Efficacy and safety of temelimab in multiple sclerosis: Results of a randomized phase 2b and extension study.

BACKGROUND: The envelope protein of human endogenous retrovirus W (HERV-W-Env) is expressed by macrophages and microglia, mediating axonal damage in chronic active MS lesions. OBJECTIVE AND METHODS: This phase 2, double-blind, 48-week trial in relapsing-remitting MS with 48-week extension phase assessed the efficacy and safety of temelimab; a monoclonal antibody neutralizing HERV-W-Env. The primary endpoint was the reduction of cumulative gadolinium-enhancing T1-lesions in brain magnetic resonance imaging (MRI) scans at week 24. Additional endpoints included numbers of T2 and T1-hypointense lesions, magnetization transfer ratio, and brain atrophy. In total, 270 participants were randomized to receive monthly intravenous temelimab (6, 12, or 18 mg/kg) or placebo for 24 weeks; at week 24 placebo-treated participants were re-randomized to treatment groups. RESULTS: The primary endpoint was not met. At week 48, participants treated with 18 mg/kg temelimab had fewer new T1-hypointense lesions (p = 0.014) and showed consistent, however statistically non-significant, reductions in brain atrophy and magnetization transfer ratio decrease, as compared with the placebo/comparator group. These latter two trends were sustained over 96 weeks. No safety issues emerged. CONCLUSION: Temelimab failed to show an effect on features of acute inflammation but demonstrated preliminary radiological signs of possible anti-neurodegenerative effects. Current data support the development of temelimab for progressive MS. TRIAL REGISTRATION: CHANGE-MS: ClinicalTrials.gov: NCT02782858, EudraCT: 2015-004059-29; ANGEL-MS: ClinicalTrials.gov: NCT03239860, EudraCT: 2016-004935-18.

Temelimab, an IgG4 Anti-Human Endogenous Retrovirus Monoclonal Antibody: An Early Development Safety Review.

INTRODUCTION: Temelimab (formerly called GNbAC1) is an immunoglobulin (Ig) G4 monoclonal antibody that targets the human endogenous retroviral envelope protein HERV-W-Env, shown to be associated with the pathogenesis of certain autoimmune disorders such as multiple sclerosis (MS) and type 1 diabetes mellitus (T1D). By neutralizing HERV-W-Env, temelimab could act as a disease-modifying therapy for these disorders. It is currently in clinical development for MS and T1D. METHODS: The safety information on temelimab (including potential infusion-related reactions, malignancies, pregnancies and antidrug antibodies) collected during three phase I and four phase II clinical trials was reviewed and is summarized in this article. RESULTS: In the entire development program, 54 healthy volunteers received single doses of temelimab in three phase I studies, and 334 MS or T1D patients received temelimab for a total estimated exposure of 465 patient-years in four phase II trials. No differences were observed between numbers of treatment-emergent adverse events (TEAEs) or serious adverse events (SAEs) between treatment groups (including placebo), and the number of SAEs was limited. Furthermore, no differences were observed in laboratory evaluations, vital signs, electrocardiogram (ECG), or physical examinations between treatment groups. Rare potential infusion-related reactions were reported. Temelimab treatment was not associated with an increased risk of infections or infestations. CONCLUSION: These results suggest that treatment with temelimab was not associated with any particular type of AE. Overall, temelimab was safe and very well tolerated over the tested dose range after repeated monthly administrations.

A safety and pharmacodynamics study of temelimab, an antipathogenic human endogenous retrovirus type W envelope monoclonal antibody, in patients with type 1 diabetes.

AIM: To report the first study of temelimab, a monoclonal antibody neutralizing the pathogenic human endogenous retrovirus type W envelope, in patients with type 1 diabetes (T1D). MATERIALS AND METHODS: This double-blind, placebo-controlled, randomized clinical trial recruited adult patients with T1D within 4 years postdiagnosis and remaining C-peptide secretion. Sixty-four patients were randomized (2:1) to monthly temelimab 6 mg/kg or placebo during 24 weeks followed by a 24-week, open-label extension, during which all patients received temelimab. The primary objective was the safety and tolerability of temelimab. The secondary objective was to assess the pharmacodynamics response such as C-peptide levels, insulin use, HbA1c, hypoglycaemia and autoantibodies. RESULTS: Temelimab was well tolerated without any group difference in the frequency or severity of adverse events. Concerning exploratory endpoints, there was no difference in the levels of C-peptide, insulin use or HbA1c between treatment groups at weeks 24 and 48. The frequency of hypoglycaemia events was reduced with temelimab (P = 0.0004) at week 24 and the level of anti-insulin antibodies was lower with temelimab (P < 0.01); the other autoantibodies did not differ between groups. CONCLUSIONS: Temelimab appeared safe in patients with T1D. Pharmacodynamics signals (hypoglycaemia and anti-insulin antibodies) under temelimab were observed. Markers of ß-cell functions were not modified by treatment. These results need to be further explored in younger patients with T1D with earlier disease onset.

A High-dose Pharmacokinetic Study of a New IgG4 Monoclonal Antibody Temelimab/GNbAC1 Antagonist of an Endogenous Retroviral Protein pHERV-W Env.

PURPOSE: Temelimab/GNbAC1 is a humanized immunoglobulin G4 monoclonal antibody antagonist of the human endogenous retrovirus W envelope protein, which is associated with multiple sclerosis (MS) pathophysiology and possibly with other autoimmune disorders. Human endogenous retrovirus W envelope protein is expressed in the central nervous system of patients with MS, and sufficient amount of temelimab must reach the target. The safety of very high dosages of temelimab should be tested to support further clinical trials in MS. METHODS: This randomized, placebo-controlled, dose-escalation study evaluated the safety and pharmacokinetic profile of temelimab in 24 healthy volunteers after a single intravenous infusion at doses of 36, 60, 85, and 110 mg/kg administered sequentially. FINDINGS: Temelimab was well tolerated, with no particular adverse drug reactions at any dose. The maximal dose of 110 mg/kg could be administered, and no antidrug antibodies were induced. After administration of 36-110 mg/kg, mean temelimab Cmax increased from 859 to 2450 µg/mL, and AUC values increased from 319,900 to 1,030,000 µg·h/mL. There was an approximate dose-proportional increase in exposure, similar to observations at lower doses. IMPLICATIONS: The favorable data in terms of safety and pharmacokinetic variables support temelimab use at high doses in future MS trials to optimally neutralize the temelimab target in the central nervous system. ClinicalTrials.gov identifier: NCT03574428.

The risk of malignancy is not increased in patients with multiple sclerosis treated with subcutaneous interferon beta-la: analysis of data from clinical trial and post-marketing surveillance settings.

BACKGROUND: Risks that are potentially associated with long-term therapies should be assessed. OBJECTIVE: The present analyses were performed to determine the risk of malignancy in patients with multiple sclerosis (MS) receiving subcutaneous (sc) interferon (IFN) beta-1a, using pooled safety data from key clinical trials and data from the Merck Serono Global Drug Safety database. METHODS: The standard Medical Dictionary for Regulatory Activities query "malignancies" was used to retrieve relevant cases from each data set. The incidence of malignancies per 1000 patient-years was calculated using the pooled safety data from clinical trials. The reporting rates of malignancy types were calculated for the post-marketing setting based on sales volume. Malignancies were grouped by organ localization and classified as medically confirmed or not medically confirmed according to the source of each report. The number of reported cases of each type was compared with the expected number in the general population. RESULTS: Analysis of pooled safety data from 12 key clinical trials did not show an increased incidence of malignancy per 1000 patient-years with sc IFN beta-1a (4.0; 95% confidence interval (CI): 2.9-5.5) compared with placebo (6.4; 95% CI: 3.3-11.2). Analysis of the database shows that among the medically confirmed cases, reported to expected ratios ranged from 1 : 6 to 1 : 18 for solid tumours and from 1 : 2 to 1 : 9 for lymphohaematopoietic tumours. CONCLUSION: Safety data from both clinical trial and post-marketing settings suggest that treatment with sc IFN beta-1a does not increase the risk of malignancy in patients with MS.

Pregnancy outcomes in multiple sclerosis following subcutaneous interferon beta-1a therapy.

BACKGROUND: Women with multiple sclerosis (MS) are advised to discontinue interferon-beta therapy before trying to conceive. Unplanned pregnancies occur and risks related to exposure remain unclear. METHODS: To determine pregnancy outcomes following interferon-beta therapy, we examined pregnancies from a global drug safety database containing individual case safety reports received in the post-marketing setting and safety data from clinical trials of subcutaneous interferon beta-1a in MS. RESULTS: One thousand and twenty-two cases of exposure to subcutaneous interferon beta-1a during pregnancy were retrieved; 679 had a documented outcome. In cases for which exposure duration was available (n = 231), mean time of foetal exposure to subcutaneous interferon beta-1a before treatment discontinuation was 28 days; most pregnancies (199/231; 86.1%) were exposed for ≤ 45 days. To avoid bias, only outcomes for prospective data (n = 425) in pregnancies exposed to interferon beta-1a in utero were analysed further. Of these, 324 (76.2%) resulted in normal live births and four (0.9%) in live births with congenital anomalies (3 [0.7%] were 'major'). Four (0.9%) pregnancies resulted in stillbirths (1 [0.2%] with foetal defects). There were 5 (1.2%) ectopic pregnancies, 49 (11.5%) spontaneous abortions and 39 (9.2%) elective terminations. Most pregnancies exposed to subcutaneous interferon beta-1a in utero were associated with normal live births. The rates of spontaneous abortion and major congenital anomalies in live births were in line with those observed in the general population. CONCLUSIONS: These data should be taken into account when considering options for women with MS who become pregnant or who are planning pregnancy while on treatment with subcutaneous interferon beta-1a.