Scancell Holdings plc provided an update on its two ongoing Phase 1/2 clinical trials with lead cancer vaccine assets SCIB1/iSCIB-1+ and Modi-1. Encouraging data from these open label studies provides validation for the Company's decision to concentrate its strategic focus and resources on these two assets. SCIB1/iSCIB1+: The open-label, Phase 2 single arm SCOPE trial is investigating the safety and tolerability of using SCIB1/iSCIB1+, the company's lead ImmunoBody® cancer vaccine, in combination with checkpoint inhibitors in patients with advanced melanoma. The current trial is designed to determine whether any clinical effect is unlikely to be due to checkpoints alone based on the rate of clinical responses in each cohort, that is, with either a single or double checkpoint combination.

The trial is progressing well, with 73% of the required number of patients receiving SCIB1 in combination with two checkpoint inhibitors (ipilimumab and nivolumab) recruited to date. The company expects the initial topline data readout from this double checkpoint arm of the study in fourth quarter 2023. Following the data readout, Scancell intends to initiate a similar double checkpoint cohort with iSCIB1+ before the end of the year.

iSCIB1+ has a number of competitive advantages, with potentially increased potency due to modifications to the product using Scancell's propriety AvidiMab ® platform, and an extended patent life to 2039. iSCIB1+ is able to be used by a broader patient population because it incorporates more melanoma-specific epitopes. If positive, data generated by iSCIB1+ could lead to the initiation of a potential, rapid clinical development programme in second half 2024.

An adapted registration trial could yield Phase 2 data within 2 years and would provide the company with a pathway to a potential deal. The Phase 3 data could be complete within the following 3 years. Modi-1: Modi-1 is the first vaccine based on Scancell's Moditope® platform.

Recruitment is progressing well in the ModiFY open-label Phase 2a dose expansion study investigating the safety, tolerability and preliminary efficacy of Modi-1 as a monotherapy and in combination with checkpoint inhibitors in patients with ovarian, triple negative breast, renal and head and neck cancers. The cohort of 16 ovarian cancer patients receiving Modi-1 has now been fully recruited. All patients had failed on previous treatments and their disease was actively progressing when they entered the study.

Following treatment with Modi-1 44% of patients achieved stable disease for at least 8 weeks, with some patients experiencing a longer duration of disease stability for 4 months or more. Four patients are still ongoing in this cohort. The number of patients who have experienced long periods of stable disease following monotherapy with Modi-1 is encouraging in this difficult to treat cancer and the Company believes that combination therapy with checkpoint inhibitors, which are not currently approved for the treatment of ovarian cancer, could further improve outcomes for this patient group.

Evaluation of Modi-1 plus checkpoint inhibitors in other tumour types in the ongoing Phase 1/2 study, will provide supporting data for this proposed combination use.