X0609 4 2026-06-04 0 0001727196 Scholar Rock Holding Corp SRRK 0001569248 Burow Kristina false 301 BINNEY STREET CAMBRIDGE MA 02142 1 0 0 0 0 Common Stock 2026-06-04 4 A 0 6839 0.00 A 117710 D Common Stock 2345711 I See footnote Stock Option (Right to Buy) 45.33 2026-06-04 4 A 0 4310 0 A 2036-06-04 Common Stock 4310 4310 D Each restricted stock unit ("RSU") represents the contingent right to receive, upon vesting of the RSU, one share of the Issuer's common stock. The shares subject to this RSU vest on the earlier of June 15, 2027 or on the date of the Issuer's next Annual Meeting subject to continued service to the Issuer through such date. Consists of 110,871 shares of common stock and 6,839 RSUs. The shares are held by ARCH Venture Fund VIII, L.P. ("ARCH VIII"). ARCH Venture Partners VIII, L.P. ("GPLP"), as the sole general partner of ARCH VIII, may be deemed to beneficially own the shares held by ARCH VIII. ARCH Venture Partners VIII, LLC ("GPLLC"), as the sole general partner of GPLP, may be deemed to beneficially own the shares held by GPLP. The GPLP and GPLLC disclaim beneficial ownership of such securities, except to the extent of any pecuniary interest therein. The managing directors of the GPLLC are Keith L. Crandell, Clinton Bybee and Robert Nelsen, and they may be deemed to beneficially own the shares held by ARCH VIII. Messrs. Crandell, Bybee and Nelsen disclaim beneficial ownership of such shares, except to the extent of any pecuniary interest therein. The Reporting Person is a managing director of the GPLP. The Reporting Person owns an interest in the GPLP but does not have voting or investment control over the shares held by ARCH VIII. The Reporting Person disclaims ownership of such shares, except to the extent of her pecuniary interest therein. Options to vest and become fully exercisable on the earlier of the first anniversary following the date of grant or on the date of the Issuer's next Annual Meeting, subject to continued service to the Issuer through such date. /s/ Junlin Ho, Attorney-in-Fact for Kristina Burow 2026-06-08