Alector Announces Pricing of Underwritten Offering

Alector, Inc. (“Alector,” Nasdaq: ALEC), a biotechnology company focused on developing therapies to counteract the devastating progression of neurodegeneration, today announced the pricing of an underwritten offering of common stock. Alector is selling 36,600,000 shares of common stock. The shares of common stock are being sold at an offering price of $2.05 per share, which represents a premium of approximately 7.3% over the closing price on October 15, 2026. The gross proceeds to Alector from this offering are expected to be $75,030,000.00 before deducting the underwriting discounts and commissions and other estimated offering expenses. All shares of common stock to be sold in the offering are being offered by Alector. The offering is expected to close on or about October 19, 2026, subject to the satisfaction of customary closing conditions.