Phio Pharmaceuticals and researchers with Helmholtz Zentrum München — the German Research Center for Environmental Health (HMGU) — are working together to develop new approaches to boost the immune system in fighting cancer. The collaboration aims to use Phio’s proprietary self-delivering RNAi (sd-rxRNA) technology to inhibit checkpoint molecules in immune cells, stopping the immune dampening signals produced by cancer cells from doing their job. Research will be led by Elfriede Nößner, PhD, head of the immunoanalytics research group. "Available data shows that Phio Pharmaceuticals' self-delivering RNAi technology is ideally suited to inhibit checkpoints in immune effector cells such as T cells and NK cells in the microenvironment of solid tumors or inflammatory diseases,” Nößner said in a press release. “I look forward to working with the Phio team on targets beyond their interesting checkpoint-inhibiting self-delivering RNAi pipeline." Immunotherapies are now a standard approach to treating several types of cancers. They are commonly designed to either help flag cancer cells so a patient’s immune system can more easily detect and kill them, or by blocking signals that cancer cells produce to evade immune cell actions. The latter approach is often achieved through immune checkpoint inhibitors, a class of immunotherapies used to treat several cancer types. These include the PD-1 inhibitors Opdivo (nivolumab) and Keytruda (pembrolizumab), the PD-L1 inhibitor Tecentriq (avelumab), and the CTLA-4 inhibitor Yervoy (ipilimumab). Despite being safe and effective, these treatments fail to stop cancer growth in all patients. Phio is hoping to develop a better immunotherapy using its sd-rxRNA technology. sd-rxRNA are small pieces of RNA molecules designed to target and inhibit specific genes, while having a stability and potency similar to chemical compounds. “The therapeutic and built-in delivery properties of sd-rxRNA compounds provide for a powerful method to harness the immune system to attack cancer,” the company states on its website. These novel small molecules can be used to modify patients' own T and NK cells, immune cells that directly fight threats, to improve how they work. The modified cells are then expanded in the lab and infused back to the patient, where they will possibly fight cancer more effectively. The approach “weaponizes immune cells boosting their ability to detect and destroy tumor cells,” the company states.