According to a study presented at the Society of Nuclear Medicine and Molecular Imaging 2023 Annual Meeting, tailoring treatment intervals based on early-response biomarkers can improve outcomes for men undergoing 177Lu-PSMA prostate cancer treatment.
The treatment method approved by the FDA in 2022, is effective for treating metastatic castration-resistant prostate cancer. However, responses to treatment can vary significantly between patients.
Standardized Dosing May Not Be Ideal
“Currently, a standardized dosing interval is used for 177Lu-PSMA treatment,” said Andrew Nguyen, senior staff specialist at St. Vincent’s Hospital in Sydney.
“However, monitoring early-response biomarkers to adjust treatment intervals may improve patient outcomes.”
Details of the Study
The study followed 125 men receiving six weekly doses of 177Lu-PSMA as part of a clinical program.
Researchers used 177Lu-SPECT/CT imaging after each dose and assessed patients’ prostate-specific antigen (PSA) levels after the second dose to determine future treatment plans.
Patients were divided into three groups based on their responses. Group 1 (35% of participants), who showed a substantial reduction in PSA levels and partial response on imaging, were advised to stop treatment until PSA levels increased.
Group 2 (34%), with stable or decreased PSA and disease stability on imaging, continued their six-week treatment plan until it was no longer beneficial.
Group 3 (31%), whose PSA levels rose and showed disease progression on imaging, were offered the chance to try a different treatment.
Results and Future Implications
The personalized dosing strategy allowed one-third of the patients to take a “treatment holiday” while maintaining the same progression-free and overall survival outcomes.
Another third of the men, who showed early signs of disease progression, were given the chance to try a potentially more effective therapy.
The median treatment-free time for patients who paused treatment was 6.1 months. Median overall survival was 19.2 months, 13.2 months, and 11.2 months for Groups 1, 2, and 3, respectively.
According to Nguyen, St. Vincent’s Hospital will continue stratifying patients by these early response biomarkers.
If the results are confirmed in a prospective clinical trial, he hopes the strategy will be more widely adopted to improve patient outcomes.
If you care about prostate cancer, please read studies about 5 types of bacteria linked to aggressive prostate cancer and a new strategy to treat advanced prostate cancer.
For more information about prostate cancer, please see recent studies about new ways to lower the risk of prostate cancer spread, and results showing three-drug combo boosts survival in metastatic prostate cancer.
The study was published in the Journal of Nuclear Medicine.
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