Auden's story started in March 2010, when he had a cancerous mole removed. Although it put him at risk for more skin cancer, he continued to live an active life, running, biking and hiking.
But in September 2011, Auden said his doctors sat him down and told him the cancer had returned and had spread throughout his body. The official diagnosis was stage 4 melanoma.
"Some people survive, 90-odd percent don't," he said. "There's no doubt that was tough news. I had trouble not being emotional about it every time I thought of the concept of not being there to watch the kids grow up."
Auden's wife, Amy, was pregnant with the couple's third child when doctors told her husband that his median life expectancy was between six and nine months.
Two years of radiation and other experimental treatments later, Auden is still alive, but time is running out, his doctors say. Auden's wife said that when they started the campaign, he only had three to six months to live.
When Auden learned about the anti-PD-1 drugs and their ability to treat melanoma, he got excited. Studies of Merck's version of the drug found that 38 percent of participants in a clinical trial for patients with melanoma saw tumors shrink. Of those who took the highest doses of the drug, 52 percent experienced tumor shrinkage.
Dr. Jedd Wolchok, an oncologist who has not met or treated Auden but has corresponded with him through email, told ABCNews.com that immune cells typically don't attack cancer in a meaningful way because of a kind of natural brake function called PD-1. But the new anti-PD-1 drugs cancel out that brake and allow the immune cells to attack the cancer.
Although there are currently no anti-PD-1 drugs in "compassionate use" trials -- trials for individuals who don't qualify for clinical trials but still want the drug -- Wolchok said there was a chance the drug could offer Auden long-term benefits.
"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, and hatched the "Save Locky's Dad" campaign during a sleepless night at 3 a.m. Maybe he 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 thought.
The "Save Locky's Dad" campaign took hold, launching more than a month ago with the goal of reaching 150,000 signatures. Once it attained that goal, the Audens upped it to 200,000. The goal is now set at a million signatures.
"It's really surpassed anything that we could have imagined," Amy Auden said.
Emails poured into the Audens' inbox from people wishing them luck and sharing stories of how their relatives used the drugs and had positive results.
And now, as Nick's condition becomes more dire, he continues to wait for the drug companies to give him a chance at survival.
"I am having a double craniotomy Monday followed by brain radiation," he said. "The tumors keep growing and without PD-1 they will continue to grow until I lose cognitive ability and slip into a coma."