Step Pharma Progresses into Oncology Clinical Trials with STP938, the World’s Most Advanced CTPS1 Inhibitor

St. Genis-Pouilly, France, 28 July 2022

Step Pharma, a world leader in CTPS1 inhibition for the targeted treatment of cancer, announces today that its lead asset STP938 has cleared both an Investigational New Drug (IND) application by the Food and Drug Administration (FDA), and a clinical trial application (CTA) by the UK’s Medicines and Healthcare products Regulatory Agency (MHRA), enabling Step Pharma to progress STP938, its first-in-class, selective CTPS1 inhibitor into the clinic in the US and UK.

STP938 has now entered an open label, first-in-human, Phase 1/2 study to evaluate the safety, tolerability, pharmacokinetics, and preliminary efficacy of STP938 in adult subjects with relapsed/refractory B cell and T cell lymphomas. Further details of the study can be found on clinicaltrials.gov under the identifier NCT05463263. Patients with such cancers currently face high relapse rates from existing treatments.

Step Pharma is pioneering a novel class of oral drugs that specifically inhibits nucleotide synthesis and the enzyme cytidine triphosphate synthase 1 (CTPS1) in particular, originally identified as an essential gene for lymphocyte proliferation. By targeting CTPS1, Step Pharma has unlocked the ability to selectively target the de novo pyrimidine synthesis pathway in cancer cells. This ground-breaking approach should enable the highly selective treatment of both blood cancers and solid tumours.

Andrew Parker, Chief Executive Officer of Step Pharma, said:

“Our unique approach to cancer treatment has the potential to yield a novel targeted cancer therapy that can form the backbone of both blood and solid tumour cancer treatment regimens. We are delighted to have moved STP938 into the clinic for hard-to-treat lymphomas with the ultimate goal of improving the lives of millions of cancer patients.”

Dr. Brian Schwartz, Chief Medical Officer, commented:

“The clinical trial approvals by both the US FDA and UK MHRA are a significant milestone for Step Pharma and our highly differentiated lead candidate STP938, as we become a clinical-stage company and move at speed to bring this first-in-class treatment to cancer patients with high unmet medical needs.”

Step Pharma will initially investigate STP938 in blood cancers, with a focus on T cell lymphomas, where there has been no improvement in five-year survival rates for over 20 years. However, as studies have shown that all cancer cells require CTPS1 for DNA synthesis, STP938 could be a key component of a multitude of cancer treatment regimens.