Equillium, Inc. announced topline data from its Phase 2, single dose, proof-of-concept study of EQ101 in adult patients with moderate, severe or very-severe alopecia areata, an autoimmune disease driven by an immune cell attack of the hair follicles that causes hair loss. The primary objectives of the study were to evaluate the safety and tolerability profile of EQ101, as well as signs of efficacy using Severity of Alopecia Tool scores, where a score of 100 represents total scalp hair loss and a score of 0 represents no scalp hair loss. Results from the study demonstrated a favorable safety and tolerability profile with no serious adverse events, and improvements in SALT scores above the published historically low placebo response rates.

Of all subjects that completed 24 weeks of treatment (baseline SALT of 35 to 100, n=25), 20% achieved a SALT score of less than or equal to 20 by week 24. Of those subjects with moderate to severe AA at baseline that completed 24 weeks of treatment (SALT score 35 to < 95, n=17), 29% achieved a SALT score of less than or equal to 20 by week 24, and a mean SALT improvement from baseline of 18%. EQ101 is a novel multi-cytokine inhibitor with a targeted mechanism of action against cytokines IL-2, IL-9 and IL-15, which are key drivers of the pathogenic T cells implicated in AA.

To be eligible for the Phase 2 study for the treatment of AA, subjects were required to have at least 35% scalp hair loss due to AA, as measured by SALT, and a current hair loss episode of at least six months, but not more than seven years. The study enrolled 36 subjects at multiple clinical trial sites, with a mean baseline SALT score of 76. Twenty-five subjects completed the study; eleven subjects discontinued the study early, of which only five were attributed to adverse events.

Throughout 24 weeks of treatment and 4 weeks of follow up, EQ101 was well tolerated with no SAEs and no notable changes in safety laboratory (coagulation, hematology, chemistry, liver function, urinalysis, cholesterol), electrocardiogram, vital signs, or physical exam findings were reported. The majority (98.9%) of adverse events were Grade 1 or 2, with the most common being upper respiratory tract infection, headache and fatigue. The two (1.1%) Grade 3 events in two subjects considered related to study treatment were a case of transient lymphocytopenia and fatigue.

Preliminary data also indicate reductions of cell surface CD132 on both CD8 and NK cells in peripheral blood consistent with EQ101 target engagement and pharmacodynamic response.