Harpoon Therapeutics Granted Orphan Drug Designation from FDA for HPN217 for Treatment of Multiple Myeloma

SOUTH SAN FRANCISCO, Calif., Jan. 13, 2021 (GLOBE NEWSWIRE) — Harpoon Therapeutics, Inc. (NASDAQ: HARP), a clinical-stage immunotherapy company developing a novel class of T cell engagers, today announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation for HPN217 for the treatment of multiple myeloma. HPN217, a tri-specific T cell activating recombinant protein construct (TriTAC^®) targets B-cell maturation antigen (BCMA), a well-validated antigen expressed on malignant multiple myeloma cells. Harpoon has four drug product candidates in clinical development for the treatment of solid and hematologic malignancies based on its proprietary TriTAC platform.

“Orphan Drug Designation for multiple myeloma represents a significant milestone in the development of HPN217 and recognizes its potential to address a significant unmet medical need for the patients suffering from this condition,” said Jerry McMahon, Ph.D., President and Chief Executive of Harpoon Therapeutics. “I am pleased with the clinical progress we are making with this program and we are planning to present interim data from the ongoing Phase 1/2 dose escalation trial later this year.”

The FDA’s Orphan Drug Designation program provides orphan status to drugs defined as those intended for the safe and effective treatment, diagnosis or prevention of rare diseases that affect fewer than 200,000 people in the United States. Orphan Drug Designation qualifies the sponsor of the drug for certain development incentives, including tax credits for qualified clinical testing, prescription drug user fee exemptions and seven-year marketing exclusivity upon FDA approval.

About the Phase 1/2 Trial for HPN217

In April 2020, Harpoon announced dosing of the first patient with HPN217 (BCMA TriTAC) in a Phase 1/2 clinical trial focused on relapsed/refractory multiple myeloma (RRMM). HPN217 is covered by a global development and option agreement with AbbVie Inc. (NYSE: ABBV). Dose escalation for HPN217 in the Phase 1/2 clinical trial is progressing rapidly. HPN217 has been well tolerated, and no DLTs had been observed as of the most recent December 1, 2020 data cutoff date. A presentation of interim data is anticipated in 2021, with initiation of a dose expansion cohort in the second half of 2021.

For additional information about the trial, please visit clinicaltrials.gov using the identifier NCT04184050.

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. HPN424 targets PSMA and is in a Phase 1/2a trial for metastatic castration-resistant prostate cancer. HPN536 targets mesothelin and is in a Phase 1/2a trial for cancers expressing mesothelin, initially focused on ovarian and pancreatic cancers. HPN217 targets BCMA and is in a Phase 1/2 trial for relapsed, refractory multiple myeloma. HPN328 targets DLL3 and is in a Phase 1/2 trial for small cell lung cancer and other DLL3-associated tumors. 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. For additional information about Harpoon Therapeutics, please visit www.harpoontx.com.

Cautionary Note on 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 “may,” “will,” “expect,” “plan,” “anticipate,” “target,” “estimate,” “intend” 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 progress, timing, scope and anticipated results of clinical trials, the timing of the presentation of data, the association of data with potential treatment outcomes, the development and advancement of product candidates, the timing of development milestones for product candidates, and the anticipated potential impacts to Harpoon Therapeutics’ business from the ongoing COVID-19 pandemic. Many factors may cause differences between current expectations and actual results, including unexpected safety or efficacy data observed during clinical studies, clinical trial site activation or enrollment rates that are lower than expected, unanticipated or greater than anticipated impacts or delays due to COVID-19, changes in expected or existing competition, changes in the regulatory environment, the uncertainties and timing of the regulatory approval process, and unexpected litigation or other disputes. 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 the “Risk Factors” sections contained therein. 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, Inc.
Georgia Erbez
Chief Financial Officer
650-443-7400
media@harpoontx.com

Westwicke ICR
Robert H. Uhl
Managing Director
858-356-5932
robert.uhl@westwicke.com