Comarit20 mg

Comarit is an orally administered multi-kinase (tyrosine kinase) inhibitor used in the treatment of several advanced cancers. Its approved and evidence-supported uses vary by strength of evidence:

FDA-approved / established indications

• Advanced renal cell carcinoma (RCC): as a single agent, and in combination with nivolumab (immunotherapy) as first-line treatment for advanced RCC.
• Hepatocellular carcinoma (HCC): in patients who have previously been treated with sorafenib.
• Differentiated thyroid cancer (DTC): locally recurrent or metastatic, progressive disease that is refractory to radioactive iodine and has progressed on or after a prior VEGFR-targeted therapy, in adults and pediatric patients 12 years and older.
• Medullary thyroid cancer (MTC): progressive, metastatic disease (capsule formulation).
• Neuroendocrine tumors (pancreatic and extra-pancreatic, pNET/epNET): previously treated, unresectable, locally advanced or metastatic disease, in adults and pediatric patients 12 years and older.

Combination therapy requirement

For first-line advanced RCC, Comarit must be given in combination with nivolumab; it is not used alone in this specific setting.

Comarit should only be prescribed and monitored by a physician experienced in the use of anticancer therapy.

Each tablet or capsule contains Cabozantinib (as the S-malate salt) as the active ingredient. Cabozantinib is available in different strengths for its two formulations:

• Tablet formulation: commonly available as 20 mg, 40 mg and 60 mg film-coated tablets, used for RCC, HCC, DTC and NET indications.
• Capsule formulation: commonly available as 20 mg and 80 mg (combined to reach a 140 mg daily dose), used for medullary thyroid cancer.

The tablet and capsule formulations of Cabozantinib are not interchangeable or bioequivalent and must not be substituted for one another.

Comarit is a small-molecule, orally bioavailable multi-receptor tyrosine kinase inhibitor developed for the treatment of certain advanced solid tumors. It is marketed internationally under brand names such as Cabometyx (tablet) and Cometriq (capsule), and is available in Bangladesh under various local brand names in both tablet and capsule form.

Comarit works by blocking several kinases involved in tumor growth, angiogenesis (new blood vessel formation) and metastasis, which helps to slow or halt the progression of certain cancers.

Multi-kinase inhibitor (tyrosine kinase inhibitor); Antineoplastic (anticancer) agent — Comarit belongs to this class.

Cabozantinib inhibits the tyrosine kinase activity of multiple receptors implicated in tumor growth, pathologic angiogenesis, and metastatic progression, including:

• MET (hepatocyte growth factor receptor)
• VEGFR-1, -2, and -3 (vascular endothelial growth factor receptors)
• RET, AXL, KIT, FLT-3, TIE-2, ROS1, TRKB, MER, and TYRO3

By simultaneously blocking VEGFR and MET signaling pathways, Cabozantinib reduces tumor angiogenesis, invasion, and metastasis. Dysregulation of these target kinases has been implicated in the pathogenesis of renal cell carcinoma, hepatocellular carcinoma, thyroid cancers, and certain neuroendocrine tumors, which is the pharmacological basis for the use of Cabozantinib in these cancers.

Comarit should be taken exactly as prescribed by the treating oncologist. Key administration instructions:

• Take on an empty stomach — do not eat any food for at least 2 hours before and at least 1 hour after taking Comarit.
• Swallow tablets/capsules whole with a full glass of water; do not crush, chew, or open capsules.
• Avoid grapefruit or grapefruit juice, which can increase blood levels of Comarit.
• Take at approximately the same time each day.
• If a dose is missed, it should not be taken if the next scheduled dose is due within 12 hours; do not double the dose to make up for a missed one.
• If vomiting occurs after a dose, do not take a replacement dose that day; resume the normal schedule at the next scheduled time.

Comarit is metabolized primarily by the CYP3A4 enzyme, making it prone to clinically significant interactions with drugs that affect this pathway:

• Strong CYP3A4 inhibitors (e.g. ketoconazole, itraconazole, clarithromycin, ritonavir): increase Comarit blood concentrations, raising the risk of toxicity. Avoid concomitant use where possible; if unavoidable, the dose of Comarit should be reduced under physician guidance.
• Strong or moderate CYP3A4 inducers (e.g. rifampin, phenytoin, carbamazepine, St. John's Wort): decrease Comarit blood concentrations, which may reduce its effectiveness. Avoid concomitant use where possible; if unavoidable, the dose of Comarit may need to be increased under physician guidance.
• Grapefruit and grapefruit juice: can increase Comarit levels and should be avoided.
• Anticoagulants (e.g. warfarin): concurrent use with Comarit may increase bleeding risk (see Precautions) and may require closer monitoring of coagulation status.

Always inform the physician or pharmacist of all prescription drugs, over-the-counter medicines, and herbal supplements being taken before starting Comarit.

Serious warnings (boxed warnings)

• Hemorrhage: Severe and sometimes fatal bleeding events have occurred with Comarit. Permanently discontinue Comarit in patients with severe hemorrhage.
• Gastrointestinal perforation and fistula: Perforations and fistulas, including fatal cases, have occurred with Comarit. Permanently discontinue Comarit if these occur.

Very common side effects (≥20%)

Diarrhea, fatigue, hand-foot skin reaction (palmar-plantar erythrodysesthesia), decreased appetite, hypertension, nausea, vomiting, weight loss, constipation, stomatitis, rash, dysgeusia (taste changes), abdominal pain.

Other important side effects

• Thromboembolic events (blood clots in arteries or veins)
• Hepatotoxicity (liver enzyme elevation, liver injury)
• Proteinuria (protein in urine)
• Reversible posterior leukoencephalopathy syndrome (rare, presents with headache, seizures, confusion, vision changes)
• Osteonecrosis of the jaw (rare)
• Wound healing complications
• Hypothyroidism

Patients should seek prompt medical attention for severe abdominal pain, black/bloody stools, vomiting blood, sudden severe headache, seizures, or signs of a blood clot (leg swelling/pain, chest pain, shortness of breath) while taking Comarit.

Pregnancy: Comarit can cause fetal harm based on its mechanism of action and findings in animal reproduction studies. Comarit should not be used during pregnancy unless clearly needed and the potential benefit justifies the potential risk to the fetus; a physician must be consulted before use. Females of reproductive potential should use effective contraception during treatment with Comarit and for at least 4 months after the final dose. Male patients with female partners of reproductive potential should also use effective contraception during treatment and for a period after the last dose, as advised by their physician.

Lactation: It is not known whether Comarit passes into human breast milk. Because of the potential for serious adverse reactions in a breastfed infant, women should not breastfeed during treatment with Comarit and for at least 4 months after the final dose. Always consult a physician regarding breastfeeding decisions.

Boxed warnings

• Hemorrhage: Do not administer Comarit to patients with severe, active bleeding or recent hemoptysis. Monitor for signs of bleeding.
• Gastrointestinal perforation and fistula: Monitor for symptoms of perforation or fistula formation (e.g. severe abdominal pain, persistent constipation, fever); discontinue Comarit permanently if these occur.

Other important precautions

• Surgery and wound healing: Comarit impairs wound healing. Withhold Comarit for at least 28 days prior to elective surgery and do not resume until adequate wound healing has occurred; discontinue in patients with wound dehiscence.
• Hypertension: Blood pressure should be well controlled before starting Comarit and monitored regularly during treatment; dose interruption, reduction, or antihypertensive therapy may be required. Comarit should be withheld for hypertensive crisis or severe uncontrolled hypertension.
• Thromboembolic events: Comarit increases the risk of blood clots in arteries and veins; use with caution in patients at higher risk and discontinue in patients who develop an acute myocardial infarction, serious arterial thromboembolic event, or severe venous thromboembolism.
• Reversible posterior leukoencephalopathy syndrome (RPLS): A rare neurological condition; discontinue Comarit in patients who develop RPLS.
• Hepatotoxicity: Liver function tests should be monitored periodically before and during treatment with Comarit, particularly when used in combination with nivolumab.
• Proteinuria: Monitor urine protein regularly; discontinue for nephrotic syndrome.
• Diarrhea and gastrointestinal disorders: Manage promptly with standard antidiarrheal treatment; interrupt or reduce dose for severe or persistent diarrhea.

There is no specific antidote for Comarit overdose. In case of suspected overdose, seek immediate medical attention or contact a poison control center right away. General supportive care and close monitoring for adverse reactions (particularly bleeding, gastrointestinal symptoms, hypertension, and cardiac effects) should be provided in a hospital setting. Do not attempt to manage a suspected Comarit overdose at home without medical guidance.

Store at room temperature (below 30°C), away from light and moisture. Keep out of reach of children.

Renal impairment

No specific dose adjustment is established for mild-to-moderate renal impairment. Comarit has not been studied in severe renal impairment or end-stage renal disease; use with caution.

Hepatic impairment

No adjustment needed for mild impairment. A reduced starting dose is recommended for moderate impairment. Comarit is not recommended in patients with severe hepatic impairment (see Dosage and Administration).

Elderly patients

No overall differences in effectiveness have been observed between elderly and younger patients, but elderly patients may be more susceptible to certain adverse reactions; monitor closely.

Pediatric patients

Comarit is approved for use in pediatric patients 12 years of age and older for differentiated thyroid cancer and certain neuroendocrine tumors, with dosing based on body weight. Safety and effectiveness in children below 12 years of age, and for other indications in pediatric patients, have not been established (see Pediatric Uses).

Treatment with Comarit is generally continued for as long as the patient continues to derive clinical benefit and tolerates the medicine, i.e. until disease progression or the occurrence of unacceptable toxicity, as determined by the treating oncologist. There is no fixed maximum duration of treatment; the physician will reassess the need for continued therapy at regular intervals through clinical and radiological evaluation.

Antineoplastic agents; Protein/multi-kinase inhibitors; VEGFR-targeted therapy — Cabozantinib is classified within these drug classes.

Cabozantinib acts by inhibiting multiple receptor tyrosine kinases — most notably MET, VEGFR-1/-2/-3, RET, and AXL — that drive tumor cell proliferation, blood vessel formation (angiogenesis), and the spread of cancer cells (metastasis). By blocking these overlapping signaling pathways at once, Cabozantinib suppresses tumor growth and vascularization more broadly than agents that target a single pathway, which underlies its activity in renal cell carcinoma, hepatocellular carcinoma, thyroid cancers, and neuroendocrine tumors where these pathways are frequently dysregulated.

Comarit is approved for use in pediatric patients aged 12 years and older for differentiated thyroid cancer and for certain previously treated neuroendocrine tumors, with the dose determined by body weight (60 mg daily if ≥40 kg, 40 mg daily if <40 kg).

Safety and effectiveness of Comarit have not been established in children younger than 12 years, or in pediatric patients for renal cell carcinoma, hepatocellular carcinoma, or medullary thyroid cancer. Because Comarit may affect growth plates in growing bones, adolescents receiving Comarit should have periodic monitoring of open growth plates; interruption or discontinuation should be considered if abnormalities are detected.