In July 2022, the U.S. FDA granted Breakthrough Device Designation to PMX for the treatment of endotoxic septic shock. The program is intended to expedite the development, assessment and review of certain medical devices for life-threatening or irreversibly debilitating conditions. (FDA Breakthrough Devices Program)

TIGRIS was a multicentre, open-label, randomized, controlled Phase 3 trial conducted at 19 U.S. centres. The study enrolled 157 adults with endotoxic septic shock, identified using EAA™ results and organ dysfunction criteria, and randomized participants 2:1 to PMX plus standard care or standard care alone.

In the prespecified adjusted Bayesian analysis, TIGRIS reported a 95.3% posterior probability of benefit for 28-day all-cause mortality and a greater than 99% probability of benefit at 90 days. Complete results were published in The Lancet Respiratory Medicine in 2026.

Spectral submitted its Premarket Approval application for PMX in May 2026. In June, following completion of its filing review, the FDA accepted the application for filing and initiated the substantive review process.

The TIGRIS trial publication: Polymyxin B haemoadsorption in endotoxic septic shock (Tigris): a multicentre, open-label, Bayesian, randomised, controlled, phase 3 trial 

The trial methods are detailed in  “Bayesian methods: a potential path forward for sepsis trials”.

PMX is indicated for patients with Sepsis and endotoxemia or suspected gram negative infection.

Recent data suggests that the best patients for PMX therapy have the following characteristics:

• Septic shock requiring continuous vasopressor support 
• EAA ≥0.60 and <0.90 
• Multiple Organ Dysfunction (MODS>9)

The graphic describes the decision making process that should be followed to prescribe PMX hemoadsorption therapy.^[2]

Additionally, patients who received PMX therapy had a greater increase in mean arterial pressure as well as a decreased requirement for vasopressors.^[3]