Pomamac is a brand which contains Pomalidomide, is an immunomodulatory agent primarily used in the treatment of multiple myeloma, a type of blood cancer. It is also approved for treating Kaposi sarcoma under specific conditions.

Mechanism of Action

Pomalidomide functions as a thalidomide analogue and modulates the immune system by inhibiting angiogenesis (the formation of new blood vessels) and directly suppressing the growth of myeloma cells. It achieves this by acting as a cereblon E3 ligase modulator, leading to the degradation of specific proteins essential for myeloma cell survival.

Pomalidomide is a potent immunomodulatory agent offering significant benefits in the treatment of relapsed and refractory multiple myeloma and certain cases of Kaposi sarcoma. Due to its potential for severe adverse effects, particularly teratogenicity, careful patient selection, monitoring, and adherence to safety protocols are essential during therapy.

Indications

Multiple Myeloma:

• In combination with dexamethasone for patients who have received at least two prior therapies, including lenalidomide and a proteasome inhibitor, and have demonstrated disease progression on or within 60 days of completion of the last therapy. 

Kaposi Sarcoma:

• For patients with AIDS-related Kaposi sarcoma after failure of highly active antiretroviral therapy (HAART) or in patients with Kaposi sarcoma who are HIV-negative.

Dosage and Administration

The recommended starting dose of pomalidomide for multiple myeloma is 4 mg orally once daily on days 1 through 21 of each 28-day cycle. It is administered in combination with low-dose dexamethasone. Treatment continues until disease progression or unacceptable toxicity occurs. Dose adjustments may be necessary based on individual patient tolerance and specific adverse reactions.

Clinical Efficacy

Clinical trials have demonstrated the efficacy of pomalidomide in combination with dexamethasone for relapsed and refractory multiple myeloma. In a phase III trial, patients receiving this combination showed a significant extension in progression-free survival and overall survival compared to those receiving high-dose dexamethasone alone.

Side Effects

Common side effects of pomalidomide include:

• Fatigue
• Anemia
• Neutropenia
• Constipation
• Nausea
• Diarrhea
• Back pain
• Upper respiratory tract infections

Serious adverse effects may include severe neutropenia leading to infections, deep vein thrombosis, pulmonary embolism, and hepatotoxicity. Regular monitoring of blood counts and liver function tests is recommended during treatment.

Contraindications and Precautions

• Pregnancy: Pomalidomide is contraindicated during pregnancy due to a high risk of severe, life-threatening birth defects. Women of childbearing potential must use effective contraception and undergo regular pregnancy testing before and during treatment.

• Hematologic Toxicity: Patients should be monitored for hematologic toxicity, including neutropenia and thrombocytopenia. Dose modifications may be necessary based on the severity of these effects.

• Thromboembolic Events: There is an increased risk of deep vein thrombosis and pulmonary embolism. Prophylactic anticoagulation should be considered, especially when used in combination with dexamethasone.

Drug Interactions

• Caution is advised when co-administering pomalidomide with strong inhibitors or inducers of CYP1A2 and CYP3A4 enzymes, as these may alter pomalidomide plasma concentrations. Monitoring for adverse effects is recommended when used concomitantly with these agents.

Pharmacokinetics

• Pomalidomide is rapidly absorbed following oral administration, with peak plasma concentrations occurring within 2 to 3 hours. It is primarily metabolized in the liver and has a half-life of approximately 7.5 hours. The drug is eliminated through both renal and fecal pathways.

Regulatory Status

• Pomalidomide received FDA approval in February 2013 for the treatment of multiple myeloma and in May 2020 for Kaposi sarcoma. It is also approved in the European Union and other countries for similar indications.