Families Heartbroken Over Loss Of Experimental Drug

BOSTON (CBS) - From a distance, Caleb Welin of Cambridge looks like a normal 9-year-old when he's outside playing ball with his dad. If you look closer, there's something different.

Caleb suffers from Fragile X Syndrome, a disorder similar to autism that causes a number of cognitive issues as well as intense anxiety.

"There were days when he would cry when we put his shoes on because he knew we were leaving the house and he was so scared," his mother, Melissa, explained.

Many kids born with Fragile X often have tantrums when situations become too overwhelming for them.

For Caleb, a trip to the Big Apple Circus was a disaster.

"We didn't make it through the opening music," Melissa said. "It was too much of a sensory overload," said Eric Welin, Caleb's dad.

All of that changed back in 2009 when Caleb enrolled in a trial of a drug called Arbaclofen. "We see the little boy that was locked inside," Melissa explained, choking back tears.

The Welins say the drug transformed their son and their lives. They even went back to the Big Apple Circus.

"It was the same circus both times. It was night and day," Melissa said. "His friends were so proud of him that he was able to do it. We were so proud of him," she added.

But now the drug is gone.

The Cambridge manufacturer, Seaside Therapeutics, informed families the study was over. The letter stated that even though some saw dramatic results, statistically, the benefits were not evident.

The Welins say Caleb and hundreds of kids like him saw the benefits every day.

"They become the kids that they would have been," Melissa said.

Part of the problem is that with many drugs, it's fairly cut and dry to determine if a drug improves symptoms.

But experts on Fragile X say problems like anxiety and social isolation are subjective which makes it tougher to measure.

Dr. Amanda Bennett took part in the drug trial.

"It's been difficult to find an outcome measure that the FDA would approve. The company being so small, [it] essentially ran out of resources to continue to study the drug," she said.

The Welins and other Fragile x families have desperately tried to find someone with the money to continue to study the drug, with no luck.

When the circus comes back to town next spring, they say they aren't sure if Caleb will be able to go.

"To not be able to do the normal childhood things, it breaks my heart," Melissa said. "It makes me feel like I'm not giving him the childhood he deserves."

Fragile X families are now appealing to Congress, hoping for a miracle.