Exelixis Announces Genentech Presentation of Preliminary Phase 1B Trial Results for the Combination of Cobimetinib and Atezolizumab at ASCO 2016 Annual Meeting

On June 5, 2016 Exelixis, Inc. (NASDAQ:EXEL) reported that its collaborator Genentech, a member of the Roche Group, will present preliminary results from a phase 1b clinical trial evaluating the safety and clinical activity of cobimetinib, an Exelixis-discovered MEK inhibitor, in combination with atezolizumab, an anti-PD-L1 antibody discovered and developed by Genentech, in patients with metastatic colorectal cancer (CRC) (Press release, Exelixis, JUN 5, 2016, View Source;p=RssLanding&cat=news&id=2175111 [SID:1234513003]). The results will be the subject of an oral presentation (Abstract #3502) today at the 2016 American Society of Clinical Oncology (ASCO) (Free ASCO Whitepaper) Annual Meeting, which is being held June 3-7 in Chicago, Illinois. Johanna Bendell, M.D., director of the Gastrointestinal Cancer Research Program at the Sarah Cannon Research Institute/Tennessee Oncology, Nashville, Tennessee, will present the results.

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!

"These early data on the combination of cobimetinib, an Exelixis-discovered MEK inhibitor, and atezolizumab, an anti-PD-L1 antibody discovered and developed by Genentech, are encouraging and warrant further study in people with previously-treated metastatic colorectal cancer, including those with microsatellite stable disease," said Michael M. Morrissey, Ph.D., president and chief executive officer of Exelixis. "Based on these results, Genentech has initiated the COTEZO phase 3 trial in patients with unresectable locally advanced or metastatic colorectal cancer."

This ongoing phase 1b trial includes both a dose escalation stage and dose expansion stage. The trial’s primary objective is the evaluation of the safety and tolerability of the combination. Secondary endpoints include objective response rate (ORR) per RECIST, duration of response, progression-free survival (PFS), overall survival (OS), as well as evaluation of biomarkers.

As of the February 12, 2016 data cut-off, 23 patients with advanced CRC (22 with mutant KRAS and one with wild-type KRAS) were enrolled during the trial’s escalation and expansion phases. No dose-limiting toxicities were observed. The median follow-up for safety in CRC patients was 3.8 months, with a range of 1.1 to 15.1 months. There were no all-cause grade 5 or treatment-related grade 4 AEs reported, and incidence of treatment-related grade 3 AEs was 35% (n=8). The most common treatment-related AEs, regardless of severity, included: diarrhea (70% of patients); fatigue (52%); dermatitis acneiform (44%); rash (35%); and nausea, maculopapular rash and pruritus (each 26%).

The ORR for the combination was 17%, including four confirmed partial responses; additionally five patients achieved stable disease. The median duration of response was not yet reached, with a range of 5.4 to more than 11.1 months.

Median PFS for all CRC patients enrolled in the trial was 2.3 months, with a range of 1.8 to 9.5 months. The six-month PFS was 35%. Median OS for all CRC patients was not evaluable, while six-month OS was 72%.

Recently Initiated COTEZO Phase 3 Pivotal Trial

In June 2016 Genentech initiated COTEZO, a phase 3 pivotal trial of the combination of cobimetinib and atezolizumab in unresectable locally advanced or metastatic colorectal cancer. The trial is expected to enroll 360 patients who have received at least two prior chemotherapies in the metastatic disease setting. The primary endpoint of the COTEZO trial is overall survival. More information about the COTEZO phase 3 pivotal trial is available at www.clinicaltrials.gov.

Additional Cobimetinib Data Presented at ASCO (Free ASCO Whitepaper) 2016

The oral presentation in colorectal cancer is one of eight cobimetinib abstracts being presented at the ASCO (Free ASCO Whitepaper) 2016 Annual Meeting this week. Additional data presentations include studies of cobimetinib in combination with other therapies to treat triple-negative breast cancer and BRAF-mutant melanoma. For full logistical information on these other presentations, please see Exelixis’ ASCO (Free ASCO Whitepaper) announcement press release issued on April 20, 2016, available online here.

About the Cobimetinib Development Collaboration

Exelixis discovered cobimetinib internally and advanced the compound to investigational new drug (IND) status. In late 2006, Exelixis entered into a worldwide collaboration agreement with Genentech, under which Exelixis received initial upfront and milestone payments for signing the agreement and submitting the IND. Following the determination of the maximum tolerated dose in phase 1 by Exelixis, Genentech exercised its option to further develop cobimetinib.

Under the terms of the collaboration, Exelixis is entitled to an initial equal share of U.S. profits and losses resulting from sales of cobimetinib to treat any form of cancer, which will decrease as sales increase, and will share in U.S. marketing and commercialization costs. In November 2013, Exelixis exercised its option to co-promote cobimetinib in the United States and, under the terms of the agreement, the company is fielding 25 percent of the U.S. sales force for the product’s first commercial indication in specific forms of BRAF mutation-positive advanced melanoma, closely coordinating its efforts with Genentech. Outside of the United States, Exelixis is eligible to receive royalties on any sales.

Cobimetinib in combination with vemurafenib is now approved in multiple countries, including the United States, European Union, Switzerland, Canada, Australia and Brazil, to treat specific forms of BRAF mutation-positive advanced melanoma. Further country approvals are anticipated in 2016 and beyond. Cobimetinib is also the subject of a clinical development program aimed at evaluating its potential in combination with a variety of investigational and approved therapies in disease settings including metastatic melanoma, triple-negative breast cancer and advanced solid tumors.

COTELLIC Indication

COTELLIC (cobimetinib) is a prescription medicine that is used with ZELBORAF (vemurafenib), to treat a type of skin cancer called melanoma that has spread to other parts of the body or cannot be removed by surgery, and that has a certain type of abnormal "BRAF" gene.

A patient’s healthcare provider will perform a test for the BRAF gene to make sure that COTELLIC is right for them. It is not known if COTELLIC is safe and effective in children under 18 years of age.

COTELLIC Important Safety Information

Patients should avoid sunlight during treatment with COTELLIC. COTELLIC can make their skin sensitive to sunlight. They may burn more easily and get severe sunburns. To help protect against sunburn, they should wear clothes that protect their skin, including their head, face, hands, arms, and legs. They should use lip balm and a broad-spectrum sunscreen with SPF 30 or higher.

COTELLIC may cause serious side effects, including risk of new skin cancers, bleeding problems, heart problems, severe rash, eye problems, liver problems, muscle problems (rhabdomyolysis), and photosensitivity. Patients should tell their doctor if they are pregnant or plan to become pregnant, as COTELLIC and ZELBORAF can harm an unborn baby. Patients who take COTELLIC should use effective methods of birth control during treatment, for 2 weeks after stopping COTELLIC, and for at least 2 months after stopping ZELBORAF. Do not breastfeed during treatment with COTELLIC and for 2 weeks after the final dose. Patients along with their healthcare provider should decide if they will take ZELBORAF or breastfeed. Patients should not do both.

Patients should tell their healthcare provider about all the medicines they take. Some types of medicines will affect the blood levels of COTELLIC.

Common side effects of COTELLIC include diarrhea, sunburn or sun sensitivity, nausea, fever, and vomiting. COTELLIC can also cause changes in blood test results.

Patients should tell their healthcare provider if they have any side effect that bothers them or that does not go away. These are not all the possible side effects of COTELLIC. For more information about side effects, patients should ask their healthcare provider or pharmacist.

Patients should call their doctor for medical advice about side effects. They may report side effects to FDA at (800) FDA-1088 or www.fda.gov/medwatch. They may also report side effects to Genentech at (888) 835-2555.

Please see full COTELLIC Prescribing Information and Patient Information for additional Important Safety Information.