Equillium Reports Positive Phase 2 Results for EQ101 in Alopecia Areata

Equillium, Inc., a clinical-stage biotechnology firm specializing in novel therapies for autoimmune and inflammatory disorders, has unveiled positive topline data from its Phase 2 proof-of-concept (PoC) study of EQ101 in adult patients suffering from moderate to severe alopecia areata (AA). This autoimmune disease results in hair loss due to immune cells targeting hair follicles. The study aimed to assess the safety and efficacy of EQ101 by monitoring Severity of Alopecia Tool (SALT) scores, where a score of 100 indicates complete scalp hair loss and 0 represents no hair loss.

The results showed a favorable safety profile for EQ101, with no serious adverse events reported. At the end of the 24-week treatment period, 20% of all subjects reached a SALT score of 20 or lower. Among those with moderate to severe AA, 29% achieved this benchmark. Additionally, the mean improvement in SALT scores for this subgroup was 18%.

Rodney Sinclair, MD, the study's principal investigator, highlighted the significance of these findings: "Placebo rates in this indication are consistently below 10%. Thus, having 20% of patients reaching a SALT score of 20 or less, and 29% of moderate and severe patients, signifies promising drug activity." He emphasized the need for novel therapies beyond the currently approved Janus kinase inhibitors, stressing that EQ101’s targeted multi-cytokine inhibition offers a promising new therapeutic pathway.

EQ101 functions as a multi-cytokine inhibitor, targeting IL-2, IL-9, and IL-15, which are instrumental in the pathogenic T cells involved in AA. The Phase 2 study enrolled 36 subjects, each with at least 35% scalp hair loss, and followed them through 24 weeks of intravenous treatment and an additional four weeks of monitoring. With a mean baseline SALT score of 76, the study saw 25 subjects complete the treatment, while 11 discontinued, five of whom due to adverse events. Despite this, EQ101 demonstrated a strong safety profile, with most adverse events being mild to moderate, including upper respiratory infections, headaches, and fatigue.

Moreover, further analysis of the responder group—excluding those whose SALT scores increased by 20% or more—showed even more compelling improvements. For these 21 subjects, the mean SALT improvement was 26.3%, with specific subgroups showing varied responses: 78.8% improvement for moderate cases and 33.5% for severe cases.

Preliminary data also indicated reductions in cell surface CD132 on CD8 and NK cells in peripheral blood, aligning with EQ101’s mechanism of action and pharmacodynamic response. Dr. Maple Fung, Equillium’s Chief Medical Officer, expressed enthusiasm about these results, indicating that EQ101 is both well-tolerated and efficacious for AA patients with significant hair loss. Fung noted the company's plans to transition to subcutaneous delivery in future placebo-controlled studies, focusing on dose and regimen optimization across different AA severity subgroups.

Equillium plans to continue investigating EQ101's potential not only for alopecia areata but also for other dermatological conditions where IL-2, IL-9, and IL-15 inhibition could be beneficial, such as vitiligo and atopic dermatitis.

In summary, the Phase 2 study of EQ101 has yielded promising results, suggesting that this multi-cytokine inhibitor could become a viable treatment option for patients suffering from AA and possibly other related conditions.