Organization	12 Months Ended
Dec. 31, 2019
Organization
Organization	1. Organization Description of business Aptinyx Inc. (the “Company” or “Aptinyx”) was incorporated in Delaware on June 24, 2015 and maintains its headquarters in Evanston, Illinois. Aptinyx is a clinical‑stage biopharmaceutical company focused on the discovery, development, and commercialization of novel, proprietary, synthetic small molecules for the treatment of brain and nervous system disorders. Aptinyx has a platform for discovering proprietary compounds that work through a novel mechanism: modulation of N‑methyl‑D‑aspartate receptors (“NMDAr”), which are vital to normal and effective brain and nervous system functions. This mechanism has applicability across a number of brain and nervous system disorders. Liquidity and capital resources The Company has incurred losses and negative cash flows from operations since inception and had an accumulated deficit of $162.9 million as of December 31, 2019. The Company expects to incur substantial operating losses for the next several years and will need to obtain additional financing in order to complete clinical studies and launch and commercialize any product candidates for which it receives regulatory approval. There can be no assurance that such financing will be available or will be at terms acceptable to the Company. As of December 31, 2019, the Company had cash and cash equivalents of $98.8 million which, when combined with the proceeds received from the Company’s follow-on offering discussed below (see Note 16), it believes will be sufficient to fund its planned operations for a period of at least twelve months from the date of the issuance of these financial statements. Initial public offering On June 20, 2018, the Company’s registration statement on Form S-1 (File No. 333‑225150) relating to the initial public offering (“IPO”) of its common stock became effective and on June 25, 2018, the IPO closed. Pursuant to the IPO, the Company issued and sold 7,359,998 shares of common stock at a public offering price of $16.00 per share, which included 959,999 shares sold pursuant to the exercise of the underwriters’ option to purchase additional shares. The Company received net proceeds of $106.5 million after deducting underwriting discounts and commissions and other offering costs of $3.0 million. The shares began trading on the Nasdaq Global Select Market on June 21, 2018. Upon the closing of the IPO, all of the Company’s outstanding shares of convertible preferred stock automatically converted into 20,306,497 shares of common stock at the applicable conversion ratio. On June 7, 2018, the Company effected a one-for-27.58621 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each series of the Company's redeemable convertible preferred stock (see Note 10). Accordingly, all share and per share amounts for all periods presented in the financial statements have been adjusted retroactively, where applicable, to reflect this reverse stock split and adjustment of the preferred stock conversion ratios. The Company is also authorized to issue 10 million shares of undesignated preferred stock, par value $0.01, in one or more series. As of December 31, 2019, no shares of preferred stock were issued or outstanding.

1. Organization

Description of business

Aptinyx Inc. (the “Company” or “Aptinyx”) was incorporated in Delaware on June 24, 2015 and maintains its headquarters in Evanston, Illinois.

Aptinyx is a clinical‑stage biopharmaceutical company focused on the discovery, development, and commercialization of novel, proprietary, synthetic small molecules for the treatment of brain and nervous system disorders. Aptinyx has a platform for discovering proprietary compounds that work through a novel mechanism: modulation of N‑methyl‑D‑aspartate receptors (“NMDAr”), which are vital to normal and effective brain and nervous system functions. This mechanism has applicability across a number of brain and nervous system disorders.

Liquidity and capital resources

The Company has incurred losses and negative cash flows from operations since inception and had an accumulated deficit of $162.9 million as of December 31, 2019. The Company expects to incur substantial operating losses for the next several years and will need to obtain additional financing in order to complete clinical studies and launch and commercialize any product candidates for which it receives regulatory approval. There can be no assurance that such financing will be available or will be at terms acceptable to the Company.

As of December 31, 2019, the Company had cash and cash equivalents of $98.8 million which, when combined with the proceeds received from the Company’s follow-on offering discussed below (see Note 16), it believes will be sufficient to fund its planned operations for a period of at least twelve months from the date of the issuance of these financial statements.

Initial public offering

On June 20, 2018, the Company’s registration statement on Form S-1 (File No. 333‑225150) relating to the initial public offering (“IPO”) of its common stock became effective and on June 25, 2018, the IPO closed. Pursuant to the IPO, the Company issued and sold 7,359,998 shares of common stock at a public offering price of $16.00 per share, which included 959,999 shares sold pursuant to the exercise of the underwriters’ option to purchase additional shares. The Company received net proceeds of $106.5 million after deducting underwriting discounts and commissions and other offering costs of $3.0 million. The shares began trading on the Nasdaq Global Select Market on June 21, 2018. Upon the closing of the IPO, all of the Company’s outstanding shares of convertible preferred stock automatically converted into 20,306,497 shares of common stock at the applicable conversion ratio.

On June 7, 2018, the Company effected a one-for-27.58621 reverse stock split of its issued and outstanding shares of common stock and a proportional adjustment to the existing conversion ratios for each series of the Company's redeemable convertible preferred stock (see Note 10). Accordingly, all share and per share amounts for all periods presented in the financial statements have been adjusted retroactively, where applicable, to reflect this reverse stock split and adjustment of the preferred stock conversion ratios.

The Company is also authorized to issue 10 million shares of undesignated preferred stock, par value $0.01, in one or more series. As of December 31, 2019, no shares of preferred stock were issued or outstanding.