On June 28, the Senate Health, Education, Labor, and Pensions Committee voted to approve S. 1695—legislation that would authorize the FDA to clear generic versions of biotech drugs as “interchangeable” if there is evidence that the new version produces the same clinical results without posing safety risks. The measure is intended to make generic drugs more affordable and available to patients. But whether the legislation will move forward for approval is not clear.
Several competing versions of the bill, including some that would impose fewer requirements for generic versions of drugs, have been introduced in the House. And both chambers have to agree on legislation before sending it to the President for approval.
The current bill, which was sponsored by Sen. Edward Kennedy (D-MA) and four bipartisan co-sponsors, would give the FDA authority to decide the “interchangeability” of a generic biotech drug. The generic drug manufacturer would have to provide evidence that there were no meaningful differences between conventional drugs and their generic biotech version in purity, potency, and safety.
Market exclusivity to brand-name biotech versions would be granted for 12 years, and generic makers would have to wait at least four years before challenging a patent or applying for a generic version with the FDA.
David Charles, MD, associate professor and vice-chair of neurology for Education and Development at Vanderbilt and vice-chair of the Academy's Legislative Affairs Committee, told Neurology Today in a phone interview that he is against interchangeability of the generics. (He argued against that interchangeability in an Op-ed in the July 3 Neurology Today: “Approval of Generic Biologics: Why We Can't Afford a Dangerous Shortcut,” page 4.)
In Neurology Today, he wrote: “The science involved dictates that no two biologic drugs are completely interchangeable. Even biologic drugs in the same FDA category designed to treat the same disease or condition have unique characteristics. This is because the performance characteristics of an injected biologic drug are largely determined by the manufacturing process, not by a chemical formula as they are in conventional or “tablet” drugs.”
Conventional pharmaceuticals are generally small chemical molecules produced with different ingredients added under tightly controlled conditions. By contrast, biologic medicines are often large protein molecules manipulated through complex methods.
Dr. Charles said that it is important that patients have access to the best options, which can include generics. However, he expressed concern that the process for manufacturing biologics and conventional chemical-based drugs may differ, leading to differences in safety and efficacy. Because of these differences, he said rigorous clinical trials must be conducted before approval.
Mike Amery, AAN legislative counsel for federal affairs, noted that Sen. Kennedy said he would like to include the measure with other legislation concerning the FDA in conference negotiations with the House, and that approval by other Democratic leaders is up in the air. If Democratic leaders in the House disagree with the Senate's version of the legislation and decide to hold markups and hearings, the proposal may be left out of the negotiations. The hearings were slated to occur at press time.
“I don't think that anyone really knows what will happen,” Amery concluded.