Candel Therapeutics, Inc. (CADL) has announced positive results from its Phase III clinical trial evaluating CAN-2409, a viral immunotherapy, in patients with localized prostate cancer. The study met its primary endpoint, demonstrating a statistically significant improvement in disease-free survival (DFS) when CAN-2409 was combined with radiation therapy and valacyclovir, compared to standard of care (SOC) alone.
The Phase III trial enrolled 745 patients with intermediate-to-high-risk localized prostate cancer. Participants were randomized to receive either CAN-2409 plus valacyclovir with SOC or SOC alone. The trial was conducted under a Special Protocol Assessment (SPA) with the U.S. Food and Drug Administration (FDA).
Clinically Meaningful Improvement in Disease-Free Survival
According to the company's press release, patients treated with the CAN-2409 combination achieved a 14.5% relative improvement in DFS compared to the placebo control arm after 54 months. The study also revealed a highly significant effect of CAN-2409 on prostate cancer-free survival (p=0.0046). Furthermore, the treatment arm demonstrated a substantial increase in the proportion of patients achieving a prostate-specific antigen (PSA) nadir, a marker associated with better cancer control outcomes, compared to the placebo control arm (67.1% vs. 58.6%, respectively; p<0.0164).
Dr. Glen Gejerman, a principal investigator in the trial, stated, "The improvement observed in disease-free survival in this Phase III clinical trial is clinically meaningful. We have not seen significant advances in this indication in decades. CAN-2409 has demonstrated the potential to significantly improve long-term outcomes without adding substantial toxicity to standard-of-care radiation."
Pathological Complete Responses and Safety Profile
Two-year post-treatment biopsies showed an 80.4% pathological complete response rate in CAN-2409-treated patients, compared to 63.6% in the control arm (p=0.0015). The median follow-up time for the study population was 50.3 months.
The company reported that CAN-2409 was generally well-tolerated, with a safety profile consistent with previous studies. No new safety signals were identified. Adverse events related to treatment with the candidate were mostly mild to moderate in severity, including flu-like symptoms, fever, and chills.
Regulatory Pathway and Market Opportunity
Candel plans to initiate discussions with the FDA regarding the regulatory pathway for CAN-2409 in intermediate-to-high-risk localized prostate cancer. The company believes that the data generated from this study could be sufficient to seek regulatory approval for CAN-2409 in this indication.
Paul Peter Tak, president and CEO of Candel, noted that the study validates previous observations of CAN-2409 activity in difficult-to-treat solid tumors and confirms synergies with radiation therapy in prostate cancer models. He also emphasized that the SPA agreement with the FDA means that the safety and efficacy data could be sufficient for regulatory approval.
In the United States, over 100,000 men are diagnosed annually with localized prostate cancer, with more than 50,000 receiving radiotherapy. Candel estimates the addressable market for CAN-2409 in this area to be over $10 billion.
Phase II Monotherapy Trial
Candel also reported top-line data from its Phase II study evaluating CAN-2409 as a monotherapy in patients with low-to-intermediate risk localized prostate cancer undergoing active surveillance. While the data showed numerical improvement in time to radical treatment and the percentage of patients achieving negative biopsies at 1-year post-treatment, these improvements did not reach statistical significance.
