New York: Results from a recent study showed padeliporfin vascular-targeted photodynamic therapy (PDT) to be effective for partial-gland ablation of intermediate-risk prostate cancer. The study, based on interim results of a prospective phase IIb trial was presented remotely as part of the canceled 2020 Annual Meeting of the American Urological Association (AUA).
The results demonstrated comparative efficacy in low-risk prostate cancer in this phase II study designed specifically to evaluate vascular-targeted photodynamic therapy for intermediate-risk disease.
Andrew T. Tracey, Memorial Sloan Kettering Cancer Center, New York, and colleagues had aimed to investigate padeliporfin vascular-targeted photodynamic therapy for intermediate-risk prostate cancer.
The study included 50 men with grade group 2 cancer (Gleason 3-4) evaluated via transrectal ultrasound-guided biopsy. They were treated with one to two sessions of unilateral hemiablation using padeliporfin vascular-targeted photodynamic therapy.
A total of 50 men were treated, 49 underwent 3-month biopsy, and 40 of 49 (82%) exhibited no grade group ≥2 cancer in the index lobe at 3 months.
MRI and template, 14-core transrectal ultrasound-guided biopsy (with fusion for Prostate Imaging–Reporting and Data System 3+ lesions) were performed 3 and 12 months after treatment.
Gleason grade 4 or 5 (grade group 2+) cancer was the primary endpoint. Additional data included adverse events and patient-reported quality of life.
Key findings include:
Of 49, 11 (22%) underwent per-protocol second hemiablation treatment for grade group 2 tumor at 3 months: 9 for residual cancer and 3 for newly identified tumors (n = 2, contralateral; n=1, bilateral).
A total of 16 men have undergone 12-month biopsy: 15 of 16 (94%) exhibited no Gleason grade 4 or 5 cancer, including 6 of 7 (86%) patients who received two treatments.
Of the remaining men awaiting 12-month biopsy, 30 of 33 (91%) exhibited no grade group 2+ cancer detected on 3-month biopsy in the treated lobe.
By 3 months, the median decline in International Index of Erectile Function 5 score from baseline was –1.0 (interquartile range, –7, 0).
Median improvement in International Index of Erectile Function 5 score was –1.0 (interquartile range, –1 to 5), with pad-free continence observed in 100% of patients.
Grade 3 treatment-related adverse events occurred in 6 (12%) patients. All procedure-related prostate/pelvic pain resolved by 3 weeks.
"These interim data suggest that padeliporfin vascular-targeted photodynamic therapy may be effective for partial-gland ablation of intermediate-risk prostate cancer, the researchers concluded. "The therapy exerts minimal impact on urinary and sexual function."