Breaking Down the Phase 2 LASER trial of 177Lu-PSMA-617 in Clear Cell RCC

The ongoing phase 2 LASER trial (NCT06964958) is evaluating whether 177Lu-PSMA-617, a beta-emitting prostate-specific membrane antigen (PSMA)-targeting radiopharmaceutical, is efficacious and safe as a treatment option for patients with PSMA-positive advanced clear cell renal cell carcinoma (RCC).

Praful Ravi, MB, BChir, MRCP, spoke with CancerNetwork® at the 2025 Kidney Cancer Research Summit following his presentation on the trial. When prompted about the trial design, he mentioned the pretreated nature of the patient population: all were required to have received immunotherapy and a tyrosine kinase inhibitor (TKI), either sequentially or combined. All patients were also required to have PSMA-avid disease with no PSMA-negative lesions.

Further, the trial plans to, at first, enroll 9 patients, and then once 1 response is observed, enroll an additional 15 patients. Out of those 24 patients, if 3 have responses, the trial will be considered successful.

Ravi, a medical oncologist at the Lank Center for Genitourinary Oncology at Dana-Farber Cancer Institute, was unable to comment on the status of dosing and tolerability, as no patient had received treatment at the time of the interview; however, LASER plans to treat the first person by the end of July.

Transcript:

CancerNetwork: How is this trial designed?

The standard therapies are immune therapy and TKI, so [patients need to have] at least 1 of each; they can be in combination or sequentially. It’s a phase 2 study, it’s a single-center study, it’s a small study, it’s an academic trial, and it’s an investigator-sponsored trial. Novartis is funding and providing the drug. The eligibility is that patients will get a PSMA PET/CT, and if they’ve got PSMA-avid disease and no PSMA-negative lesions, they’ll be eligible to get 2 cycles of treatment, then, they will have another PET scan. If that PET scan shows residual avid disease, they’ll get up to 4 more cycles. If that PET scan shows no residual avid disease, they’ll stop treatment. The plan is to enroll 9 patients. Initially, if we see at least 1 response out of those 9 patients, we’ll enroll a further 15 patients. The trial will be successful, or [we’ll] declare it a success if we see at least 3 out of 24 responses overall.

When will the first patient be dosed?

The trial just activated 2 weeks ago, so we’ve had a couple of patients already screened. It’s too early to say. No patient has yet received treatment as we speak, but probably by the end of the month, we’ll have the first patient [receive treatment].

Reference

Ravi P, Xie W, Berg S, et al. LASER – a phase 2 trial of 177Lu-PSMA-617 as systemic therapy for renal cell carcinoma. Presented at the 2025 Kidney Cancer Research Summit; July 17-19, 2025; Boston, MA.