OncoGenex Announces Custirsen Phase 3 “ENSPIRIT” Trial Update

On April 30, 2015 OncoGenex Pharmaceuticals reported it has filed an amendment with the U.S. Food and Drug Administration, as well as initiated filing with regulatory agencies in other countries, to amend the statistical design and analysis plan of its pivotal, international Phase 3 ENSPIRIT trial evaluating custirsen in the treatment of non-small cell lung cancer (NSCLC) (Press release, OncoGenex Pharmaceuticals, APR 30, 2015, View Source [SID:1234503226]). OncoGenex recently regained the rights to the investigational compound from Teva Pharmaceuticals Ltd. and is currently in the process of assuming sponsorship for all clinical development related to custirsen.

Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:

Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing

                  Schedule Your 30 min Free Demo!

The protocol amendment is designed to reduce the number of required patients enrolled in the trial and include an earlier, more rigorous second interim futility analysis. The protocol will now also include additional analyses, specifically an evaluation of overall survival (OS) by patient histology, as well as the effect of custirsen’s efficacy among patients with poor prognostic risk factors. These changes do not affect the criteria for enrollment or conduct of the study, which continues to accrue patients. Enrollment is expected to be completed in the second half of 2016.

Know more, wherever you are:
Latest on Lung Cancer, book your free 1stOncology demo here.

"The majority of people with NSCLC do not have specific genetic mutations that will respond to targeted therapy. New treatment options like custirsen, added to standard of care chemotherapy, are urgently needed for patients to control their cancer once it has progressed," said Cindy Jacobs, PhD, MD, Chief Medical Officer and Executive Vice President of OncoGenex. "We believe these rigorous protocol changes reflect the most responsible course of action for these patients, who unfortunately do not have the gift of time. These changes will provide the critical information we need to more quickly understand custirsen’s activity and guide future development plans."

Under the revised protocol, the following changes include:

A reduced sample size: Changes to trial sample size were based on revising the hypothesized hazard ratio to 0.75 instead of 0.80, resulting in a sample size of 700 patients instead of 1,100. This change maintains a power of 90% while assessing for a more clinically meaningful difference.

Revised timing of second survival futility analysis: The second analysis will now take place when 40% of events occur, instead of the original 50%. As previously reported, OncoGenex expects this to occur in mid-2015. An Independent Data Monitoring Committee recommended the ENSPIRIT trial continue based on the outcome of the first interim futility analysis in August 2014. Trial results will remain blinded to the Independent Data Monitoring Committee and OncoGenex, as the sponsor, unless futility is observed.

Additional analyses: An evaluation of OS by patient histology, and the effect of custirsen’s efficacy among patients with varying risk factors and disease parameters, will now be conducted.

"These protocol changes will provide us with a more expedient path to assess custirsen’s potential survival benefit," said Scott Cormack, President and CEO of OncoGenex. "Reducing the sample size of the trial will enable us to evaluate the potential of custirsen in an earlier timeframe, hopefully accelerating the path to regulatory review and potential availability. We believe these are important steps in our efforts to give patients with advanced NSCLC more choices when their initial treatments fail."

Conference Call Details

OncoGenex will host a conference call at 4:30 p.m. Eastern Time today, Thursday, April 30, 2015, to provide an overview of today’s announcement. A live event will be available on the Investor Relations section of the OncoGenex website at www.OncoGenex.com. Alternatively, you may access the live conference call by dialing (877) 606-1416 (U.S. & Canada) or (707) 287-9313 (International). A webcast replay will be available approximately two hours after the call and will be archived on www.OncoGenex.com for 90 days.

About the Phase 3 ENSPIRIT Trial

The Phase 3 ENSPIRIT trial is an international, randomized, open-label trial designed to evaluate custirsen for the treatment of advanced or metastatic non-small cell lung cancer (NSCLC) in 700 patients who have progressed after initial chemotherapy treatment. The trial will investigate if combining custirsen with docetaxel, a standard second-line NSCLC chemotherapy, has the potential to improve survival outcomes compared to docetaxel alone in these patients. The trial is expected to enroll patients at approximately 50 sites globally. For more information on the ENSPIRIT trial, please visit View Source

Custirsen is also being evaluated in the ongoing Phase 3 AFFINITY trial with second-line chemotherapy in men with metastatic castrate-resistant prostate cancer. After regaining development control of custirsen, and based on the improved survival benefit observed in poor prognostic patients treated with custirsen in the completed Phase 3 SYNERGY trial, OncoGenex plans to seek regulatory guidance regarding amendments to the AFFINITY protocol.

About Custirsen

Custirsen is an experimental drug that is designed to block the production of the protein clusterin, which may play a fundamental role in cancer cell survival and treatment resistance. Clusterin is upregulated in tumor cells in response to treatment interventions such as chemotherapy, hormone ablation and radiation therapy and has been found to be overexpressed in a number of cancers, including prostate, lung, breast and bladder. Increased clusterin production has been linked to faster rates of cancer progression, treatment resistance and shorter survival duration. By inhibiting clusterin, custirsen is designed to alter tumor dynamics, slowing tumor growth and resistance to partner treatments, so that the benefits of therapy, including survival, may be extended.

Custirsen has Fast Track designation by the U.S. Food and Drug Administration for NSCLC and metastatic castrate-resistant prostate cancer.