Company: HURA
Filing Date: 2025-05-06
Form Type: S-4/A
Source: 0001193125-25-113920
Chunk: 441

Company: TuHURA Biosciences, Inc./NV
Filing Date: 2025-05-06
Form: S-4/A
Chunk 441
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 with advanced Merkel cell carcinoma who completed treatment and protocol-directed 28-day safety evaluation follow-up period, seven patients exhibited primary resistance to first line treatment with a checkpoint inhibitor who did not receive subsequent therapies prior to receiving IFx-2.0. Five of seven patients received single agent anti-PD(L)-1 as initial therapy while two of seven patients received multiple CPIs as initial therapy including anti-PD-1, followed by anti-PD-1/anti-CTLA-4 therapy. All seven patients exhibited primary resistance to checkpoint inhibitor therapy progressing on average 3.3 months while receiving CPI therapy. These seven patients are graphically presented below:

This data demonstrating the potential for IFx-2.0 to overcome primary resistance to anti-PD(L)-1 therapy and formed the clinical rationale for examining IFx-2.0 as adjunctive therapy with Keytruda(anti-PD-1) in first line therapy among checkpoint inhibitor naïve patients with advanced or metastatic Merkel cell carcinoma. Unlike the phase 1b where IFx-2.0 was administered after patients progressing on anti-PD(L)-1 therapy, we believe IFx-2.0 could potentially provide a higher response rate to Keytruda when administered prior to patients progressing failing Keytruda.

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The remaining seven (7) patients received multiple checkpoint inhibitor therapy including anti-CTLA-4/anti-PD-1 therapy and/or investigational agent(s) and or chemotherapy as 2 or 3 line therapy prior to treatment with IFx-2.0. This patient population is not representative of patients to be enrolled in the phase 3 trial.

Importantly, IFx-2.0 is not an intratumoral therapy like oncolytic viral therapies whose anti-tumor activity is limited to accessible, injected lesions in limited stages of cancer. In contrast, IFx-2.0’s mechanism of action is to prime and activate an innate immune response in injected lesions leading to a systemic anti-tumor response. The Company chose to examine IFx-2.0 in cutaneous malignancies because human skin has a high density of DCs which are very efficient in presenting foreign antigens to immune cells. Local injection of IFx-2.0 into cutaneous lesion(s) has resulted in immune cell infiltration, and in the context of MHCI and MHCII, tumor neoepitope presentation to naïve B and T cells followed by activation of tumor specific B and T cells