Scancell Holdings plc has announced positive data from its ongoing Phase 2 SCOPE trial, evaluating SCIB1 in combination with ipilimumab and nivolumab for advanced melanoma. The trial's initial results indicate a significant improvement in progression-free survival (PFS) compared to double checkpoint inhibitors alone.
Promising Efficacy Data
Data from the first cohort of 25 patients showed an 80% PFS rate at 6 months. Furthermore, 20% (5 patients) achieved a complete response (CR), and 84% (21 patients) demonstrated disease control (stable disease or tumor regression). The objective response rate (ORR) was 72% (18 patients), with continued tumor shrinkage observed over time. These results were verified through scans at 19 and 25 weeks.
Dr. Heather Shaw, Medical Oncologist at University College Hospital, London, commented, "Based upon the emergent striking PFS, DCR and ORR results from cohort 1 so far and the lack of toxicity relating to the agent itself, SCIB1 is a promising product that would be a significant addition to ipilimumab and nivolumab and would be an important step forward in improving first line therapy for advanced melanoma patients."
Comparison with Double Checkpoint Inhibitors
The observed outcomes compare favorably to reported results for double checkpoint inhibitors alone, which typically show a PFS of 65%, CR of 16%, DCR of 58%, and ORR of 48%. The data suggests that SCIB1, when combined with ipilimumab and nivolumab, leads to more sustained and durable responses.
SCOPE Trial Details and Future Plans
The SCOPE trial (NCT04079166) is a Phase 2, multicenter, open-label study assessing SCIB1 and iSCIB1+ in patients with advanced unresectable melanoma. The trial aims to determine the response rate, safety, and tolerability of SCIB1 or iSCIB1+ when added to nivolumab with ipilimumab or SCIB1 with pembrolizumab. The study involves approximately 16 sites in the UK.
Cohort 2 is evaluating SCIB1 with pembrolizumab (9/43 patients recruited), and cohort 3 is investigating iSCIB1+ with ipilimumab and nivolumab (33/43 patients recruited). Scancell anticipates that all cohort 3 patients will reach week 25 during H2 2025. This will inform the selection of the optimal vaccine for a planned phase 2/3 randomized, adapted registration trial.
SCIB1 and iSCIB1+ Overview
SCIB1 is derived from Scancell's ImmunoBody® DNA Vaccine platform and is designed to stimulate the immune system to identify and destroy tumors. SCIB1 is restricted to HLA.A2 matched patients. iSCIB1+ is an enhanced version of SCIB1, modified using Scancell's AvidiMab® platform, and includes additional melanoma-specific epitopes, potentially broadening its applicability to a larger patient population.
Prof Lindy Durrant, Chief Scientific Officer at Scancell, stated, "The SCOPE study continues to yield excellent results with a PFS of 80% and five patients now achieving a complete response. We are particularly impressed with the progression free survival data as this will be the primary endpoint of the next trial, a phase 2/3 randomised, adapted trial, and the key outcome for product registration. We look forward to providing further updates on our progress given the extremely positive results to date."
