Sabizabulin Benefit in Hospitalized COVID Seen Early in Disease Course

WASHINGTON -- The investigational agent sabizabulin reduced the risk of mortality in hospitalized COVID-19 patients who were only on supplemental oxygen at the time of their admission, according to a subgroup analysis of a phase III trial.

Of 88 patients with a documented comorbidity who also needed oxygen by mask or nasal prongs -- a World Health Organization (WHO) ordinal scale score of 4 -- deaths were significantly lower among those receiving oral sabizabulin compared with those on placebo (5.2% vs 27.6%; P=0.0090), reported Paula Skarda, MD, of Regions Hospital in St. Paul, Minnesota.

Patients assigned sabizabulin also saw significant reductions in length of hospital stay (13 vs 24 days with placebo), as well as in days spent in the intensive care unit (4 vs 17 days) or on a ventilator (3 vs 17 days).

"Overall, this analysis suggest that the antiviral and anti-inflammatory actions of sabizabulin contributes early in the prevention of COVID-19 progression to acute respiratory distress syndrome [ARDS] and death," Skarda said during her presentation at IDWeek.

The findings come on the heels of an interim analysis of the full trial population -- which included patients with a WHO score of 4-6 -- that showed a 51.6% relative reduction in mortality at 60 days with the oral microtubule disruptor. An FDA advisory committee is slated to meet next month to discuss whether the data are sufficient to support the emergency use of sabizabulin in patients with moderate-to-severe COVID-19 at high risk for ARDS.

However, not everyone at IDWeek was convinced by the results, with some attendees suggesting patient selection may have influenced the large mortality benefit observed in the trial.

"If you look at mortality with COVID right now, it is extremely low, so for me, if you have a high mortality, you aren't choosing patients well," session co-moderator Adarsh Bhimraj, MD, of Houston Methodist Hospital, told MedPage Today.

"This is just one trial, so we need to see these results replicated in other populations," Bhimraj cautioned. "The skepticism voiced by the audience here is well-founded."

Skarda reported on outcomes in 88 patients in the randomized, international, double-blind trial who had a WHO ordinal scale score of 4, who had a documented comorbidity, and for whom all vital statistics were known. This included 59 patients assigned to daily sabizabulin and 29 to placebo, with treatment given along with standard of care for 21 days or until discharge.

Comorbidities (a requirement for enrollment in those with a WHO score of 4) included asthma, chronic lung disease, diabetes, hypertension, severe obesity, older age, or an immunocompromising condition, among others.

Patients were an average age of 66-69, their body mass index was about 31, and blood oxygen level was 91% at hospital admission. With regard to COVID-19 vaccination status, less than a third of the sabizabulin group had received at least one dose versus a little more than a third for the placebo group; more patients assigned to sabizabulin had received three doses or more.

Over 75% of patients received dexamethasone during their treatment course, 95% received corticosteroids overall, and about 10% received remdesivir (Veklury).

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