OncoGenex Pharmaceuticals, Inc., a biopharmaceutical company developing new therapies that address treatment resistance in cancer patients, has announced its Phase 3 ENSPIRIT trial evaluating custirsen in the treatment of non-small cell lung cancer (NSCLC) will continue moving forward, through recommendation of the Independent Data Monitoring Committee (IDMC) due to completion of the first interim futility analysis.
Custirsen is an experimental drug designed to block the production of clusterin, a protein involved in cancer cell survival and treatment resistance. After cancer therapies such as chemotherapy, hormone ablation and radiation therapy, clusterin becomes upregulated on the surface of tumor cells, increasing cancer progression and resulting in shorter survival.
Custirsen blocks clusterin and therefore interferes with tumor dynamics, slowing its growth and diminishing the resistance to complementary treatments.
In the initial phases of the ENSPIRIT trial, 294 patients suffering from different types of cancer received custirsen, with only mild cytotoxic side effects.
The Phase 3 trial began in 2012 and is an international, randomized, open-label trial with the aim to evaluate the survival benefit for custirsen in the treatment of advanced or metastatic non-small cell lung cancer in 1,100 patients who have progressed after initial chemotherapy treatment. Two cohorts of patients randomly received custirsen plus docetaxel (a chemoterapeutic drug) or docetaxel alone.
From the two futility analyses set to finish the trial, one has reached completion, allowing progression of the trial and further enrollment.
“While the results of the study remain blinded to OncoGenex and Teva, we are very pleased that ENSPIRIT has passed this important early interim futility analysis. We remain strong in our belief that targeting mechanisms of treatment resistance is a critical path forward in the fight against cancer and we continue to actively pursue this approach through the two ongoing Phase 3 trials of custirsen and the seven Phase 2 trials of apatorsen in four tumor types.” Scott Cormack, President and CEO of OncoGenex said in the company’s press release.
The second futility analysis will be conducted later in the study, and meanwhile, the U.S. Food and Drug Administration (FDA) has granted Fast Track designation for the evaluation of custirsen in the ENSPIRIT trial.
In addition, custirsen will be evaluated in the current Phase 3 AFFINITY study alongside second-line chemotherapy in men with metastatic castrate-resistant prostate cancer, with expected final results in the end of 2015 or beginning of 2016.