Despite missing the mark in a phase 2, Lexicon is standing by its neuropathic pain therapy

Lexicon Pharmaceuticals has missed the mark in a phase 2 aiming to treat a common complication of shingles known as postherpetic neuralgia. However, the Texas biotech is standing by its therapy, saying the trial still demonstrates “clear evidence of effect.”

The topline results, which were released Wednesday after market close, come from a proof-of-concept study, dubbed Relief-PHN-1. The study assessed therapy LX9211, which was licensed from Bristol Myers Squibb in 2016, among 79 patients with postherpetic neuralgia, a neuropathic pain condition that affects nerve fibers and skin.

While LX9211 reduced patients’ average daily pain score by 2.42 from baseline at six weeks compared to a reduction of 1.62 in the placebo arm, the results weren’t statistically significant and therefore failed to meet the study’s primary endpoint.

Despite this, the biotech touts a clear distinction between the efficacy of LX9211 versus placebo on average daily pain score, starting at the first week of treatment and consistently maintained after.

The study follows a summer readout from a separate phase 2 trial, called Relief-DPN-1, that assessed the same therapy among 319 patients with diabetic neuropathy, a form of nerve pain caused by high blood sugar. The therapy holds a fast-track designation from the FDA in the indication.

In that study, LX9211 improved average daily pain after six weeks compared to placebo in the low-dose group (100 mg initial dose followed by 10 mg daily doses), achieving statistical significance and thereby hitting the study’s main target. The trial missed statistical significance in its high-dose arm (200 mg initial dose followed by 20 mg daily doses).

The biotech noted that in the most recent study, there was no low-dose arm, just patients receiving a high-dose regimen.

“These results in postherpetic neuralgia achieve our goal for this small, 79-patient study of establishing clear evidence of effect supporting the further development of LX9211 in another neuropathic pain condition,” Craig Granowitz, M.D., Ph.D., Lexicon’s SVP and chief medical officer, said in a Dec. 21 release. He dubbed the results as “broadly consistent” with those achieved in Relief-DPN-1 and said the readout bolsters confidence in moving LX9211 forward as a potential solution for neuropathic pain patients needing additional treatment options.

No serious adverse events or deaths were reported in the study, with dizziness the most commonly reported event.