“I said, ‘That’s just what I’m looking for,’’’ Woods recalled, reciting the paper’s title from memory, like a mantra. “‘The isolation and characterization of renal cancer initiating cells from human Wilms tumor xenografts unveils new therapeutic targets.’ It was amazing.”

Like thousands of parents before him, Woods soon discovered that drugmakers avoid testing experimental drugs like IMGN901 on children, even on kids who didn’t respond to last-resort treatments.

He had stepped into the blunt reality of research on rare pediatric diseases. Pharmaceutical companies have developed few new children-focused drugs because the market is small and testing is fraught with dire risks for young patients who can’t give consent.

For Woods, it was the beginning of a yearlong journey to get a pediatric clinical trial of IMGN901 under way.

He was up against a system that pits desperate parents against cancer-drug makers. The U.S. has taken an incentive approach, offering rewards worth tens of millions of dollars to encourage research. Families and advocates say it’s not enough, and are using social media to get organized and pushing for legislation in Washington. In May, they got support from a group of 26 senators, who wrote to the U.S. National Institutes of Health, urging it to make sure children are included in studies when possible.

“Too often, children get left behind as treatments are developed for adults,” Mississippi Republican Roger Wicker and Rhode Island Democrat Jack Reed said in the letter. “It is critical that we continue to make progress on this front.”

IMGN901 roots

IMGN901 traces its roots to the 1980s, when ImmunoGen Inc. started developing a drug targeting a molecule called CD56. Following setbacks in multiple trials, the drugmaker most recently focused its research program on adult lung cancer, the world’s most common and deadly tumor.

CD56 is found on the surface of almost all cells in Wilms tumor and some other pediatric cancers in nerves and muscles. Children’s cancer experts found IMGN901 promising as early as 2009, according to Malcolm Smith, associate branch chief of pediatric oncology at the National Cancer Institute. ImmunoGen made the drug available for testing in mice and models but when researchers showed interest in testing it in children in 2010, the company indicated that it wanted to wait until its own lung cancer trial was complete, Smith said. ImmunoGen, in an e-mailed statement, said it was unable to verify 2010 communications about a possible pediatric trial.

Most drugs aren’t studied in children -- sometimes for good reasons, as trials can harm patients. Still, pediatric doctors need information on dosage and side effects specific to their young patients.

‘I beg you’

When companies do agree to pediatric trials, they typically wait until after mid-stage studies on adults are done, said Peter Adamson, chairman of the government-supported COG, which organizes studies in a network of about 200 hospitals. It’s not soon enough for researchers and parents like Jennifer Seigel.

“As a mother, it is horrific watching your child suffer waiting for a successful treatment,” Seigel, a nurse practitioner, wrote in a 2013 letter to ImmunoGen. “I beg of you to consider pushing this drug into a pediatric clinical trial.” Her son died in January 2014, 3 1/2 years after being diagnosed with Wilms tumor.

Oncology drugs sell about $100 billion a year globally. The vast majority of the 1.7 million cancers diagnosed in the U.S. annually, about 77 percent, are in people at least 55 years old. Children and teens represent about 1 percent, and the chance that a child will develop cancer before 20 is about 0.3 percent.

From a business perspective, it’s an unprofitable market for most drugmakers.

“They’re not able to make any money in tiny patient populations, so they’re not going to invest in the drug,” Woods said.

Congress has stepped in to encourage children-focused cancer research with the Creating Hope Act of 2011, which some lawmakers are currently pushing to extend to 2027. The legislation rewards companies that get a drug approved first for use in children with a valuable voucher for fast review of any other drug: It’s essentially the right to get a more lucrative drug to the market months earlier than through the usual approval track. Six vouchers have so far been awarded, and four of them were resold -- the most recent for $350 million.

Stellablue’s cancer

When Stellablue was diagnosed at 4, Woods dropped six tile jobs, and the family packed up their home facing Montana’s Chestnut Mountain and drove 700 miles to Seattle Children’s Hospital.

Woods and his wife, Andrea, had just had their second daughter, Soren. To be close to the hospital, the Woods bought a used 25-foot camper for about $4,000. They lived for months in the parking lot. “We’re a close family,” Woods said. “Living on top of each other isn’t the end of the world.”

During the nine months of Stellablue’s first treatment, Woods spent most of his days reading about cancer.

“I had to become an oncologist,” he said.

When Stellablue relapsed four months later, her chances for survival plunged to 30 percent from 92 percent. She started a more aggressive program. If it didn’t work, she would effectively be out of options.

Woods’ petition

Woods reached out to ImmunoGen by e-mail, pleading with the company to start testing IMGN901 in Wilms tumors.

“Right now, I feel like we are waiting around,” Woods wrote in September 2013. “Waiting for you (ImmunoGen) to take the initiative and move forward with this research on your drug and try it in Wilms tumor.”

In November 2013, ImmunoGen announced that its adult lung cancer trial had failed and it would stop making and experimenting with the product. Woods contacted leading experts including Smith, the National Cancer Institute pediatric oncologist, and rallied other Wilms tumor parents. Woods also made a surprise visit to ImmunoGen’s booth at a cancer conference in Chicago. A few days later, on June 4, 2014, he started a petition on change.org, saying that the Children’s Oncology Group, or COG, was ready to test IMGN901, and only one thing stood in the way:

“The drug company which owns this drug (ImmunoGen) has been hesitant to provide a supply of it to the COG to run this trial,” the petition read. “They have sent mixed messages about whether they will provide the drug or not.”

By June 18, about 1,000 people had signed: “Great job everyone!” Woods wrote. Five days later, “a petition you signed was victorious!” he wrote, after learning the company would supply the drug to the trial.

Limited supplies

Supplies of the drug are limited, and ImmunoGen said it wanted to ensure they were adequate to last for a full trial before making the drug available to the COG for testing on children. ImmunoGen said it had agreed to give away the drug for free before Woods’ campaign began, but was also making sure the group had the necessary funding to run the study.

“We had put considerable scientific, financial, and emotional capital into it and were happy to provide supplies once the COG had an FDA-compliant trial in place,” ImmunoGen said in an e-mailed statement. “The petition had no impact on our decision.”

The drugmaker said it’s committed to making a difference for cancer patients, and is also providing IMGN901 to the University of Texas MD Anderson Cancer Center, for a separate study on adult blood cancers.

‘Premature success story’

Funded by NCI, the pediatric trial began in 2015. It has now about 20 children with relapsed cancers, including Wilms tumor, but is enrolling at a brisk pace with the aim to reach 150, according to NCI’s Smith.

“This is a premature success story because we don’t know whether the drug is going to work,” said James Geller, the pediatric cancer doctor at Cincinnati Children’s Hospital Medical Center who runs the trial. “The biggest success will be if it impacts the health of children and their families.”

For now, Stellablue doesn’t need the experimental drug her father worked so hard to get into trials, and her family hopes she never will. Three years after undergoing the aggressive chemotherapy program that sent her father looking for other options, she remains cancer-free. Although she still suffers from side effects of the treatment, including pain and breathing difficulty, she’s the strongest she’s been in years. She went skiing this winter and recently ran a half-mile without stopping to walk.

Back at work in Bozeman, installing tile, Woods is aiming for a new career at 40: He’s taking a temporary position at a cancer laboratory near Portland, Oregon, where he’ll be looking at hard-to-treat cases of Wilms tumor. If the situation works out, he’d like to work in cancer research full time.

“No matter how it goes, lots of good things will come out of it,” he said. “Cancer is never far from my mind.”

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