Condensed Statements of Stockholders’ (Deficit) Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2018
Statements of stockholders' (deficit) equity
Stock issuance costs capitalized	$ 2,902	$ 2,902

The amount of stock issuance costs capitalized during the period.

No definition available.

Name:	aptx_StockIssuanceCostsCapitalized
Namespace Prefix:	aptx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration