Eli Lilly has been forced to discontinue development of schizophrenia drug candidate, pomaglumetad methionil (mGlu2/3), after disappointing results in the second of two phase III clinical trials.
The decision is a setback for Lilly, which had been hoping to position pomaglumetad methionil as a successor to its flagship schizophrenia drug Zyprexa (olanzapine), which is being hit hard by generic competition since losing patent protection last year.
An analysis of the phase III HBBN study revealed that it was unlikely to meet its primary efficacy endpoint, while a phase II study called HBCO looking at pomaglumetad methionil in combination with other antipsychotics was similarly disappointing, said Lilly in a statement.
Pomaglumetad methionil was different from existing antipsychotic drugs because it worked on glutamate rather than dopamine receptors, but worrying signs of a lack of efficacy had already been seen in phase II studies reported in 2009.
The company pressed on because of a positive efficacy signal in a patient subgroup, but reported that its first phase III trial was negative last month, prompting analysts to scale back their expectations of approval and slash sales forecasts.
President of Lilly Research Laboratories Jan Lundberg said: "I'm disappointed in what these results mean for patients with schizophrenia who still are searching for options to treat this terrible illness", whilst reaffirming the company's commitment to neuroscience research.
The company said it would have to take a $25m-$30m charge in relation to the termination of the programme in its third-quarter results.
The demise of pomaglumetad methionil comes in the wake of a string of negative trial results for Lilly, which badly needs new product launches as it is also facing patent expiries for blockbuster osteoporosis drug Evista (raloxifene).
Alzheimer's drug candidate solanezumab missed its endpoint in to phase III trials earlier this month, although there were signs of some efficacy and it had been given little chance of success given the earlier failure of Pfizer' similar drug bapineuzumab.
Meanwhile, a comparative study of the firm's osteoporosis drug Forteo (teriparatide) with rival drug risedronate on back pain was negative, and Daiichi Sankyo-partnered blood thinner Effient (prasugrel) failed to show superiority to clopidogrel in preventing heart attacks and strokes in cardiovascular patients.
Other drugs in Lilly's pipeline are now becoming even more crucial to the company, notably oncology candidate ramucirumab which is in phase III testing for metastatic colorectal cancer, metastatic gastric adenocarcinoma and hepatocellular cancer.