ARCH Venture Fund XII, L.P. and affiliated reporting persons filed a Schedule 13D with the SEC on October 26, 2026, disclosing beneficial ownership of 13,692,507 shares of common stock of City Therapeutics, Inc. following events dated October 19, 2026.

Key Highlights

  • Aggregate beneficial ownership: Each reporting person disclosed shared beneficial ownership of 13,692,507 shares of City Therapeutics, Inc. common stock, representing 25.6% of the class.
  • No sole voting or dispositive power: All seven reporting persons reported 0.00 shares with sole voting or sole dispositive power; all 13,692,507 shares are held on a shared basis.
  • Series B purchase: On May 20, 2026, ARCH Venture Fund XII, L.P. purchased 2,027,006 shares of Series B Preferred Stock at $13.3201 per share, a figure that reflects a 1.0983-for-1 stock split effected immediately prior to the IPO closing.
  • Conversion at IPO: Each share of Series B Preferred Stock automatically converted into one share of common stock at the closing of the issuer's initial public offering, according to the filing.
  • Seven reporting persons: The filing covers ARCH Venture Fund XII, L.P.; ARCH Venture Partners XII, L.P.; ARCH Venture Partners XII, LLC; and four individuals: Robert Nelsen, Keith Crandell, Kristina Burow, and Steven Gillis.
  • Source of funds: ARCH Venture Fund XII, L.P. and ARCH Venture Partners XII, L.P. listed "WC" (working capital) as the source of funds; the remaining reporting persons listed "AF" (affiliated funds).

ARCH Venture Group Discloses Shared 25.6% Position After City Therapeutics IPO

According to the Schedule 13D filing, the triggering event for this statement was October 19, 2026. The seven reporting persons are connected through a general partner chain: ARCH Venture Partners XII, L.P. is the sole general partner of ARCH Venture Fund XII, L.P., and ARCH Venture Partners XII, LLC is the sole general partner of ARCH Venture Partners XII, L.P. Robert Nelsen, Keith Crandell, Kristina Burow, and Steven Gillis are identified in the filing as the "AVP XII Investment Committee Members" of ARCH Venture Partners XII, LLC. The business address of all reporting persons is listed as 8755 West Higgins Road, Suite 1025, Chicago, IL 60631.

The filing states that on May 20, 2026, ARCH Venture Fund XII, L.P. purchased 2,027,006 shares of Series B Preferred Stock of City Therapeutics, Inc. at a purchase price of $13.3201 per share. The filing notes that the share count "reflects a 1.0983 for 1 stock split effected immediately prior to the closing of the initial public offering." Upon the IPO closing, each Series B Preferred share automatically converted into one share of common stock. The filing was cut off before the October 19, 2026 transaction description was complete, so no further details of that event are available from the source text.

City Therapeutics, Inc. is identified in the filing as having its principal executive offices at 399 Binney Street, Cambridge, Massachusetts 02142. The issuer's common stock has a par value of $0.0001 per share and carries CUSIP number 178782108. The filing disclosed that none of the reporting persons had been convicted in a criminal proceeding or been party to a qualifying civil proceeding involving securities laws during the five years prior to the filing date.

What Was Disclosed

ARCH Venture Fund XII, L.P. and six affiliated entities and individuals filed a Schedule 13D disclosing shared beneficial ownership of 13,692,507 shares, equal to 25.6% of City Therapeutics, Inc. common stock, with the triggering event dated October 19, 2026.