Toragen Inc. has announced positive safety data from its ongoing Phase 1 clinical trial evaluating TGN-S11, a small molecule drug candidate, in patients with Stage 4 Human Papillomavirus (HPV)-associated cancers. The open-label, non-randomized study is assessing TGN-S11 as a monotherapy and in combination with Keytruda (pembrolizumab), a PD-1 checkpoint inhibitor, in patients with relapsed, resistant, or metastatic HPV-associated cancers.
Phase 1 Trial Design
The Phase 1 trial is structured in two parts. Part 1 involves escalating doses of TGN-S11 monotherapy, while Part 2 evaluates TGN-S11 in combination with the standard dose of Keytruda. The dose escalation phase includes up to five cohorts of three to six patients receiving increasing doses of TGN-S11. The Keytruda combination phase also consists of up to five levels of three to six patients, with escalating doses of TGN-S11 alongside Keytruda.
Safety and Efficacy Data
In Part 1, nine patients were treated with TGN-S11 monotherapy across the first three dose cohorts. No safety issues were identified, and one-third of the patients exhibited drug activity, demonstrated by decreases in tumor size and circulating tumor HPV DNA (ctHPV DNA). In Part 2, three patients were treated with TGN-S11 in combination with Keytruda. Again, no safety issues were observed, and two of these three patients showed drug activity, with reductions in tumor size and ctHPV DNA. One patient in the combination arm experienced a 93% reduction in ctHPV DNA and continues to receive combination therapy.
Ongoing Study and Future Plans
The study is currently ongoing, with patients being dosed in Part 1 Cohort 4 and Part 2 Level 2. "We have been very pleased with the positive safety profile for TGN-S11...in combination with Keytruda in this ongoing Phase 1 trial," said Dr. Sandra Coufal, Toragen’s CEO. "The drug activity observed in 5 of these 12 subjects is also very encouraging. Based on the current progress, we believe both parts of the study will be completed by the end of 2024."
About TGN-S11
TGN-S11 is a uniquely selective drug targeting cancers caused by viruses. Toragen is a clinical-stage biotechnology company based in San Diego, California, and has the only HPV E5 protein inhibitor in human clinical trials.
