UPDATE: PSMA‑Targeted CAR‑NK Cells for mCRPC Shows Promising Results

A new, promising concept was explored for men with metastatic castration‑resistant prostate cancer: PSMA‑targeted CAR‑NK cells engineered to be an off‑the‑shelf immunotherapy that aims to combine targeted tumor killing with a safer toxicity profile. The work, presented at AUA 2026 meeting, comes from investigators affiliated with the Cancer Hospital, Chinese Academy of Medical Sciences, who translated a nonviral, engineered‑NK product from preclinical models into a first‑in‑human Phase 1 trial designed to test safety and early biological activity. (Note: we talked about it in this article)

The team moved an NK‑based product into clinical testing after showing robust, antigen‑dependent cytotoxicity in vitro against PSMA‑positive prostate cancer cells and tumor control in xenograft models, building a clear translational rationale to test the approach in patients. They chose nonviral engineering for the CAR to shorten manufacturing timelines and reduce vector‑related risks, and they tuned CAR signaling for NK effector programs so the product would deliver strong immediate cytotoxicity with limited long‑term persistence, a profile that could reduce severe cytokine release and neurotoxicity compared with some CAR‑T programs.

Efficacy signals were meaningful for an initial safety cohort.
Eight heavily pretreated men had received the product across four dose levels (DL1: 1 patient; DL2: 3 patients; DL3: 3 patients; DL4: 1 patient).
All patients had PSA reductions from baseline, four patients (50%) had PSA declines >30%, and three patients (37.5%) had declines >60%. Imaging at baseline and at one month showed disease stability in all eight patients, with one of the patient (DL3) demonstrating marked objective improvement across liver, nodal, and bone lesions alongside a maximal PSA fall of 68%, a depth of response that, if durable, would be noteworthy in this heavily pretreated population.

Taken together, these data deliver a clear message: an allogeneic, nonviral PSMA‑CAR‑NK product can be delivered safely and shows early biological activity in mCRPC. The limited persistence of the cells (detectable for about one to two weeks) likely contributes to the favorable acute safety profile but raises the practical question about durability of response. Future development will need to address whether repeated dosing, cytokine support, or combination strategies are required to convert these promising early PSA and imaging signals into lasting clinical benefit.

Source.