SOUTH SAN FRANCISCO, Calif., March 27, 2023 (GLOBE NEWSWIRE) — Harpoon Therapeutics, Inc. (NASDAQ: HARP) (the “Company”), a clinical-stage immuno-oncology company developing novel T cell engagers, today announced that it has closed a private placement of redeemable preferred stock and warrants to purchase common stock to certain institutional and other accredited investors for aggregate gross proceeds to the Company of $25 million, before deducting offering expenses, which does not include any proceeds that may be received upon exercise of the warrants. The private placement included participation from new and existing investors, including New Leaf, Arix Bioscience, Invus, OrbiMed and K2 HealthVentures. SVB Securities provided exclusive financial advisory services to the Company. The Company intends to use the net proceeds to complete its ongoing Phase 1 clinical studies for two TriTAC® T cell engagers, including HPN217 (BCMA) being studied in a Phase 1 trial for patients with relapsed and refractory multiple myeloma, and HPN328 (DLL3), a Phase 1 / 2 study for patients with multiple neuroendocrine tumors, including small cell lung cancer and neuroendocrine prostate cancer. The proceeds will also be used for working capital and other general corporate purposes. “In these challenging markets we are appreciative of the ongoing support from our investors, including those who have been with us for many years and have supported the discovery and development of our novel T cell engagers. This support will provide us sufficient capital, beyond our anticipated 2023 milestones, into the second half of 2024,” said Julie Eastland, President and CEO of Harpoon. Investors purchased an aggregate of (i) 25,000 shares of preferred stock at a price per share of $1,000 and (ii) warrants to purchase 7,485,762 shares of common stock with an exercise price of $0.978885 per share, which represents a 35% premium to the closing price of common stock at the time of the signing of the definitive agreements with respect to the private placement. The preferred stock issued in the private placement is not convertible into common stock and is redeemable at any time at the option of the Company and mandatorily redeemable by the Company upon the occurrence of certain events, including the receipt of proceeds in connection with certain strategic transactions, and on the third anniversary of the closing date, in each case subject to a return multiple. Additional information regarding the private placement will be included in a Form 8-K to be filed by the Company with the Securities and Exchange Commission, and this press release is subject to the further detail provided in the Form 8-K. The offer and sale of the foregoing securities were made in a transaction not involving a public offering and the securities have not been registered under the Securities Act of 1933, as amended (the “Securities Act”), or applicable state securities laws. Accordingly, the securities may not be reoffered or resold in the United States except pursuant to an effective registration statement or an applicable exemption from the registration requirements of the Securities Act and such applicable state securities laws. This press release does not constitute an offer to sell or the solicitation of an offer to buy the securities, nor shall there be any sale of the securities in any state in which such offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of such state. About Harpoon Therapeutics Harpoon Therapeutics is a clinical-stage immuno-oncology company developing a novel class of T cell engagers that harness the power of the body’s immune system to treat patients suffering from cancer and other diseases. T cell engagers are engineered proteins that direct a patient’s own T cells to kill target cells that express specific proteins, or antigens, carried by the target cells. Using its proprietary Tri-specific T cell Activating Construct (TriTAC®) platform, Harpoon is developing a pipeline of novel TriTACs initially focused on the treatment of solid tumors and hematologic malignancies. Harpoon has also developed a proprietary ProTriTAC™ platform, which applies a prodrug concept to its TriTAC platform to create a therapeutic T cell engager that remains inactive until it reaches the tumor. Harpoon’s third proprietary technology platform, extended release TriTAC-XR, is designed to mitigate cytokine release syndrome. For additional information about Harpoon Therapeutics, please visit www.harpoontx.com. Cautionary Note Regarding Forward-Looking Statements Any statements in this press release about the Company’s future expectations, plans and prospects, as well as any other statements regarding matters that are not historical facts, may constitute “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements are subject to risks and uncertainties and actual results may differ materially from those expressed or implied by such forward-looking statements. Such statements include, but are not limited to, statements associated with the intended use of net proceeds from the private placement, potential exercise of the warrants, the sufficiency of the Company’s capital to fund its operations into the second half of 2024, the expected completion of its ongoing clinical studies, and other statements containing the words “anticipates,” “believes,” “expects,” “intends,” “plans,” “will” and similar expressions. You should not place undue reliance on forward-looking statements because they involve known and unknown risks, uncertainties, and assumptions that are difficult or impossible to predict and, in some cases, beyond the Company’s control. These forward-looking statements are based upon the Company’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, which include, without limitation, risks associated with market conditions. These and other risks are described in additional detail in the Company’s filings with the U.S. Securities and Exchange Commission (SEC). All forward-looking statements contained in this press release speak only as of the date hereof, and the Company specifically disclaims any obligation to update any forward-looking statement, whether because of new information, future events or otherwise. Contacts: ICR Westwicke:Robert H. UhlManaging Director858-356-5932robert.uhl@westwicke.com Media:uncapped Communications303-588-0599kerry.walton@uncappedcommunications.com