Repotrex 40 mg

Primary Indications

1. ROS1-Positive Non-Small Cell Lung Cancer (NSCLC): For adult patients with locally advanced or metastatic lung cancer that tests positive for a ROS1 gene rearrangement.
2. NTRK Gene Fusion-Positive Solid Tumors: For adults and pediatric patients (12 years and older) who have advanced or metastatic solid tumors (such as lung, thyroid, or soft tissue cancers) caused by an NTRK gene fusion. It is used when the cancer has progressed after previous treatments or when there is no satisfactory alternative therapy.

How it Works

• The Problem: In certain cancers, the ROS1 or NTRK genes fuse with other genes abnormally. This fusion acts like a broken signal, constantly instructing the cancer cells to multiply and grow.
• The Solution: Repotrectinib physically blocks these specific abnormal proteins, shutting down the signaling pathway that drives the tumor’s growth.
• Next-Generation Design: Unlike older treatments, Repotrectinib’s compact molecular structure is designed to overcome “resistance mutations” that tumors often develop to evade older drugs. It is also specifically engineered to cross the blood-brain barrier effectively, making it highly effective at treating cancer that has spread to the central nervous system or brain.

Standard Dosage & Administration

• Starting Dose (Days 1–14): 160 mg (which is four 40 mg capsules) taken orally once daily.
• Maintenance Dose (Day 15 onwards): 160 mg (four capsules) taken twice daily.
• Intake: The capsules must be swallowed whole and should never be opened, crushed, or chewed. They can be taken with or without food.
• Missed Dose: If a dose is missed or if the patient vomits after taking it, that dose should be skipped. The patient should take the next scheduled dose at the regular time without doubling up.

Important Precautions

• CNS Effects: Central nervous system effects are common, with dizziness being the most frequently reported side effect (affecting over 60% of patients). Other potential CNS effects include balance issues (ataxia) and cognitive or mood changes.
• Monitoring: Doctors will closely monitor liver function tests (ALT/AST) and uric acid levels, as the drug can cause liver toxicity and hyperuricemia (elevated uric acid). Patients are also monitored for breathing issues like interstitial lung disease (ILD) or unexplained muscle pain.
• Interactions: Patients should avoid grapefruit and certain medications (moderate to strong CYP3A inhibitors or inducers) as they can significantly alter how much of the drug stays in the body.