The tool helps predict who will respond best to prostate cancer therapy

A new prognostic tool developed by researchers at UCLA Jonsson Comprehensive Cancer Center and five other institutions helps predict which men with advanced metastatic prostate cancer will respond favorably to a new targeted therapy.

The tool, described in a study published today in Lancet Oncology, analyzes a wide range of images and clinical data and is intended to help physicians considering treating patients with prostate-specific membrane antigen Lutetium-177 or LuPSMA.

LuPSMA, which binds to PSMA proteins and provides targeted radiation to prostate cancer tissue, offers a new option to men with PSMA-positive metastatic cancer that is resistant to castration, meaning that it has stopped responding to hormone therapy. LuPSMA is currently pending approval by the U.S. Food and Drug Administration.

Candidates for therapy are usually examined using a technique initiated by UCLA and UC San Francisco called PSMA PET imaging, which combines positron emission tomography with a PET-sensitive drug to detect prostate cancer throughout the body and verify PSMA expression in tumors.

New research shows that a combination of clinical features and PSMA imaging features of PSMA and that it can be used to predict which patients will have improved progression-free survival (slower disease progression) and improved overall survival (hope of life) as a result of treatment.

“To date, there has been no validated tool to adequately predict the response of patients with advanced metastatic prostate cancer to treatment with LuPSMA,” said lead author Dr. Andrei Gafita, postdoctoral fellow in the Ahmanson division of translational thermostatics in the department of medical pharmacology at UCLA’s David Geffen School of Medicine. “Most importantly, this study suggests that screening with PSMA PET imaging could help select patients who are more likely to benefit from this treatment.”

Creating the “nomogram”

The predictive tool, commonly called a nomogram, was developed by researchers from institutions in Europe, Australia, and the United States who analyzed data from 270 prostates. cancer patients who were treated with LuPSMA a clinical trials or through compassionate use.

The research team used eight parameters, including the PSMA PET parameters and factors such as the time elapsed since the initial diagnosis, the state of chemotherapy and hemoglobin levels, to create the mathematical formula that allows the tool predict survival.

Based on the nomogram, the researchers also created a website risk calculator which predicts the probability of overall and progression-free survival in response to LuPSMA. Predictions are used to stratify men into high-risk or low-risk groups.

In the men studied, those identified by the tool as low risk had a longer overall survival (24 months) and progression-free survival (6 months) than those classified as high risk (6 months and 2 months, respectively).

The findings of the research are encouraging, Gafita said, and may provide the basis for patient selection for LuPSMA therapy. However, he points out that until its clinical validity is demonstrated in prospective trials, the tool should be used with caution and should not replace the clinical judgment of treating physicians.

“Our validation a tool it can find applications particularly in institutions where LuPSMA has just been introduced as a new therapeutic option, ”he said.