Tenax trounced by phase 3 heart failure readout

Shares in Tenax Therapeutics lost more than 85% of their value this morning after its lead drug for patients with a form of heart failure spectacularly failed a late-stage trial.

Topline results from the phase 3 LEVEL trial of TNX-103, an oral formulation of calcium sensitiser levosimendan, showed that the drug was unable to improve how far patients with pulmonary hypertension (PH) due to heart failure with preserved ejection fraction (HFpEF) could walk compared with placebo.

Intravenous levosimendan is well established as a therapy for people with advanced heart failure, although it was never introduced in the US and Canada, and North Carolina-based Tenax has been developing it in both IV and oral forms for PH associated with HFpEF, which has no FDA-approved therapies.

In its update, the company revealed that LEVEL did not meet its primary endpoint of improvement in the 6-minute walk distance versus placebo, or the key secondary endpoint of improvement in Kansas City Cardiomyopathy Questionnaire total symptom score.

Putting a positive spin on the findings, the company said that a subgroup of patients in the study with more severe disease showed a "substantial beneficial treatment effect," adding that it plans to request a meeting with the FDA and the EMA in Europe to see if it can revise its current approach to support a filing.

"Having reviewed the available trial results, I am encouraged we have a clear path forward," said Tenax's chief medical officer Stuart Rich, who suggested that LEVEL had enrolled "too many patients with less severe disease."

There was a 26-metre improvement in the 6-minute walk distance compared to placebo among patients who walked less than the trial median of 333 metres at baseline, which was accompanied by a 49% decrease in NT-proBNP – a biomarker for heart failure severity – and a "clinically meaningful" reduction in systolic blood pressure.

"Taken together, these data support TNX-103's substantial cardiovascular and pulmonary biologic effects on reducing the severity of disease in patients with pulmonary hypertension due to HFpEF," asserted Rich.

The scale of the selloff in the company's stock suggests, however, that Tenax will have its work cut out convincing investors there is a route forward, and Cantor analyst Olivia Brayer Saunders described the topline result as "ugly," according to a Reuters report.

Full results from LEVEL are due to be presented at the European Society of Cardiology (ESC) congress in Munich, Germany, later this month. Tenax is also running a second trial of the drug, LEVEL-2, which started in March.

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