Cybrexa Therapeutics Doses First Patient with CBX-12 in Phase 2 Ovarian Cancer Trial

Cybrexa Therapeutics, a biotech firm specializing in oncology, has announced the commencement of a Phase 2 clinical trial for CBX-12, targeting women with platinum-resistant or refractory ovarian cancer. This marks a significant step following promising Phase 1 results, which exhibited a 40% response rate in TOP1-naïve ovarian cancer patients. CBX-12 deploys Cybrexa's unique alphalex™ technology to deliver the topoisomerase 1 (TOP1) inhibitor, exatecan, directly to tumor cells, minimizing harm to healthy tissues.

The trial, an open-label study, will assess the safety, tolerability, and efficacy of two dosing regimens of CBX-12: 125 mg/m² and 100 mg/m², administered every 21 days. This study is pivotal for the advancement of CBX-12, which has demonstrated broad activity not only in ovarian cancer but also in breast, non-small cell lung cancer (NSCLC), thymic, gallbladder, and colorectal cancers during Phase 1 trials. The safety profile of CBX-12 was also deemed manageable.

Cybrexa's CEO, Per Hellsund, emphasized the importance of this milestone for patients battling aggressive ovarian cancer. He highlighted CBX-12's potential both as a standalone treatment and in combination therapies. The company is planning additional Phase 2 trials in various solid tumors in 2025.

CBX-12's design incorporates a pH-Low Insertion Peptide (pHLIP®), a linker, and exatecan, a second-generation TOP1 inhibitor. This composition aims to increase efficacy and reduce toxicity by delivering the drug directly into the cytoplasm of cancer cells. Unlike antibody-drug conjugates that depend on antigen expression, CBX-12 uses pHLIP® to target acidic cell surfaces selectively.

Furthermore, Cybrexa plans to collaborate with the National Cancer Institute (NCI) on a Phase 2 study of CBX-12 in colorectal cancer in 2025. The company is also progressing its broader pipeline, including CBX-15, expected to enter clinical trials in 2025 for the treatment of solid tumors using monomethyl auristatin E (MMAE) as its payload.

Cybrexa's alphalex™ technology represents a novel approach to cancer treatment, focusing on antigen-independent delivery systems. Developed at Yale University and the University of Rhode Island, pHLIP® peptides target acidic cell surfaces, optimizing the delivery of potent anti-cancer agents while reducing off-target effects.

Cybrexa Therapeutics, founded in 2017 and based in New Haven, Connecticut, is led by a team of experienced life science entrepreneurs and drug development scientists. The company aims to revolutionize cancer treatment standards through its innovative pipeline, targeting a range of tumors including breast, ovarian, and non-small cell lung cancers.

For more details about the Phase 2 study of CBX-12, visit ClinicalTrials.gov (NCT06315491).

CBX-12, a pioneering peptide-drug conjugate (PDC), aims to enhance exatecan delivery to tumor cells, increasing the efficacy and reducing the toxicity of TOP1 inhibition. As an antigen-independent therapy, it offers potential for patients ineligible for other targeted treatments and could be used in combination with other anti-cancer agents.

Cybrexa's alphalex™ technology platform is designed to enable targeted delivery of potent cancer treatments, aiming to change oncology care standards. The platform includes a pH-Low Insertion Peptide (pHLIP®), a linker, and a small molecule anti-cancer agent, making it a versatile tool for developing new oncology therapies.