Nektar Sinks After Pain Drug Misses Goals of Mid-Stage Study

Nektar Therapeutics (NKTR), a developer of drugs for pain and cancer, sank the most in five years after its experimental chronic pain therapy failed to show enough benefit in a mid-stage study.

Nektar fell 24 percent to $10.54 at 4 p.m. New York time for the biggest decline since April 9, 2008. The shares of the San Francisco-based company have gained 42 percent this year.

Nektar’s drug, NKTR-181, is designed to enter the brain slowly to avoid the euphoric high feeling that can lead to abuse of opioid painkillers. Though patients on the medicine experienced less pain during the study, those on placebo didn’t have an expected increase in pain, the company said in a statement yesterday.

“Even though the trial clearly failed, there should be a path forward for this safe and efficacious opioid,” Simos Simeonidis, an analyst with Cowen & Co., wrote in a research note today. “We reiterate our outperform rating and view this weakness as a buying opportunity.”

The study of 213 patients was in the second of three phases generally required for regulatory approval.

To contact the reporter on this story: Meg Tirrell in New York at

To contact the editor responsible for this story: Reg Gale at

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