Alector, Inc. — Form 10-Q

Alector amended its 2019 Employee Stock Purchase Plan effective June 15, 2026. Key changes: (1) Current offering period runs June 1–November 30, 2026 (vs. standard six-month periods); (2) No offering period December 1–15, 2026; next period starts December 16, 2026; (3) Purchase price remains 85% of lower of enrollment or exercise date FMV; (4) New 10,000-share purchase limit per employee per period (effective Dec 2026 forward); (5) Contribution limit stays 15% of compensation. No material financial impacts disclosed; this is administrative restructuring of offering schedule.