FC 049A RANDOMISED DOSE RANGING, PLACEBO-CONTROLLED, PHASE II STUDY ASSESSING THE EFFICACY AND SAFETY OF BI 655064, AN ANTAGONISTIC ANTI-CD40 ANTIBODY, IN PATIENTS WITH LUPUS NEPHRITIS
Authors: Jayne David , Furie Richard , Romero-Diaz Juanita , Amano Hirofumi , Noppakun Kajohnsak , Gomez Harold Michael , Recto Rhona , Belsack Valérie , Fagan Nora , Padula Steven , Revollo Ivette , Wu Jing , Visvanathan Sudha , Steffgen Jürgen 
Published: May 2021

Abstract

Background and Aims
In patients (pts) with SLE, activation of the CD40–CD40L pathway results in stimulation and proliferation of B cells and other inflammatory cell types. The subsequent generation of autoantibodies and their deposition in the kidney, as well as activation of myeloid and resident kidney cells, result in local inflammation and eventually, kidney injury. Thus, CD40 is an appealing therapeutic target in lupus nephritis (LN). BI 655064 is a humanised anti-CD40 monoclonal antibody that blocks the CD40 pathway in a nanomolar range and downregulates activated B cells.
This study assessed the efficacy and safety over 52 weeks (wks) of three doses of subcutaneous BI 655064 compared with placebo, as add-on to mycophenolate and steroids, in pts with active proliferative LN (ClinicalTrials.gov number: NCT02770170).

Method
Overall, 121 pts with LN were randomised, double blind, in a 2:1:1:2 ratio to placebo or BI 655064 120 mg, 180 mg or 240 mg, and received a weekly loading dose for the first 3 wks, followed by dosing every 2 wks for the 120 and 180 mg doses, and weekly (120 mg) for the 240 mg group. Key inclusion criteria included an active ISN/RPS class III or IV (±V) renal biopsy within 3 months prior to screening and a screening protein/creatinine ratio of ≥1 mg/mg. Randomisation was stratified based on race (Asian vs non-Asian) and screening protein/creatine (UP/UC) ratio (&lt;3 vs ≥3). The primary efficacy endpoint was complete renal response (CRR), defined as 24 h proteinuria &lt;0.5 g/day and stable eGFR at Wk 52.

Results
The placebo response in this trial was higher than expected (48.3%; Table 1); none of the  BI 655064 doses increased rates of CRR at Wk 52 compared with placebo. However, CRR at Wk 52 based on creatinine-adjusted proteinuria, assessed using spot urine, showed a better response in the 180 mg group (50%) vs placebo (42.5%), and the 180 mg dose showed a greater change from baseline over time vs placebo from Wk 4. Time to CRR was shorter in the 180 mg group (17.3 wks) vs placebo (20.4 wks). The 180 mg group also showed improvement vs placebo in total SLEDAI (SELENA) and its subscores.
The unexpected high placebo response prompted a post hoc analysis evaluating confirmed CRR (cCRR), whereby confirmation of the endpoint was required at both Wks 46 (penultimate visit on treatment) and 52. A 15.2% higher cCRR in the 180 mg group (44.3%) vs placebo (29.1%) was observed (p=0.26).
While based on a small sample size, there were more reports of infection-related severe and serious adverse events and neutropenia in the 240 mg group compared with placebo. Of note, in those who experienced neutropenia, a clinical impact (e.g. increase in infections) was not established. Aside from these observations, safety data were comparable across treatment groups.
Larger decreases from baseline were observed in the percentage of CD27−IgD−CD95+, CD27−IgD+CD95+, CD27+IgD+CD95+ and CD27+IgD−CD95+ B-cell subsets in the 180 and 240 mg groups compared with placebo.
Treatment-emergent anti-drug antibodies (ADAs) were detected in five pts treated with BI 655054, all at low titre, and in one who received placebo; ADAs had no impact on pharmacokinetics or safety.

Conclusion
The trial did not meet its primary CRR endpoint. However, when confirmation of CRR was required at both Wks 46 and 52, the resultant decrease in the placebo response generated an effect size of 15.2% and 9.1% in favour of 180 mg and 240 mg BI 655064, respectively.