Tuesday, January 3, 2012
Gene Therapy Is Back And Is Working for Some Patients
Now some new developments are coming to fruition and there is some legitimate reason for enthusiasm that gene therapy may prove viable for some of the most series of genetic disorders.
Some 28 of 30 patients with the rare Lebers’s congenital amaurosis blindness treated with an adeno-associated virus vector delivering a potentially curative gene have had improved eyesight. Gene therapies for two other diseases that cause blindness are under evaluation.
The much more common hemophilia B is also being studied with a gene therapy given with the adeno-associated virus approach. In this disease, the individual cannot produce the blood clotting protein called Factor IX and so must receive frequent IV infusions The virus with the inserted gene for Factor IX production is given intravenously and goes to the liver where it infects the patient’s liver cells which then produce the needed Factor IX protein.. So far in six patients who have gotten the gene therapy have had Factor IX rise from zero to 2-12% of normal. Low but enough to prevent bleeding in four patients and enough that two others could reduce the frequency of their regular intravenous infusions of Factor IX.
Kids with severe combined immune deficiency (SCID) have been treated with gene therapy and found to have much reduced infection risk. The same for a few children with Wiskott-Aldrich syndrome, another severe form of immune deficiency. In an NIH sponsored symposium, (October 7, 2011 issue of Science,) it was reported that 86 patients had by then received gene therapy and been improved.
There are many issues to be resolved before gene therapy becomes commonplace. Among them are concerns that the viral vector can produce cancer by turning on an oncogene. But, now a decade later, it appears that the promise of gene therapy will become a reality in the not too distant future. Chalk this up to terrific innovation. It will ultimately be a transformative medical megatrend.
Praise for Dr Schimpff
The craft of science writing requires skills that are arguably the most underestimated and misunderstood in the media world. Dumbing down all too often gets mistaken for clarity. Showmanship frequently masks a poor presentation of scientific issues. Factoids are paraded in lieu of ideas. Answers are marketed at the expense of searching questions. By contrast, Steve Schimpff provides a fine combination of enlightenment and reading satisfaction. As a medical scientist he brings his readers encyclopedic knowledge of his subject. As a teacher and as a medical ambassador to other disciplines he's learned how to explain medical breakthroughs without unnecessary jargon. As an advisor to policymakers he's acquired the knack of cutting directly to the practical effects, showing how advances in medical science affect the big lifestyle and economic questions that concern us all. But Schimpff's greatest strength as a writer is that he's a physician through and through, caring above all for the person. His engaging conversational style, insights and fascinating treasury of cutting-edge information leave both lay readers and medical professionals turning his pages. In his hands the impact of new medical technologies and discoveries becomes an engrossing story about what lies ahead for us in the 21st century: as healthy people, as patients of all ages, as children, as parents, as taxpayers, as both consumers and providers of health services. There can be few greater stories than the adventure of what awaits our minds, bodies, budgets, lifespans and societies as new technologies change our world. Schimpff tells it with passion, vision, sweep, intelligence and an urgency that none of us can ignore.
-- N.J. Slabbert, science writer, co-author of Innovation, The Key to Prosperity: Technology & America's Role in the 21st Century Global Economy (with Aris Melissaratos, director of technology enterprise at the John Hopkins University).