31 October 2022

Scancell Holdings plc

("Scancell" or the "Company")

First patient dosed in the expansion phase of the monotherapy arms of ModiFY

Cohort 3 of ModiFY trial open for recruitment in combination with a CPI

Well tolerated safety profile seen with Modi-1 at the higher dose in the first-in-human clinical trial

Scancell Holdings plc (AIM: SCLP), the developer of novel immunotherapies for the treatment of cancer and infectious disease, today announces that the first patient in the expansion phase of the monotherapy arms in the multicentre Phase 1 Modi-1 clinical trial (ModiFY) has been enrolled and dosed. In addition, Cohort 3 of ModiFY is now open for recruitment in combination with a checkpoint inhibitor (CPI). Expansion into the monotherapy arms and the start of combination dosing follows review of the safety data from the Cohort 2 patients by the Safety Review Board.

The ModiFY study is a first-in-human clinical trial, with Modi-1, the first candidate from Scancell's Moditope^® platform, being administered alone or in combination with CPIs in patients with head and neck, triple negative breast and renal tumours and as a monotherapy in patients with ovarian cancer, where there are no approved CPI therapies. This open label study will recruit up to 125 patients in up to 20 clinical trial sites across the UK.

Cohort 1 of the study confirmed the safety profile of a low dose of two citrullinated vimentin peptides. The objective for Cohort 2 of the trial was to assess the safety of the two citrullinated vimentin peptides plus an enolase peptide at a higher dose. All three patients in Cohort 2 have successfully received two doses and the injections were well tolerated with no safety concerns. Encouragingly, all three patients showed a delayed type hypersensitivity response to the vaccine, which is indicative of a T cell response, and the first patient to be assessed has shown a partial tumour response at first radiological reassessment. However, this early observation requires further confirmation with subsequent scans, plus analysis of responses in the remainder of the Cohort 2 patients.

Based on the safety data from Cohort 2, the ModiFY trial will now expand at this dose for Modi-1 monotherapy in all four tumour types and the first patient in these expansion cohorts has now been dosed. In parallel, patients in Cohort 3 will receive Modi-1 plus a CPI to assess if this combination is safe in patients where CPIs are provided as standard of care. Modi-1 stimulates CD4 T cells which may directly impact tumour growth however, in some patients these T cells may need to be protected by CPIs if the tumour environment is highly immunosuppressive. Modi-1 peptides are linked to AMPLIVANT^®, a potent adjuvant which enhanced the immune response 10-100-fold and resulted in highly efficient tumour clearance, including protection against tumour recurrence, in preclinical models. AMPLIVANT^® is the subject of a worldwide licensing and collaboration agreement with ISA Pharmaceuticals for the manufacturing, development, and commercialisation of Modi-1.

The Company expects further safety and immunogenicity data to be available in H2 2022 and early efficacy data in 2023. Further information relating to the clinical trial can be found on the Company's website at www.scancell.co.uk and at https://clinicaltrials.gov.

Prof Lindy Durrant, Chief Executive Officer, Scancell, commented: "This is an encouraging milestone for the Company, showing that the higher dose of Modi-1 is generating immune responses that may be having an impact on tumour growth. We are encouraged that there were no safety concerns in Cohort 2, allowing us to proceed with the monotherapy expansion and into Cohort 3 in combination with checkpoint inhibitors, and look forward to announcing further safety and immunogenicity data in H2 2022."

This announcement contains inside information for the purposes of Article 7 of Regulation (EU) 596/2014 (MAR).

About Scancell

Scancell is a clinical stage biopharmaceutical company that is leveraging its proprietary research, built up over many years of studying the human adaptive immune system, to generate novel medicines to treat significant unmet needs in cancer and infectious disease. The Company is building a pipeline of innovative products by utilising its four technology platforms: Moditope^® and ImmunoBody^® for vaccines and GlyMab^® and AvidiMab^® for antibodies.

Adaptive immune responses include antibodies and T cells (CD4 and CD8), both of which can recognise damaged or infected cells. In order to destroy such cancerous or infected cells, Scancell uses either vaccines to induce immune responses or monoclonal antibodies (mAbs) to redirect immune cells or drugs. The Company's unique approach is that its innovative products target modifications of proteins and lipids. For the vaccines (Moditope^® and ImmunoBody^®) this includes citrullination and homocitrullination of proteins, whereas its mAb portfolio targets glycans or sugars that are added onto proteins and / or lipids (GlyMab^®) or enhances the potency of antibodies and their ability to directly kill tumour cells (AvidiMab^®).

For further information about Scancell, please visit: https://www.scancell.co.uk/