Skip to main content

RS Oncology Unveils Innovative Drug in Initial Clinical Trials for Mesothelioma and Lung Cancer Treatment


Newly Established U.S. Biotechnology Firm Specializing in Rare Conditions Introduces Three Case Studies in France

LILLE, France, August 03, 2023--(BUSINESS WIRE)--With a focus on offering groundbreaking scientific advancements to those patients who are most likely to gain from emerging treatments, RS Oncology introduces PRX3. This unique drug target has promising potential for the therapy of mesothelioma, a type of cancer linked to asbestos. Positioned in the mitochondria, or the cellular powerhouses, PRX3 serves as a vital protection against oxidative stress, selectively targeting cancer cells and sparing healthy ones.

You can access the entire release, which includes multimedia elements, at the following link:

A first-of-its-kind Phase 1 clinical trial named MITOPE is currently assessing PRX3 inhibitor RSO-021 (find more details at, identifier NCT05278975, under the sponsorship of RS Oncology, LLC [RSO], based in Boston, USA). The trial continues to escalate doses across four UK locations, with expected enrollment completion by Q2 2024. Phase 2 will incorporate more locations in the final quarter of 2023.

During the 2023 International Mesothelioma Interest Group (iMig) conference held in Lille, France in June, initial experiences with RSO-021 within MITOPE were shared with an international gathering of mesothelioma experts. The symposium was named New Horizons for Cancer Therapy - Exploring Oxidative Stress Weaknesses.

Brian Cunniff, Ph.D., RSO's Chief Science Officer and Assistant Professor of Pathology and Laboratory Medicine at the University of Vermont Cancer Center, illustrated how cancer cells harness elevated levels of Reactive Oxygen Species (ROS) to promote cancer growth. He further detailed the identification of PRX3 as a valuable target to capitalize on ROS dependence in cancer. The mechanism of RSO-021 is to irreversibly attach to and inhibit PRX3, leading to cancer-specific cell death. Dr. Cunniff expressed enthusiasm for "RSO-021, an invigorating new treatment alternative for those battling mesothelioma, that takes advantage of a common tumor cell weakness through a previously unseen method, making tumor cells incapable of eliminating harmful waste. We eagerly anticipate the practical application of our laboratory insights in collaboration with RS Oncology."

Dr. Sean Dulloo, a UK researcher affiliated with University Hospitals of Leicester and the University of Leicester, provided preliminary insights into the safety and effectiveness of MITOPE. He presented three cases illustrating significant tumor response, with disease stabilization and enhanced life quality.

Professor Dean Fennell, a leading authority and IMIG 23 research medal recipient also hailing from Leicester, encapsulated the changing mesothelioma treatment scenario and the ongoing demands. He remarked that "PRX3 represents a fresh and engaging therapeutic approach with a potential to treat various cancers, particularly those like mesothelioma where current solutions fall short. We are eager to observe the preliminary clinical findings."

For detailed information regarding the MITOPE clinical trial, visit Mesothelioma UK. NIHR supports this study.

About RS Oncology

RSO is a clinical-phase biotech organization headquartered in Cambridge, Massachusetts. Their mission revolves around the global elimination of mesothelioma and similar diseases through pioneering science and a unique business approach. Their primary focus currently lies in developing innovative therapies that alter mitochondrial pathways, which control diseases related to oxidative stress, including mesothelioma and various other cancers.