Adding metastasis-directed therapy (MDT) to intermittent hormone therapy improves disease control in patients with oligometastatic prostate cancer, according to research published in JAMA Oncology.
Researchers found that MDT plus hormone therapy improved progression-free survival (PFS) and eugonadal PFS, compared with hormone therapy alone, in the phase 2 EXTEND trial.
The trial (ClinicalTrials.gov Identifier: NCT03599765) enrolled patients with multiple oligometastatic solid tumors, including 87 patients with prostate cancer. These patients had 5 or fewer metastases and were treated with hormone therapy for at least 2 months prior to enrollment.
Half of patients (n=43) received MDT and hormone therapy, and the other half (n=44) received hormone therapy alone. Baseline characteristics were well balanced between the arms.
MDT consisted of radiation to all sites of disease. Hormone therapy consisted of a luteinizing hormone–releasing hormone agonist/antagonist with or without a second-generation androgen receptor-targeting agent. A planned hormone therapy break occurred 6 months after enrollment, and patients resumed hormone therapy at progression.
At a median follow-up of 22 months, the median PFS and median eugonadal PFS were improved in the MDT arm. The median PFS was not reached in the MDT-hormone therapy arm and was 15.8 months in the hormone therapy-alone arm (hazard ratio [HR], 0.25, 95% CI, 0.12-0.55, P <.001). The median eugonadal PFS was not reached in the combination arm and was 6.1 months in the control arm (HR, 0.32; 95% CI, 0.11-0.91; P =.03).
The overall survival data were immature, and the median time to subsequent systemic therapy was similar between the treatment arms.
There were no grade 4 or 5 adverse events (AEs) in either arm. Grade 3 AEs in the combination arm were hypertension (n=1), prostate infection (n=1), and urinary tract pain (n=1). Grade 3 AEs in the hormone therapy-alone arm were noninfective cystitis (n=1), lymphocyte decrease (n=1), and sepsis (n=1).
The researchers concluded that combining MDT with intermittent hormone therapy “may allow for excellent disease control while facilitating prolonged eugonadal testosterone intervals” in patients with oligometastatic prostate cancer.
Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.
Tang C, Sherry AD, Haymaker C, et al. Addition of metastasis-directed therapy to intermittent hormone therapy for oligometastatic prostate cancer: The EXTEND phase 2 randomized clinical trial. JAMA Oncol. Published online April 6, 2023. doi:10.1001/jamaoncol.2023.0161
This article originally appeared on Cancer Therapy Advisor