant							590,668		590,668					500,000
Stock Options [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Income tax benefits recognized from stock-based compensation									$ 0	$ 0
Number of options granted							77,000	157,673	1,663,454	283,919
Future stock-based compensation for unvested employee options granted and outstanding							$ 7,400,000		$ 7,400,000
Future stock-based compensation, requisite service period									2 years 7 months 6 days
Stock Options [Member] | 2014 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period									4 years
Number of shares available for grant							17,780		17,780			1,800,000	238,329
Stock Options [Member] | 2014 Equity Incentive Plan [Member] | Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of fair market value									110.00%
Stock Options [Member] | 2014 Equity Incentive Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Contractual term of option									10 years
ISOs [Member] | 2014 Equity Incentive Plan [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Contractual term of option									5 years
Restricted Stock Units [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized stock based compensation expense							$ 800,000		$ 800,000
Stock units granted							0	0	414,710	8,967
Vesting percentage							100.00%		100.00%
Fair value of restricted stock units vested									$ 23,000,000	$ 600,000
Weighted average grant-date fair value of all restricted stock units granted									$ 5.25	$ 5.33
Weighted average remaining vesting period									2 months 12 days
Restricted Stock Units [Member] | 2014 Equity Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock units granted									414,710
Weighted average grant-date fair value of all restricted stock units granted									$ 5.25
Warrants to Purchase Stock [Member] | 2010 and 2012 Convertible Promissory Notes [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Common Warrant Shares							6,804		6,804
Weighted Average Exercise Price per Share							$ 365.25		$ 365.25
Warrants term									10 years
Expiration period									2024-11
Underwriter [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Common Warrant Shares							1,100		1,100
Weighted Average Exercise Price per Share							$ 535.50		$ 535.50
Warrants term									10 years
Expiration period									2024-11
March 2022 Common Warrants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Common Warrant Shares							2,130,656		2,130,656		4,000,000
Weighted Average Exercise Price per Share							$ 4.5		$ 4.5		$ 4.5
Expiration period									2027-03
March 2022 Common Warrants [Member] | Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Common Warrant Shares					2,122,924
Weighted Average Exercise Price per Share					$ 4.5
March 2022 Pre-funded Warrants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of Common Warrant Shares							927,806		927,806		1,280,965
Weighted Average Exercise Price per Share							$ 0.15		$ 0.15		$ 0.15
Expiration period									2027-03
March 2022 Pre-funded Warrants [Member] | Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Weighted Average Exercise Price per Share					$ 0.15
Controlled Equity Offering Sales Agreement [Member] | Cantor [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock (shares)									1,877,170
Common stock, maximum aggregate purchase price																$ 25,000,000.0
Net proceeds from sale of common stock									$ 7,400,000
Securities Purchase Agreement [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Sale and issuance of warrants to purchase common stock									$ 10,000,000
Number of common stock purchased upon issuance of warrants			22,598,870
Weighted Average Exercise Price per Share			$ 0.4425
Underwritten Public Offering [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock (shares)						2,666,667
Price per unit						$ 3.75
Number of common stock purchased upon issuance of warrants						1,333,333
Public offering price per pre-funded warrant						$ 3.60
Per share exercise price for pre-funded warrant						$ 0.15
Measurement term						5 years
Proceeds from offering after deducting underwriting discount and other estimated offering expenses						$ 13,800,000
Weighted Average Exercise Price per Share						$ 4.50
Underwritten Public Offering [Member] | Subsequent Event [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Issuance of common stock (shares)	3,450,000
Price per unit	$ 20
Proceeds from offering after deducting underwriting discount and other estimated offering expenses	$ 69,000,000
Underwritten Public Offering [Member] | March 2022 Common Warrants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from warrant exercise							$ 8,400,000
Warrants exercised							1,869,327
Underwritten Public Offering [Member] | March 2022 Pre-funded Warrants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Proceeds from warrant exercise							$ 0
Warrants exercised							353,155
Underwritten Public Offering [Member] | Securities Purchase Agreement [Member] | Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Net proceeds from sale of common stock											$ 60,000,000
Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares available for grant							1,864		1,864
Percentage of outstanding stock maximum									1.00%
Number of shares available for issuance under the plan on the first day of each year							3,729		3,729
Number of shares purchases by employees									0