A patient who failed trametinib later responded to the avutametinib/defactinib combination. This suggests that resistance to one MEK inhibitor does not preclude a response to a different agent or combination targeting the same pathway, offering a viable later-line treatment strategy.
CPK elevation is a frequent lab finding with avutametinib but is almost always asymptomatic and doesn't cause clinical muscle weakness. This understanding has led to less stringent criteria for drug discontinuation, allowing more patients to remain on effective therapy despite the biomarker change.
When managing side effects from highly effective therapies like MEK inhibitors, it's often better to temporarily hold treatment and then resume at the original dose rather than immediately dose-reducing. This strategy maintains dose intensity, which is critical for maximizing the drug's therapeutic benefit.
While trametinib carries a ~6% risk of congestive heart failure, this specific toxicity has not been observed with the avutametinib/defactinib combination. This distinct safety profile makes the doublet a potentially safer option, especially for patients with cardiac risk or who failed trametinib due to heart issues.
For BRAF V600E low-grade serous ovarian cancer patients who progress on dabrafenib/trametinib, clinicians can appeal for the KRAS-approved combination avutametinib/defactinib. This strategy is based on evidence of the drug's activity in KRAS wild-type patients, offering a rational off-label option.