Early study results from Johnson & Johnson show promising antitumor activity with combination of pasritamig and docetaxel in advanced prostate cancer
February 26, 2026 – Biotechnology, Clinical Trials, Drug Discovery, Other, Pharmaceutical – ASCO 2026, Johnson & Johnson, Metastatic Castration-Resistant Prostate Cancer, T-cell engaging antibodies, oncology
- Combination demonstrates deep PSA responses and favorable safety profile with plans to advance into Phase 3
- Data highlight the potential of this first-in-class next-generation T-cell engager to expand the role of immunotherapy in prostate cancer.
26 February 2026 — New Jersey, US — Johnson & Johnson today announced preliminary results from a Phase 1b study evaluating pasritamig (JNJ-78278343), a first-in-class bispecific T-cell engaging antibody, in combination with docetaxel in patients with metastatic castration-resistant prostate cancer. The combination demonstrated a safety profile consistent with docetaxel alone, with no new or unexpected safety signals observed. The regimen also showed clinically meaningful efficacy, including high rates of prostate-specific antigen (PSA) responses and sustained PSA reductions, supporting continued development and advancement into Phase 3 studies. The results were presented for the first time at the 2026 American Society of Clinical Oncology (ASCO) Genitourinary Cancers Symposium (Abstract #171).
Pasritamig is designed to engage the immune system through a novel mechanism of action, binding CD3 on T cells and human kallikrein 2 (KLK2). KLK2 is a novel, highly specific prostate cancer target with minimal expression outside prostate tissue. By both activating and directing T cells to KLK2-expressing tumor cells, pasritamig enables targeted immune engagement. This differentiated, prostate-specific approach was intentionally built to focus immune activity on prostate cancer cells, which may help limit effects on healthy tissue, and supports administration in a doctor’s office rather than hospital setting.
“These data represent an important step forward for patients with advanced prostate cancer,” said Professor Shahneen Sandhu,* M.D., Ph.D., MBBS, FRACP, Associate Professor, Consultant Medical Oncologist and researcher at Peter MacCallum Cancer Centre, and study investigator. “In a disease where outcomes remain poor for many patients, seeing encouraging clinical activity alongside a favorable safety profile in combination with docetaxel reinforces the potential of this approach and supports further clinical development.”
“Based on these findings, we are increasingly confident in the potential of pasritamig to meaningfully improve outcomes for people with prostate cancer,” said Charles Drake, M.D., Ph.D., Vice President, Prostate Cancer and Cross Cancer Immuno-Oncology, Johnson & Johnson. “The ability to combine pasritamig with docetaxel, where prior approaches in the field have fallen short, gives us a strong foundation for Phase 3 development. What we’re seeing with this combination, including deep and durable PSA responses, underscores the promise of this combination immunotherapy approach and our commitment to advancing innovation that can make a difference for patients.”
About Johnson & Johnson
At Johnson & Johnson, we believe health is everything. Our strength in healthcare innovation empowers us to build a world where complex diseases are prevented, treated, and cured, where treatments are smarter and less invasive, and solutions are personal. Through our expertise in Innovative Medicine and MedTech, we are uniquely positioned to innovate across the full spectrum of healthcare solutions today to deliver the breakthroughs of tomorrow and profoundly impact health for humanity. Learn more at https://www.jnj.com/
