The fragile support for a Senate bill that would allow the FDA to approve generic versions of biologic drugs is deteriorating at the same time House lawmakers are trying to persuade leaders not to allow for such a provision in an FDA bill.

Generic and brand name lobbyists say generic makers miight threaten to pull their support for the bill if a provision they say would give brand companies continuous monopoly rights is not changed, Congress Daily reports (subscription required).

A sticking point was how long to give brand-name drugmakers exclusive rights to sell free of generic competition. The senators settled on 12 years, a number most believe can’t change without crumbling the entire deal.

The Generic Pharmaceutical Association raised the concern after the markup that brand biologic drugs would be allowed to also receive 12 years of exclusivity for any changes made to a drug, such as FDA approval to treat a new disease or a new form of administration, further delaying generic competition.

Congressional and industry sources said brand and generic lobbyists met with staff over the weekend, but an agreement can’t be reached on what at first was thought to be a technical fix. The latest issue has been addressed at the staff level and hasn’t yet reachedlawmakers, though generic supporters are trying to move up the ranks with their concerns.

Generic companies want lawmakers to lower the exclusivity number aand add on years for beneficial changes, similar to the way traditional chemical drugs are handled. Chemical drugs get five years of exclusivity, while three years are added on if changes are made to improve the drug.

“We’re not looking for an additional 12 years,” says Sandi Dennis, deputy general counsel for healthcare regulatory affairs at the
Biotechnology Industry Organization. “We do think that it is important to have incentives for the development of significant new uses of biotechnology products.” BIO doesn’t support lowering the original exclusivity period, though, to make room for the additional years.

“Twelve years is a good, reasonable compromise and we’re sticking with it,” Enzi spokesman Michael Mahaffey says. Without a consensus, Kennedy’s intention to insert the generic biologic bill into an omnibus FDA bill set for conference might be in
jeopardy.

In the House, Rep. Anna Eshoo, D-Calif., led a bipartisan group of 11 House Energy and Commerce Committee members in writing committee and Health Subcommittee leaders about not including a generic biologicx provision in the FDA bill, which reauthorizes agency programs and overhauls drug safety at FDA.

“We believe the establishment of a pathway for approval of biosimilars (generic biologics) is appropriate for Congress to consider,
but only after consideration of the views of all stakeholders and full deliberation, hearings and markup by the appropriate committees,” states the letter written Wednesday.

The House Energy and Commerce Committee has not considered generic biologic legislation. BIO also believes generic biologic legislation should be considered separate of the omnibus FDA bill.

Energy and Commerce Health Subcommittee Chairman Frank Pallone, D-N.J., was not optimistic about the chances of the House allowing inclusion of a generic biologic provision in the FDA bill in conference. Pallone said House members have not reached a consensus on generic biologics and one would be tough to reach before they hope to conference.

The FDA bill must be passed by the end of the month to prevent the agency from sending out layoff notices to employees.