Are the side effects of Repotrectinib severe?

Are the side effects of Repotrectinib severe?

Repotrectinib can cause myalgia, with or without elevated creatine phosphokinase levels. In clinical trials, the incidence of myalgia was 13%, with 0.7% being Grade 3 events. Within a 7-day window, 3.7% of patients experienced concurrent creatine phosphokinase elevation. Patients should be alert to any unexplained muscle pain, tenderness, or weakness and report it to their physician promptly. Serum creatine phosphokinase levels should be monitored during treatment, especially every 2 weeks during the first month, and thereafter based on patient symptoms and clinical need. Physicians may initiate supportive care as indicated and suspend, reduce the dose, or discontinue treatment based on severity.

Hyperuricemia

The incidence of hyperuricemia as an adverse reaction was 5%, with 0.7% of patients experiencing Grade 3 or 4 severe hyperuricemia. One patient without a prior history of gout required treatment with urate-lowering medication. Serum uric acid levels should be monitored periodically before and during treatment with Repotrectinib. If hyperuricemia occurs, urate-lowering drugs (e.g., allopurinol, febuxostat) should be initiated as clinically indicated. Based on severity, physicians may withhold treatment, resume at the same or reduced dose upon improvement, or permanently discontinue.

Bone Fractures

Fracture events occurred in 2.3% of patients, involving sites including ribs (0.5%), foot (0.5%), spine (0.2%), acetabulum (0.2%), sternum (0.2%), and ankle (0.2%). Some fractures occurred at sites of tumor involvement or previously irradiated areas. In pediatric patient studies, one 12-year-old patient experienced ankle/foot fracture, and one 10-year-old patient experienced stress fracture. Repotrectinib is not approved for use in children under 12 years of age. Patients presenting with signs of fracture such as pain, changes in mobility, or deformity should be evaluated promptly. There are no data on the effect of this drug on healing of known fractures or on future fracture risk.