After decades of research and testing, the FDA approves belatacept, and a new class of transplant drugs first discovered by Emory doctors.
Back in September, Dr. Christian P. Larsen, Director of the Emory Transplant Center, shared a story with you here on our blog about belatacept, a new medication that was being studied to determine its ability to help block the immune system from graft rejection after kidney transplants. It’s been less than a year since we shared that story on belatacept with you, and since that time, the FDA has now approved belatacept for use for that exact purpose.
Since the early 1990s, Emory surgeon-scientists Christian P. Larsen, MD, DPhil and Thomas C. Pearson, MD, DPhil have been searching for ways to promote immune tolerance of a transplanted organ. In collaboration with other Emory researchers and researchers at Bristol-Myers Squibb, they played a leading role in discovering belatacept and driving its development. The recent FDA approval of use of belatacept is the first time a new class of drugs has been developed for transplant since the 1990s.
So what led to this approval of a new class of drugs? From a research perspective, in the 1990s, Larsen and Pearson found that CTLA4-Ig, a fusion protein of which belatacept is a modified type, could control graft rejection in mice, but found that it didn’t work as well in non-human primates. Bristol-Myers Squibb researchers then developed a panel of hundreds of modified forms of CTLA4-Ig, and sifted through the mutated proteins to find two that could make CTLA4-Ig bind tighter to its target and work more effectively. Larsen and Pearson then showed that the enhanced version could prevent graft rejection in a non-human primate model for kidney transplant at Yerkes Research Center.
Once the determination was made that modified versions of the CTLA4-lg fusion proteins could work to prevent graft rejection on primates, belatacept was developed and tested. In two parallel studies with more than 1,200 participants over two years, patients taking belatacept had similar graft survival rates to those taking the calcineurin inhibitor cyclosporine, while maintaining higher kidney function and lower blood pressure and cholesterol. In addition, belatacept can be given every few weeks, in contrast to calcineurin inhibitors, which must be taken twice a day.
There is still room for improvement, though. Compared with cyclosporine-treated patients, belatacept-treated patients had a higher rate of early acute rejection – a temporary flare-up of the immune system against the donated kidney. However, in most cases the acute rejection was successfully treated with drugs and did not lead to graft failure. The Emory Transplant Center team is researching approaches to reduce this risk.
“Our goal is to achieve a normal life span for kidney transplant patients, and have them survive dialysis-free,” Larsen, Director of the Emory Transplant Center, says. “We believe belatacept can help us move toward that goal.”
Clinical trials are now also being conducted to determine if belatacept will have similar positive outcomes on liver transplant and pancreatic islet transplant patients.
For more information on belatacept, you can check out the video below. If you have additional questions, leave them in the comments for Dr. Larsen or Dr. Pearson and we’ll make sure they see them and give you a response!
For more information on the FDA’s approval of belatacept, visit: http://shared.web.emory.edu/whsc/news/releases/2011/06/fda-approves-transplant-drug-that-preserves-kidneys,-avoids-toxicity.html