Targacept (NASDAQ:TRGT) and AstraZeneca (NYSE:AZN) are dropping plans to seek regulatory approval on their depression drug candidate after the compound failed its remaining phase 3 clinical trials.
The two drug companies were developing TC-5214 as an adjunct treatment to treat major depressive disorder in patients who did not adequately respond to the first line of depression treatments. But the compound, discovered by Winston-Salem, North Carolina-based Targacept and developed under a 2009 partnership with AstraZeneca, failed its first phase 3 study last November. A month later, the companies announced failure in a second phase 3 trial.
Targacept had planned five phase 3 studies for TC-5214, its lead drug candidate; two trials were to study fixed dosing and another two trials to study flexible dosing. The psychiatric community is undecided whether flexible or fixed dosing better demonstrates statistical significance when compared to a placebo. A fifth phase 3 trial was to be a safety study.
The studies did not yield an answer to the fixed vs. flexible dosing debate. The first two failed TC-5214 phase 3 studies were flexible dosing. With failures in the two fixed dosing phase 3 trials, it appears the compound may not be effective at all with either flexible or fixed dosing — results that led the companies to abandon further development plans. AstraZeneca will take a $50 million impairment charge for the drug failure.
Targacept CEO Donald deBethizy said in a statement that the company has been preparing for this outcome since TC-5214 failed its first phase 3 trial. Future plans will be announced by the end of April. Targacept has no U.S. Food and Drug Administration-approved drugs. But deBethizy added that Targacept’s pipeline includes other drug candidates with multiple disease targets. DeBethizy said Targacept has more than $225 million in cash to develop that drug pipeline. That pipeline includes potential treatments for schizophrenia, attention-deficit/hyperactivity disorder, asthma, type 2 diabetes and Alzheimer’s disease.
Targacept, a spinout from R.J. Reynolds, is based on research developing compounds that target the body’s neuronal nicotinic receptors, or NNRs. In 2009, the company reached a development deal with AstraZeneca that paid Targacept $200 million upfront with an additional $540 million in additional payments contingent on achieving milestones.
A Deep-dive Into Specialty Pharma
A specialty drug is a class of prescription medications used to treat complex, chronic or rare medical conditions. Although this classification was originally intended to define the treatment of rare, also termed “orphan” diseases, affecting fewer than 200,000 people in the US, more recently, specialty drugs have emerged as the cornerstone of treatment for chronic and complex diseases such as cancer, autoimmune conditions, diabetes, hepatitis C, and HIV/AIDS.
Ending work on the the TC-5214 program does not end the relationship between Targacept and AstraZeneca. The drug partners are moving ahead on another drug candidate, an experimental Alzheimer’s disease treatment. Work on AZD1446 stems from a 2005 agreement between the two companies. Late last year, AstraZeneca announced it would finance and conduct phase 2 work on the compound.
[Image from photostock]
