A Phase I-II Study Using Rexin-G Tumor-Targeted Retrovector Encoding a Dominant-Negative Cyclin G1 Inhibitor for...

Area of Science:

• Oncology
• Gene Therapy
• Cancer Research

Background:

• Pancreatic adenocarcinoma is often refractory to standard chemotherapy like gemcitabine.
• Targeted gene delivery systems offer a novel approach to cancer treatment.
• Rexin-G is a replication-incompetent retroviral vector designed to target tumor-specific proteins.

Purpose of the Study:

• To evaluate the safety and antitumor activity of escalating doses of Rexin-G.
• To assess Rexin-G in patients with gemcitabine-refractory pancreatic adenocarcinoma.
• To identify potential adverse events and therapeutic responses.

Main Methods:

• Phase I/II clinical trial design with escalating doses of Rexin-G.
• Safety analysis included monitoring for adverse events and specific immunological markers.
• Efficacy analysis assessed objective response rates, progression-free survival (PFS), and overall survival (OS).

Main Results:

• Rexin-G demonstrated a favorable safety profile with only grade 1 adverse events.
• No patients developed neutralizing antibodies, replication-competent retrovirus, or vector integration in PBLs.
• Significant antitumor activity was observed, including one complete response, two partial responses, and stable disease in 15 patients. Median PFS and OS improved with higher doses.
• One patient achieved a complete response and remains cancer-free 10 years post-treatment.

Conclusions:

• Rexin-G is a uniquely safe and effective targeted gene delivery system for pancreatic cancer.
• The observed antitumor activity and long-term survival warrant further investigation.
• FDA fast-track designation underscores the potential of Rexin-G in treating refractory pancreatic cancer.