Conservatives are calling on the Food and Drug Administration to stop denying approvals for new drugs that could be lifesaving for Americans with chronic or fatal brain tumors.
The FDA on Thursday said it would block several new drugs for the disease, including two drugs that were approved in March for treating acute thromboembolism in people with multiple myeloma, a cancer that often strikes men and women who have lost their immune systems to multiple sclerosis.
The move is a setback for the medical community, which has long lobbied for FDA approval of drugs that have shown promise for treatment of the disease.
And it could delay a pivotal phase 3 trial for one of the drugs, the first phase of which is due to begin later this month.
The drugs are part of a multiyear effort by the NIH and the Mayo Clinic to develop drugs to treat brain tumors that affect about 2 million Americans.
The agency last year approved a drug, metronidazole, that treats acute thymic and other malignant glioma and glioblastoma, but the Mayo clinic and other doctors have said it is not yet safe for people to take on.
The FDA on Tuesday said it was reviewing whether metronIDAZole is safe for adults, but had not yet made a decision.
In a statement, the FDA said it will review the Mayo study.
The study will be part of the Phase 3 trial, which began last spring and is expected to conclude later this year.
The agency said the drugs’ potential to reduce the risk of brain tumor growth is of concern.
“Our primary focus is on preventing new patients from getting caught up in the system and the FDA has repeatedly said that this is not a new strategy, but rather an ongoing strategy,” said Dr. Mark Rabinowitz, head of the Mayo research program.
The new drug, called bovine spongiform encephalopathy vaccine-induced neurotoxicity (BSEN), was approved by the FDA in November and is the first drug approved to treat BSE, a neurodegenerative disorder caused by the viral protein BSE-10.
BSE causes neurological damage, such as seizures and cognitive problems, and is spread through saliva and urine.
The Mayo clinic said BSE vaccine is safe and effective for treating BSE and that it is a promising first step toward a vaccine that could one day treat Bse in people without BSE.
But the agency said it could take years for the drug to be licensed for clinical use, and the company has not provided data showing that it has reduced the risk for BSE patients.
Bovine Spongiform Encephalopathy Vaccine-Induced Neurotoxicity (bsen) has a potential benefit for the treatment of BSE but the drug does not appear to be safe and may cause side effects, the agency warned.
The drug is not approved for use in humans and has not been approved for marketing in the United States.
The vaccine is being evaluated for a number of indications, including treating Bse, which is often the most severe form of the neurological disorder.
The drug’s manufacturer, Novartis, has said that it would seek to move BSE vaccines to Phase 3 trials for use as treatment for people with the disease in the coming years.
The BSE drug is part of an ongoing effort by researchers and doctors to develop vaccines to treat the disease that can help prevent the spread of Bse.
The NIH has said Bse could be the first vaccine approved for human use.