Myalgia and Rigidity as Adverse Effects of Trametinib Therapy

Area of Science:

• Pediatric Oncology
• Pharmacology
• Neuro-oncology

Background:

• Mitogen-activated extracellular kinase (MEK) inhibitors like trametinib and selumetinib are emerging treatments for pediatric low-grade gliomas (LGG).
• Trametinib is orally administered with limited myelosuppression but known side effects include rash, diarrhea, and fatigue.
• Selumetinib is associated with skin irritation, diarrhea, and musculoskeletal pain.

Purpose of the Study:

• To report a case of severe adverse effects in a pediatric patient treated with trametinib for LGG.
• To highlight previously undocumented side effects of trametinib in this patient population.

Main Methods:

• A case report of an 8-month-old male infant with progressive LGG post-chemotherapy.
• Initiation of trametinib therapy due to its liquid formulation and favorable side effect profile.
• Monitoring and documentation of adverse events following trametinib administration.

Main Results:

• The patient developed severe diarrhea, abdominal pain, neck pain, rigidity, and decreased stamina.
• These symptoms led to the discontinuation of trametinib.
• All reported symptoms resolved within one week of drug cessation.

Conclusions:

• This case represents the first documented instance of trametinib-induced myalgia and rigidity in a pediatric patient with LGG.
• Clinicians should be aware of these rare but significant adverse effects when considering trametinib for pediatric LGG.
• Careful monitoring for adverse events is crucial in pediatric patients receiving MEK inhibitor therapy.