Safety, PK and Efficacy of NOX66 as a Monotherapy and Combined With Carboplatin in Refractory Solid Tumours

Idronoxil is a synthetic small molecule that pre-clinical studies have identified as a strong candidate for development as a chemo-sensitising drug. Human studies using idronoxil administered in oral and intravenous dosage forms have shown that the drug is highly susceptible to Phase 2 metabolism, resulting in loss of bio-activity. NOX66 is idronoxil in a new dosage formulation developed specifically to protect the drug from Phase 2 metabolism and thereby ensure retention of the majority of administered drug in a bio-active form. The main purpose of the current study is to confirm the safety of the new dosage formula both as a monotherapy and in combination with carboplatin, given that it is anticipated that the drug will be present in the body in a bio-active form at considerably higher levels than previously achieved. A secondary objective is to observe if NOX66 is able to restore response to carboplatin in tumours considered unresponsive to this chemotherapy, and moreover to provide a meaningful clinical benefit in combination with a lower-than-normal dosage of carboplatin. Patients will be drawn from 5 cancer types: prostate cancer, lung cancer, breast cancer, ovarian cancer, head and neck cancer. The study will commence with a Phase 1a (Run-in) arm comparing the relative tolerability and safety of two different dosages of idronoxil/NOX66 as a 14-day monotherapy course. Providing there is no dose limiting toxicity (DLT), patients then progress onto the Phase 1b (Combination) arm of the study, remaining on the same dosage. In this arm, patients receive 6 treatment cycles, each of 28 days comprising NOX66 (idronoxil) treatment on Days 1-7 and carboplatin on Day 2 of each treatment cycle. Any meaningful clinical responses occurring in the Phase 1b (Combination) Arm will trigger a Phase IIa (Combination) Arm where an additional 10 patients will be recruited into a maximum of 2 cohorts of the same tumour type (prostate, lung, breast, ovarian, or head and neck). These patients will receive the same combination dosage providing the observed clinical responses and treated with that dosage for a maximum of 6 treatment cycles.