Onchilles reports early systemic activity with intratumoral N17350 in Phase I/II trial

Onchilles Pharma has reported the first clinical findings from its Phase I/II OP-NEU-101 study of intratumoral N17350 in patients with advanced solid tumours.

Preliminary data from the first dose cohort showed no dose-limiting toxicities in three heavily pretreated patients and early evidence of activity beyond the injected tumour in one patient with Merkel cell carcinoma.

N17350 is an investigational therapy derived from a cancer-killing enzyme found in human neutrophils and is designed to activate the ELANE pathway.

The treatment is administered directly into a tumour, where it is intended to kill cancer cells and release tumour-associated antigens that could help stimulate a broader immune response.

Onchilles is investigating whether this approach could generate patient-specific immune activity without requiring tumour sequencing, antigen selection or individualised manufacturing.

The clearest early clinical signal was observed in a patient with Merkel cell carcinoma whose disease had progressed despite previous avelumab-based treatment and radiotherapy.

One of six lesions included in the assessment was injected with N17350.

At Week 8, an investigator assessment using RECIST 1.1 found that all five non-injected lesions were no longer detectable on imaging.

These included one lesion selected for formal measurement and four additional lesions monitored for their presence or absence.

FDG-PET imaging also showed reductions of between 56% and 60% in SUVmax across the lesion groups assessed.

An independent radiology review of a separate lesion also reported reduced FDG uptake, providing an additional observation consistent with activity outside the injected tumour.

The company said these findings may indicate systemic immune activation, although the results are preliminary and based on a single patient.

Initial immune profiling in the Merkel cell carcinoma patient showed a shift toward a more effector-dominant and less immunosuppressive immune profile.

Preliminary pharmacokinetic analysis detected no active N17350 enzyme in plasma at sampled timepoints.

No treatment-emergent anti-drug antibodies were identified.

Onchilles said the absence of detectable circulating active enzyme, together with the immune findings, is consistent with the possibility that treatment of the injected tumour triggered an immune response rather than N17350 directly reaching distant lesions through the bloodstream.

Across the first dose cohort, three patients received N17350 at 1 mg/mL and completed the dose-limiting toxicity assessment period without a dose-limiting toxicity.

The findings supported progression to the next dose level.

Alain Patrick Algazi, MD, Professor of Clinical Medicine at the University of California San Francisco and presenting author, said the early data suggest the treatment may be capable of producing immune activity beyond the injected tumour.

He added that larger datasets will be needed to determine whether the effect can be reproduced across additional patients and tumour types.

Onchilles is presenting the findings at the 41st Annual Meeting of the Society for Immunotherapy of Cancer.

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Related Topics and Keywords

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