Tomivosertib (also known as eFT508) is a novel, potent and highly selective oral small molecule inhibitor of mitogen-activated protein kinase interacting kinases 1 and 2, or collectively, MNK1/2. MNK1/2 play a crucial role in the development of many tumors, including by controlling in a coordinated manner the expression of multiple factors that attenuate an immune response.
The interaction between a patient’s tumor and immune system has been described as a cyclical process referred to as the cancer immunity cycle. Our studies have shown that tomivosertib acts on multiple points in the cancer immunity cycle simultaneously, underscoring its therapeutic potential in combination with existing checkpoint inhibitor treatments. Our preclinical and clinical studies suggest combining tomivosertib with a checkpoint inhibitor can overcome mechanisms of resistance to checkpoint inhibitors, resulting in enhanced sensitivity to checkpoint inhibitors and a higher response rate. In addition, our preclinical data demonstrate that tomivosertib as a single agent promotes antitumor immunity that persists after stopping drug treatment.
We are completing a 39 patient Phase 2 trial with tomivosertib in combination with checkpoint inhibitors. Tomivosertib is added as a combination therapy to patients already receiving checkpoint inhibitors in FDA-approved indications and experiencing insufficient response to their checkpoint therapy alone (CPI-A). Tomivosertib will also be studied in combination with paclitaxel to treat patients with metastatic breast cancer in a 40 patient Phase 2a trial in Canada fully funded by Stand Up to Cancer (SU2C) Canada.