 Presented positive interim Phase 1 clinical trial data for PSMA-targeting HPN424 in prostate cancer at ASCO20, supporting increased dose escalation Dosed first patient with HPN217 targeting BCMA for the treatment of multiple myeloma, triggering a 50 million milestone payment from AbbVieSOUTH SAN FRANCISCO, Calif., Aug. 05, 2020 GLOBE NEWSWIRE -- Harpoon Therapeutics, Inc. Nasdaq: HARP, a clinical-stage immunotherapy company developing a novel class of T cell engagers, today reported financial results for the second quarter ended June 30, 2020 and provided a corporate update.Our TriTAC T cell engager pipeline continues to advance and we were pleased with the encouraging interim Phase 1 data for our lead program, HPN424, that we presented at the ASCO20 Virtual meeting, said Gerald McMahon, Ph.D., President and Chief Executive Officer of Harpoon Therapeutics. We also announced early data from our second program, HPN536, which has continued to advance in a dose escalation trial for mesothelin malignancies. In addition, we advanced our third clinical program, HPN217, into the clinic which triggered a 50 million milestone payment from AbbVie, and submitted an IND for HPN328, our fourth TriTAC pipeline program. Looking ahead to the second half of 2020, we are preparing to advance HPN328 into the clinic for the treatment of DLL3-expressing tumors including small cell lung cancer.Second Quarter 2020 Business Highlights and Other Recent Developments In April, Harpoon announced the first patient was dosed with HPN217 in a Phase 12 clinical trial focused on relapsedrefractory multiple myeloma RRMM. HPN217 is covered by a global development and option agreement with AbbVie Inc. and dosing of the first patient in the clinical trial triggered a 50 million milestone payment, which was received in June. HPN217 targets B-cell maturation antigen BCMA, a well-validated target expressed on multiple myeloma cells. HPN217 is Harpoons third product candidate to enter the clinic. In April, Harpoon appointed Andrew R. Robbins and Joseph S. Bailes, M.D., to its Board of Directors as independent board members. Among his many achievements, Mr. Robbins is credited with leading the highly successful U.S. launch of BRAFTOVI encorafenib MEKTOVI binimetinib in BRAF-mutant metastatic melanoma. Dr. Bailes is a medical oncologist with substantial experience in clinical practice, legislation, public policy and advocacy. For nearly two decades, he served in various executive leadership capacities with ASCO, including as President. In May, Harpoon presented interim data from the ongoing dose-escalation portion of a Phase 1 trial for HPN424 in patients with metastatic castration-resistant prostate cancer mCRPC at the American Society of Clinical Oncology ASCO 2020 Virtual Scientific Program. At the time of the data cutoff, 44 patients with progressive mCRPC had been treated in 11 cohorts. Initial safety data showed that HPN424 is generally well tolerated, and cytokine-related adverse events were transient and manageable. Early signals of clinical activity were suggested by multiple patients remaining on study for more than 24 weeks, and several patients with serum PSA declines. Additionally, pharmacokinetic data confirmed half-life extension, which supports the weekly dosing schedule, and pharmacodynamic data supports T cell activation and target engagement, which are consistent with the expected mechanism of action. Patient enrollment continues in the dose escalation phase of the trial in the U.S. and Europe, with a goal to identify a dose for an expansion phase planned for the second half of 2020. In May, Harpoon provided a corporate pipeline update. In addition to reiterating and expanding upon HPN424 data presented at ASCO20, Harpoon provided an update on HPN536, its TriTAC currently being studied for the treatment of mesothelin-expressing tumors. Harpoon highlighted that the dose escalation portion of the study was progressing and, as of May 2020, included 15 ovarian and 10 pancreatic cancer patients. Adverse events were shown to be transient and manageable, and early pharmacokinetic data showed half-life extension supporting once-weekly dosing. In addition, Harpoon also presented advancements in the companys second platform, ProTriTAC, which builds upon the core elements of the TriTAC platform by utilizing a prodrug approach, designed to allow T cell engagers to address cancer targets that would be limited by on-target toxicities. In July, Harpoon appointed Joanne Viney, Ph.D., to its board of directors as an independent board member. Dr. Viney is an entrepreneurial scientist and experienced biotech executive with deep autoimmune and inflammatory disease expertise and currently serves as President, CSO and Co-founder of Pandion Therapeutics.Second Quarter 2020 Financial Results Harpoon ended the second quarter of 2020 with 175.4 million in cash, cash equivalents, and marketable securities compared to 155.1 million as of December 31, 2019. The increase was due to a 50.0 million milestone payment received from AbbVie, partially offset by cash used in operations. Revenue for the second quarter ended June 30, 2020 was 2.8 million compared to 1.1 million for the second quarter ended June 30, 2019. For the six months ended June 30, 2020, revenue was 6.1 million compared to 2.1 million for the six months ended June 30, 2019. During both the three and six month periods, the increase in revenue was primarily due to revenue recognized from the upfront payment under the development and option agreement with AbbVie, signed in November 2019. Research and development RD expense for the second quarter ended June 30, 2020 was 11.9 million compared to 10.0 million for the second quarter ended June 30, 2019. For the six months ended June 30, 2020, RD expense was 24.4 million, compared to 19.4 million for the six months ended June 30, 2019. The increase for both periods primarily arose from higher clinical development and personnel-related expense, which included conducting preclinical studies and the continuation and preparation of the clinical trials for HPN424, HPN536, HPN217 and HPN328. These higher expenses were offset by a decrease in manufacturing costs due to a scale up of manufacturing activities in 2019 compared to 2020 to support our four TriTAC product candidates in various stages of development. General and administrative GA expenses for the quarter ended June 30, 2020 was 3.9 million compared to 3.7 million for the quarter ended June 30, 2019. GA expense for the six months ended June 30, 2020 was 7.9 million compared to 9.6 million for the six months ended June 30, 2019. For the quarter ended June 30, 2020, the increase was primarily attributable to an increase in personnel expenses due to an increase in headcount, offset by a decrease in legal fees associated with the Maverick Litigation incurred in 2019. For the six months ended June 30, 2020, the decrease was due to higher expenses incurred in 2019 primarily related to legal fees associated with Maverick litigation and consulting and accounting services, partially offset by an increase in personnel expenses related to an increase in headcount and other professional services to support our operations as a public company. Net loss for the quarter ended June 30, 2020 was 12.7 million compared to 11.8 million for the quarter ended June 30, 2019. The net loss for the six months ended June 30, 2020 was 25.2 million compared to 25.4 million in the first six months of the prior year.COVID-19 Update In response to the ongoing COVID-19 pandemic, Harpoons executive offices remain closed in compliance with county and state shelter-in-place orders, substantially all of the companys employees continue to telecommute, with only a limited the number of staff working in the companys laboratory. Harpoon is currently continuing its clinical trials it has underway at sites in the United States, and has not yet experienced any material delays or impacts as a result of the pandemic. In addition, Harpoons third-party contract manufacturers continue to operate at or near normal levels and the company does not currently anticipate material interruptions. Harpoon continues to assess the potential impact of the COVID-19 pandemic on its business and operations, including its programs, expected timelines, expenses, manufacturing and clinical trials. The full extent to which the COVID-19 pandemic may have a negative impact on Harpoons business, results of operations and financial condition will depend on future developments that are highly uncertain and cannot be accurately predicted.About Harpoon TherapeuticsHarpoon Therapeutics is a clinical-stage immunotherapy company developing a novel class of T cell engagers that harness the power of the bodys immune system to treat patients suffering from cancer and other diseases. T cell engagers are engineered proteins that direct a patients 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 12a trial for metastatic castration-resistant prostate cancer. HPN536 targets mesothelin and is in a Phase 12a trial for cancers expressing mesothelin, initially focused on ovarian and pancreatic cancers. HPN217 targets BCMA and is in a Phase 12 trial for relapsed, refractory multiple myeloma. HPN328 targets DLL3 and Harpoon plans to initiate a Phase 12 trial in the second half of 2020. 