A firm developing therapies that leverage immune cells to treat solid tumors has closed its latest round of equity financing.
Harpoon Therapeutics said Sunday that it had raised $70 million in the Series C round, led by OrbiMed, with new investors Cormorant, Ridgeback Capital Investments, Lilly Asia Ventures and NS Investment participating. Also participating were existing investors MPM Capital, Oncology Impact Fund, Arix Bioscience, New Leaf Venture Partners and Taiho Ventures.
The South San Francisco, California-based company is developing T-cell engagers using its platform, dubbed Tri-specific T-cell Activating Construct, or TriTAC, along with a protease-activated form, ProTriTAC. Its lead product, HPN424, is in a Phase I study for metastatic, castration-resistant prostate cancer. According to the ClinicalTrials.gov database, the trial started at the end of July and is planned to enroll 40 patients, particularly at the Sarah Cannon Research Institute in Nashville, Tennessee.
Next year, Harpoon plans to start a Phase I study of another candidate, the mesothelin-targeting HPN536, in mesothelin-expressing tumors, as well as the BCMA-targeting HPN217, in in the blood cancer multiple myeloma. The first ProTriTAC product candidate is expected to enter IND-enabling studies – preclinical studies to support clinical investigational – also next year. The company also has undisclosed targets under the TriTAC platform for which it has partnered with Chicago-based drugmaker AbbVie, in addition to HPN823, a DLL3-targeting drug in preclinical studies for small-cell lung cancer, according to its pipeline page.
The only T-cell engager currently on the market is Amgen’s Blincyto (blinatumomab), which targets the CD19 antigen and is used to treat acute lymphoblastic leukemia, developed using the company’s Bi-specific T-cell Engager, or BiTE platform. At the upcoming American Society of Hematology meeting, Amgen plans to present Phase I data on AMG 420, a BCMA-targeting BiTE antibody for multiple myeloma. According to an abstract, among 35 patients treated with AMG 420, six achieved complete responses at various dose levels. Bispecific antibodies like AMG 420 and others under development by companies like Celgene and GlaxoSmithKline are seen as potential competition to BCMA-targeting CAR-T cell therapies for multiple myeloma, particularly Celgene-partnered bluebird bio’s bb2121, though there is evidence the two modalities could be used sequentially.
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