Finally, a long-promised revolution may be unfolding, based on a series of recent studies. Cell therapy (typically using a patient’s own stem cells) has finally started to show benefit in patients with crippling heart pain (known as angina) who literally have no other treatment option. As for gene therapy, remember the movie “Lorenzo’s Oil?” The disease featured in that story is now responding to gene therapy. In another study, kids have had their sight restored, while a third has used gene therapy to correct a rare immunological disorder.
Like all revolutions, battles are won and lost along the way. The bruising battle for cell-based therapies to treat disease was evident a few years ago when the Journal of the American College of Cardiology published several studies in a special section. One study used patient’s own bone marrow cells to successfully regenerate cardiac tissue from 5 months to 8.5 years after a heart attack. This is long after any intervention is expected to reverse major damage done to heart tissue. Two other studies in the same issue of JACC reported the effects of using two types of widely available growth factor therapies to promote new coronary vascularization. Both studies were stopped early because of ominous results.
Recently, I talked to Dr. Douglas Losordo, Northwestern University Medical School, Chicago. In a randomized trial of “no option” patients with chronic angina, use of patients’ own stem cells plus growth factor therapy led to significant improvements that the patients themselves could recognize. (Sometimes, “significant” benefit is technically achieved but the differences are so small that they are not relevant to the patient’s day-to-day life.)
Dr. Losordo said, “The good news here is that you're talking about a reduction in approximately 14 episodes of angina per week and the patients will tell you, ‘Gee, I can do stuff now that I really couldn't do before.’ It’s really a quality of life change for the patients.”
As an investigator long involved in such research, he said many previous studies “completely failed.” Thus, Dr. Losordo added, “It's refreshing to finally have something that looks like a possible win. It's phase II, so we can't say for sure that this is a therapy that will move forward, but this is a large population of patients that is disabled with symptoms. If we could offer something beyond what we currently have I think that would be a very positive thing.”
Gene Therapy
Gene therapy requires that scientists match a disease, condition, or disorder with a gene mutation and then, find the mutation within an individual patient and insert a gene that corrects the problem. There has been remarkable progress in sequencing the human genome, as well as identifying some links among gene mutations or irregularities and specific diseases, disorders, and conditions. However, using these discoveries to treat patients remains highly experimental.
The good news is that researchers may be reversing the tide of disappointing data in recent years. Just before Thanksgiving (how appropriate!), Rob Logan, PhD, senior staff at the National Library of Medicine, cited three recent reports suggesting impressive progress in gene therapy.
In a study published in Science, investigators arrested the development of adrenoleukodystropy (ALD), in two children. ALD causes a degeneration of the fatty insulation of nerve cells, which results in progressive brain damage. The impact of the disease on patients and caregivers was the focus of the 1992 movie, 'Lorenzo's Oil.'
In a second study, reported by The Lancet in October, gene therapy restored the sight of five children and several adults with a rare, congenital eye disease. All patients had a gene mutation that prevented them from making a retina protein. An added gene (that remained in the body of each patient's cells) stimulated the development of the missing protein, which helped partially restore their vision.
A third study, reported in the New England Journal of Medicine, described how gene therapy overcame a rare immunological disorder in eight of 10 patients.
Dr. Logan said, “Now normally, we would not highlight three studies about experimental treatments for a different disease that provide preliminary results based on a few patients. However, the announcement of the successful ALD intervention in Science by itself resulted in an accompanying editorial titled 'A Comeback for Gene Therapy.'”
None of these therapies are ready for prime time yet, but it is very encouraging to finally be able to say that this revolution appears to be coming – this time, sooner as opposed to later.
You can read more about the progress being made to move from genes to personalized medicine here: http://bit.ly/697dwP
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