"This kind of medicine is not the kind of medicine that if it works, it works for a few weeks and stops working," said Wolchok, a melanoma specialist at Memorial Sloan-Kettering Cancer Center in New York. "If medications like this work, they tend to benefit people for months or years. Some people might even be 'cured.'"
Auden said he was told that in order to be accepted into a clinical trial for the anti-PD-1 drug, he would need to have either no brain tumors or brain tumors that were at least no longer growing. Wolchok explained that the drug had the potential to cause brain swelling in people with existing brain disease.
Since Auden had brain tumors, he and his oncologist, who declined to be interviewed for this story, worked to stabilize the tumors using a combination of drugs and other therapies. After months of monitoring his brain scans, Auden got good news in July: His tumors had not grown, and he qualified for the Merck trial.
They high-fived in the doctor's office.
But hours later, Auden experienced abdominal pain and sent his doctor a message. The doctor said to go straight to an emergency room, because there was a possibility he had a perforated intestine.
"Sure enough, I did," Auden said. "That instantly disqualifies you for the trial."
Auden's wife, of course, had other plans, hatched during those sleepless nights at 3 a.m.
Maybe Auden could become an individual case study under compassionate use rules, which give people access to experimental drugs even if they don't fit into clinical trials, she said she thought.
"I could not sleep," Amy Auden told ABCNews.com. "I was lying awake at night thinking, I can't just lie here and do nothing."
"Save Locky's Dad" launched in September.
"I want my dad to get the PD-1 drug because then I can do the things I like to do with him all the time," Locky says in a video on the "Save Locky's Dad" website, flashing a smile that's missing two front teeth between shots of the two playing Frisbee.
But by October, the companies still hadn't granted Auden access to the drug, and he needed surgery to remove two tumors that had grown in his brain since the site's launch.
"His oncologist says he must have the drug now to survive," his wife, Amy Auden, told ABCNews.com in an email that week. "The tumors do not stop growing throughout this process."
The FDA gave Merck's drug "breakthrough therapy" status in April, allowing the pharmaceutical company to speed up clinical trials in the hopes of approving it, and making it more widely available, sooner, according to company filings.
But that meant it would need to increase its supply of the drug for the ramped-up clinical trials, which Merck spokesman Steven Cragle said was no easy feat. Because the drug is made from mammalian cells, it takes time to literally grow the supply in a lab. As such, Merck only has enough for the clinical trials.
"Nature is working against us," Cragle said. "It's hard to conceptualize why we can't just 'bake a bigger loaf of bread,' so to speak."
He added that Merck is working to make enough of the drug to develop an expanded access program -- which would benefit patients like Auden, who don't fit into clinical trials -- but there's no timeline for it yet.
"Not everyone has as short a window as I," Auden said in October. "Why can't they supply me now rather than me missing by a couple of months? Imagine Amy explaining that to the kids ..."
Although Auden was the highest profile patient seeking the anti-PD-1 drug outside of a clinical trial, he was not the only one, Cragle said.
In a statement on the "Save Locky's Dad" website following Auden's death, the family declared "this mission is not over."
"In the end, Nick's death beams a spotlight on a glaring need for change in compassionate access practices for life-saving drugs in late-stage investigational trials," they said in a statement. " More on this, when the time is right."