High-Dose Intravenous Vitamin C Combined with Docetaxel in Men with Metastatic Castration-Resistant Prostate Cancer:...

Area of Science:

• Oncology
• Clinical Trials
• Pharmacology

Background:

• High-dose intravenous vitamin C (HDIVC) shows preclinical promise for cancer treatment.
• Larger prospective randomized trials are needed to confirm HDIVC efficacy.
• Metastatic castration-resistant prostate cancer (mCRPC) remains a challenging diagnosis.

Purpose of the Study:

• To evaluate the clinical benefit of combining HDIVC with docetaxel in patients with progressive mCRPC.
• To assess the impact of HDIVC on prostate-specific antigen (PSA) response, adverse events, and survival.
• To investigate the role of HDIVC in improving quality of life and reducing oxidative stress.

Main Methods:

• A double-blind, placebo-controlled phase II trial randomized 47 mCRPC patients 2:1 to docetaxel with either HDIVC or placebo.
• Coprimary endpoints included PSA50 response and adverse event rates.
• Secondary endpoints assessed overall survival, radiographic progression-free survival, and quality of life.

Main Results:

• The PSA50 response rate was 41% with HDIVC versus 33% with placebo (P=0.44), with comparable adverse events.
• No significant differences were observed in quality of life scores.
• Median radiographic progression-free survival (10.1 vs 10.0 months) and overall survival (15.2 vs 29.5 months) were not significantly different.

Conclusions:

• Combining HDIVC with docetaxel did not improve PSA response, toxicity, or clinical outcomes in mCRPC patients.
• HDIVC did not reduce indicators of oxidative stress.
• Findings do not support the routine use of HDIVC in mCRPC treatment outside of clinical trials.