Filed pursuant to Rule 424(b)(3)
Registration No. 333-269912
PROSPECTUS
Up to
1,995,708 Shares of Common Stock and 2,095,493
Shares of Common Stock Issuable Upon Exercise
of Warrants
Apexigen, Inc.
This prospectus
relates to the resale by the 2023 PIPE Investors (as defined below) and the Placement Agent (as defined below) named in this prospectus as selling securityholders (or their permitted transferees) (the Selling Securityholders) of up to
4,091,201 shares of our Common Stock, including (i) 1,995,708 shares held by the 2023 PIPE Investors (the 2023 PIPE Shares and, together with the Warrant Shares (as defined below), the Common Shares), which shares were
purchased at a price of $1.40 per share, (ii) 1,995,708 shares issuable upon the exercise of an aggregate of 1,995,708 warrants (the 2023 PIPE Warrants), each of which is exercisable at a price of $1.40 per share held by investors (the
2023 PIPE Investors) that entered into a Securities Purchase Agreement with us on January 23, 2023 (the Purchase Agreement), pursuant to which we issued and sold to such investors shares of our Common Stock, par value $0.0001
per share (Common Stock) and the accompanying 2023 PIPE Warrants in a private placement (the 2023 Private Placement) and (iii) 99,785 shares issuable upon the exercise of an aggregate of 99,785 warrants (the Placement
Agent Warrants, together with the 2023 PIPE Warrants, the Warrants, and, such shares issuable upon exercise of the Warrants, the Warrant Shares), exercisable at a price of $1.75 held by Brookline Capital Markets, a
division of Arcadia Securities, LLC, our placement agent for the 2023 Private Placement, or certain of its affiliates (the Placement Agent). The 2023 PIPE Warrants were all purchased as a part of a unit that consisted of one share of our
Common Stock and one warrant. The purchase price of each unit was $1.40 and the purchase price of each warrant was negligible.
The shares
of Common Stock being offered for resale pursuant to this prospectus by the Selling Securityholders represent approximately 16.6% of shares outstanding as of February 8, 2023. Given the number of shares of Common Stock being registered for
potential resale by this prospectus, such sales, or the perception in the market that the Selling Securityholders intend to sell such shares, could increase the volatility of the market price of our Common Stock or result in a significant decline in
the public trading price of our Common Stock.
The Selling Securityholders may sell any, all or none of the securities and we do not know
when or in what amount the Selling Securityholders may sell their securities hereunder following the effective date of this registration statement. The Selling Securityholders may sell the securities described in this prospectus in a number of
different ways and at varying prices. The Selling Securityholders will pay any underwriting discounts and commissions and expenses incurred by them in disposing of these securities. We provide more information about how the Selling Securityholders
may sell their securities in the section titled Plan of Distribution appearing elsewhere in this prospectus.
We will
not receive any of the proceeds from such sales, but we will receive the proceeds from the exercise for cash of the Warrants. We believe the likelihood that Selling Securityholders will exercise their Warrants, and therefore the amount of cash
proceeds we would receive, is dependent upon the trading price of our Common Stock, the last reported sales price for which was $0.69 per share on March 20, 2023. If the trading price of our Common Stock is less than the $1.40 exercise price per
share of the 2023 PIPE Warrants or the $1.75 exercise price per share of the Placement Agent Warrants, we expect that the applicable Selling Securityholders will not exercise their Warrants. We could receive up to an aggregate of approximately
$3.0 million if all of the Warrants are exercised for cash, but we will only receive such proceeds if and when the Selling Securityholders exercise the Warrants. There is no guarantee the Warrants will be in the money following the time they
become exercisable and prior to their expiration, and as such, the Warrants may expire worthless and we may receive no proceeds from the exercise of Warrants. To the extent that any of the Warrants are exercised on a cashless basis, we
will not receive any proceeds upon such exercise. We do not expect to rely on the cash exercise of Warrants to fund our operations. Instead, we intend to rely on our primary sources of cash discussed elsewhere in this prospectus to continue to
support our operations.
We will bear all costs, fees and expenses incurred in effecting the registration of these securities other than
any underwriting discounts and commissions and expenses incurred by the Selling Securityholders, as described in more detail in the section titled Use of Proceeds appearing elsewhere in this prospectus.
Our Common Stock is traded on The Nasdaq Capital Market (Nasdaq) under the symbol APGN. Our public warrants are traded
on Nasdaq under the symbol APGNW. On March 20, 2023, the last quoted sale price for our Common Stock as reported on Nasdaq was $0.69 per share and the last reported sale price of our warrants was $0.07 per warrant.
We are an emerging growth company, as defined under the federal securities laws, and, as such, may elect to comply with certain
reduced public company reporting requirements for future filings.
Investing in our securities involves a high degree of risk.
Before buying any securities, you should carefully read the discussion of the risks of investing in our securities in the section titled Risk Factors beginning on page 9 of this prospectus.
You should rely only on the information contained in this prospectus or any prospectus supplement or amendment hereto. We have not
authorized anyone to provide you with different information.
Neither the Securities and Exchange Commission nor any state
securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.
The date of this prospectus is March 21, 2023.