If this exon-skipping drug is approved, she estimates 15 percent of boys with Duchenne could be helped, those with the type that skips exon 51. As a class of drugs, they could help up to 85 percent of boys with the disease.
Stock prices for its manufacturer, Sarepta Therapeutics. , have soared.
If Sarepta Therapeutics can get accelerated approval, the drug could be available in six to nine months, according to McNary. Otherwise, the wait could be four or five years -- too late for Austin.
"We are very encouraged by the data we have seen to date," said Chris Garabedian, president and CEO of Sarepta Therapeutics, which makes the drug and is pressing the FDA to take action.
"If we start using the drug earlier in patients, we might be able to stabilize whatever state they are in for a longer period of time," said Garabedian. "We are not going to end up creating Olympic athletes from this drug, but we are encouraged this could really halt or slow the progression."
McNary is reaching out to media and online petition sites to encourage as many people as possible to write letters of support to the FDA.
But as she waits approval, Austin gets weaker. In the last few months, he has lost all upper body control and must be lifted 100 percent of the time.
Just recently, he was diagnosed with sleep apnea and must go on a nighttime machine to keep his lungs inflated.
Austin keeps his spirits high, according to McNary.
On Halloween, he dressed his wheelchair up as a hot dog stand, carrying his dachshund in a cloth bun. And just recently, his father and uncle took him hunting. They held up the gun for Austin and he shot his first buck -- an eight-pointer.
McNary is convinced that if the FDA can move on approving the drug that has healed Max, it can also help Austin.
Until then, he's "hanging in there," she said. "He has a huge zest for life."