CRESTWOOD, Ky. (WDRB) -- Owen McMasters spends some of his down time killing the bad guys in "Call of Duty" on his Xbox. But his doctors are running out of the ammo they need to fight his cancer.

The nationwide shortage of the drug Methotrexate has left McMasters and countless other children at Kosair Children's Hospital at risk of not having the medication they need. This week, federal officials claim they're working with drug makers to beef up the supply.

The drug is used to treat the type of leukemia known as ALL or Acute Lymphoblastic Leukemia. Owen, 12, has been undergoing aggressive treatment since November.

"It kinda makes me feel pretty bad. I just try to stick through it," he said.

His parents, Beth and Kelly McMasters, an attorney and cancer surgeon respectively, say they're concerned for Owen's well-being and for the other children at Kosair. Owen's doctors have told them they have "no confidence" that Louisville will have enough doses of Methotrexate for Owen when he starts a significant treatment in early March.

"Owen has done everything that is asked of him," said Beth McMasters. "He doesn't complain, he doesn't say 'I don't want to go to chemo,' he doesn't say anything other than that I will do what I can do to get well. Given that attitude it's not fair that the drug that he needs would not be available."

His father, Dr. Kelly McMasters, is a cancer surgeon at the University of Louisville and sits on the board of a pharmaceutical company. He says Methotrexate is a generic drug that's cheap to make. He believes there's no incentive for the drug makers to produce it.

"It's an absolute embarrassment that the United States of America can't provide children with the critical drugs that they need to cure them of cancer," he said.

In a statement to WDRB News, the FDA writes "product will be available by the end of this month to meet demand and avert a shortage," said Shelly Burgess in an emailed response to a reporter's questions.

"It's very frustrating. We'll get Owen the treatment he needs. There are a lot of kids out there with leukemia. I just want this solved for those children as well," said Kelly McMasters.

Beth chimed in: "And as a mother it's not acceptable. We will do whatever it takes. If we have to go to another country... we'll go to another country."

The federal Food and Drug Administration announced Wednesday it was working with pharmaceutical companies to help ramp up production.

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