$250,000,000

Common Stock

We have entered into an Open Market Sale AgreementSM (the sales agreement) with Jefferies LLC (Jefferies), as our sales agent, relating to the shares of our common stock offered by this prospectus supplement and the accompanying base prospectus, or this prospectus. In accordance with the terms of the sales agreement, we may offer and sell shares of our common stock having an aggregate offering price of up to $250,000,000 from time to time through or to Jefferies, as our agent.

Our common stock is listed on The Nasdaq Global Market (Nasdaq), under the symbol "AVBP." On May 8, 2026, the last reported sale price of our common stock was $29.50 per share.

Sales of our common stock, if any, under this prospectus will be made in sales deemed to be "at the market" offerings as defined in Rule 415 promulgated under the Securities Act of 1933, as amended (the Securities Act). Jefferies is not required to sell any specific amount of securities but will act as our sales agent using commercially reasonable efforts consistent with their normal trading and sales practices, on mutually agreed terms between Jefferies and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.