Gene Therapy for BCG-Unresponsive Non-Muscle Invasive Bladder Cancer: Current Evidence and Future Directions

Area of Science:

• Oncology
• Gene Therapy
• Urothelial Carcinoma

Background:

• Bladder cancer, predominantly urothelial carcinoma, presents challenges in high-risk non-muscle invasive bladder cancer (NMIBC) management.
• Current treatments like Bacillus Calmette-Guérin (BCG) have limitations including recurrence, unresponsiveness, and progression.
• Radical cystectomy is invasive, highlighting the need for alternative bladder-sparing therapies for BCG-unresponsive NMIBC.

Purpose of the Study:

• To review the current landscape of gene therapy for BCG-unresponsive NMIBC.
• To summarize findings from recent clinical and preclinical studies in this area.
• To highlight the potential of gene therapy as a bladder-sparing alternative.

Main Methods:

• Narrative review of peer-reviewed literature.
• Integration of findings from clinical and preclinical studies.
• Focus on gene therapy approaches for BCG-unresponsive NMIBC.

Main Results:

• Nadofaragene firadenovec, the first FDA-approved gene therapy for BCG-unresponsive NMIBC with carcinoma in situ (CIS), showed a 53% complete response at 3 months and 43% bladder preservation at 60 months.
• Cretostimogene grenadenorepvec (CG0070) demonstrated a 47% 6-month complete response rate in a phase II study.
• Detalimogene voraplasmid (EG-70) achieved a 47% 6-month complete response in a phase I/II study.
• Future research will focus on patient selection, novel vectors, and combination therapies.

Conclusions:

• Gene therapy offers a significant advancement for BCG-unresponsive NMIBC.
• These therapies provide bladder-sparing alternatives when conventional treatments are limited.
• Ongoing research aims to further optimize gene therapy outcomes for bladder cancer patients.