With the FDA set for a speedy review of Novartis’ new targeted radioligand therapy for a stubborn form of prostate cancer, a new survey by Cardinal Health shows the drug is already winning favor with oncologists.
But although the majority of cancer specialists are showing enthusiasm for the therapy, known as 177Lu-PSMA-617, they also pointed to logistical challenges that could dampen its uptake.
“While these providers are impressed with the [safety and efficacy] data, aspects of the eligibility criteria are concerning,” the report concluded. “Further research is needed to assess all factors influencing providers’ decision-making.”
The Swiss drugmaker picked up the drug in its $2.1 billion acquisition of Endocyte in 2018 and secured a priority review from the FDA last September, setting it up for a potential FDA nod for patients with metastatic castration-resistant prostate cancer during the first half of this year.
Cardinal Health asked 287 community oncologists about their perceptions of the drug based on phase 3 trial results showing it added four months to the lives of patients and reduced the risk of death by 38% when given alongside the standard of care.
In an encouraging sign for the drugmaker, more than half (51%) of the oncologists found both the safety and efficacy data “compelling” and said they were “very likely” to prescribe it to their patients, while another 33% said they were “somewhat likely” to prescribe it based on the efficacy data alone. Just 1% said they did not find the safety and efficacy data compelling and were “not at all likely” to prescribe the treatment.
But the survey also highlighted potential sticking points. Key among them was the need for a diagnostic test known as a PSMA-gallium scan to determine whether a patient’s cancer expresses a protein that makes them a suitable candidate for the drug. Sixty-eight percent of oncologists said access to the scan was the biggest potential barrier to treatment.
A sizable percentage (64%) also raised concerns about the availability and access to the drug itself. The drug must be administered in a nuclear-licensed facility, meaning most community oncologists would need to send their patients off-site for treatment, Bruce Feinberg, D.O., Cardinal Health’s chief medical officer and a co-author of the study, said in an interview.
He said Novartis will need to work to ensure the additional steps don’t become barriers to treatment, particularly since there’s a competing drug already on the market: Bayer’s radium-223 radiotherapy Xofigo, which was approved in 2013. That drug also must be administered in a nuclear-licensed facility but has a different mechanism of action and doesn’t require a PSMA scan, Feinberg said. Patients enrolled in the Novartis phase 3 clinical trial were not allowed to have received that drug, which the oncologists flagged as a limitation of the study.
“The precision medicine story is very compelling, and, if it turns out that I can get these scans done quickly and I have a therapy which I know is going to be impacting the patient population that I’m treating, then I may be more likely to use [the Novartis] therapy,” Feinberg said. But if the logistics become too unwieldy, “the result of that may be a greater likelihood of just taking the easier step and giving the drug that’s already in the market.”
Radioligand therapies like the Novartis drug combine a small molecule or peptide that targets a protein found in cancer cells with a radioactive material that blocks tumor growth by damaging DNA. They deliver radiation more precisely than traditional radiation therapy does, killing cancer cells while sparing healthy cells.
In the case of 177Lu-PSMA-617, the ligand targets a protein in prostate cancer cells known as PSMA to deliver radiation from a radioactive isotope of lutetium. The treatment aims to help patients who have run out of other treatment options.
The drug is considered the crown jewel in Novartis’ growing radioligand portfolio, which it has been building up through a series of acquisitions including deals with Molecular Partners and iTheranostics last year.
Cardinal Health surveyed the oncologists during virtual meetings between June and October 2021 and presented the findings last week at the American Society of Clinical Oncologists Genitourinary Cancers Symposium. Feinberg said if the drug is approved, the healthcare services company will conduct follow-up surveys to gain a clearer picture of how it’s being used in practice.