Merger Accounting - Summary of Purchase Price Paid in Merger (Detail) - USD ($) $ / shares in Units, $ in Thousands		May 28, 2020	Dec. 31, 2020	May 27, 2020	Dec. 31, 2019
Business Acquisition [Line Items]
Purchase price:		$ 38,834
Common stock outstanding			15,367,730		6,091,250
Zafgen [Member]
Business Acquisition [Line Items]
Number of shares of the combined organization owned by Zafgen stockholders	[1]	3,124,337
Multiplied by the fair value per share of Zafgen common stock	[2]	$ 11.88
Fair value of consideration issued in effect of the Merger		$ 37,119
Transaction costs		1,715
Purchase price:		$ 38,834
Common stock outstanding				37,492,044

[1] The number of shares of 3,124,337 represents the historical 37,492,044 shares of Zafgen common stock outstanding immediately prior to the closing of the Merger, adjusted for the Reverse Stock Split.

[2] Based on the last reported sale price of Zafgen common stock on the Nasdaq Global Market on May 28, 2020, the closing date of the Merger, and after giving effect to the Reverse Stock Split.