The asthma treatment Targacept (Nasdaq:TRGT) is developing actually did not perform as well in clinical trials as initially thought.

Targacept last month released top-line phase 2 results for TC-6987 that showed the asthma compound met both goals in the clinical trial. But the Winston-Salem, North Carolina drug developer has revised its top-line results and said the discovery of a “statistical analysis error” now shows they met just one of the two phase 2 endpoints. Targacept is evaluating its plans for developing TC-6987, which also failed in a separate study as a diabetes treatment. But the revised results of the compound are just the latest bit of bad news for the company, which is refocusing its drug pipeline following the phase 3 clinical trial failure of former lead drug, depression candidate TC-5214.

In the asthma study, TC-6987 was evaluated on its ability to increase an asthma patient’s expiratory volume — the amount of air a patient can blow out after full inspiration. The drug candidate could be used in addition to existing low-dose inhaled corticosteroids or on its own as a separate drug.

Targacept had initially reported that the compound met the endpoint of changing expiratory volume from baseline to pre-dosing on day 28 of the four-week study. The company said the compound also met a second endpoint of changing expiratory volume two hours post-dose on day 28 of the study. Reanalysis of the results show that the compound just hit the second target.

Targacept, a spinout from tobacco giant R.J. Reynolds, develops compounds that have an effect on the body’s neuronal nicotinic receptors, or NNRs. Besides TC-6987, the company also has clinical-stage programs in schizophrenia and Alzheimer’s disease. AZD1446, an experimental Alzheimer’s disease treatment, is currently in a mid-stage clinical trial financed and conducted by drug partner AstraZeneca (NYSE:AZN).

Targacept has said that its goal with TC-6987 was to detect a signal of a potential NNR effect in treatments other than central nervous system disorders. The company said TC-6987′s asthma results showed it met that goal. But the company must now determine whether that is enough to continue TC-6987′s development.

“We are in the process of considering potential next steps for this compound and indication,” Targacept President and CEO Donald deBethizy said in a statement. “We regret not having discovered the statistical analysis error initially.”