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On ERV, Abbie Smith provides an update on a pioneering treatment for hemophilia that uses viruses to insert missing genes in a patient’s DNA. Hemophilia results from from the mutation or deletion of a gene that makes a blood clotting agent called Factor IX; without it, hemophiliacs are at risk for uncontrolled bleeding. While Factor IX can be delivered pharmaceutically, utilizing viruses to modify patients’ DNA yields long-term improvements in natural Factor IX production. Abbie writes, “the amount of therapeutic Factor IX these patients needed (on average) dropped from 2613 IU/kg to 206. The people who got the ‘high’ dose of virus dropped that down to 92 IU/kg. They went from 15-16 ‘bleeding episodes’ a year, to one.” They also saved $2.5 million.

Next, Abbie revisits research on treating HIV by removing CCR5 receptors that the virus uses to enter white blood cells. Much excitement was generated in 2008 when the “Berlin Patient” was declared to be functionally cured of HIV after receiving bone marrow from a donor with a mutation that preludes manufacture of the CCR5 protein. Now scientists are considering using gene therapy to disable CCR5 production in HIV patients, but there’s a catch: some HIV quasispecies utilize other receptor proteins, and even a small population of such viruses can take over when a patient is not producing CCR5. For this reason, Abbie writes that this therapy may hold more promise as a vaccine for HIV than as a cure.

Meanwhile, HIV itself has been genetically modified to help some sufferers of acute lymphoblastic leukemia by training cytotoxic T cells to target cancerous B cells. Abbie writes, “for all the time HIV has stolen from people, from families, its nice to see it giving some time back.”