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. 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.