Experimental Cancer Drugs Show Promise in Prostate and Lung Cancer Trials

An experimental immunotherapy drug has shown early promise in treating advanced prostate cancer, with nearly half of patients experiencing tumor shrinkage in an ongoing clinical trial. Meanwhile, Eli Lilly's cancer drug selpercatinib demonstrated a significant reduction in recurrence risk for early-stage lung cancer patients in a separate Phase 3 trial.

The prostate cancer drug, known as VIR-5500, is a "masked T-cell engager" designed to activate the body's immune system to fight cancer. Early trial results showed that 82% of patients receiving the highest doses experienced drops in PSA levels, a key marker used to track prostate cancer. In the ongoing, not yet peer-reviewed trial, patients with advanced prostate cancer who had not responded to other treatments were given VIR-5500, with nearly half showing tumor shrinkage both at primary sites and in metastatic tumors that had spread beyond the prostate.

"We believe that such treatments may in the long term lead to cures," said the lead researcher. "We do need more data, but the results are stunning." Because these trials are still ongoing and involve small patient groups, it's too early to determine full clinical success, and the data have not yet been peer-reviewed. Still, the early findings offer promising hope for treating cancers that have been difficult to target with existing immunotherapies.

In lung cancer research, Eli Lilly's Phase 3 LIBRETTO-432 clinical trial for Retevmo (selpercatinib) demonstrated a highly statistically significant improvement in event-free survival for patients with early-stage non-small cell lung cancer. The trial results showed that selpercatinib significantly reduced the risk of disease recurrence or death in patients with RET fusion-positive non-small cell lung cancer. This trial is the first randomized Phase 3 study evaluating a selective RET kinase inhibitor as adjuvant therapy, reinforcing the value of genomic testing in cancer treatment.

The overall safety profile of selpercatinib was consistent with previous studies, and detailed results are expected to be presented at an upcoming medical congress. The trial enrolled 151 patients who received either selpercatinib or placebo, marking a significant step in the treatment of early-stage lung cancer.

A separate study published in JAMA Network Open revealed that racial disparities persist in receipt of curative treatment for early-stage non-small cell lung cancer. The analysis included 28,287 non-Hispanic Black and non-Hispanic White patients aged 66 to 85 years who received a diagnosis of stage I or II NSCLC. Overall, 82.3 percent of patients received curative treatment, but adjusted probabilities of receiving curative treatment were significantly lower for Black patients compared with White patients across multiple time periods.

These disparities were associated primarily with surgical treatment across time, with a sharp increase in stereotactic body radiotherapy use observed. "If you're developing cures for cancer, but it's not getting into the hands of everybody who needs it, then you haven't succeeded," said the study author. "The next step has to ask why — and what we're going to do differently."

The prostate cancer findings offer hope for treating other cancers as well. If further research confirms that masked T-cell engagers are safer and more effective, they could be combined with standard treatments such as chemotherapy or radiation to achieve stronger results. Similar therapies are already showing early promise in prostate cancer, with trials underway for pancreatic, colorectal, and lung cancers.