Equillium announces topline data from Type B portion of EQUALISE study

Equillium announced topline data from the Type B portion of the Phase 1b EQUALISE study evaluating itolizumab in lupus nephritis patients. The data suggests high complete and partial response rates with rapid and deep reduction in urine protein creatinine ratio, or UPCR, when itolizumab was added to mycophenolate mofetil/mycophenolic acid and corticosteroids. The topline data delivered to our partner, Ono Pharmaceutical, represents the first of two data set triggers leading to their decision as to whether to exercise their option to acquire itolizumab, which is expected in the second half of 2024. A total of 17 subjects were enrolled in the study, with 16 subjects analyzed as completing through Week 36. Based on published guidelines for the management of lupus nephritis from the European League Against Rheumatism, or EULAR, and European Renal Association-European Dialysis and Transplant Association, or ERA-EDTA, clinical activity assessments in this study are focused on the change in UPCR from baseline; proportion of apLN subjects with a complete response, or CR, defined as 50% or greater reduction in UPCR and less than 0.5-0.7 g/g; and proportion of subjects achieving a partial response, defined as 50% or greater reduction in UPCR. Subjects were highly proteinuric: baseline mean UPCR of 4.9 g/g. Percent reduction from baseline in median spot UPCR is 73%. Best clinical response observed by week 36 or their EOS visit: 6 of 16 (37.5%) subjects achieved CR. Additional 7 of 16 subjects achieved PR. There was a greater overall response rate achieved in patients receiving itolizumab by 12 and 28 weeks than expected compared to the ORR in patients receiving standard of care alone using data generated from the Accelerating Medicines Partnership Lupus Network. Results are comparable to those observed in the Phase 3 AURORA1 study of voclosporin. Consistent with the decline in UPCR overtime, subjects were able to taper their systemic corticosteroids over the course of the study with greater than80% reduction by Week 24. Itolizumab induced consistent pharmacodynamic responses in patients reducing the levels of cell surface CD6 on T cells, which is known to reduce T cell activity. Itolizumab treatment was also associated with reductions in absolute lymphocyte counts, another known pharmacodynamic effect. As noted in other studies of drugs whose mechanism leads to reductions in ALC, such as the S1P modulators, the reduction in ALC observed here was not associated with increased rates of infection or other adverse clinical signals. The majority of TEAEs were assessed as mild or moderate in severity, with the two most common TEAEs being lymphopenia and peripheral edema. Two subjects had at least one serious adverse event, none of which were related to study treatment.