Etrolizumab versus infliximab for the treatment of moderately to severely active ulcerative colitis (GARDENIA): a randomised, double-blind, double-dummy, phase 3 study.

BACKGROUND: Etrolizumab is a gut-targeted anti-ß7 integrin monoclonal antibody. In a previous phase 2 induction study, etrolizumab significantly improved clinical remission versus placebo in patients with moderately to severely active ulcerative colitis. We aimed to compare the safety and efficacy of etrolizumab with infliximab in patients with moderately to severely active ulcerative colitis. METHODS: We conducted a randomised, double-blind, double-dummy, parallel-group, phase 3 study (GARDENIA) across 114 treatment centres worldwide. We included adults (age 18-80 years) with moderately to severely active ulcerative colitis (Mayo Clinic total score [MCS] of 6-12 with an endoscopic subscore of ≥2, a rectal bleeding subscore of ≥1, and a stool frequency subscore of ≥1) who were naive to tumour necrosis factor inhibitors. Patients were required to have had an established diagnosis of ulcerative colitis for at least 3 months, corroborated by both clinical and endoscopic evidence, and evidence of disease extending at least 20 cm from the anal verge. Participants were randomly assigned (1:1) to receive subcutaneous etrolizumab 105 mg once every 4 weeks or intravenous infliximab 5 mg/kg at 0, 2, and 6 weeks and every 8 weeks thereafter for 52 weeks. Randomisation was stratified by baseline concomitant treatment with corticosteroids, concomitant treatment with immunosuppressants, and baseline disease activity. All participants and study site personnel were masked to treatment assignment. The primary endpoint was the proportion of patients who had both clinical response at week 10 (MCS ≥3-point decrease and ≥30% reduction from baseline, plus ≥1-point decrease in rectal bleeding subscore or absolute rectal bleeding score of 0 or 1) and clinical remission at week 54 (MCS ≤2, with individual subscores ≤1); efficacy was analysed using a modified intention-to-treat population (all randomised patients who received at least one dose of study drug). GARDENIA was designed to show superiority of etrolizumab over infliximab for the primary endpoint. This trial is registered with ClinicalTrials.gov, NCT02136069, and is now closed to recruitment. FINDINGS: Between Dec 24, 2014, and June 23, 2020, 730 patients were screened for eligibility and 397 were enrolled and randomly assigned to etrolizumab (n=199) or infliximab (n=198). 95 (48%) patients in the etrolizumab group and 103 (52%) in the infliximab group completed the study through week 54. At week 54, 37 (18·6%) of 199 patients in the etrolizumab group and 39 (19·7%) of 198 in the infliximab group met the primary endpoint (adjusted treatment difference -0·9% [95% CI -8·7 to 6·8]; p=0·81). The number of patients reporting one or more adverse events was similar between treatment groups (154 [77%] of 199 in the etrolizumab group and 151 [76%] of 198 in the infliximab group); the most common adverse event in both groups was ulcerative colitis (55 [28%] patients in the etrolizumab group and 43 [22%] in the infliximab group). More patients in the etrolizumab group reported serious adverse events (including serious infections) than did those in the infliximab group (32 [16%] vs 20 [10%]); the most common serious adverse event was ulcerative colitis (12 [6%] and 11 [6%]). There was one death during follow-up, in the infliximab group due to a pulmonary embolism, which was not considered to be related to study treatment. INTERPRETATION: To our knowledge, this trial is the first phase 3 maintenance study in moderately to severely active ulcerative colitis to use infliximab as an active comparator. Although the study did not show statistical superiority for the primary endpoint, etrolizumab performed similarly to infliximab from a clinical viewpoint. FUNDING: F Hoffmann-La Roche.

Pharmacokinetics, Pharmacodynamics, and Safety of Etrolizumab in Children With Moderately to Severely Active Ulcerative Colitis or Crohn's Disease: Results from a Phase 1 Randomized Trial.

BACKGROUND: Etrolizumab, a humanized anti-ß7 antibody, has not been studied in children. Here, we evaluate the pharmacokinetics, pharmacodynamics, and safety of etrolizumab in children with inflammatory bowel disease. METHODS: Patients age 4 to 17 years with moderately to severely active ulcerative colitis or Crohn's disease were randomized 1:1 to receive 1.5mg/kg of etrolizumab subcutaneously every 4 weeks (q4w) or 3.0mg/kg every 8 weeks (q8w) for 16 weeks in this open-label phase 1 trial. Pharmacokinetics, pharmacodynamics, safety, and efficacy were assessed. RESULTS: Of the 24 patients treated, 21 completed the study. In the groups of 1.5mg/kg q4w and 3.0mg/kg q8w, respectively, mean (SD) maximum concentration (Cmax) was 9.8 (4.86) µg/mL and 18.1 (6.25) µg/mL; and mean (SD) area under the curve within a dosing interval (AUCtau) was 167 (86.9) and 521 (306) µg·day/mL after the last dose. The Cmax increased dose proportionally. The AUC over an 8-week period was slightly higher in the 3.0mg/kg q8w dose group. Median half-life was similar for both dosing regimens. Median numbers of free ß7high gut-homing T and B cell subsets declined below 10% of baseline, confirming ß7 target engagement and complete/near-complete receptor occupancy. Adverse events were consistent with the safety profile in adults. Approximately 60% of patients achieved a clinical response. CONCLUSIONS: Etrolizumab showed a dose-proportional increase in Cmax and a slightly greater than dose-proportional increase in AUCtau. Both regimens achieved complete/near-complete ß7 receptor occupancy, with a similar relationship to concentration as adults. Etrolizumab was well tolerated and demonstrated clinical activity in children.

An Open-Label Tolerability and Actual-Use Human Factors Study of Etrolizumab Autoinjector in Healthy Volunteers.

INTRODUCTION: Etrolizumab is a novel, dual-action, anti-ß7 integrin antibody in development for patients with moderate to severe ulcerative colitis or Crohn's disease. Phase 3 studies use a prefilled syringe (PFS) for etrolizumab administration. In parallel, an autoinjector (AI) is being developed to increase delivery options for patients if etrolizumab is approved. Here we describe the overall development strategy and detail the first-in-human study of this AI. METHODS: This open-label study of healthy volunteers evaluated the tolerability and usability of the etrolizumab AI under development. The primary endpoint was the proportion of participants with greater than mild pain following injection. Adverse events (AEs) and usage errors were also assessed. Results were reported by injection site (thigh vs abdomen) and needle training (experienced vs naive). Pharmacokinetic (PK) variability between participants was an exploratory endpoint. RESULTS: Thirty participants completed the study; 97% of them did not experience any pain greater than mild, and 50% did not experience any pain at all. Three usage errors were observed, one of which resulted in delivery of a partial dose of etrolizumab. No patterns of usage errors were observed. Mild injection site reactions (ISRs) were reported; all resolved by the end of the study. Participants injecting into the abdomen reported more ISRs than those injecting into the thigh; needle training did not influence AE incidence or severity. CONCLUSIONS: Results from this first-in-human study demonstrate that single injections of etrolizumab 105 mg using an AI were well tolerated in healthy volunteers, with transient, mild pain and minimal usage errors. Results from this study also informed the design of a subsequent PK comparability study evaluating exposure of etrolizumab administered by either the PFS or the AI. Overall, the availability of an AI may provide an attractive option for patients desiring a convenient, easy-to-use delivery mechanism for etrolizumab. TRIAL REGISTRATION: NCT02629744.

Comparable Pharmacokinetics, Safety, and Tolerability of Etrolizumab Administered by Prefilled Syringe or Autoinjector in a Randomized Trial in Healthy Volunteers.

INTRODUCTION: Etrolizumab is a novel, dual-action anti-ß7 integrin antibody studied in phase 3 trials in patients with inflammatory bowel disease. An autoinjector (AI) is being developed in parallel to complement the prefilled syringe with needle safety device (PFS-NSD) for subcutaneous (SC) administration in these trials. Here we demonstrate the comparable pharmacokinetics, tolerability, and safety of both devices. METHODS: This randomized, open-label, two-part study in healthy participants evaluated the comparability of etrolizumab exposure between the AI and the PFS-NSD. Part 1 (pilot) involved a small number of participants, and initial results were used to finalize the design of the larger part 2 (pivotal) study. In both parts, participants were randomly assigned to receive a single SC dose of etrolizumab 105 mg by AI or PFS-NSD. Randomization was stratified by body weight. Primary pharmacokinetic outcomes were Cmax, AUClast, and AUC0-inf. RESULTS: One hundred and eighty healthy participants (part 1, n = 30; part 2, n = 150) received a single SC dose of etrolizumab by AI or PFS-NSD. Primary pharmacokinetic results from part 1 supported modification of the part 2 study design. Results from part 2 demonstrated that etrolizumab exposure was equivalent between devices, with geometric mean ratios (GMRs) between AI and PFS-NSD of 102% (90% confidence interval [CI] 94.2-111) for Cmax, 98.0% (90% CI 89.3-107) for AUClast, and 97.6% (90% CI 88.6-107) for AUC0-inf. Median tmax and mean terminal t1/2 were also similar between devices. GMRs and 90% CIs of all primary pharmacokinetic parameters were fully contained within the predefined equivalence limits (80-125%). CONCLUSION: This pharmacokinetic study demonstrated that single SC injections of etrolizumab 105 mg using an AI or a PFS-NSD resulted in equivalent etrolizumab exposure and similar safety and tolerability in healthy participants. Taken together, these results support the use of an AI for etrolizumab administration. TRIAL REGISTRATION: NCT02996019.

An engineered human IgG1 antibody with longer serum half-life.

The serum half-life of IgG Abs is regulated by the neonatal Fc receptor (FcRn). By binding to FcRn in endosomes, IgG Abs are salvaged from lysosomal degradation and recycled to the circulation. Several studies have demonstrated a correlation between the binding affinity of IgG Abs to FcRn and their serum half-lives in mice, including engineered Ab fragments with longer serum half-lives. Our recent study extended this correlation to human IgG2 Ab variants in primates. In the current study, several human IgG1 mutants with increased binding affinity to human FcRn at pH 6.0 were generated that retained pH-dependent release. A pharmacokinetics study in rhesus monkeys of one of the IgG1 variants indicated that its serum half-life was approximately 2.5-fold longer than the wild-type Ab. Ag binding was unaffected by the Fc mutations, while several effector functions appeared to be minimally altered. These properties suggest that engineered Abs with longer serum half-lives may prove to be effective therapeutics in humans.

Engineered human IgG antibodies with longer serum half-lives in primates.

The neonatal Fc receptor (FcRn) plays an important role in regulating the serum half-lives of IgG antibodies. A correlation has been established between the pH-dependent binding affinity of IgG antibodies to FcRn and their serum half-lives in mice. In this study, molecular modeling was used to identify Fc positions near the FcRn binding site in a human IgG antibody that, when mutated, might alter the binding affinity of IgG to FcRn. Following mutagenesis, several IgG2 mutants with increased binding affinity to human FcRn at pH 6.0 were identified at Fc positions 250 and 428. These mutants do not bind to human FcRn at pH 7.5. A pharmacokinetics study of two mutant IgG2 antibodies with increased FcRn binding affinity indicated that they had serum half-lives in rhesus monkeys approximately 2-fold longer than the wild-type antibody.

Humanized anti-interleukin-2 (IL-2) receptor alpha therapy: long-term results in uveitis patients and preliminary safety and activity data for establishing parameters for subcutaneous administration.

Therapy for severe uveitis is frequently long-term immunosuppression using systemic corticosteroids and cytotoxic agents, but side effects make long-term therapy difficult. A long-term (>4 year) Phase I/II single armed interventional study using intravenous anti-IL-2 receptor alpha treatments (daclizumab) and a short-term Phase II study evaluating the use of a subcutaneous daclizumab formulation were conducted. Patients were tapered off their systemic immunosuppressive therapy and received daclizumab infusions or subcutaneous injections at intervals varying from 2 to 6 weeks. In the long-term study, seven of ten enrolled patients were tapered from their original immunosuppressive medications and maintained exclusively on repeated daclizumab infusions for control of their uveitis for over 4 years. No patient was permanently removed from therapy for an adverse event ascribed to the medication. The use of 6-week infusion intervals led to recurrence of uveitis, while 2- to 4-week intervals did not. Only one patient developed measurable anti-daclizumab antibodies but this disappeared when subcutaneous therapy was begun. In the short-term study, four of the five patients receiving the subcutaneous formulation met the study endpoints for success within the first 12 weeks. All five were successful by 26 weeks. These studies provide preliminary evidence that regularly administered long-term daclizumab therapy can be given in lieu of standard immunosuppression for years to treat severe uveitis and that subcutaneously administered daclizumab appeared to be a clinically viable treatment strategy. These studies suggest that anti-IL-2 receptor blockade could be useful in the treatment of Th1-mediated autoimmune conditions.