15 November 2018 - - US-based clinical-stage immunotherapy company Harpoon Therapeutics, Inc has closed a USD 70m Series C equity financing, the company said.

OrbiMed served as the lead new investor, along with new investors Cormorant, Ridgeback Capital Investments, Lilly Asia Ventures and NS Investment.

Harpoon's existing investors MPM Capital, Oncology Impact Fund, Arix Bioscience, New Leaf Venture Partners and Taiho Ventures, LLC also participated in the Series C financing round.

Harpoon plans to use the proceeds from the financing to support further advancement of its immunotherapy programs based on its TriTAC (Tri-specific T cell Activating Construct) and ProTriTAC (Protease-activated Tri-specific T Cell Activating Construct) platforms, which are designed to harness the natural power of the body's immune system to fight cancer and other diseases.

Harpoon's TriTAC platform was designed to advance the therapeutic potential of T cell engagers, with a long half-life extended format.

Harpoon is developing a pipeline of four wholly owned TriTAC product candidates. Harpoon's lead product candidate, HPN424, is currently in a Phase 1 clinical trial for the treatment of metastatic castration-resistant prostate cancer, or mCRPC.

In addition, in 2019, Harpoon plans to initiate Phase 1 clinical trials for HPN536 (a mesothelin-targeting TriTAC) for the treatment of mesothelin-expressing tumors, and HPN217 (a BCMA-targeting TriTAC) for the treatment of multiple myeloma.

The ProTriTAC platform effort is yielding T-cell engagers against additional targets based on tumor protease-dependent activation in the tumor microenvironment, and Harpoon expects to advance its first ProTriTAC product candidate to IND-enabling studies in 2019.

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 T cell engagers, or TriTACs, initially focused on the treatment of solid tumors and hematologic malignancies.

Harpoon recently announced its second technology platform, ProTriTAC, that applies a prodrug concept to TriTAC in order to create T cell engagers that are designed to be preferentially active in the tumor microenvironment.