Aug. 18 (Bloomberg) — Eli Lilly & Co. and Amylin Pharmaceuticals Inc.’s diabetes drug Byetta was linked to deaths in two patients with an inflamed pancreas, say U.S. regulators who are seeking stronger warnings for the medicine.

Amylin’s shares fell 13 percent, the most in more than seven years, after the Food and Drug Administration posted information on the deaths on its Web site today. Those who died were among six Byetta users who entered the hospital since October because of a condition known as acute pancreatitis.

The drug, available in the U.S. since June 2005, is Amylin’s leading product, with sales that rose 17 percent in the second quarter from a year earlier. Amylin, of San Diego, and Indianapolis-based Lilly agreed to warn of the risk of pancreatitis in October, after 30 milder cases were reported.

“Given the number of patients on the drug, it’s not alarming, but it’s a concern,” said Michael G. King, an analyst at Rodman & Renshaw in New York, by telephone today. The stock reaction is “probably justified,” although it’s unclear how the announcement will affect prescriptions and use, he said.

Amylin fell by $4.45 to $29.76 at 4 p.m. in Nasdaq Stock Market composite trading, after earlier dropping 18 percent. Lilly dropped 73 cents, or 1.5 percent, to $48.05 on the New York Stock Exchange.

`More Prominent’ Warnings

The FDA is working with Amylin to add “stronger and more prominent warnings” on Byetta’s risks, the agency said today on its Web site. The new cases were marked by bleeding or tissue death, the FDA said. The patients who didn’t die were recovering, the agency said.

Lilly’s portion of the profit from Byetta climbed 27 percent in the second quarter to $101.2 million, the drugmaker reported July 24. Amylin reported on July 21 that Byetta sales rose 17 percent in the quarter to $177.5 million.

“Amylin and Lilly are committed to patient safety and to working with the FDA to ensure that our Byetta product label continues to provide physicians and patients with information about the risk of pancreatitis,” said Amylin spokeswoman Anne Erickson in an e-mailed statement.

Long-Acting Byetta

Diabetes patients have an increased risk of pancreatitis, Erickson said in the statement, and as many as 20 percent of patients with the condition develop complications. Patients taking Byetta weren’t at a greater risk for complications or death, Erickson said.

The new information could affect development of the companies’ next version of Byetta, Byetta LAR, said Tim Anderson, an analyst at Sanford C. Bernstein & Co. in New York, in a note to investors today.

The experimental treatment Byetta LAR is designed to be taken once weekly instead of the standard injections given twice daily. Because the drug stays in the body longer and can’t be “turned off” if pancreatitis develops, the FDA may have concerns about the condition when it considers it for approval, Anderson said. He still estimates approval in 2010 and U.S. sales of $1.5 billion of the new drug by 2015.

No signs distinguish severe forms of pancreatitis reported in today’s advisory from less severe forms of the condition, the FDA said. Patients who develop pancreatitis while taking Byetta should be treated for the condition and shouldn’t take the drug again. Doctors whose patients have a history of pancreatitis should consider other treatments, the agency said.

Boosting Insulin

Byetta, a synthetic hormone, stimulates cells in the pancreas to produce insulin when blood sugar is high, helping to convert that sugar into energy.

The pancreas, a large gland behind the stomach, secretes enzymes that aid digestion. Severe cases of pancreatitis may cause bleeding, tissue damage and infection, and lead to the release of toxins and enzymes into the bloodstream that can injure the heart, lungs, kidneys or other organs.

The illness affects about 80,000 people a year and can be life-threatening, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

Research teams discover link between gene, type 2 diabetes

The Yomiuri Shimbun

Two groups of researchers in Japan have identified a gene that is directly linked to the occurrence of diabetes, a discovery that is likely to help in the early identification of people who may be susceptible to the disease.

One group of researchers from the Institute of Physical and Chemical Research (Riken) and another from the International Medical Center of Japan separately studied individual diabetic cases involving Japanese patients.

Their findings, summarized in their respective reports, were published in the online edition of the U.S. medical journal Nature Genetics on Monday.

The researchers found a link between a gene known as KCNQ1 and the onset of type 2 diabetes–the variant affecting 90 percent of Japan’s 8.2 million diabetic patients.

The prevalence of type 2 diabetes is attributed to a lack of physical exercise, excessive eating and genetics.

Studies involving Europeans and Americans earlier led to the discovery of another gene linked to type 2 diabetes. However, as genetic impacts were known to vary among genetically distinct populations, a separate study on Japanese people became essential to prove the genetic aspect.

The two Japanese teams separately conducted large-scale studies, with the Riken team comparing the genes of a total of 9,000 people with and without type 2 diabetes.

Both teams found a small genetic variation, known as a single nucleotide polymorphism (SNP), in DNA sequences of KCNQ1 genes of the patient group in their separate studies.