pillsA phase 3 clinical study of a developmental once-daily lithium carbonate product called Lithium QD has failed, its maker announced on Monday.

Noven Pharmaceuticals announced that its Lithium QD failed to achieve its primary goal of a change from baseline symptoms compared to placebo in the phase 3 trial. Phase 3 is typically the final stage of human testing before a drug is submitted to U.S. Food and Drug Administration (FDA) regulators for an approval decision.

There is no once-a-day lithium medication currently available in the U.S.

The Phase 3 trial was a multi-center, double-blind, randomized, placebo-controlled, parallel-group study of Lithium QD. Approximately 240 subjects were randomized. The primary objectives of the four-week study were to determine the efficacy and safety of Lithium QD compared to placebo in the treatment of acute symptoms of mania in subjects with Bipolar I disorder. The primary efficacy endpoint was change from baseline compared to placebo using the Young Mania Rating Scale (YMRS).

“Both the Noven and JDS teams are very surprised and disappointed that the study did not achieve its primary endpoint,” said Robert C. Strauss, Noven’s President, CEO & Chairman. “We are currently analyzing the data to determine why statistical efficacy was not achieved.”

“Based on our understanding of the efficacy of lithium and the delivery profile of this formulation, we continue to believe that Lithium QD has the potential to be a valuable once-daily option in the lithium therapy category,” said Strauss. “Accordingly, we remain committed to the continued development of this important product. We plan to complete our analysis of the data and consult with the FDA regarding appropriate next steps to advance development.”

Lithium QD is subject to U.S. patents that extend to 2022 and may also benefit from three years of exclusivity under the Hatch-Waxman Act. Currently there are no FDA-approved once-daily lithium products on the market. The current U.S. market for lithium products, calculated at branded prices, is estimated to exceed $400 million annually.