Mutations in the gene that encodes the KRAS protein are frequently encountered in various human cancers. They are found in about 30% of non-small cell lung cancers (NSCLCs), making KRAS the single most common gene mutated in this cancer. The rate of KRAS mutations in other cancers, such as pancreatic or colorectal, is even higher.
A mutant KRAS protein that is always in the “on” position activates many signaling pathways, many of which lead to unrestrained growth and proliferation of cancer cells. This makes KRAS an appealing treatment target. However, challenges abound, and researchers are exploring several different approaches to treating KRAS-mutant cancers.
Unlike mutations in proteins known as receptor tyrosine kinases, like EGFR or ALK, mutated KRAS is a very difficult protein to target with cancer drugs. (So much so that the National Institutes of Health (NIH) has undertaken a special effort to intensify the effort towards successful targeting of mutant KRAS, known as the RAS Initiative.) Continue reading…
“Array BioPharma (Nasdaq: ARRY) and Pierre Fabre today jointly announced top-line results from Part 1 of the Phase 3 COLUMBUS (Combined LGX818 Used with MEK162 in BRAF Mutant UnresectableSkin Cancer) study evaluating LGX818 (encorafenib), a BRAF inhibitor, and MEK162 (binimetinib), a MEK inhibitor, in patients with BRAF-mutant advanced, unresectable or metastatic melanoma. The study met its primary endpoint, significantly improving progression free survival (PFS) compared with vemurafenib, a BRAF inhibitor, alone.”
“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.
“Three Phase 3 trials with binimetinib continue to enroll in advanced cancer patients: NRAS-mutant melanoma (NEMO / NCT01763164), low-grade serous ovarian cancer (MILO / NCT01849874) and BRAF-mutant melanoma (COLUMBUS / NCT01909453). NRAS-mutant melanoma represents the first potential indication for binimetinib, with a projected regulatory filing from the NRAS-mutant melanoma study estimated to be in 2015.”
Editor’s note: This is a press release from a company that is testing a new potential treatment for melanoma called binimetinib, or “MEK162.” The drug is being tested in clinical trials (learn more about clinical trials). One of the trials is enrolling melanoma patients whose tumors have mutations in the NRAS gene, as detected by molecular testing. Another is enrolling patients with BRAF mutations.
Someone had to do it; now it looks like Novartis may be the first. The pharma company’s new series of clinical trials, SIGNATURE (also known as, ‘bring the protocol to the patient,’ or ‘P2P’), is recruiting patients with different cancers to receive investigational targeted drugs selected to match the distinct genetic changes found in each patient’s tumor. Continue reading…
Among melanomas, BRAF-mutated disease gets the vast majority of attention. Fifty percent of melanomas harbor BRAF mutations, which can be targeted with BRAF inhibitors. However, despite its notoriety, BRAF is not the only important melanoma mutation.
Another melanoma-linked mutation can be found in the NRAS gene. Like BRAF mutations, NRAS mutations are ‘driver mutations’—a tumor with an NRAS mutation is dependent on the mutation for its growth and survival. Continue reading…
While melanomas with BRAF mutations can be targeted with a combination of BRAF inhibitors and MEK inhibitors, the treatment can have side effects such as fever, light sensitivity, and rashes. But early results of a phase I clinical trial suggest that BRAF-mutant melanomas could be treated safely and effectively with a new combination: LGX818, a BRAF inhibitor developed by Novartis and MEK162, a MEK inhibitor developed by Array BioPharma. Moreover, using these drugs together may decrease common side effects of targeted BRAF treatments, including skin toxicities and muscle and joint pain. A phase III trial of this new combination treatment is expected to begin later in 2013.
A phase II study suggests that a MEK inhibitor drug benefits people who have melanomas with NRAS mutations, which currently have no targeted treatments. The drug, called MEK162, shrank tumors in 20% of NRAS-mutated melanoma patients (6 out of 30). MEK162 also shrank tumors in 20% of BRAF-mutated melanoma patients (8 out of 41), as well as tumors that had spread to the brain in two patients. This study is registered with ClinicalTrials.gove as number NCT01320085, and is now recruiting more patients with NRAS mutations.
Ascierto PA, Schadendorf D ... Zubel A, Dummer R. The Lancet Oncology. Mar 2013.
The MEK inhibitor MEK162 is the first agent to show some activity in patients with NRAS– and BRAF-mutated advanced melanoma, according to the conclusions of a phase II study, evaluating the drug’s safety and efficacy, published in Lancet Oncology. In addition, treatment with MEK162 resulted in the shrinkage of target brain metastases in two patients.
Research paper here: http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(13)70024-X/abstract