NEW YORK – The US Food and Drug Administration on Thursday approved Novartis' BRAF/MEK inhibitor combination Tafinlar plus Mekinist (dabrafenib plus trametinib) for pediatric patients with low-grade glioma harboring BRAF V600E mutations.
The FDA approved the combination based on results from the Phase II/III TADPOLE trial, in which patients on Tafinlar-Mekinist lived for a median of 20.1 months without their cancers progressing versus 7.4 months when patients received standard-of-care chemotherapy. The overall response rate with Novartis' combination therapy was 47 percent versus 11 percent on standard of care.
The agency also approved a liquid formulation of Tafinlar plus Mekinist, making it easier to administer to young children.
When investigators initially presented the TADPOLE data during the American Society of Clinical Oncology (ASCO) annual meeting last year, it spurred discussion among oncologists about the importance of ensuring equitable biomarker testing for these patients. Although it's estimated that some 17 percent of pediatric patients with low-grade gliomas harbor BRAF V600E mutations, many receive treatment without undergoing any molecular profiling to explore personalized treatment options.
BRAF V600E mutations can be detected using a variety of diagnostic technologies including PCR, next-generation sequencing, and immunohistochemistry. Despite the availability of cheaper and easily accessible diagnostic technologies, like IHC, widespread testing access for the pediatric glioma patient population still has a long way to go, especially in low- and middle-income countries, the researchers emphasized at the ASCO meeting.
"It is more important than ever to test for genetic mutations in patients living with low-grade glioma," Roger Packer, the senior VP of the Center for Neurosciences and Behavioral Medicine at Children's National Hospital, said in a statement about the new approval. "This has the potential to change the way healthcare providers treat these patients, offering a significant advancement compared to chemotherapy."
The Tafinlar-Mekinist combination is already approved in the US for the treatment of refractory cancers regardless of tumor type, advanced melanoma, and metastatic non-small cell lung cancers. Patients must have BRAF V600E mutations to receive the treatment in these settings. The FDA has approved several companion diagnostics for identifying best responders to BRAF inhibitors, including a 2021 approval of a therapeutic group indication for Foundation Medicine's FoundationOne CDx test when it is used to identify melanoma patients eligible for BRAF/MEK inhibitor combination therapy including Tafinlar-Mekinist.