Wednesday, November 21, 2012

Smart drug improves survival in older patients with acute myeloid leukemia

Gemtuzumab ozogamicin (marketed by Wyeth as Mylotarg) is a drug-linked monoclonal antibody that was used to treat acute myelogenous leukemia from 2000-2010. It was withdrawn from market in June 2010 when a clinical trial showed the drug increased patient death and added no benefit over conventional cancer therapies.

Gemtuzumab is a monoclonal antibody to CD33 linked to a cytotoxic agent from the class of calicheamicins. CD33 is expressed in most leukemic blast cells but also in normal hematopoietic cells, the intensity diminishing with maturation of stem cells. In the United States, it was approved under an accelerated-approval process by the FDA in 2000 for use in patients over the age of 60 with relapsed acute myelogenous leukemia (AML); or those who are not considered candidates for standard chemotherapy.

Within the first year after approval, the FDA required a black box warning be added to Gemtuzumab packaging. The drug was noted to increase the risk of veno-occlusive disease in the absence of bone marrow transplantation. Later the onset of VOD was shown to occur at increased frequency in Gemtuzumab patients even following bone marrow transplantation. The drug was discussed in a 2008 JAMA article, which criticized the inadequacy of postmarketing surveillance of biologic agents. 

Common side effects of administration included shivering, fever, nausea and vomiting. Serious side effects included severe myelosuppression (suppressed activity of bone marrow, which is involved in formation of various blood cells [found in 98% of patients]), disorder of the respiratory system, tumor lysis syndrome, Type III hypersensitivity, venous occlusion, and death. 

Now researchers from a major phase III Cancer Research UK-funded trial led by Cardiff University, have come out with an interesting conclusion that is, adding GO to treatment could improve the effectiveness of chemotherapy without excessively increasing side effects, providing a potential lifeline for older AML patients who are often too frail to tolerate more intensive chemotherapy regimes.....

Ref :
Smart drug improves survival in older patients with acute myeloid leukemia

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