Accelerated Approval Phase 3 Registration Trial of IFx-2.0 in Front-Line advanced or metastatic Merkel cell carcinoma (MCC) as an adjunctive therapy to Keytruda®

TuHURA has entered into a Special Protocol Assessment (SPA) agreement with the FDA for a single Phase 3 randomized placebo and injection controlled trial for IFx-2.0, its lead innate immune agonist, as adjunctive therapy to Keytruda® (pembrolizumab) in the first line treatment of patients with advanced or metastatic Merkel cell carcinoma, who are checkpoint inhibitor-naïve utilizing the FDA’s accelerated approval pathway. Enrollment for the Phase 3 will take approximately 14 – 18 months, with topline data potentially being available 6 to 7 months following the last patient enrolled. If successful, this single Phase 3 trial would form the basis of a Biologics License Application (BLA). 

20-25 US clinical centers

Randomized Placebo Controlled Phase 3 Trial

Key Secondary Endpoint:

Progression Free Survival (PFS)

In designing the Phase 3 trial for IFx-2.0, we worked with the deputy director of the FDA’s Oncology Center of Excellence (OCE) on what we believe is a unique trial design. Consistent with the FDA’s Project Front Runner initiative, the FDA recommended investigating IFx-2.0 in the front-line treatment setting rather than in patients who are progressing on checkpoint inhibitor therapy like we did in our phase 1b trial.

In doing so, data from a primary endpoint of objective response rate, or ORR, that is of sufficient magnitude and duration and with a favorable risk/benefit profile could be sufficient to support accelerated approval. Furthermore, OCE requested that the Company consider incorporating a key secondary endpoint that is of clinical benefit such that results from a key secondary endpoint of progression-free survival, or PFS, that is adequately powered with statistical assumptions in the statistical analysis plan provided to the FDA, if achieved without a detrimental effect on overall survival, or OS, could be adequate to support conversion to regular approval satisfying the requirement for a confirmatory trial.

A Special Protocol Assessment agreement is a binding written agreement between the U.S. Food and Drug Administration (FDA) and a trial sponsor that indicates the FDA has agreed to the study’s design, charters, and statistical analysis plan and if the study endpoints are met within the context of the SPA Agreement such results would be adequate to support accelerated and regular approval. A Special Protocol Assessment agreement does not increase the likelihood of marketing approval for the product and may not lead to a faster or less costly development, review, or approval process. The study population, dose, schedule, and study design for the trial are based on the response rates observed in the Company’s Phase 1b trial in checkpoint inhibitor naïve patients with advanced Merkel cell carcinoma who exhibited primary resistance to anti PD(L)-1 checkpoint inhibitors such as Keytruda® Based on correspondence with the FDA, patients with advanced Merkel cell carcinoma represent a patient population with an unmet medical need. TuHURA’s study is designed to determine if IFx-2.0 can increase the objective response rate when used as adjunctive therapy to Keytruda in first line treatment of checkpoint inhibitor naïve patients with advanced Merkel cell carcinoma when compared to Keytruda alone.