Eli Lilly & Co failed to win support from a U.S. advisory panel Wednesday for what aims to be the first drug not made from pig enzymes to help certain pancreatic patients digest food. The drug was designed to compete with Abbott Labs’ drug Creon, among others.

In a 7-4 vote, a Food and Drug Administration panel of outside experts said they were not convinced the experimental medicine, known chemically as liprotamase, worked well enough for patients to absorb enough needed nutrients. One member of the panel abstained.

In particular, panelists raised concerns that liprotamase does not appear to work better than currently approved treatments derived from pigs, or “porcine derived.”

“We know it’s better than placebo, but we don’t know if it’s as good as the porcine products,” said panelist Ronald Fogel, a Michigan-based physician.

Lilly’s Alnara Pharmaceuticals Inc subsidiary is seeking FDA approval to market the drug to patients with pancreatic insufficiency due to various causes, such as cystic fibrosis, in order to help them digest food. The drug is derived from microbial enzymes.

In a statement after the meeting, Lilly said it remained confident in the clinical trial data submitted to the FDA. The FDA will weigh the panel’s vote before making its final decision, although it usually follows its advisers’ recommendations.

Even if approved, the drug is unlikely to be a big boost to Lilly’s bottom line, but could help it offset a looming financial blow from generic rivals to other medicines coming off patent protection.

The drugmaker is losing patent protection on drugs that account for half its revenue by 2014. Other potential new products for the drugmaker have fizzled.

Liprotamase is a type of pancreatic enzyme product, or PEP, long used to treat pancreatic insufficiency. Currently available options generate $1 billion in global sales, according to Citi analysts. Citi had said liprotamase could see $300 million in U.S. sales in 2015 if approved.

Panelists at the meeting said the drug clearly had some effect that seemed promising. But they called for more data, especially trials comparing it to currently-approved products as well as for more data on children.

Patients with pancreatic insufficiency from cystic fibrosis or other conditions currently must take dozens of pills a day when they eat food to help them properly digest and absorb nutrients.

Alnara representatives said their product could help reduce the pill burden for patients so that just 5 to 10 pills were needed on average. Several patient groups also urged the panel to give them another option.

Of particular concern, said panelist and physician Jesse Joad of the University of California at Davis, was that patients could be attracted to taking fewer pills but end up with a drug that worked less well and hindered growth, especially in younger patients.

Panel chairman and University of Maryland medical professor Jean-Pierre Raufman, echoing other panelists, said: “I was not convinced that the data showed meaningful efficacy for this agent although it’s obviously greatly needed.”

Shares of Lilly closed up less than 1 percent at $35.03.