BY NATALIE GROVER
(Reuters) - Isis Pharmaceuticals Inc's experimental diabetes drug took a longer-than-expected 36 weeks to show a statistically significant reduction in blood sugar levels in patients with type 2 diabetes.
The mid-stage study had aimed to prove that a 200 mg dose of the drug taken over 26 weeks would work better than a placebo on 92 patients suffering from uncontrolled blood sugar, despite treatment.
Isis did not disclose the effect of the drug, ISIS-PTP1B, at 26 weeks. The company's stock fell nearly 10 percent on Tuesday.
Deutsche Bank's Alethia Young said the data looked less robust than some commonly prescribed treatments and Isis's own experimental glucagon receptor, ISIS-GCGR.
Isis noticed that blood sugar levels kept falling even after dosing was stopped after 26 weeks, and expects the drug to lower sugar levels further over a longer duration, analysts said.
The company could conduct an additional trial and/or narrow the target population, Laidlaw & Co analyst Yale Jen told Reuters.
The trial's other main goal assesses the "incidence, severity, dose-relationship of adverse effects, and changes in laboratory evaluations as a measure of safety" at the end of 38 weeks.
Type 2 diabetes is a chronic condition which occurs when the body does not use insulin properly. It afflicts up to 95 percent of the roughly 29 million diabetics in the United States.
Isis's drug inhibits the protein tyrosine phosphatase-1B, or PTP-1B, which acts as a negative regulator of insulin.
The treatment is aimed at allowing patients to effectively use insulin and treating those beginning to fail oral therapies, extending the time they have before becoming reliant on insulin.
Patients treated with ISIS-PTP1B had a 0.7 percentage points mean reduction in glycated hemoglobin, compared with a average fall of 0.2 percentage points in placebo-treated patients, Isis said.
Glycated hemoglobin, also known as HbA1c, is used to measure how well diabetes is being controlled.
The company expects ISIS-PTP1B will be used in conjunction with most other commonly used diabetes drugs, including insulin, GLP-1 agonists and more traditional medicines such as metformin.
Isis stock was down 8.5 percent at $62.83 in late morning trading, and Laidlaw's Jen said investors were overreacting.
"Some Isis investors are quite spoiled," he said. "They looking at the stock like the Super Bowl, they need a 45 to 2 outcome instead of a 28 or 24 which is probably more realistic."
(Editing by Savio D'Souza)