IL17A/F nanobody sonelokimab in patients with plaque psoriasis: a multicentre, randomised, placebo-controlled, phase 2b study

BACKGROUND: Sonelokimab (also known as M1095) is a novel trivalent nanobody comprised of monovalent camelid-derived (ie, from the Camelidae family of mammals, such as camels, llamas, and alpacas) nanobodies specific to human interleukin (IL)-17A, IL-17F, and human serum albumin. Nanobodies are a novel class of proprietary therapeutic proteins based on single-domain, camelid, heavy-chain-only antibodies. We assessed the efficacy, safety, and tolerability of sonelokimab across four dosage regimens compared with placebo in patients with plaque-type psoriasis. Secukinumab served as an active control.

METHODS: This multicentre, randomised, placebo-controlled, phase 2b trial was done at 41 clinics and research sites in Bulgaria, Canada, Czech Republic, Germany, Hungary, Poland, and the USA. Participants (aged 18-75 years) with stable moderate to severe plaque-type psoriasis (defined as an Investigator's Global Assessment [IGA] score of ≥3, a body surface area involvement of ≥10%, and a Psoriasis Area and Severity Index score of ≥12) for more than 6 months before randomisation, who were candidates for systemic biological therapy were included. Participants previously treated with more than two biologics or any therapy targeting IL-17 were excluded. Randomisation was stratified by weight (≤90 kg or >90 kg) and previous use of biologics. Investigators, participants, and vendors remained masked for the duration of the study, with the exception of each site's study drug administrator (who did not complete any other assessments in the study) and a study monitor who only assessed drug preparation, administration, and accountability. The study sponsor remained masked until all week 24 data were clean and locked. Participants were randomly assigned (1:1:1:1:1:1) using a centralised interactive response technology system to one of six parallel treatment groups: placebo group, sonelokimab 30 mg group, sonelokimab 60 mg group, sonelokimab 120 mg normal load group, sonelokimab 120 mg augmented load group, or secukinumab 300 mg group. All participants underwent a 4-week screening period, a 12-week placebo-controlled induction period, a 12-week dose maintenance or escalation period, and a 24-week response assessment or dose-holding period. During the placebo-controlled induction period (weeks 0-12), participants received either placebo (at weeks 0, 1, 2, 3, 4, 6, 8, and 10), sonelokimab 30 mg, 60 mg, or 120 mg normal load (at weeks 0, 2, 4, and 8), sonelokimab 120 mg augmented load (at weeks 0, 2, 4, 6, 8, and 10), or secukinumab 300 mg (at weeks 0, 1, 2, 3, 4, and 8), with placebo given at weeks 1, 3, 6, and 10 in the sonelokimab 30 mg, 60 mg, and 120 mg normal load groups, at weeks 1 and 3 in the sonelokimab 120 mg augmented load group, and at weeks 6 and 10 in the secukinumab 300 mg group. During the dose maintenance or escalation period (weeks 12-24), participants assigned to the placebo group received sonelokimab 120 mg (at weeks 12, 14, 16, and then every 4 weeks); those assigned to sonelokimab 30 mg or 60 mg groups with an IGA score of more than 1 were escalated to 120 mg and then every 4 weeks, and those with an IGA score of 1 or less stayed on the assigned dose at week 12 and then every 4 weeks; those assigned to the sonelokimab 120 mg groups received sonelokimab 120 mg at week 12 and then every 8 weeks (normal load group) or every 4 weeks (augmented load); and those assigned to the secukinumab 300 mg group received secukinumab 300 mg at week 12 and then every 4 weeks. During this period, placebo was given at week 14 in all groups, except in participants who initially received placebo, and at week 16 in the sonelokimab 120 mg normal load group. In the response assessment with dose-holding period (weeks 24-48), participants in the sonelokimab 30 mg or 60 mg groups who had dose escalation to 120 mg remained on the same regimen regardless of the IGA score at week 24. Participants in the secukinumab 300 mg group also remained on the same regimen regardless of IGA score at week 24. Participants in the sonelokimab 30 mg and 60 mg groups without dose escalation, and all participants in the two sonelokimab 120 mg groups (including placebo rollover patients) were eligible to stop the study drug at week 24. Those participants with an IGA score of 0 at week 24 received placebo; these participants resumed the previous dose of sonelokimab every 4 weeks when they had an IGA score of 1 or more (assessed every 4 weeks). Participants in these groups with an IGA score of 1 or more at week 24 continued on the same dosage. All study treatments were administered as subcutaneous injections. The final dose in all groups was given at week 44. The primary outcome was the proportion of participants in the sonelokimab groups with an IGA of clear or almost clear (score 0 or 1) at week 12 compared with the placebo group. The primary outcome and safety outcomes were assessed on an intention-to-treat basis. The study was not powered for formal comparisons between sonelokimab and secukinumab groups. This trial is registered with ClinicalTrials.gov, NCT03384745.

FINDINGS: Between Aug 15, 2018, and March 27, 2019, 383 patients were assessed for eligibility, 313 of whom were enrolled and randomly assigned to the placebo group (n=52), the sonelokimab 30 mg group (n=52), the sonelokimab 60 mg group (n=52), the sonelokimab 120 mg normal load group (n=53), the sonelokimab 120 mg augmented load group (n=51), or the secukinumab 300 mg group (n=53). Baseline characteristics of participants were similar among the groups. At week 12, none (0·0% [95% CI 0·0-6·8]) of the 52 participants in the placebo group had an IGA score of 0 or 1 versus 25 (48·1% [34·0-62·4], p<0·0001) of 52 participants in the sonelokimab 30 mg group, 44 (84·6% [71·9-93·1], p<0·0001) of 52 participants in the sonelokimab 60 mg group, 41 (77·4% [63·8-87·7], p<0·0001) of 53 participants in the sonelokimab 120 mg normal load group, 45 (88·2% [76·1-95·6], p<0·0001) of 51 participants in the sonelokimab 120 mg augmented load group, and 41 (77·4% [63·8-87·7], p<0·0001) of 53 participants in the secukinumab 300 mg group. During the placebo-controlled induction period, 155 (49·5%) of 313 participants had one or more mostly mild to moderate adverse event; the most frequent adverse events in all participants on sonelokimab during weeks 0-12 were nasopharyngitis (28 [13·5%] of 208 participants), pruritus (14 [6·7%] participants), and upper respiratory tract infection (nine [4·3%] participants). One patient from all sonelokimab-containing groups had Crohn's disease that developed during weeks 12-52. Over 52 weeks, sonelokimab safety was similar to secukinumab, with the possible exception of manageable Candida infections (one [1·9%] of 53 participants in the secukinumab group had a Candida infection vs 19 [7·4%] of 257 participants in all sonelokimab-containing groups).

INTERPRETATION: Treatment with sonelokimab doses of 120 mg or less showed significant clinical benefit over placebo, with rapid onset of treatment effect, durable improvements, and an acceptable safety profile.

FUNDING: Avillion.