Rare Leukemia Rx Approved

Marqibo approved for Philadelphia chromosome negative acute lymphoblastic leukemia

(RxWiki News) Marqibo (vincristine sulfate liposome injection) has been approved by the U.S. Food and Drug Administration to treat adults with a rare type of leukemia called Philadelphia chromosome negative (Ph-) acute lymphoblastic leukemia (ALL).

This is an aggressive type of blood/bone marrow cancer that is more often seen in children than in adults.

The National Cancer Institute projects that about 6,000 people will be diagnosed this year with this cancer.

Marqibo is approved for patients whose leukemia has come back (relapsed) at least two times, or whose disease has gotten worse after anti-cancer therapies. Healthcare professionals give this drug weekly as an injection.

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“Marqibo’s approval demonstrates the FDA’s commitment to the development and approval of drugs that address serious, unmet medical needs,” said Richard Pazdur, MD, director of the Office of Hematology and Oncology Products in the FDA’s Center for Drug Evaluation and Research.

“Marqibo provides an additional option for Philadelphia chromosome negative acute lymphoblastic leukemia patients whose disease is unresponsive to available therapies.”

The drug’s effectiveness was analyzed in a single clinical trial in adult patients whose leukemia had returned at least two times despite standard treatments, and who had at least one earlier treatment response lasting at least 90 days.

The study was designed to see if the drug resulted in either a complete remission (CR) or a complete remission with incomplete blood count recovery (CRi).

Of the 65 patients enrolled, 10 patients, or 15.4 percent, responded with either a CR or CRi.

In these 10 patients, the disease remained in remission for a median (middle) 28 days. The median time to the first elapse, death or next therapy was 56 days.

The safety of Marqibo was evaluated in two single-arm trials of 83 patients who received the clinical treatment regimen. Serious adverse events such as low white blood cell counts with fever, low blood pressure, respiratory distress and cardiac arrest occurred in 76 percent of the patients studied.

The most common side effects observed during clinical studies include constipation, nausea, low blood cell counts, fever, nerve damage, fatigue, diarrhea, decreased appetite and insomnia.

Marqibo is in the FDA’s accelerated approval program, which allows the agency to approve a drug to treat a serious disease based on clinical data showing that the drug benefits patients. The manufacturers continues clinical trials as part of this approval.

Prescribing information for Marqibo will carry a Boxed Warning alerting patients and health care professionals that the drug must be given only through a vein (intravenously) because it is deadly if administered in other ways, such as into the spinal fluid.

The Boxed Warning also states that Marqibo has different dosage recommendations than a vincristine sulfate injection alone. To avoid overdose, it is important for health care professionals to verify the drug name and the dose before administration. Special requirements for preparation of the drug are detailed in the label.

Marqibo is marketed by Talon Therapeutics Inc., based in South San Francisco, California. 

Review Date: 
August 9, 2012