Phase 2 MITOPE Study Initiates with First Patient Receiving RSO-021 for Mesothelioma and Lung Metastases

A clinical-stage biotechnology firm, RS Oncology (RSO), is advancing its mission to develop innovative treatments for mesothelioma and related diseases. The company has reported a significant milestone in its UK-based multicenter study, MITOPE (NCT05278975), with the successful administration of its experimental drug, RSO-021, to the first patient in the Phase 2 dose expansion phase.

Malignant pleural effusion (MPE), characterized by fluid accumulation in the lung's lining, is a prevalent and debilitating symptom among cancer patients, particularly those in the late stages of the disease. RSO's RSO-021 is a novel therapy administered weekly into the pleural space post-drainage of MPE via a catheter. Following the completion of Phase 1 in the fourth quarter of 2023, RSO has established a recommended dose and confirmed the safety and tolerability of RSO-021.

The Phase 2 expansion of MITOPE is exploring the efficacy of RSO-021 in several patient groups, including those with MPE due to malignant pleural mesothelioma (MPM) prior to standard treatment, patients with relapsed disease post-first line treatment, those with local metastatic lung disease, and patients with MPE from advanced metastatic cancers of the breast, ovary, and non-small cell lung, in combination with systemic paclitaxel.

Prof. Dean Fennell, spearheading the Mesothelioma Research Programme at Leicester University Hospitals, underscores the difficulty in treating mesothelioma, especially at later stages of diagnosis. He highlights RSO-021's unique mechanism, which offers a promising new avenue for patients with limited treatment options.

Jarrett Duncan, CEO of RS Oncology, emphasizes the significance of the Phase 2 trial's commencement, viewing it as a major step forward for patients and caregivers. RSO-021 is a small molecule that targets mitochondrial peroxiredoxin 3 (PRX3), selectively eliminating cancer cells by inducing oxidative stress while leaving healthy cells unharmed, as demonstrated in preclinical studies.

RS Oncology is dedicated to scientific innovation and global collaboration, aiming to enhance the lives of those afflicted with aggressive cancers. The company's primary focus is on developing RSO-021 for pleural mesothelioma and lung metastatic cancers, which is currently under evaluation in the Phase 2 MITOPE study.

About RSO-021 and RS Oncology

RSO-021 is a groundbreaking small molecule that irreversibly binds to PRX3, a key component in the antioxidant signaling network of cancer cells. By inhibiting this network, RSO-021 has shown the potential to selectively target and destroy malignant cells while preserving healthy ones.

RS Oncology is at the forefront of developing therapies for aggressive forms of cancer, with a particular emphasis on pleural mesothelioma and cancers that have metastasized to the lungs. The company's commitment to advancing RSO-021 through clinical trials reflects its dedication to improving patient outcomes and offering new hope to those battling these challenging diseases.