Tenax Therapeutics, Inc. (TENX) · Oct 8, 2026 · Other events

Tenax clinical update narrows LEVEL-2 after failed LEVEL trial

LEVEL-2 amended — Enriched criteria showed >34-meter benefit versus placebo; enrollment temporarily paused

Tenax’s clinical update reframes the failed LEVEL trial around a narrower LEVEL-2 population, but enrollment pauses while the protocol is amended.

Tenax is a development-stage biotech building oral levosimendan for pulmonary hypertension associated with HFpEF; LEVEL-2 is its second global Phase 3 trial and the company says its cash runway extends through Q2 2028.

The filing does not undo the LEVEL failure; it narrows the rescue strategy. The first Phase 3 trial missed its overall 6-minute-walk primary endpoint, with only a 3.5-meter treatment difference and a p-value of 0.63 (Primary and Key Secondary Endpoints). The company’s new argument is that patients with lower baseline walking capacity responded much better: the prespecified subgroup below 333 meters showed a 26.3-meter advantage versus placebo, while the overall population did not. 〔0〕

The protocol amendment is a genuine operational change, not just a presentation of old data. Tenax plans to enroll patients with either baseline 6-minute walk distance of 100–300 meters, or 300–400 meters plus right atrial enlargement. In the LEVEL population matching those criteria, the company reports a treatment effect above 34 meters versus placebo, with more than half of LEVEL participants meeting the proposed criteria. This could make the confirmatory study more sensitive to the drug’s apparent effect, but it also means the program now depends on a narrower, more selected patient population rather than broad confirmation in the original population.

The temporary enrollment pause is the cost of the redesign. Screening and randomization have been paused while the amendment and centralized echocardiography review are implemented; Tenax estimates that fewer than 5% of primary-analysis patients were enrolled under the looser criteria. 〔1〕 The pause is not described as a regulatory or safety hold, but it adds execution risk and makes the timeline less clean even though the company has not quantified a major delay.

Safety is supportive on serious outcomes but materially less clean on tolerability. Serious adverse events were balanced at about 11% in each arm, yet any adverse event occurred in 86.7% of TNX-103 patients versus 71.9% on placebo, with treatment-related events at 38.3% versus 17.4% and discontinuations at 8.3% versus 1.7% (Safety). 〔2〕 That profile does not invalidate the program, but it weakens the company’s broad “well-tolerated” framing and will matter if the narrower population is eventually used to support registration.

Relative to the standing story, this is partly new rather than a fresh clinical win. The LEVEL miss was already public, so the major news is the data-driven redesign of LEVEL-2, the enrollment pause, and the planned FDA interaction—not a reversal of the failed primary endpoint. Tenax has requested a Type C meeting, while the protocol design paper and further development updates are expected in Q1 2027. 〔3〕

Bottom line: Tenax has a more focused way to test its drug, but it has not repaired the failed Phase 3 result. The event modestly improves the logic of LEVEL-2 while adding a pause, narrower eligibility, and a clearer tolerability burden to the development story.

What to watch next

FDA Type C meeting and LEVEL-2 protocol paper, Q1 2027

Original filing on SEC EDGAR

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