Lenalidomide

Lenalidomide is a prescription drug used for the treatment of anemia in myelodysplastic syndromes (MDS) and for the treatment of multiple myeloma. MDS is characterized by inadequate production of mature blood cells, and multiple myeloma is a cancer of the plasma cells in bone marrow. Lenalidomide is very similar to thalidomide, another drug used to threat multiple myeloma.

The U.S. Food and Drug Administration approved lenalidomide in December 2005.

Other Names

Lenalidomide is marketed as Revlimid by Celgene.

Uses

Lenalidomide is approved to treat related disorders of the blood:

• MDS-associated anemia that requires blood transfusions
• multiple myeloma, in combination with dexamethasone, in people who have been treated previously

How Lenalidomide is Taken

Lenalidomide is available in 5 mg, 10 mg, 15 mg and 25 mg oral capsules. The dosage depends on the condition being treated.

MDS

For MDS, the recommended starting dose is 10 mg daily with water. The dose may be adjusted according to response.

Multiple myeloma

For multiple myeloma, the recommended starting dose is 25 mg/day with water on days 1-21 of repeated 28-day cycles.

How Lenalidomide Works

The mechanism of lenalidomide is not known. However, the drug modulates the immune system, has anticancer properties, and prevents the formation of new blood vessels (antiangiogenesis).

Studies have shown that lenalidomide boosts the function of the immune system by stimulating the production of certain types of T cells. In the lab, lenalidomide inhibits the growth of multiple myeloma cells and causes cell death. By preventing the growth of new blood vessels, lenalidomide would cut off the supply of nutrients to growing tumors.

How the Body Affects Lenalidomide

Lenalidomide is rapidly absorbed following oral administration with peak circulating levels occurring between 0.625 and 1.5 hours. How lenalidomide is metabolized is not known. Approximately 66% of lenalidomide is eliminated unchanged through urinary excretion.

Side Effects

The most common side effects observed with lenalidomide are the following:

• low platelet counts (thrombocytopenia)
• low white blood cell counts (neutropenia)
• diarrhea
• itching
• rash
• fatigue

Risks and Precautions

Because of its similarity to thalidomide (which has caused birth defects in humans), lenalidomide is CONTRAINDICATED in women who are or may become pregnant and who are not using birth control or who are not continually abstaining from sexual intercourse.

Drug Interactions

Lenalidomide is unlikely to interact with drugs that influence the activity of the CYP enzymes, which metabolize a variety of drugs.

Research

The effectiveness of lenalidomide was studied in 43 patients with low-risk MDS who have no response to erythropoietin or who were unlikely to benefit from conventional therapy.^[1] The response rate was 56% and 74% had showed signs of low blood cell levels. Low blood cell counts required interruption of treatment or a dose reduction in 58% of the affected patients. Response rate was dependent on the type of mutation that caused the cancer.

The effectivness of Lenalidomide plus dexamethasone was compared to treatment with dexamethasone alone in a multicenter trial of over 300 patinets with multiple myeloma.^[2] Complete, near-complete, or a partial response was seen in 61% of patients given the lenalidomide-dexamethasone treatment. The same outcome was seen in 20% of patients given dexamethasone with a placebo. A complete response was seen in 14% and 0.6% of patients given lenalidomide or dexamethasone alone, respectively.

References

1. ↑ List A, Kurtin S, Roe DJ, et al. Efficacy of lenalidomide in myelodysplastic syndromes. N Engl J Med. 2005 Feb 10;352(6):549-57. Abstract | Full Text | PDF
2. ↑ Weber DM, Chen C, Niesvizky R, et al. Lenalidomide plus dexamethasone for relapsed multiple myeloma in North America. N Engl J Med. 2007 Nov 22;357(21):2133-42. Abstract | Full Text | PDF | Press Release

External Links

FDA: Patient Information Sheet