Tonix halts major depression disorder drug after phase 2 failure

Tonix Pharmaceuticals’ pipeline has taken another hit as the biotech drops a major depression disorder therapy after the drug flamed out of a phase 2 trial.

The trial assessed 132 adults aged 17-65 years diagnosed with MDD who took a 39.4 mg dose of the tianeptine hemioxalate extended-release tablets, called TNX-601 ER, once a day for six weeks. The primary endpoint was a change in baseline depression severity, as measured by the Montgomery-Åsberg Depression Rating Scale (MADRS)—but the drug “did not achieve clinical or statistical significance,” the biotech revealed in a post-market release yesterday.

“Based on these efficacy results, we are discontinuing development of TNX-601 ER,” CEO Seth Lederman, M.D., said in the release.

Lederman was understandably keen to focus on the future, stressing that the company is looking forward to two topline readouts both due next month. These involve findings from a phase 2 study of TNX-1900 in chronic migraine followed by phase 3 results for TNX-102 SL in fibromyalgia that the company hopes will set up an approval filing with the FDA.

TNX-102 SL has recently experienced its own clinical woes. Tonix had originally been investigating the cyclobenzaprine drug for fibromyalgia-like long COVID but finally abandoned that indication in September after it failed to show a statistically significant improvement in pain symptoms compared to placebo in a phase 2 trial of patients with long COVID.

The upcoming readouts don’t seem to be enough to convince investors, who sent Tonix’s already flatlining shares down 17% to 48 cents apiece when the markets opened this morning following a Tuesday close of 59 cents.

At least culling another candidate from the pipeline will keep costs down for the cash-strapped company. Tonix spent almost $100 million in the first six months of this year, from roughly $120 million on hand as of the end of December to just $25 million as of June 30. Last month, the company brought in $4.5 million by selling off some stock at 50 cents a share.

The biotech previously announced that resources would be focused on its central nervous system pipeline and work deprioritized on a COVID vaccine and other preclinical programs.