The first patient has been dosed in a Phase 2 extension study investigating the cancer vaccine DSP-7888 (ombipepimut-S) in combination with the checkpoint inhibitor Keytruda (pembrolizumab), in people with platinum-resistant ovarian cancer. The announcement follows promising data from the first portion of this Phase 1b/2 clinical trial (NCT03311334). The Phase 2 part is actively recruiting patients at sites across the United States. "Patients with platinum-resistant ovarian cancer have a high unmet need with limited treatment options; therefore, we are excited to advance the study of DSP-7888 plus pembrolizumab and evaluate its role and potential benefits," Patricia Andrews, said in a press release. Andrews is CEO and global head of oncology at Sumitomo Dainippon Pharma Oncology (SDP Oncology). Cancer patients are considered platinum-resistant if they do not respond to a specific type of chemotherapeutic agent that contains the chemical element of platinum. Cisplatin and carboplatin are two examples of regularly prescribed, platinum-containing chemotherapy medications. Patients who are platinum-resistant are typically resistant to other forms of chemotherapy, and also typically have worse clinical outcomes, with a median survival time of less than one year. In the search for a new line of treatment, researchers at SDP Oncology developed the DSP-7888 vaccine, which harnesses the body's immune system to attack cancer cells. Research has shown that certain types of cancer cells, including ovarian tumors, express the protein Wilms Tumor 1 (WT1) at high levels, allowing developers to use WT1 as a target to guide treatments. WT1 is considered the number-one target for cancer immunotherapy by the National Cancer Institute. The DSP-7888 vaccine consists