Experts Grapple With Nuances of Navigating New Frontier in Melanoma

“Emerging data showing improved survival with targeted and immunotherapeutic approaches are rapidly altering the standard of care for patients with melanoma. For BRAF-positive patients with metastatic or unresectable melanoma, the standard of care includes a BRAF inhibitor in combination with a MEK inhibitor. For patients with or without BRAF mutations, there are immunotherapeutic options available in frontline and in resistant disease settings.

“Questions remain, however, in terms of how to optimally sequence and/or combine both targeted agents and immunotherapies. And, for BRAF-mutant disease, when is it appropriate to switch from a targeted approach to an immunotherapeutic one?”


Exelixis Announces Positive Overall Survival Results from Phase 3 Pivotal Trial of Cobimetinib in Combination with Vemurafenib in Patients with BRAF V600 Mutation-Positive Advanced Melanoma

“Exelixis, Inc.EXEL, -1.02% today announced positive overall survival (OS) results from coBRIM, the phase 3 pivotal trial evaluating cobimetinib, a specific MEK inhibitor discovered by Exelixis, in combination with vemurafenib in previously untreated patients with unresectable locally advanced or metastatic melanoma carrying a BRAF V600 mutation. Exelixis’ collaborator Genentech, a member of the Roche Group, informed the company that coBRIM met its secondary endpoint of demonstrating a statistically significant and clinically meaningful increase in overall survival for patients receiving the combination of cobimetinib and vemurafenib, as compared to vemurafenib monotherapy. Ongoing study monitoring did not identify any new safety signals. Long-term safety data are expected later this year. These data will be the subject of a presentation at an upcoming medical meeting.”


Binimetinib And Encorafenib Combination Shows Promising Clinical Activity And Potential Differentiated Safety In BRAF-Mutant Melanoma

“Array BioPharma’s (NASDAQ: ARRY) wholly-owned MEK inhibitor, binimetinib, and BRAF inhibitor, encorafenib, were showcased at the 2015 annual meeting of the American Society of Clinical Oncology (ASCO). At the meeting, preliminary data for the combination of binimetinib and encorafenib from a Phase 1b/2 dose escalation and expansion study in patients with BRAF-mutant melanoma who are BRAF inhibitor treatment naive were shared during an oral presentation. Results from the study indicate that binimetinib and encorafenib may be safely combined and show encouraging clinical activity consistent with MEK/BRAF inhibitor expectations in patients with BRAF-mutant melanoma who are BRAF inhibitor treatment naive. In addition, a differentiated safety profile relative to other MEK/BRAF inhibitor combinations is emerging in the dose range currently being used in the Phase 3 COLUMBUS trial.  Array expects updated BRAF melanoma data from the ongoing Phase 2 combination trial (LOGIC-2) of binimetinib and encorafenib followed by the addition of a third targeted agent identified based on genetic testing at the time of progression will be submitted to a scientific conference later this year.  LOGIC-2 utilizes the same dose of binimetinib and encorafenib currently being studied in the COLUMBUS trial.”


Cobimetinib and Vemurafenib Combination Treatment Is Highly Active in BRAF+ Melanoma

“Roche (SIX: RO, ROG; OTCQX: RHHBY) today announced follow-up data from two studies of the investigational MEK inhibitor cobimetinib in combination with Zelboraf® (vemurafenib). Updated data from the pivotal coBRIM Phase III study showed the combination helped people with previously untreated BRAF V600 mutation-positive advanced melanoma live a median of one year (12.3 months) without their disease worsening or death (progression-free survival; PFS) compared to 7.2 months with Zelboraf alone (hazard ratio [HR]=0.58, 95 percent confidence interval [CI] 0.46-0.72).1

“ ‘The combination of cobimetinib and Zelboraf extended the time people lived without their disease getting worse to a year,’ said Sandra Horning, M.D., Chief Medical Officer and Head of Global Product Development. ‘These results are exciting because they underscore the importance of combining medicines that target the signals, which cause about half of all melanomas to grow.’ “


GSK's Melanoma Study Stopped Early on Survival Boost

The gist: In the U.S. and Australia, oncologists are allowed to prescribe a treatment that combines the drugs Mekinist (trametinib) and Tafinlar (dabrafenib) for people with unresectable or metastatic melanoma whose tumors have a V600E or V600K mutation in the BRAF gene. European regulators would like to see more data on the benefits and risks of the treatment before approving it for European patients. The company that produces the treatment was conducting a clinical trial with volunteer patients to capture that data, but has now decided to halt the trial, which was comparing the combo treatment to the drug Zelboraf (vemurafenib). The trial found that the combo treatment has such a significant improvement on patient survival that the patients who had been taking vemurafenib for comparison should be allowed to switch to the combo treatment, and the trial ended early.

“GlaxoSmithKline has stopped a Phase III study of its combination therapy for advanced cutaneous melanoma ahead of schedule after it showed a significant survival benefit.

“The UK drug giant said an Independent Data Monitoring Committee (IDMC) has made the recommendation as it emerged patients with metastatic melanoma – carrying a BRAFV600 mutation – who took a combo of Mekinist (trametinib) and Tafinlar (dabrafenib) demonstrated an overall survival benefit compared to those taking vemarufenib.

“Safety signals were also good, remaining consistent with that for the MEK inhibitor and BRAF inhibitor observed to date, the firm said.”


Two Array-Invented MEK Inhibitors Showcased At ASCO

“Two Array BioPharma-invented MEK inhibitors, binimetinib (MEK162) and selumetinib, were showcased at the 50th annual meeting of the American Society of Clinical Oncology (ASCO).  At the meeting, preliminary data for the combination of binimetinib and CDK4/6 inhibitor LEE011 (discovered by Novartis Institutes for BioMedical Research in collaboration with Astex Pharmaceuticals) from a Phase 1b/2 dose-escalation study conducted by Novartis in NRAS-mutant melanoma indicates the combination demonstrated an acceptable safety profile for most patients with promising preliminary antitumor activity.  Additionally, preliminary data for selumetinib showed favorable clinical activity in pediatric patients with neurofibromatosis type 1 (NF1) and plexiform neurofibromas (PNs).”

Editor’s note: This article discusses a melanoma treatment that combines two durgs: binimetinib (aka MEK162) and selumetinib. A clinical trial recently found that the combo shows promise for melanoma patients whose tumors have mutations in the NRAS gene, as detected by molecular testing. Binimetinib is also being tested as a potential treatment for patients whose tumors have mutations in the BRAF gene.


Conference Abstract – MAP Kinase Pathway Alterations in BRAF-Mutant Melanoma Patients With Acquired Resistance to Combined RAF/MEK Inhibition

“Treatment of BRAF-mutant melanoma with combined dabrafenib and trametinib, which target RAF and the downstream MAP–ERK kinase (MEK)1 and MEK2 kinases, respectively, improves progression-free survival and response rates compared with dabrafenib monotherapy. Mechanisms of clinical resistance to combined RAF/MEK inhibition are unknown. This study represents an initial clinical genomic study of acquired resistance to combined RAF/MEK inhibition in BRAF-mutant melanoma, using WES and RNA-seq. The presence of diverse resistance mechanisms suggests that serial biopsies and genomic/molecular profiling at the time of resistance may ultimately improve the care of patients with resistant BRAF-mutant melanoma by specifying tailored targeted combinations to overcome specific resistance mechanisms.”

Editor’s note: We previously covered the benefits of a dabrafenib/trametinib combo for advanced-stage melanoma. However, some patients’ tumors become resistant to this drug combination and new treatment routes need to be considered. This study is exploring how molecular testing of specific genetic mutations in patients’ tumors might be used to help guide treatment decisions after they become resistant to the dabrafenib/trametinib combo.


New Treatments for Advanced Melanoma Presented at AAD

“In recent years, the FDA has approved new drugs for the treatment of advanced melanoma, which has presented new ways to treat the disease, according to a presentation at the American Academy of Dermatology annual meeting.

“ ‘In the last four years there have been four new drugs that have been FDA-approved for melanoma and what’s even more exciting is that they really speak to two new ways to treating melanoma,’ Allan C. Halpern, MD, MSc, chief of dermatology service at Memorial Sloan-Kettering Cancer Center, told Healio.com.

“The most recent FDA approval, in January, was the combination of a BRAF inhibitor and a MEK inhibitor for treating advanced melanoma.”


Immunotherapy, BRAF Inhibitor Sequence Affected Outcomes in Metastatic Melanoma

“Prior treatment with immunotherapy did not limit response to BRAF inhibitors among patients with metastatic melanoma, according to results of a retrospective study.

“However, patients who underwent initial treatment with BRAF inhibitors and subsequently received immunotherapy with ipilimumab (Yervoy, Bristol-Myers Squibb) demonstrated poorer outcomes, results showed.

“Patients with BRAF-positive metastatic melanoma have several treatment options, including BRAF inhibitors vemurafenib (Zelboraf, Hoffmann-La Roche) and dabrafenib  (Taflinar, GlaxoSmithKline), the MEK inhibitor trametinib (Mekinist, GlaxoSmithKline), and the immunotherapy agents ipilimumab and interleukin-2. Yet, there are limited data with regard to optimal sequencing, according to researchers.”