Here are the 424B prospectus supplements from Sutro Biopharma, Inc. (STRO) in our archive over the last 12 months, newest first, and each one links through to the document itself with the summary and the scores our analysis gives it.
A 424B covers the supplement that carries the terms of a priced offering, so if you follow STRO and want that one kind of document rather than the whole filing history, this is the page to keep. The company's other filings, of every form, are on the full STRO filings page.
Sutro Biopharma is registering up to $100.0 million of common stock for sale under a Sales Agreement with TD Securities (USA) LLC (TD Cowen) pursuant to an at-the-market program. Sales may occur from time to time in negotiated transactions, block trades or other methods permitted under Rule 415.
The shares trade on Nasdaq under the symbol STRO (last reported sale $24.91 on March 31, 2026). The prospectus supplement states there were 8,584,309 shares outstanding as of December 31, 2025 and discloses dilution and net tangible book value metrics tied to an illustrative $100.0 million placement.
Sutro Biopharma, Inc. is conducting a primary offering of 7,868,383 shares of common stock at $13.98 per share, raising gross proceeds of $109,999,994. After $6,600,000 in underwriting discounts and commissions, Sutro expects approximately $103,399,995 in proceeds before expenses and estimates net proceeds of about $102.7 million.
The company plans to use the cash, together with existing balances, for general corporate purposes, including research, clinical and process development, manufacturing, working capital, potential acquisitions or investments, and capital expenditures. Combined with cash, cash equivalents and marketable securities as of January 1, 2026 and the additional $110.0 million before costs, Sutro expects to have approximately $251.4 million in capital resources, which it estimates will fund operations into the second quarter of 2028.
As context, 8,563,888 shares of common stock were outstanding as of September 30, 2025. The offering price of $13.98 per share is expected to result in immediate dilution of $13.04 per share to new investors, based on an as adjusted net tangible book value of $0.94 per share after the transaction. Leerink Partners LLC, TD Securities (USA) LLC and LifeSci Capital LLC are underwriting the deal, and the company, its directors and executive officers are subject to 60‑day and 90‑day lock-up periods, respectively, with specified exceptions.