FRIDAY, June 4, 2021 (HealthDay News) — Patients with advanced prostate cancer may find new hope: Researchers identify a new potential treatment for metastatic castration-resistant men prostate cancer, for which there is no cure.
Metastatic castration-resistant prostate cancer means that the disease continues to spread despite treatments that eliminate male hormones (androgens) such as testosterone, which is thought to “feed” the tumor.
When added to standard care, this novel targeted radiotherapy improved survival for these cancer patients, the researchers report.
Dr Michael Morris, Head of the Prostate Cancer Section, said, “The study offers treatment potential where there was really little for the most advanced patient, but it opens a door to exploring the benefits of this drug in many earlier patient populations.” ” At Memorial Sloan Kettering Cancer Center in New York City.
In about 80% of prostate cancers, there is a protein on the surface of the cancer cell called prostate-specific membrane antigen (PSMA). It is also distributed on prostate cancer that has spread to bone, lymph nodes or soft tissue. Still, PSMA is not on normal tissues, so it was a good target for both diagnosis and therapeutics, Morris explained.
The new drug has two components, a targeting molecule and a payload that delivers radiation. It is given intravenously.
“Each molecule of the drug is trying to bind to the PSMA-containing cells, which are typically prostate cancer cells. As the drug binds to it, the cell brings the drug into the interior of the cell. Radiation, which is associated with the drug. So, it’s the payload of the drug, it’s also brought into the interior of the cell. And there, it irradiates the cell and kills it as well as neighboring cells,” Morris said.
To be part of the trial, patients must have had a disease that had progressed through testosterone-lowering therapy, which has been the standard for decades, Morris said. They also had to progress through another class of drugs known as androgen-receptor pathway inhibitors. chemotherapy.
“What happens when you go on for prostate cancer treatment is that if you respond, you stay on that therapy or stay on that regimen until no side effects prevent you from continuing the therapy. or it no longer works because the disease has become resistant to it,” Morris explained.
The trial involved 831 participants. Patients were randomized two-by-one between June 2018 and October 2019 to receive a new treatment called lutetium-labeled PSMA-617, plus standard care or just standard care.
The new treatment increased the overall median survival for these patients to 15.3 months versus 11.3 months for these patients who had very advanced disease. It also increased a measure called radiographic progression-free survival, which shows disease control while on the drug, from 3.4 months to 8.7 months.
The study is being presented online at the annual meeting of the American Society of Clinical Oncology, which will be held June 4-8. Findings presented at medical meetings are considered preliminary until published in a peer-reviewed journal. Drugmaker Novartis funded the study and plans to submit the data to regulatory authorities for review and possible approval.
Prostate cancer is the most common cancer in American men and the second leading cause of cancer-related death. The positive results of the study mean that patients who have very advanced disease may have a new treatment option.
“It also means that, usually in prostate cancer as well as other diseases that you develop and explore as a new therapy for the most advanced patients, the patients usually benefit earlier and Often we will see those benefits in less ill patients who have less-resistant disease,” Morris said.
Current studies are now looking at therapy for patients who have a prior disease, who have not yet received chemotherapy, as well as those who are just starting treatment for prostate cancer.
Ash Tiwary, systems chair in the Milton and Carroll Petrie Department of Urology at Mount Sinai Health System in New York City, said the study offers a lot of promise for patients, offering new hope to those with advanced prostate cancer. It also has a reasonable side effect profile, said Tiwari, who was not involved in the study.
“Androgen deficiency is a mainstay of treatment for advanced prostate cancer, but cure rates are low and patients eventually become castrate-resistant,” Tewari said. “Therapies need to be tailored more closely to the individual patient profile.”
The study found that taking into account the average outcomes for overall survival, Tiwari said the additional four months of life could be very meaningful for someone who lives to see an important family milestone, such as Grandson’s wedding.
“This is a good example of when a well-conducted clinical trial backed by scientific data can have an impact in a patient’s life. And we should always look at these options with curiosity, caution,” he said.
US National Cancer Institute offers more prostate cancer.
SOURCES: Michael Morris, MD, medical oncologist, head, Prostate Cancer Section, Memorial Sloan Kettering Cancer Center, New York City; Ash Tiwary, MD, professor and systems chair, Milton and Carroll Petrie Department of Urology, Mount Sinai Health System, New York City; 2021 Annual Meeting of the American Society of Clinical Oncology, June 4-8, 2021