Phase 1 Trial Overview
The phase 1 poly-ICLC trial (NCT03262103) represents a significant step forward in the treatment of locally advanced oligometastatic prostate cancer. Led by Ash Tewari, MBBS, MCh, FRCS, and discussed by Ketan K. Badani, MD, the trial tested the safety of a novel approach: developing a personalized vaccine from biopsied prostate cancer cells and administering it through sequential intratumoral plus systemic intramuscular injection of poly-ICLC.
Safety and Efficacy
Safety results, published in Cancer Research and presented at major urologic oncology conferences, revealed that the treatment was well tolerated. Among 12 evaluable patients, there were no dose-limiting toxicities or treatment-emergent adverse event withdrawals. Notably, 80% of patients (8 out of 10) had prostate-specific antigen (PSA) levels of less than 0.1 ng/ml at 1 year of follow-up, and 66.7% (8 out of 12) showed a lower Gleason score post-radical prostatectomy.
Implications for Prostate Cancer Treatment
This trial underscores the potential of personalized vaccines in prostate cancer treatment, offering a mechanism to target cancer cells via specific biomarkers like PSMA. The approach aims to reduce and eliminate metastatic disease, enabling localized treatment with curative intent. While the extrapolation of this vaccine strategy to other cancers, such as kidney cancer, remains complex, the ongoing trials for prostate cancer mark an exciting advancement in oncology.
Conclusion
The phase 1 trial's findings highlight the safety and potential efficacy of a personalized vaccine approach in treating locally advanced oligometastatic prostate cancer. As research progresses, this strategy could significantly impact the management and treatment outcomes for patients with this challenging condition.
Reference: Nair SS, Chakravarty D, Balan S, et al. Abstract CT023: Prostate cancer in situ autovaccination with the intratumoral viral mimic poly-ICLC: making a cold tumor hot. Cancer Res. 2024;84(suppl 7):CT023. doi:10.1158/1538-7445.AM2024-CT023
