Benzinga | Jan 4, 2021 07:31AM EST

Harpoon Therapeutics Doses First Patient with HPN328, an Anti-DLL3 T Cell Engager for Treatment of Small Cell Lung Cancer and other DLL3-Associated Tumors

Harpoon Therapeutics, Inc. (NASDAQ:HARP), a clinical-stage immunotherapy company developing a novel class of T cell engagers, today announced that the first patient has been dosed with HPN328, a delta like ligand 3- (DLL3) targeting TriTAC(r), in a Phase 1/2 clinical trial as an investigational treatment of small cell lung cancer (SCLC) and other tumors associated with DLL3 expression. The company has presented preclinical data on HPN328 showing that the drug was well tolerated in cynomolgus monkeys at 1 and 10 mg/kg, and pharmacokinetic data supported the potential for once weekly dosing. When administered to mice bearing human SCLC xenografts and human T cells, HPN328 eradicated tumors.

"We are pleased with the rapid progress of our clinical programs, based on our proprietary TriTAC platform, with patient dosing now underway for our fourth product candidate, HPN328, that targets DLL3," said Natalie Sacks, M.D., Chief Medical Officer of Harpoon Therapeutics. "Treatment options for small cell lung cancer are limited, as are options for other DLL3-associated tumors such as neuroendocrine prostate cancer. Data from preclinical studies suggest that HPN328 has substantial anti-tumor activity, which provides the rationale for investigating its potential benefit in these patients."

"We are excited to participate in this trial of a promising agent that will hopefully benefit patients with small cell lung cancer and other neuroendocrine tumors," said Melissa Johnson, M.D., Program Director of Lung Cancer Research at Sarah Cannon Research Institute. The first patient was treated at Sarah Cannon Research Institute at Tennessee Oncology.

"I am excited that Harpoon's fourth TriTAC drug candidate, HPN328, has advanced into the clinic focusing on SCLC, an aggressive and deadly disease with a significant unmet need, as its initial indication," said Jerry McMahon, Ph.D., President and Chief Executive Officer of Harpoon Therapeutics. "Each of Harpoon's four TriTAC clinical programs are progressing well and we expect data to emerge from our clinical trials throughout 2021."