Harpoon Therapeutics to Present Interim Tolerability and Response Data from Phase 1/2 Clinical Trial of T Cell Engager HPN328 at ESMO Congress 2023

SOUTH SAN FRANCISCO, Calif., Oct. 09, 2023 (GLOBE NEWSWIRE) — Harpoon Therapeutics, Inc. (Nasdaq: HARP), a clinical-stage immunotherapy company developing novel T cell engagers, today announced that it will present interim monotherapy data from its Phase 1/2 clinical trial evaluating HPN328 in small cell lung cancer (SCLC) and other neuroendocrine neoplasms (NEN) in a poster presentation at the European Society of Medical Oncology Congress (ESMO) 2023 taking place in Madrid, Spain from October 20-24, 2023. HPN328 targets delta-like ligand 3 (DLL3) and is derived from Harpoon’s proprietary Tri-specific T cell Activating Construct (TriTAC^®) platform designed to recruit a patient’s own immune cells to kill tumor cells.

“We are excited to present data from over 70 patients with multiple tumor types in HPN328 monotherapy cohorts, with an emphasis on our ongoing 1 mg priming cohorts with target doses up to 24 mg. Full enrollment of these 1 mg priming dose cohorts will be the basis for selecting our recommended Phase 2 dose(s) by the end of this year. In our poster, we will share tolerability data from all enrolled patients and preliminary response data in patients at doses above the efficacy threshold of 1.215 mg,” said Luke Walker, M.D., Chief Medical Officer for Harpoon Therapeutics. “In addition to nearing completion of monotherapy dose optimization, we have recently initiated enrollment in our combination cohorts evaluating HPN328 plus atezolizumab to enable future development in early lines of therapy.”

Details of the ESMO poster presentation are as follows:

Abstract Title: Interim Results from a Phase 1/2 Study of HPN328, a Tri-Specific, Half-Life (T1/2) Extended DLL3-targeting T-Cell Engager in Patients (pts) with Small Cell Lung Cancer (SCLC) and other Neuroendocrine Neoplasms (NEN)
Presentation Number: 698P
Session Number/Title: Developmental Therapeutics
Session Date, Time: Monday, October 23, 2023, 12:00 – 13:00 CEST
Presenter: Noura Choudhury, M.D.
Location: Hall 8

The poster will also be available on Harpoon’s website following the presentation.

For more details about the ESMO Annual Meeting, please visit:
https://www.esmo.org/meeting-calendar/esmo-congress-2023

About Harpoon Therapeutics
Harpoon Therapeutics is a clinical-stage immunotherapy 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.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as “expect,” “will,” and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. These forward-looking statements are based on Harpoon Therapeutics’ expectations and assumptions as of the date of this press release. Each of these forward-looking statements involves risks and uncertainties that could cause Harpoon Therapeutics’ clinical development programs, future results or performance to differ significantly from those expressed or implied by the forward-looking statements. Forward-looking statements contained in this press release include, but are not limited to, statements about the expected timing, progress, and results of Harpoon Therapeutics’ clinical trials, including interim results of clinical trials and the safety and tolerability profile of product candidates, the association of interim clinical data and preclinical results with potential treatment outcomes and other statements that are not historical fact. Many factors may cause differences between current expectations and actual results, including unexpected safety or efficacy data observed during clinical studies, preliminary data and trends may not be predictive of future data or results, may not demonstrate safety or efficacy or lead to regulatory approval by the FDA or other regulatory agencies, clinical trial site activation or enrollment rates that are lower than expected, changes in expected or existing competition, changes in the regulatory environment, the uncertainties and timing of the regulatory approval process, the timing and results of unexpected litigation or other disputes, and the sufficiency of Harpoon Therapeutics’ cash resources. These and other factors that may cause Harpoon Therapeutics’ actual results to differ from those expressed or implied in the forward-looking statements in this press release are discussed in Harpoon Therapeutics’ filings with the U.S. Securities and Exchange Commission, including under “Risk Factors” in Harpoon Therapeutics’ quarterly report on Form 10-Q for the quarter ended June 30, 2023, and future filings by Harpoon Therapeutics. Except as required by law, Harpoon Therapeutics assumes no obligation to update any forward-looking statements contained herein to reflect any change in expectations, even as new information becomes available.

Contacts:

Harpoon Therapeutics
Ana Kapor
akapor@harpoontx.com