洛基维特单抗在IL-31诱导犬瘙痒模型中的起效和作用持续时间

王帆

Onset and duration of action of lokivetmab in a canine model of IL-31 induced pruritus

洛基维特单抗在IL-31诱导犬瘙痒模型中的起效和作用持续时间

翻译:赵胜楠  校对：王帆

Background–Interleukin (IL)-31 is a cytokine involved in allergic inflammation which induces pruritus across species including dogs. Using recombinant canine IL-31 we have developed a model of pruritus in the dog to evaluate onset of action and duration of effect of therapeutic drugs.

Objective–To assess the onset of action and duration of effect of lokivetmab (Cytopoint) in the IL-31-induced pruritus model.

Animals–Twenty-four purpose-bred beagle dogs (neutered males, spayed and intact females) 1.5–4.7 years old and weighing between 6 and 14 kg.

Methods and materials–Randomized, blinded, placebo-controlled studies were designed to evaluate the antipruritic properties of lokivetmab. Laboratory beagle dogs were given either placebo, 0.125, 0.5 or 2.0 mg/kg lokivetmab, subcutaneously. IL-31 then was administered to evaluate pruritus 3–5 h post-placebo or -lokivetmab administration as well as one, seven, 14, 28, 42 and 56 days post-dosing. Pruritus was evaluated over a 2 h window in animals by video monitoring and scored using a categorical scoring system.

Results–When animals were given 2.0 mg/kg lokivetmab, a significant reduction in pruritus was observed at 3–4, 4–5 and 3–5 h post-treatment (P ≤ 0.0001). When animals were given either 0.125, 0.5 or 2 mg/kg lokivetmab, the duration of effect was dose-dependent and statistically significant for 14, 28 and 42 days, respectively(P ≤ 0.0288).

Conclusion–These data indicate that a single subcutaneous injection of 2 mg/kg lokivetmab produces a significant suppression of pruritus starting 3 h post-treatment that can be sustained for 42 days.

背景—白细胞介素(IL)-31是一种参与过敏性炎症反应的细胞因子, 可在包括犬等多物种体内诱导瘙痒。使用重组犬IL-31, 我们开发了犬瘙痒模型, 以评价治疗药物的起效时间和作用持续时间。

目的—评估洛基维特单抗(赛妥敏)在IL-31诱导瘙痒模型中的起效时间和作用持续时间。

动物—24只专门饲养的比格犬 (已去势雄性、已绝育雌性和未绝育雌性) , 1.5-4.7岁, 体重6-14 kg。

方法和材料—随机、设盲、安慰剂对照研究旨在评价洛基维特单抗的止痒特性。实验室比格犬经皮下给予安慰剂、0.125、0.5或2.0 mg/kg洛基维特单抗。然后给予IL-31,以评价安慰剂或洛基维特单抗给药后3-5h以及给药后1、7、14、28、42和56天的瘙痒。通过视频监测在2h窗口内评价动物的瘙痒, 并使用分类评分系统进行评分。

结果—当给予动物2.0 mg/kg洛基维特单抗时, 在给药后3-4、4-5和3-5h观察到瘙痒显著减轻(P≤0.0001)。当给予动物0.125、0.5或2 mg/kg洛基维特单抗时, 作用持续时间呈剂量依赖性, 分别为14、28和42天, 具有统计学显著性(P≤0.0288)。

结论—这些数据表明, 2 mg/kg洛基维特单抗单次皮下注射给药后3h开始显著抑制瘙痒, 并能持续42天。

Introduction

介绍

Interleukin (IL)-31 is a cytokine best known for its pruritogenic effects across species. It was discovered back in 2004 by several groups as a cytokine belonging to the glycoprotein 130/ IL-6 cytokine family and is believed to be produced by T-helper2 (Th2) cells after allergen presentation by Langerhans cells.It also has been shown to be secreted by activated macrophages, basophils, eosinophils and keratinocytes after allergen exposure or initiation of Type 2 inflammation within tissues.

白细胞介素(IL)-31是一种细胞因子，以其跨物种的致瘙痒作用而闻名。2004年，几个研究小组发现它是一种属于糖蛋白130/IL-6细胞因子家族的细胞因子，认为是由辅助性T细胞2(Th2)在郎格罕细胞递呈过敏原后产生的。已被证明是在过敏原暴露或组织内引发2型炎症后，由激活的巨噬细胞、嗜碱性粒细胞、嗜酸性粒细胞和角质形成细胞分泌的。

Interleukin-31 binds a heterodimeric receptor (IL-31 receptor A and oncostatin M receptor beta) to activate signal transduction pathways within cells. These receptors can be found on immune cell such as macrophages, mast cells, eosinophils and basophils, as well as keratinocytes and dorsal root ganglia of peripheral neurons. When IL-31 binds its heterodimeric receptor, signalling pathways such as Janus kinase (JAK)/signal transducer and activator of transcription (STAT), phosphoinositide 3-kinase (PI3K)/AKT, and different mitogen-activated protein kinase pathways, such as extracellular signal regulated kinase (ERK), p38 and c-Jun N-terminal kinase, are activated, leading to biological changes in cells. These changes include immune cell chemotaxis, pro-inflammatory cytokine and chemokine secretion, pruritic responses in the skin, and skin barrier disruption resulting in part from alterations in cell proliferation, differentiation and barrier protein synthesis.

IL-31与异二聚体受体结合（IL-31受体A和抑瘤素M受体β），从而激活细胞内的信号转导通路。这些受体可见于巨噬细胞、肥大细胞、嗜酸性粒细胞和嗜碱性粒细胞等免疫细胞上，以及角质形成细胞和外周神经元背根神经节上。当IL-31与异二聚体受体结合时，信号通路如Janus激酶(JAK)/信号传导和转录激活因子(STAT)、磷酸肌醇3-激酶(PI3K)/AKT和不同的丝裂原活化蛋白激酶通路被激活，如细胞外信号调节激酶(ERK)、p38和c-Jun N-末端激酶，导致细胞发生生物学改变。这些改变包括免疫细胞趋化、促炎细胞因子和趋化因子分泌、皮肤瘙痒反应，以皮肤屏障破坏，导致细胞增殖、分化和屏障蛋白合成的部分改变。

Concentrations of IL-31 are elevated in pruritic allergic skin conditions and can induce scratching behaviours in a variety of species such as mice, monkeys and dogs. Studies done in laboratory beagle dogs demonstrated that when IL-31 was given by several routes (intradermally, subcutaneously and intravenously), it induced strong pruritic behaviours within minutes to hours.These findings were used to develop a novel experimental model in dogs to evaluate the antipruritic effects of canine therapeutics. This model was able to determine the onset and duration of action of commonly used treatments for atopic dermatitis (AD) or allergic dermatitis such as oclacitinib (Apoquel, Zoetis; Kalamazoo, MI, USA) and glucocorticoids.

在瘙痒性过敏性皮肤病中IL-31的浓度升高，并可诱导各种物种的抓挠行为，如小鼠、猴子和犬。在实验室比格犬上进行的研究表明，当IL-31通过几种途径（皮内、皮下和静脉）注射时，它会在几分钟到几小时内诱发强烈的瘙痒行为。这些发现被用来开发犬的新型实验模型，以评估犬治疗瘙痒症的止痒作用。该模型能够确定特应性皮炎(AD)或过敏性皮炎的常用治疗方法的起效和作用持续时间，如奥拉替尼和糖皮质激素。

Lokivetmab (Cytopoint, Zoetis) is a caninized monoclonal antibody that binds and neutralizes canine IL-31 and is given as a subcutaneous injection every four to eight weeks. It has been approved for the treatment of clinical signs associated with AD as well as other forms of allergic dermatitis in dogs across the world. In clinical trials, lokivetmab significantly reduced pruritus as early as Day (D)1 and significantly improved the condition of the dogs’ skin as early as D7, the first evaluation days for these end-points. The aim of the present study was to further characterize the onset of antipruritic action and the duration of effect of a single injection of lokivetmab s.c. in a laboratory model of IL-31-induced pruritus in beagle dogs.

洛基维特单抗（赛妥敏）是一种犬源化单克隆抗体，可结合并中和犬IL-31，每4-8周皮下注射一次。已在全球范围内获批用于治疗犬AD相关临床症状以及其他形式的过敏性皮炎。在临床试验中，洛基维特单抗早在第（D）1天就显著减轻了瘙痒，早在第7天（D7）（这些终点的第一个评估日）就显著改善了犬的皮肤状况。本研究的目的是进一步描述在IL-31诱导的比格犬瘙痒的实验室模型中，单次注射洛基维特单抗的止痒作用起效和作用持续时间。

Materials and methods

材料和方法

Animal care and ethics

动物护理与伦理学

A group of 24 purpose-bred beagles were used to complete the onset of duration study (eight neutered males, 15 spayed females, one intact female; 2–3 years old weighing 7.2–14.4 kg; originally from Marshall BioResources; North Rose, NY, USA). The duration of effect study was performed in a different set of 24 purpose-bred beagle dogs (10 neutered males, 14 spayed females; 1.5–4.7 years old weighing 6.3–14.8 kg; originally from Marshall BioResources or Ridglan Farms, Inc.; Mt. Horeb, WI, USA). All dogs for both studies were maintained and used as part of an in-house colony whose pruritic behavioural responses to exogenous IL-31 were extensively characterized in previous studies.

使用一组24只专门饲养的比格犬（8只已去势雄性、5只已绝育雌性、1只未绝育雌性；2-3岁，体重7.2-14.4公斤）完成了持续时间的研究。在另一组24只专门饲养的比格犬（10只已去势雄性、14只已绝育雌性，1.5-4.7岁，体重6.3-14.8 kg）中进行疗效持续时间研究。两项研究中的所有犬都被作为内部群体的一部分使用，其对外源性IL-31的瘙痒行为反应在以前的研究中得到了广泛的描述。

All animal procedures were performed following site-specific, local and national Animal Health IACUC guidance to assure compliance with the Animal Welfare Act, Regulations 9 CFR parts 1, 2 and 3, and with the Guide for the Care and Use of Laboratory Animals, issued by the ILAR Commission of Life Sciences, National Academy Press (Washington, DC, USA, 1996).Water and a diet (based on caloric needs) of Royal Canin Adult Medium (Royal Canin; Aimargues,France) (onset of action study) or Purina Lab diet #5007 (Purina; St Louis, MI, USA) (duration of effect study) were available. Dogs were not fasted before placebo or IL-31 dosing.

所有动物操作均按照特定中心、当地和国家动物卫生IACUC指南进行，以确保符合动物福利法，法规9CFR第1，2和3部分，以及ILAR生命科学委员会发布的实验动物护理和使用指南，国家科学院出版社。皇家成年中型犬（起效研究）或Purina Lab diet#5007（作用持续时间研究）的提供的水和饮食（基于热量需求）。在给予安慰剂或IL-31之前，犬未禁食。

Test article

试验物品

Refrigerated sterile-filtered stock solutions of vehicle (placebo) and lokivetmab were brought up to room temperature and aliquoted at volumes matched to the D0 body weights of the study animals. Each dog received a single injection of 1mL per 10 kg body weight of 20,5 or 1.25 mg/mL of lokivetmab s.c. for doses of 2, 0.5 or 0.125 mg/kg, respectively.

将冷藏无菌过滤的载体（安慰剂）和洛基维特单抗恢复至室温，并按照与研究动物的D0体重相匹配的体积等分。每只犬分别接受1 mL/10 kg体重的浓度为20、5或1.25 mg/mL洛基维特单抗，皮下注射，剂量分别为2、0.5或0.125mg/kg。

Study design

研究设计

Onset of action study. This study was run after the approval of lokivetmab to characterize onset of action of lokivetmab, and hypothesis testing was conducted at the two-sided P ≤ 0.05 level of significance. A blinded, randomized, placebo-controlled study was conducted using laboratory beagle dogs. Twenty-four dogs (n = 12 per treatment) were given either placebo or 2.0 mg/kg lokivetmab s.c. Dogs were randomized to treatments according to a randomized complete block design with blocking based on historical pruritus (based on the average of three challenge assessments before study start) and pen location. Blocks then were randomized to two batches(cohorts for pruritus assessment) of three blocks. They were then challenged with IL-31 (2.5 µg/kg) to induce pruritus before lokivetmab or placebo administration on D–7 and 2.5h post-lokivetmab or -placebo administration on D0. Pruritus was scored between 0.5h and 2.5h post-IL-31 administration on each of those days. Dogs were evaluated for pruritus between 3 and 5h post placebo or lokivetmab administration to evaluate the onset of action of lokivetmab.

起效研究。在洛基维特单抗批准后开始进行本研究，已表明洛基维特单抗的起效，并在双侧P≤0.05显著性水平下进行假设检验。使用实验室比格犬进行设盲、随机、安慰剂对照研究。24只犬（n = 12/治疗组）接受安慰剂或2.0 mg/kg洛基维特单抗皮下注射。根据随机化完全区组设计，根据瘙痒史（基于研究开始前的三次激发评估的平均值）和畜栏位置的区组，对犬进行随机分配治疗。然后将试验组随机分为3个组（用于瘙痒评估组）。然后，在给予洛基维特单抗或安慰剂D7之前和给予洛基维特单抗或安慰剂2.5h后，用IL-31(2.5µg/kg)刺激动物以诱导瘙痒。在这些研究日，在IL-31给药后0.5h至2.5h期间对瘙痒进行评分。在安慰剂或洛基维特单抗给药后3-5h评价犬的瘙痒情况，以评价洛基维特单抗的起效情况。

Duration of effect study. This study was run to investigate the duration of effect in the development of lokivetmab. Hypothesis testing was conducted at the two-sided P ≤ 0.10 level of significance because greater risk at this phase of the programme was acceptable.

疗效持续时间研究。本研究旨在研究洛基维特单抗开发中的疗效持续时间。在双侧P≤0.10显著性水平下进行假设检验，因为在项目的这一阶段风险较大是可接受的。

A blinded, randomized, placebo-controlled study was conducted using laboratory beagle dogs. Twenty-four dogs (n = 6 per treatment) were given either placebo or 0.125, 0.5 or 2.0 mg/kg lokivetmab s.c. Dogs were randomized to treatments according to a randomized complete block design, with blocking based on historical pruritus (based on the average of three challenge assessments before study start) and pen location. Blocks then were randomized to two batches(cohorts for pruritus assessment), one containing eight and the second four blocks. They then were challenged with IL-31 (1.75 µg/kg) to induce pruritus before lokivetmab or placebo administration on D–7, and challenged with IL-31 again on D1, D7, D14, D28, D42 and D56 post lokivetmab or placebo administration to evaluate the duration of antipruritic effect of the monoclonal antibody (mAb). Pruritus was scored between 0.5h and 2.5h post-IL-31 administration on each of those days.

使用实验室比格犬进行盲法、随机、安慰剂对照研究。给予24只犬（n = 6/治疗组）安慰剂或者0.125、0.5或2.0 mg/kg 洛基维特单抗，皮下注射。根据随机完全区组设计，将犬随机分配至治疗组，区组基于瘙痒史（基于研究开始前3次激发评估的平均值）和畜栏位置。然后将区组随机分为两个批次（用于瘙痒评估组），一个包含8个试验组，第二个包含4个试验组。然后在D-7天洛基维特单抗或安慰剂给药前，用IL-31(1.75µg/kg)刺激，以诱导瘙痒，并在洛基维特单抗或安慰剂给药后D1、D7、D14、D28、D42和D56再次用IL-31刺激，以评价单克隆抗体(mAb)的止痒作用持续时间。在这些研究日，在IL-31给药后0.5h至2.5h期间对瘙痒进行评分。

Induction of pruritus and video surveillance and pruritus scoring

瘙痒诱导和视频监控以及瘙痒评分

On each scheduled day of pruritus measurements, dogs were transferred to video rooms and placed in free-standing, single housed pens (approximately 90 cm x 180 cm), each equipped with ceiling-mounted cameras (Multicam Digital Surveillance System, RMISS Inc.; Wilmington, DE, USA) that digitally recorded the animals for real-time observation and/or viewing of recordings via computer links. Animals were acclimated ≥ 1h before initiation of any video observation period for pruritus assessment. For each observation period, four dogs were evaluated for 2h (recordings started~15–20 min post-challenge with IL-31) in real time by one observer using split-screen monitors. Video observers were scientists trained to observe and score pruritic behaviours in dogs. There was one observer for every four dogs, and each observer watched and scored their four dogs for the duration of the study. Observers were blinded to treatment. Categorical “yes/no” decisions were made at discrete 1 min intervals with regard to whether at least one pruritic behaviour was displayed by the study animals. Displays of pruritic behaviour such as licking/chewing of paws, flank and/or anal regions, scratching of flanks or neck, floor pawing, head-shaking and scooting of their bottom across the cage flooring were registered with a “yes” response. The cumulative number of “yes” determinations made within each observation period provided the pruritus score.

在计划的每个瘙痒测量日，将犬转移至视频室，并置于独立的单独饲养的畜栏（约90 cm x 180 cm）中，每个畜栏均配备有吸顶式摄像机，通过计算机链接对动物进行数字记录，用于实时观察和/或查看记录。在开始瘙痒评估的任何视频观察期前，使动物适应≥1h。对于每个观察期，由一名观察者使用分屏监视器实时评价4只犬2h（用IL-31刺激后约15-20min开始记录）。视频观察者是接受过观察和评分犬瘙痒行为培训的科学家。每4只犬有1名观察者，每名观察者在研究期间对其4只犬进行观察和评分。观察者对治疗设盲。对于研究动物是否表现出至少一种瘙痒行为，以不连续的1分钟间隔作出分类“是/否”决定。瘙痒行为表现如舔/啃爪子、胁腹部和/或肛门区域、抓挠胁腹部或颈部、抓地板、甩头和屁股蹭地板，均记录为“是”。每个观察期内确定为“是”的累积数量提供了瘙痒评分。

Statistical methods

统计方法

Pruritic score data for onset and duration of action studies were analysed using general mixed linear models. In both studies pre-treatment pruritic scores at D–7 were used as a covariate in the statistical models and least squares means (LSM) were used as estimates of the treatment means. If the covariate was not significant (P < a) it was dropped from the final model.

使用一般混合线性模型分析起效时间和持续时间的瘙痒评分数据。在这两项研究中，在统计模型中使用D-7时的治疗前瘙痒评分作为协变量，并使用最小二乘均值(LSM)作为治疗均值的估计值。如果协变量不显著(P < a)，则将其从最终模型中删除。

Onset of action. Scores for first hour, second hour and for the total 2h period were analysed using a model with the fixed effect of treatment, and random effects of batch, block within batch and error. Treatment comparisons were conducted using the two-sided a= 0.05 significance level. The pre-treatment (D–7) covariate used was time-matched (first hour, second hour or total).

起效时间。使用模型分析第1h、第2h和总2h周期的评分，以治疗为固定效应，以批次、批内区组和误差为随机效应。使用双侧a = 0.05显著性水平进行治疗比较。使用的治疗前(D-7)协变量为时间匹配（第1小时、第2小时或总计）。

Duration of effect. Scores for the total 2 h period were analysed using a repeated measures model with fixed effects of treatment, time and treatment-by-time, and random effects of batch, block within batch, the interaction between block and treatment within batch (animal term), and error. Treatment comparisons were conducted within time points using the two-sided a=0.10 significance level.

疗效持续时间。使用重复测量模型分析总计2h周期的评分，以治疗、时间和治疗-时间为固定效应，以批次、批内区组、批内区组和治疗间相互作用（动物术语）和误差为随机效应。使用双侧a = 0.10显著性水平在时间点内进行治疗比较。

Results

结果

Evaluation of the onset of action of lokivetmab demonstrated that a single dose (2 mg/kg s.c.) significantly reduced pruritic activity in a canine model of IL-31-induced pruritus 3–4 h post-dosing (P < 0.0001). The LSM pruritic scores [ standard error of measurement (SEM)] were 38 ±4.4 for placebo-treated animals compared to 9±2.6 for lokivetmab treated animals. Pruritus also was significantly reduced 4–5h post-dosing (51±2.2 for placebo-versus 20±5.4 for lokivetmab treated animals; P < 0.0001) or for the full 2h observation window of 3–5h post-administration with antibody (90±6.2 for placebo- versus 29±7.4 for lokivetmab treated animals; P < 0.0001.) See Figure 1 for results.

对洛基维特单抗起效时间的评估表明，在IL-31诱导瘙痒的犬模型中，单次给药(2 mg/kg 皮下注射)在给药后3-4h显著降低了瘙痒活性(P < 0.0001)。安慰剂治疗动物的LSM瘙痒评分[标准测量误差(SEM)]为38±4.4，而洛基维特单抗治疗动物为9±2.6。给药后4-5h（安慰剂组为51±2.2，洛基维特单抗治疗组为20±5.4；P < 0.0001）或抗体给药后3-5 h的完整2h观察窗（安慰剂组为90±6.2，洛基维特单抗治疗组为29±7.4；P < 0.0001），瘙痒也显著减轻。结果见图1。

Results from the duration of effect study showed that a significant reduction in pruritus was observed to D14 for a dose of 0.125 mg/kg (LSM pruritic scores SEM of 91±5.1 for placebo versus 51±5.1 for 0.125 mg/kg lokivetmab; P < 0.0001), to D28 for a dose of 0.5 mg/kg (81±8 for placebo versus 55±8 for 0.5 mg/kg lokivetmab, P = 0.0288) and to D42 for a dose of 2.0 mg/kg (90±8.7 for placebo versus 61±8.7 for 2 mg/kg lokivetmab, P = 0.0245). No significant differences were seen on D56 for any of the doses tested. See Figure 2 for results.

疗效持续时间研究的结果显示，至D14，0.125 mg/kg剂量组观察到瘙痒显著减轻（LSM瘙痒评分SEM，安慰剂组为91±5.1，洛基维特单抗组为51±5.1；P < 0.0001），D28，0.5 mg/kg剂量组观察到显著减轻（安慰剂组为81±8，洛基维特单抗组为55±8，P = 0.0288），第42天2.0 mg/kg剂量组（安慰剂组为90±8.7，洛基维特单抗2 mg/kg组为61±8.7，P = 0.0245）。D56时，所有试验剂量组均未观察到显著差异。结果见图2。

Discussionn.

讨论

Lokivetmab (Cytopoint) is a caninized monoclonal antibody that binds and neutralizes canine IL-31. Its ability to control/treat clinical signs associated with AD confirms that IL-31 is a key mediator in canine AD.IL-31 has been shown to elicit pruritic responses in multiple species and induce several pro-inflammatory cytokines from a variety of immune cells implicated in allergic skin disease.

洛基维特单抗(赛妥敏)是一种可结合并中和犬IL-31的犬源化单克隆抗体。其控制/治疗AD相关临床症状的能力证实IL-31是犬AD的关键介质。已证明IL-31可在多个种属中引起瘙痒反应，并从与过敏性皮肤病有关的各种免疫细胞中诱导几种促炎性细胞因子。

Intravenous administration of canine IL-31 to beagle dogs results in a rapid, transient induction of a variety of pruritic phenotypes including itching, scratching and head shaking. This phenotypic response to IL-31 was used to establish a canine model of IL-31-induced pruritus8 and allowed us to characterize the onset and dose/duration of action of lokivetmab in this model of pruritus in beagle dogs.

静脉给犬IL-31可快速、短暂地诱导各种瘙痒表型，包括瘙痒、抓挠和甩头。利用IL-31的表型反应，建立了犬瘙痒模型，并使我们能够描述洛基维特单抗在比格犬瘙痒模型中的起效和剂量/疗效持续时间。

By comparing the results of laboratory model studies to clinical field studies it is possible to determine the translatability of model studies to the clinical setting. Lokivetmab is an approved therapy to control clinical signs of itch and inflammation due to allergic dermatitis or AD in the United States, and as such, was tested in a dose-determination, randomized, blinded, placebo-controlled field study. That field study demonstrated that administration of lokivetmab at doses of 0.125, 0.5 or 2.0 mg/kg s.c. resulted in a statistically significant (P < 0.05) reduction in LSM values for owner-assessed pruritus relative to placebo for as long as 21, 35 or 49 days, respectively. Those results are in general correlation with the efficacy observed in the present study where statistically significant (P < 0.05) reduction in pruritic behaviour relative to placebo in the laboratory model was observed for 14, 28 or 42days for 0.125, 0.5 or 2.0 mg/kg doses, respectively. These results, taken together, bring relevance of the efficacy observed in the model to the efficacy observed in the field and suggest that this laboratory beagle dog IL-31-mediated pruritic model may be an attractive translational model for evaluation of IL-31 inhibitors. One critical component in applying this model for the development of inhibitors is the assurance that the binding kinetics and specificity of the test article for the canine homologue is similar to that of target species protein. Another important consideration is the pharmacokinetic properties of the test article in canine species relative to the target species.

通过比较实验室模型研究与临床现场研究的结果，可以确定模型研究与临床环境的可译性。洛基维特单抗在美国是一种获批用于控制由过敏性皮炎或AD引起的瘙痒和炎症临床症状的疗法，因此，在一项剂量确定、随机、盲法、安慰剂对照现场研究中对其进行了检测。该现场研究表明，与安慰剂相比，洛基维特单抗以0.125、0.5或2.0 mg/kg 剂量皮下注射时，犬主人评估的瘙痒的LSM值分别降低21、35或49天，且具有统计学显著性(P < 0.05)。这些结果通常与本研究中观察到的疗效相关，其中在实验室模型中观察到0.125、0.5或2.0 mg/kg剂量组分别给药14、28或42天后瘙痒行为相对于安慰剂组出现统计学显著(P < 0.05)减少。综合考虑这些结果，将模型中观察到的有效性与现场观察到的有效性相关联，并表明该实验室比格犬IL-31介导的瘙痒模型可能是评价IL-31抑制剂的一种有吸引力的转化模型。将该模型应用于抑制剂开发的一个关键组成部分是确保供试品与犬同源物的结合动力学和特异性与靶种属蛋白相似。另一个重要的考虑因素是供试品在犬种属中相对于靶种属的药代动力学特性。

There are multiple challenges associated with evaluating the onset of activity in the clinical setting that primarily are consequences of the difficulty in monitoring clientowned animals on an hourly basis for rapid onset molecules and behavioural changes associated with a visit to the veterinarian. To help establish what the predicted onset of action may be in the clinical setting, we evaluated multiple time points shortly post-administration of 2 mg/kg lokivetmab s.c. in the model. This experiment demonstrated a rapid onset of activity (within 3h) of subcutaneous lokivetmab administration. In accordance with the model efficacy data observed in this study, clinical field trials demonstrated statistically significant reduction in client-observed pruritus at the first time point evaluated, one day following a single 2 mg/kg s.c. administration. Results from the duration of effect laboratory study support the translatability of effects seen in the IL-31-induced pruritus model to effects seen in a clinical setting. These data further indicate that a single subcutaneous injection of lokivetmab (2 mg/kg) produces a significant suppression of pruritus starting 3 h post-treatment with lokivetmab and is sustained for 42 days.

在临床环境中评价起效时间存在多种挑战，主要是难以每小时监测家养动物是否出现与兽医访视相关的快速发作分子和行为变化。为了帮助确定在临床环境中预期的起效时间，我们在模型中评价了2 mg/kg洛基维特单抗皮下注射后不久的多个时间点。该实验证明皮下给予洛基维特单抗后，活性快速起效（3h内）。根据本研究中观察到的模型有效性数据，临床现场试验证明，2 mg/kg 单次皮下给药后1天，在评价的第一个时间点，客户观察到的瘙痒在统计学上显著减少。疗效持续时间实验室研究的结果支持在IL-31诱导瘙痒模型中观察到的效应可转化为在临床环境中观察到的效应。这些数据进一步表明，单次皮下注射洛基维特单抗(2 mg/kg)在洛基维特单抗治疗后3h开始显著抑制瘙痒，并持续42天。

Figure 1. Onset of antipruritic action of lokivetmab in dogs.

Laboratory-bred beagle dogs were dosed subcutaneously with either placebo or lokivetmab at 2.0 mg/kg on Day (D)0. Approximately 2.5h postdosing, pruritus was induced using canine interleukin (IL)-31. Animals were observed for pruritic behaviours for a total of 2h (3–5h post-treatment with placebo or lokivetmab). Observations were presented per hour (3–4h, 4–5h and 3–5 h post-treatment with placebo or lokivetmab). Data are expressed as least square mean (LSM)  standard error of mean (SEM). Treatment comparisons at each time point were conducted at the twosided a = 0.05 significance level (*P < 0.0001).

图1.犬中洛基维特单抗的止痒作用开始时间。

实验室饲养的比格犬在第0天皮下给予安慰剂或2.0 mg/kg的洛基维特单抗。给药后约2.5h，采用犬白介素(IL)-31诱导瘙痒。观察动物的瘙痒行为总计2h（安慰剂或洛基维特单抗给药后3-5h）。每小时观察一次（安慰剂或洛基维特单抗治疗后3-4h、4-5h和3-5h）。数据表示为最小二乘均值(LSM)平均值的标准误(SEM)。在双侧α= 0.05显著性水平(*P < 0.0001)下进行各时间点的给药比较。

Figure 2. Duration of the antipruritic effect of lokivetmab in dogs.

Laboratory-bred beagle dogs were dosed subcutaneously with either placebo or one of three different lokivetmab concentrations (0.125, 0.5 or2 mg/kg) on Day (D)0. Pruritus was induced on D1, D7, D14, D28, D42 and D56 using canine interleukin (IL)-31, and animals were observed for pruritic behaviours for a total of 2 h post-IL-31 challenge. Data are expressed as least square mean (LSM)  standard error of mean (SEM). Treatment comparisons were conducted at the two-sided a = 0.10 significance level (*P < 0.0001; **P ≤ 0.028; ***P = 0.0003).

图2。洛基维特单抗在犬体内止痒作用的持续时间。

实验室饲养的比格犬在第0天皮下注射安慰剂或三种不同浓度的洛基维特单抗(0.125、0.5或2mg/kg)中的一种。使用IL-31在D1、D7、D14、D28、D42和D56上诱导瘙痒，并在IL-31刺激后共2小时观察动物的瘙痒行为。数据用最小二乘均值(LSM)平均标准误差(SEM)表示。处理比较在双侧=0.10显著性水平上进行(*P<0.0001；**P≤0.028；***P=0.0003)。

南海

vet刘

感谢分享，看了文章用药更有把握了