Reasons for the shortage aren't entirely clear. It's likely a combination of factors such as limited manufacturing, lagging production time and lack of profits from these drugs. As Link noted, "When a manufacturer stops making a drug, there isn't always another one ready to swoop in and take over."
The Food and Drug Administration has tried to step in to remedy the problem. For example, after President Obama issued an executive order in 2011 to reduce the dire drug shortages, the FDA broadened its reporting of potential drug shortages and expedited regulatory reviews that sometimes made the shortages worse.
The New England Journal authors said the FDA's efforts should be commended but said more needed to be done. They said that the shortage of mechlorethamine eased up shortly after their study ended, with no explanation. But they warn there's no guarantee there won't be another shortage later.
"We really need a global effort to attack this problem rather than trying to do it one event at a time," Billet said.
Alonzo, now age 13, is currently cancer-free. Her lungs were badly scarred from the treatment she received though her mother said doctors were never able to say for sure this was because of the extra treatment she was forced to undergo when she relapsed.
"I don't think we'll ever know," said her mother. "What we do know is there are other children that have had to go through a lot of extra damage to their body, and there may be long-term consequences. It's all because the drug wasn't made – that's what doesn't seem right."