Candel Therapeutics’s CAN-2409 Excels in Phase III Trial, Improving Disease-Free Survival in Prostate Cancer

Groundbreaking Results for CAN-2409 Viral Immunotherapy in Prostate Cancer

Candel Therapeutics , a clinical-stage biopharmaceutical company, has announced the positive topline results from its Phase III clinical trial evaluating CAN-2409 viral immunotherapy in patients with localized prostate cancer. The trial successfully met its primary endpoint, demonstrating a statistically significant and clinically meaningful improvement in disease-free survival (DFS) for patients treated with CAN-2409 in combination with radiation therapy, compared to radiation therapy alone.

The trial, conducted under a Special Protocol Assessment (SPA) with the U.S. Food and Drug Administration (FDA), enrolled 745 patients with intermediate-to-high-risk, localized prostate cancer. The treatment arm received CAN-2409 in combination with valacyclovir and standard radiation therapy, while the control group received radiation therapy alone. The results show a 14.5% relative improvement in DFS at 54 months for patients treated with CAN-2409, marking a significant advancement in the treatment of localized prostate cancer.

A New Treatment Paradigm for Prostate Cancer

Prostate cancer remains the second-leading cause of cancer death among men in the United States, with over 100,000 new diagnoses each year. The market for localized prostate cancer treatment is substantial, potentially exceeding $10 billion in the U.S. alone. Despite the prevalence of the disease, treatment options for localized, non-metastatic prostate cancer have seen little innovation in the last two decades.

CAN-2409 is a replication-defective adenovirus designed to deliver the herpes simplex virus thymidine kinase (HSV-tk) gene directly to tumor cells. When administered alongside valacyclovir, it induces immunogenic cell death of the tumor, activating the immune system to target and destroy cancer cells. This approach has demonstrated synergy with radiation therapy, offering new hope for patients with localized prostate cancer.

Key Findings from the Phase III Trial:

Disease-Free Survival (DFS): The treatment arm showed a statistically significant improvement in DFS compared to the control group (p=0.0155; HR 0.7), with a 14.5% relative improvement observed at 54 months.

Prostate-Specific Outcomes: CAN-2409 significantly improved prostate cancer-free survival (p=0.0046; HR 0.6) and the proportion of patients achieving a prostate-specific antigen (PSA) nadir of <0.2 ng/ml (67.1% vs. 58.6%, p<0.0164).

Pathological Complete Response (pCR): The treatment arm achieved 80.4% pCR in 2-year post-treatment biopsies, compared to 63.6% in the control group (p=0.0015).

Safety Profile: The safety of CAN-2409 was consistent with previous studies, with mild to moderate flu-like symptoms, fever, and chills being the most common adverse events. No new safety signals were identified.

Looking Ahead: Regulatory Approval and Future Steps

Candel Therapeutics is now focused on initiating discussions with the FDA to explore the regulatory pathway for CAN-2409 as a treatment for intermediate-to-high-risk localized prostate cancer. The company intends to present the full data set at upcoming medical conferences and continue advancing its viral immunotherapy pipeline for other large oncology indications.

"This study not only validates our previous findings with CAN-2409 but also represents a significant step forward in improving long-term outcomes for prostate cancer patients without introducing substantial toxicity," said Dr. Paul Peter Tak, President and CEO of Candel Therapeutics. "We are excited to bring this innovative treatment closer to patients and look forward to working with the FDA to make CAN-2409 a reality for those in need."

Candel's success in this pivotal Phase 3 trial brings renewed optimism to the prostate cancer treatment landscape and demonstrates the potential of viral immunotherapy in addressing unmet needs in oncology.