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Exon skipping up for Approval

By December 24, 2015October 30th, 2016Tracy's Blog

Kyndrisa, the drug being reviewed today by an FDA advisory committee, is the first Duchenne treatment ever to go up for approval in the US. It is also the first therapy we supported when we launched Charley’s Fund in 2005. Ten years ago, it was an early-stage promising therapeutic approach that would need a lot of work to see the light of day as an actual medicine. I would love to say this is a day of total excitement and anticipation to see our intense efforts finally bear fruit in the form of a treatment or cure for Duchenne. But it’s a lot more complicated than that.

Kyndrisa has serious safety concerns and the data gathered to date do not convincingly demonstrate that the drug actually does what it is supposed to do. That is not easy to say. Charley’s Fund has invested more than $1.1 million dollars to help develop this drug platform. Let me be clear: we want it to work. But we are not here to self perpetuate; we are here to drive aggressively toward safe and effective treatments. And we won’t get there if we gloss over messy, complicated pictures and fail to frankly acknowledge shortcomings. As we watch the review underway right now, the FDA is very seriously considering shortcomings in Kyndrisa’s data. Clearly, this one is not all we hoped it would be.

I do not know whether this drug will be approved. Maybe the FDA will determine that in light of the severity of the disease, the significant safety issues are bearable and the leap of faith on efficacy is warranted. Maybe Kyndrisa does help some patients, and the large clinical trial failed to meet its endpoint because the trial wasn’t designed in the best possible way. That would be fine with me, with one HUGE caveat.

Today’s proceedings and the FDA’s ultimate decision on this one drug absolutely must not get in the way of approval of another drug coming up for review in a few weeks. Eteplirsen, a drug being developed by Sarepta Therapeutics, is a different drug with its own unique development path and data package. Frighteningly, Kyndrisa’s poor record has already derailed eteplirsen’s regulatory process, causing egregious delays in eteplirsen’s progress. In November 2013 the FDA told Sarepta not to submit a new drug application for eteplirsen, a reversal from the encouragement they had given just four months earlier. One of the reasons the Agency cited for halting eteplirsen’s progress was the fact that in a large clinical trial, Kyndrisa failed to show that it works better than a placebo. The conflation of these two very different drugs was a massive misstep that patient advocates have been trying to rectify for two full years. This was serious time lost in the race to get safe and effective drugs approved for Duchenne.

Conflating these two drugs has been wrong and has impeded progress to date.We must not allow this anymore. Whatever happens today, we must proceed with full understanding that these two drugs are based on different chemistries, and their fates must not be intertwined. Accordingly, once today is over, eteplirsen should be swiftly assessed, fairly and independently considered, and — in my opinon — approved.