Harpoon Therapeutics, a company developing cancer immunotherapies that target T cells to tumors, is abandoning its lead drug candidate after disappointing data from an early-stage prostate cancer clinical trial. While Harpoon has other candidates in its pipeline, the decision to end the lead program has left the biotech unable to compete with a growing number of competitors in the pursuit of treatments for this new drug class.
The South San Francisco biotech announced in its fourth-quarter and full-year 2021 report that it will discontinue work on the drug, HPN424 financial performance after the close on Thursday. Chief Executive Julie Eastland said in a statement that the decision was made after an analysis of data, including clinical trial results from a Phase 1/2a dose-escalation study to date.
Harpoon’s Annual Report condition The drug’s results so far have shown “moderate activity with a challenging tolerability profile.” No further details were disclosed about the drug, but the company added that it will continue to be studied throughout the course of treatment. patients in . Shares of Harpoon were trading around $3.77 at midday Friday, down more than 30% from Thursday’s close.
Harpoon is developing a therapy called a T-cell engager. These drugs consist of proteins with three main components: a part that binds to T cells, a domain that prolongs therapeutic half-life, and a third part that binds to antigens on the surface of cancer cells. The company calls its technology platform TriTAC. The simultaneous binding of TriTAC drugs to T cells and antigens is designed to activate T cells to kill target cancer cells.
HPN424 is designed to track the target of a prostate cancer protein called PSMA. Harpoon is developing drugs to treat metastatic castration-resistant prostate cancer, which means the cancer has spread and is no longer fully responsive to treatments that lower levels of testosterone that help cancer cells grow.
Moderate activity and tolerance challenges hindering HPN424 contrast with encouraging early data from Harpoon report for its prostate cancer drug prospects last June.During the annual meeting of the American Society of Clinical Oncology, the company Say At that time, 89 patients received weekly intravenous infusions of HPN424. Harpoon reported that the experimental therapy was aggressive and generally well tolerated. The drug also showed antitumor activity, including a decrease in PSA protein and circulating tumor cells, which are indicators of prostate cancer.
The group of companies developing therapies that bind to both T cells and cancer cells is growing, and Big Pharma is striking big deals for competitors. last year, Takeda Pharmaceuticals to Acquire Partner Maverick Therapeuticsa T cell engagement biotechnology isolated from Harpoon. Janux Therapeutics, in partnership with Merck, is also developing T-cell engagers. Bristol-Myers Squibb and Sanofi has struck a deal Get them to play. And last week, Rondo Therapeutics emerges from stealth to develop bispecific antibody drugs Solid tumors can be treated.The founder of this startup is Teneobio, developer of bispecific antibodies acquired by Amgen A $900 million advance was made last summer.
With Harpoon’s HPN424 now on hold, the company said it will shift resources to other TriTAC programs, three of which are in clinical development. HPN328 is in Phase 1/2 testing in small cell lung cancer; HPN217 is in Phase 1/2 testing in multiple myeloma; and HPN536 is in Phase 1/2a studies in ovarian cancer and other solid tumors that express a protein called mesothelin. Harpoon reported that it had $136.6 million in cash at the end of 2021.
Public domain image from the National Cancer Institute
