FDA Approves System to Make Blood Transfusions Safer
The U.S. Food and Drug Administration (FDA) approved the Intercept Blood System, a new system designed to remove viruses, bacteria, and other pathogens from donated blood platelets. In an analysis of 844 subjects in 10 clinical studies who received platelets using this new system, treatment reduced the number of a broad range of viruses, bacteria, and other pathogens that may contaminate platelets, including HIV, hepatitis B and C viruses, and West Nile virus. The Intercept System – which was also recently approved for the preparation of plasma to reduce the risk of transfusion-transmitted infections – also reduced the number of T cells to a level that lowers the risk of transfusion-associated graft-versus-host disease.
Source: FDA press release, December 19, 2014
Test to Confirm the Presence of HTLV-I and HTLV-II Receives FDA Approval
The MP Diagnostics HTLV Blot 2.4, a qualitative enzyme immunoassay test, was recently approved as the first FDA-licensed supplemental test for human T-cell lymphotropic virus-I/II (HLTV-I/II). This test is intended for use as an additional, more specific test for human serum or plasma specimens that have previously tested positive on an HLTV-I/II blood donor–screening test. HLTV are a group of human retroviruses known to cause diseases such as adult T-cell leukemia/lymphoma and inflammation of the nerves in the spinal cord (myelopathy). Because HTLV can be transmitted through blood, the FDA requires that donated blood be tested for HTLV-I/II antibodies; if the test is positive, the donation is discarded and the donor is notified of his or her deferral. The newly approved test will help blood establishments better counsel donors who have had positive results on an FDA-licensed HTLV-I/II screening test – many of whom are asymptomatic and unaware of the infection.
Source: FDA press release, December 11, 2014
Stem Cell Divisions Help Explain Cancer Risk Variation
Random mutations acquired during stem cell divisions correlate with lifetime cancer risk, more so than heritable mutations and environmental factors combined, according to results of an analysis of 31 different tissues published recently in Science. Using available data on the number of stem cells and their rates of division in a variety of tissues, researchers found that about 65 percent of the variation in cancer risk among tissue types can be explained by the number of stem cell divisions a tissue undergoes within its lifetime. When researchers plotted lifetime cancer risk against the total number of stem cell divisions, they found that the greater the cumulative number of stem cell divisions, the higher the cancer rate in that tissue. This association remained true even when applied to cancers with 100,000-fold differences in lifetime risk. Colorectal and basal cell tissue had the highest number of cell divisions of the tissues analyzed – and are also the most frequently observed cancer type. Bone tissue of the pelvis, head, and arms, in contrast, underwent the lowest number of stem cell divisions and had among the lowest observed cancer rates. While emphasizing the randomness of certain cancers, the study does confirm that some cancers, such as lung cancer, have a large environmental component and could be largely prevented. For all cancers, the authors stressed, early detection remains vital.
Source: Tomasetti C, Vogelstein B. Science. 2014 January 1. [Epub ahead of print]
New Indication for the JAK Inhibitor Ruxolitinib
Ruxolitinib, a JAK1 and JAK2 inhibitor approved for the treatment of intermediate or high-risk myelofibrosis, is now approved by the FDA for the treatment of polycythemia vera. This new indication is intended to treat the condition in patients who have an inadequate response to or are intolerant of hydroxyurea – another medicine often prescribed to reduce the number of red blood cells and platelets in the blood. The approval was based on results from a clinical study of 222 participants who had polycythemia vera for at least 24 weeks and had undergone a phlebotomy procedure and exhibited an enlarged spleen. Participants were randomly assigned to receive ruxolitinib or the best available therapy, as determined by the investigator on a participant-by-participant basis. At 32 weeks of follow-up, 21 percent of ruxolitinib-treated patients experienced a reduction in the need for phlebotomy and a reduction in spleen volume, compared to 1 percent of participants who received best available therapy. The most common side effects of ruxolitinib were anemia and thrombocytopenia; the most common non–blood-related side effects were dizziness, constipation, and shingles. The FDA reviewed ruxolitinib’s use for polycythemia vera under the agency’s priority review program, because, at the time the application was submitted, the drug demonstrated the potential to be a significant improvement in safety or effectiveness over available therapy in the treatment of a serious condition. The drug also received orphan product designation because it is intended to treat a rare disease.
Source: FDA press release, December 4, 2014