Athersys announced additional favorable data from its exploratory Phase 1/2 acute respiratory distress syndrome (ARDS) clinical trial. Dr. Geoff Bellingan, Medical Director at University College London Hospitals, described the data from the clinical trial, referred to as the MUST-ARDS trial, during his presentation today at the American Thoracic Society International Conference in Dallas, Texas, the longest running, large-scale conference in the world offering groundbreaking research in pulmonary, critical care and sleep medicine. His talk was titled, “Primary Analysis of a Phase 1/2 Study to Assess MultiStem® Cell Therapy, a Regenerative Advanced Therapy Medicinal Product (ATMP), in Acute Respiratory Distress Syndrome (MUST-ARDS)”.

As previously reported, subjects in the exploratory study were evaluated through 28 days for the primary clinical assessment and will be further assessed through a one-year follow-up period. The MultiStem treatment group achieved the primary endpoint of safety with the MultiStem treatment being well-tolerated and with no serious adverse events related to administration.

Day 28 Results

MultiStem Placebo ———————————– ————– ————- Intent to Treat Population n=20 n=10 ———————————– ————– ————- Day-28 Mortality 5 (25%) 4 (40%) ———————————– ————– ————- 12.9 (10.7) 9.2 (9.6) Ventilator-free (VF) days ————– ————- 18.5 [0, 22] 6.5 [0, 18.3] ———————————– ————– ————- 10.3 (8.9) 8.1 (8.9) Intensive care unit (ICU)-free days ————– ————- 12.5 [0, 18.5] 4.5 [0, 16.8] ———————————– ————– ————-

Data are: n (%), mean (SD) or median [IQR]

“ARDS is more common than people realize, and there is no cure for it because it is a heterogenous condition,” commented Dr. Bellingan. “The data from the MUST-ARDS trial is very encouraging, and I’m looking forward about the potential of having a therapy to offer ARDS patients.”

In a prospectively-defined analysis examining the effects on subjects with poorer lung function as determined by a ratio of partial pressure arterial oxygen and fraction of inspired oxygen (PaO2/FiO2) of <150, the difference between MultiStem treatment and placebo was greater than that observed in the intent to treat population. There was 25% mortality in MultiStem group vs. 50% in placebo group, 14.6 VF days in MultiStem group vs. 8.0 VF days in placebo group, and 11.4 ICU-free days in MultiStem group versus 5.9 ICU-free days in placebo group. The median values of the data set were 18.5 VF days for the MultiStem treated patients compared to 3.5 VF days for the placebo group and 12.5 ICU-free days for MultiStem patients compared to 1 ICU-free day for the placebo group.

Dr. Bellingan discussed potential mechanisms by which MultiStem may be providing benefit to ARDS patients, such as through restored endothelial integrity of the lung, reduced lung edema, increased alveolar fluid clearance, reduced immune cell infiltrate (including neutrophils, macrophages and eosinophils), and the ability to shift immune cells from a pro-inflammatory to anti-inflammatory phenotype.

A preliminary analysis of the biomarkers reveals that, similar to results from the Company’s MultiStem MASTERS-1 study for acute ischemic stroke, there was an overall reduction in pro-inflammatory cytokines in the MultiStem treatment group compared to placebo group. Specifically, certain acute inflammatory cytokines were lower in the ARDS patients that received MultiStem. The same inflammatory cytokines were also downregulated in the stroke patients that were in the MultiStem treatment group in the MASTERS-1 study, suggesting that MultiStem may work in similar way for both ARDS and stroke.

The study was designed to evaluate the impact of MultiStem treatment in subjects with acute onset of moderate to severe ARDS and was conducted at sites in the United States and United Kingdom. Treatment was required to begin within four days of ARDS diagnosis with an average treatment time of approximately two days from the diagnosis. Initially, three subjects received 300 million MultiStem cells and, after a safety review, an additional three subjects received 900 million MultiStem cells. This was followed by the larger double-blinded, placebo-controlled and randomized study of twenty subjects treated with an intravenous (IV) administration of 900 million MultiStem cells and ten subjects receiving IV placebo.

Additionally, last week, Athersys announced that its clinical program evaluating MultiStem cell therapy for the treatment of ARDS received Fast Track designation from the United States Food and Drug Administration. This important designation is given to qualified investigational therapies that show promise in providing benefit to patients in areas of significant unmet medical need. Fast Track designation allows for an expedited regulatory review process after the clinical data is submitted to help speed development of promising therapies to the market in order to help patients in areas where current standard of care is limited.

In April 2019, the Company’s collaborative partner in Japan, HEALIOS K.K. (Healios), announced the enrollment of the first patient into its MultiStem ARDS trial, referred to as the ONE-BRIDGE study. The study is intended to investigate the efficacy and safety of MultiStem therapy for patients with pneumonia-induced ARDS in Japan, and its primary endpoint will be the number of VF days in the first 28 days following treatment.

The Company will consider Healios’ progress in its ONE-BRIDGE study as it further develops its plans to move the ARDS program through clinical development.