Equillium Inc ( EQ ). announced Tuesday topline data from its Phase 2, single-dose, proof-of-concept (PoC) study of EQ101 in adult patients with alopecia areata.

Alopecia is an autoimmune disease that attacks the body’s hair follicles, causing patchy hair loss.

The primary objectives of the study were to evaluate the safety and tolerability profile of EQ101 and signs of efficacy using Severity of Alopecia Tool (SALT) scores, where a score of 100 represents total scalp hair loss and a score of 0 represents no scalp hair loss.

Study results demonstrated a favorable safety and tolerability profile. No serious adverse events and improvements in SALT scores were 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%.

“Placebo rates in this indication across studies have been consistently low — generally less than 10% of patients achieve a SALT score of 20 or less. To have 20% of patients completing the study reach a SALT score of less than or equal to 20 across all subjects, and 29% of moderate and severe patients, is a very encouraging sign of drug activity,” said principal investigator Rodney Sinclair.

The company says preliminary data indicate reductions of cell surface CD132 on CD8 and NK cells in peripheral blood consistent with EQ101 target engagement and pharmacodynamic response.

“We look forward to transitioning to a subcutaneous delivery in placebo-controlled, dose and regimen optimization studies where we expect to continue to investigate EQ101 across alopecia areata disease severity subgroups, including the important population of moderate patients with a SALT score between 35 and less than 50,” said Maple Fung, chief medical officer at Equillium ( EQ ).

Price Action: EQ shares are down 21.8% at $1.15 at last check Tuesday. During premarket trading, the shares reached as high as $1.96.

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