GlaxoSmithKline plc and iTeos Therapeutics today announced an agreement to co-develop and co-commercialise EOS-448, an anti-TIGIT monoclonal antibody currently in phase I development as a potential treatment for patients with cancer. TIGIT, part of the CD226 checkpoint axis, has demonstrated potential as a promising target for the next generation of immuno-oncology therapies based on compelling preclinical data and a phase II randomised clinical trial. With this collaboration GSK is uniquely positioned with access to antibodies that synergistically target all three known CD226 checkpoints - TIGIT, CD96 and PVRIG.

Dr Hal Barron, Chief Scientific Officer and President R&D, GSK, said: “Immuno-oncology has transformed cancer care but unfortunately less than 30 percent of patients respond to treatment with the current leading immune checkpoint inhibitors. Based on the underlying science, we believe that combinations of a PD-1, TIGIT, CD96 and PVRIG inhibitor could become transformative medicines for many patients with cancer. We are excited to collaborate with the team at iTeos and together we can play a leading role in the next generation of immuno-oncology therapies.”

Since GSK validated the role of CD226 axis targets as important in oncology, it has been strategically building a carefully constructed set of assets to target this network of checkpoint inhibitors. The addition of EOS-448 results in GSK being the only company with antibodies targeting all three known checkpoints – TIGIT (via EOS-448), CD96 (via GSK’608), and PVRIG (via GSK’562). Together with GSK’s recently approved anti-PD-1, Jemperli (dostarlimab), this comprehensive portfolio of potential next generation immuno-oncology agents will be explored through various novel combinations, including doublets and triplets, to evaluate their potential to transform treatment options for patients with multiple different cancers.

Michel Detheux, President and CEO, iTeos, said: “Through this transformative collaboration, iTeos now has access to GSK’s best-in-class resources which will provide us with a significant advantage in a highly competitive, global market. We have chosen GSK because of their commercial capabilities, experience in immuno-oncology and their commitment to invest in the rapid advancement of our TIGIT programme and create a clear path forward for EOS-448. Inspired by the multifaceted mechanism of action of EOS-448 and promising early results in clinical trials, this collaboration allows us to accelerate and expand the clinical development of EOS-448. We are more confident than ever in our ability to succeed. This collaboration validates our science and provides a catalyst for the future of iTeos. The collaboration with GSK will allow our team to continue to develop next generation immunotherapies starting with inupadenant, our highly differentiated clinical-stage A2A adenosine receptor antagonist, and to drive scientific innovation with our expertise in tumour immunology to build our pipeline.”

EOS-448 is currently in an open-label phase I study in patients with advanced solid tumours. GSK and iTeos plan to start combination studies of EOS-448 with dostarlimab in 2022. GSK’608 (anti-CD96 being developed in collaboration with 23andMe) is in phase I as monotherapy and in combination with dostarlimab. GSK expects to submit an Investigational New Drug application for GSK’562 (anti-PVRIG in-licensed as SRF-813 from Surface Oncology) by mid-2022.

Under the terms of the collaboration agreement, iTeos will receive an upfront payment of $625 million. iTeos will be eligible to receive up to an additional $1.45 billion in milestone payments, should the EOS-448 programme achieve certain development and commercial milestones.

Within the collaboration, GSK and iTeos will share responsibility and costs for the global development of EOS-448 and will jointly commercialise and equally split profits in the US. Outside of the US, GSK will receive an exclusive license for commercialisation and iTeos will receive tiered royalty payments.

The collaboration agreement is conditional upon customary conditions including review by the appropriate regulatory agencies under the Hart-Scott-Rodino Act.