TuHURA Biosciences initiates Phase 1b/2a study of IFx-Hu2.0 in carcinoma

TuHURA Biosciences (HURA) announced the initiation of its Phase 1b/2a trial of IFx-Hu2.0, TuHURA’s lead innate immune agonist, in patients with Metastatic Merkel Cell Carcinoma of Unknown Primary Origin, or MCCUP, who would not be eligible for the company’s planned Phase 3 accelerated approval trial, which is targeted to begin enrollment later in Q2 2025. IFx-Hu2.0 is designed to overcome primary resistance to checkpoint inhibitors like Keytruda and has demonstrated systemic anti-tumor specific immune responses when injected intratumorally into cutaneous, subcutaneous, or accessible nodal lesions in its prior Phase 1 and 1b trials in melanoma and advanced or metastatic Merkel cell carcinoma. The Phase 1b/2a trial is designed to assess the safety and feasibility of IFx-Hu2.0 as adjunctive therapy to pembrolizumab in adult patients with non-cutaneous MCC. The trial is designed to enroll a total of nine non-cutaneous MCC patients. The primary endpoint of the study is safety and feasibility of IFx-Hu2.0 adjuvant therapy evaluated 28 days following the last dose of IFx-Hu2.0, or Day 49 from the first IFx-Hu2.0 infusion. Data from the trial is anticipated by the end of Q4 2025 or early Q1 2026. TuHURA currently anticipates initiating the Phase 3 registrational trial in Q2. FDA’s Oncology Center of Excellence asked the company to consider a first-line randomized placebo controlled trial of Keytruda plus placebo or IFx-Hu2.0. The FDA also agreed that the trial could be conducted under their accelerated approval pathway with the use of Objective Response Rate as the primary endpoint. The FDA also asked the company to consider incorporating into its accelerated approval trial a key secondary end point of Progression Free Survival, which, if successfully achieved without a detriment to overall survival at the time of analysis, may result in the company not being required to conduct a post approval confirmatory trial, and this single trial could potentially fulfill requirement for regular approval. The company and the FDA have entered into a Special Protocol Assessment Agreement for the planned Phase 3 trial.