PASADENA, Calif.--(BUSINESS WIRE)--Xencor, Inc. (NASDAQ: XNCR), a clinical-stage biopharmaceutical company developing engineered antibodies for the treatment of cancer and other serious diseases, today announced four new XmAb® programs in development for the treatment of patients with autoimmune diseases and provided updates from dose-escalation studies evaluating its first-in-class oncology programs, including XmAb819 (ENPP3 x CD3) in patients with advanced clear cell renal cell carcinoma and XmAb808 (B7-H3 x CD28) in patients with advanced solid tumors..

加利福尼亚州帕萨迪纳市（商业新闻短讯）--Xencor，Inc.（纳斯达克：XNCR），一家开发用于治疗癌症和其他严重疾病的工程抗体的临床阶段生物制药公司，今天宣布了四个正在开发的用于治疗自身免疫性疾病患者的新XmAb®计划，并提供了评估其一流肿瘤学计划的剂量递增研究的更新，包括晚期透明细胞肾细胞癌患者的XmAb819（ENPP3 x CD3）和晚期实体瘤患者的XmAb808（B7-H3 x CD28）。。

“Xencor’s clinical pipeline of XmAb bispecific T-cell engagers and newly announced autoimmune programs have multiple near-term milestones and offer a balance of opportunities to deliver novel treatment options that could potentially make a real difference in patients’ lives. The foundation of our portfolio is world-class protein engineering, using our XmAb platforms to potentially solve complex engineering problems and rationally build drug candidates that address specific clinical opportunities,” said Bassil Dahiyat, Ph.D., president and chief executive officer at Xencor.

Xencor总裁兼首席执行官Bassil Dahiyat博士说：“Xencor的XmAb双特异性T细胞参与者临床管道和新宣布的自身免疫项目具有多个近期里程碑，为提供可能真正改变患者生活的新型治疗选择提供了机会的平衡。我们投资组合的基础是世界一流的蛋白质工程，使用我们的XmAb平台来潜在地解决复杂的工程问题，并合理地构建解决特定临床机会的候选药物。”。

“Our goal is clear—fully leverage our protein engineering strengths and reduce exposure to biological uncertainties to increase our overall opportunities for clinical success.”.

“我们的目标很明确，充分利用我们的蛋白质工程优势，减少生物不确定性的暴露，以增加我们临床成功的总体机会。”。

Clinical Progress Updates in Early-Stage Oncology Programs: XmAb819 (ENPP3 x CD3) and XmAb808 (B7-H3 x CD28)

早期肿瘤学项目的临床进展更新：XmAb819（ENPP3 x CD3）和XmAb808（B7-H3 x CD28）

XmAb819: ENPP3 x CD3 bispecific T-cell engager in Phase 1 dose escalation for patients with advanced clear-cell renal cell carcinoma (ccRCC)

XmAb819:ENPP3 x CD3双特异性T细胞参与者在晚期透明细胞肾细胞癌（ccRCC）患者的1期剂量递增中

XmAb819 is designed to engage the immune system, activating T cells for highly potent and targeted killing of tumor cells expressing ENPP3, an antigen highly expressed on kidney cancers. Xencor’s XmAb 2+1 multivalent format used in XmAb819 enables greater selectivity of ENPP3-expressing tumor cells compared to normal cells, which express lower levels of ENPP3..

XmAb819被设计用于参与免疫系统，激活T细胞以高效和靶向杀死表达ENPP3的肿瘤细胞，ENPP3是一种在肾癌中高度表达的抗原。Xencor在XmAb819中使用的XmAb 2+1多价形式与表达较低水平ENPP3的正常细胞相比，能够对表达ENPP3的肿瘤细胞产生更高的选择性。。

Clinical update: Initial evidence of anti-tumor activity has been observed in recent dose-escalation cohorts in the ongoing Phase 1 study, including RECIST responses, and the duration of treatment for several patients in earlier dose cohorts has extended beyond one year. Cytokine release syndrome remains manageable, and the tolerability profile from recent dose cohorts, including no maximum tolerated dose being reached, supports continued dose escalation toward target dose levels..

临床更新：在正在进行的1期研究中，最近的剂量递增队列中观察到了抗肿瘤活性的初步证据，包括RECIST反应，并且早期剂量队列中几名患者的治疗持续时间已超过一年。细胞因子释放综合征仍然可以控制，并且最近剂量组的耐受性概况（包括未达到最大耐受剂量）支持继续向目标剂量水平递增。。

Guidance: The Company continues to anticipate reaching target dose levels by year end and plans to provide a clinical update around initiation of the first dose expansion cohort during the first half of 2025.

指南：该公司继续预计年底达到目标剂量水平，并计划在2025年上半年启动第一个剂量扩展队列前后提供临床更新。

XmAb808: B7-H3 x CD28 bispecific T-cell engager in Phase 1 dose escalation in advanced solid tumors

XmAb808:B7-H3 x CD28双特异性T细胞参与者在晚期实体瘤的1期剂量递增中

XmAb808 is a tumor-selective, co-stimulatory CD28 bispecific antibody that binds to the broadly expressed tumor antigen B7-H3 and is constructed with the XmAb 2+1 format. Co-stimulation is required for T cells to achieve full activation, and targeted CD28 bispecific antibodies may provide conditional co-stimulation of T cells when the antibodies are bound to tumor cells..

XmAb808是一种肿瘤选择性，共刺激性CD28双特异性抗体，与广泛表达的肿瘤抗原B7-H3结合，并以XmAb 2+1形式构建。T细胞需要共刺激才能实现完全激活，当抗体与肿瘤细胞结合时，靶向CD28双特异性抗体可以提供有条件的T细胞共刺激。。

Clinical update: The majority of patients enrolled into the ongoing Phase 1 dose-escalation study are men with metastatic castration-resistant prostate cancer (mCRPC). In this group of patients, prostate specific antigen (PSA) declines have been observed during the four-week monotherapy safety run-in period.

临床更新：参加正在进行的1期剂量递增研究的大多数患者是患有转移性去势抵抗性前列腺癌（mCRPC）的男性。在这组患者中，在为期四周的单药治疗安全磨合期内观察到前列腺特异性抗原（PSA）下降。

Tolerability from recent dose cohorts remains supportive of continued dose escalation in combination with pembrolizumab..

最近剂量组的耐受性仍然支持与pembrolizumab联合持续剂量递增。。

Guidance: The Company continues to anticipate reaching target dose levels by year end and plans to provide a clinical update around initiation of dose expansion cohorts during the first half of 2025.

指导：该公司继续预计年底达到目标剂量水平，并计划在2025年上半年围绕剂量扩展队列的启动提供临床更新。

XmAb Drug Candidates for the Treatment of Patients with Autoimmune and Inflammatory Diseases and Planned Clinical Studies: Plamotamab (CD20 x CD3), XmAb657 (CD19 x CD3), XmAb942 (Xtend™ TL1A) and the XmAb TL1A x IL-23 Program

用于治疗自身免疫性和炎性疾病患者的XmAb候选药物和计划的临床研究：Plamotamab（CD20 x CD3），XmAb657（CD19 x CD3），XmAb942（Xtend™TL1A）和XmAb TL1A x IL-23计划

Plamotamab: CD20 x CD3 bispecific T-cell engager to be evaluated in patients with multi-drug resistant rheumatoid arthritis (MDR-RA), with Phase 1b/2a study anticipated to initiate in the first half of 2025

Plamotamab:CD20 x CD3双特异性T细胞参与者将在耐多药类风湿性关节炎（MDR-RA）患者中进行评估，预计将于2025年上半年启动1b/2a期研究

Xencor plans to initiate a Phase 1b/2a proof-of-concept study for plamotamab in MDR-RA in the first half of 2025. The Phase 1b portion of the study will select a priming and step-up dose regimen based on the regimen established in oncology, and will assess the initial safety, efficacy, and biomarkers of plamotamab in patients with MDR-RA.

Xencor计划在2025年上半年启动MDR-RA中plamotamab的1b/2a期概念验证研究。该研究的1b期部分将根据肿瘤学中建立的方案选择启动和递增剂量方案，并将评估plamotamab在MDR-RA患者中的初始安全性，有效性和生物标志物。

The selected dose regimen will then be evaluated in the randomized Phase 2a portion, with efficacy determined at week 24..

然后将在随机2a期部分评估所选剂量方案，并在第24周确定疗效。。

Xencor previously completed a Phase 1 clinical study of plamotamab in hematologic cancers, completing enrollment in late 2023. Results from the study showed favorable tolerability and comparable preliminary efficacy data, when cross compared to results from studies of a competitor molecule within the class, with similar patient baseline characteristics.

Xencor之前完成了plamotamab在血液系统癌症中的1期临床研究，于2023年底完成登记。。

Based on these clinical outcomes, significant B-cell depletion observed in preclinical studies, and the emergent biology supportive of B-cell targeted T cell engagers for the treatment of patients with autoimmune diseases, Xencor plans to evaluate plamotamab in MDR-RA, in which patients progressed through two prior lines of therapy..

基于这些临床结果，在临床前研究中观察到显着的B细胞耗竭，以及支持B细胞靶向T细胞参与者治疗自身免疫性疾病的新兴生物学，Xencor计划评估MDR-RA中的plamotamab，其中患者通过两种先前的治疗方案进展。。

XmAb657: Rationally designed CD19 x CD3 bispecific T-cell engager for patients with autoimmune diseases, with first-in-human Phase 1 study anticipated to initiate in the second half of 2025

XmAb657：为自身免疫性疾病患者合理设计的CD19 x CD3双特异性T细胞接受者，预计将于2025年下半年启动第一项人类1期研究

Xencor has leveraged its XmAb protein engineering platforms to create XmAb657, a potent, potentially long-acting CD19 x CD3 bispecific antibody, utilizing the XmAb 2+1 bispecific antibody format and Xtend™ Fc technology. In non-human primate studies, a single dose of XmAb657 deeply reduced B cells by over 99.98% in the peripheral compartment, bone marrow and lymph nodes, which was sustained for at least 28 days.

Xencor利用其XmAb蛋白质工程平台，利用XmAb 2+1双特异性抗体格式和Xtend™Fc技术，创建了XmAb657，这是一种有效的，潜在的长效CD19 x CD3双特异性抗体。在非人灵长类动物研究中，单剂量的XmAb657使外周隔室，骨髓和淋巴结中的B细胞深度减少了99.98%以上，持续了至少28天。

Half-life was estimated to be 15 days, which indicates a potential for durable B-cell depletion in clinical studies. XmAb657 was well tolerated preclinically, with no clinical signs of cytokine release syndrome. Xencor plans to initiate a first-in-human study during the second half of 2025..

半衰期估计为15天，这表明在临床研究中可能会持续消耗B细胞。XmAb657在临床前耐受性良好，没有细胞因子释放综合征的临床症状。Xencor计划在2025年下半年启动一项首次人体研究。。

XmAb942: A novel high-affinity anti-TL1A antibody designed for extended half-life, under development for the treatment of inflammatory bowel diseases (IBD), with first-in-human Phase 1 study anticipated to initiate in the fourth quarter 2024

XmAb942：一种新型的高亲和力抗TL1A抗体，设计用于延长半衰期，正在开发用于治疗炎症性肠病（IBD），预计将于2024年第四季度启动第一项人类第一阶段研究

XmAb942 is a monospecific anti-TL1A antibody, utilizing Xencor’s Xtend Fc domain and proprietary Fc silencing technology, with potentially class-leading potency, and is under development for patients with IBD. The two most common forms of IBD are Crohn’s disease and ulcerative colitis. Half-life preclinically was greater than 22 days, potentially supporting an 8- to 12-week dosing regimen in humans.

XmAb942是一种单特异性抗TL1A抗体，利用Xencor的Xtend Fc结构域和专有的Fc沉默技术，具有潜在的一流效力，正在为IBD患者开发。IBD的两种最常见形式是克罗恩病和溃疡性结肠炎。临床前半衰期大于22天，可能支持人类8至12周的给药方案。

An abstract with preclinical characterization was accepted for presentation at the United Europe Gastroenterology Week (UEGW) in Vienna, Austria on Tuesday, October 15. Xencor anticipates dosing the first subject in a first-in-human, single-ascending dose study of XmAb942 in the fourth quarter of 2024, with interim data during the first half of 2025..

10月15日星期二，在奥地利维也纳举行的联合欧洲胃肠病学周（UEGW）上，接受了一份具有临床前特征的摘要。Xencor预计在2024年第四季度对XmAb942进行首次人体单次递增剂量研究，并在2025年上半年提供中期数据。。

XmAb TL1A x IL-23 Program: Potential first-in-class bispecific antibody to combine two validated biological pathways of interest into one drug candidate for the treatment of IBD, leveraging Xencor’s world-class protein engineering

An expertly engineered XmAb TL1A x IL-23p19 bispecific antibody could potentially provide dual targeting of important inflammatory pathways for autoimmune and inflammatory disease, while avoiding the complexities of dosing and formulary access for two separate TL1A and IL23 targeted drugs. Xencor anticipates initiating first-in-human studies during 2026..

专业设计的XmAb TL1A x IL-23p19双特异性抗体可能为自身免疫性和炎性疾病的重要炎症途径提供双重靶向，同时避免了两种单独的TL1A和IL23靶向药物的剂量和处方集获取的复杂性。Xencor预计将在2026年启动首次人体研究。。

Conference Call and Webcast

电话会议和网络广播

Xencor will host a conference call and webcast today at 8:00 a.m. ET (5:00 a.m. PT) to review the topics outlined in this news release.

Xencor将于美国东部时间今天上午8:00（太平洋时间上午5:00）主持电话会议和网络广播，回顾本新闻稿中概述的主题。

The live webcast may be accessed through “Events & Presentations” in the Investors section of the Company’s website, located at investors.xencor.com. Telephone participants may register to receive a dial-in number and unique passcode that can be used to access the conference call. A recording will be available for at least 30 days..

可以通过公司网站Investors.xencor.com的Investors部分的“活动与演示”访问直播。电话参与者可以注册以接收拨号号码和唯一密码，这些密码可用于访问会议电话。录音将至少持续30天。。

About Xencor

关于Xencor

Xencor is a clinical-stage biopharmaceutical company developing engineered antibodies for the treatment of patients with cancer and other serious diseases. More than 20 candidates engineered with Xencor's XmAb® technology are in clinical development, and multiple XmAb medicines are marketed by partners.

Xencor是一家临床阶段的生物制药公司，开发用于治疗癌症和其他严重疾病患者的工程抗体。。

Xencor's XmAb engineering technology enables small changes to a protein’s structure that result in new mechanisms of therapeutic action. For more information, please visit www.xencor.com..

Xencor的XmAb工程技术可以对蛋白质的结构进行微小的改变，从而产生新的治疗作用机制。有关更多信息，请访问www.xencor.com。。

Forward-Looking Statements

前瞻性声明

Certain statements contained in this press release may constitute forward-looking statements within the meaning of applicable securities laws. Forward-looking statements include statements that are not purely statements of historical fact, and can generally be identified by the use of words such as “potential,” “can,” “will,” “plan,” “may,” “could,” “would,” “expect,” “anticipate,” “seek,” “look forward,” “believe,” “committed,” “investigational,” and similar terms, or by express or implied discussions relating to Xencor’s business, including, but not limited to, statements regarding expectations for clinical progress, planned presentations of clinical data, new XmAb candidates and programs, planned and in process clinical trials, the quotations from Xencor's president and chief executive officer, and other statements that are not purely statements of historical fact.

本新闻稿中的某些声明可能构成适用证券法含义内的前瞻性声明。前瞻性陈述包括不纯粹是历史事实陈述的陈述，通常可以通过使用“潜在”、“可以”、“将会”、“计划”、“可能”、“可能”、“会”、“期望”、“预期”、“寻求”、“展望”、“相信”、“承诺”、“调查”等词语来识别，也可以通过与Xencor业务相关的明示或暗示讨论来识别，包括但不限于关于临床进展预期的陈述、计划的临床数据展示、新的XmAb候选人和计划、计划中和正在进行的临床试验、Xencor总裁和首席执行官的引用以及其他不纯粹是历史事实陈述的陈述。

Such statements are made on the basis of the current beliefs, expectations, and assumptions of the management of Xencor and are subject to significant known and unknown risks, uncertainties and other factors that may cause actual results, performance or achievements and the timing of events to be materially different from those implied by such statements, and therefore these statements should not be read as guarantees of future performance or results.

此类声明是根据Xencor管理层目前的信念、期望和假设做出的，并受到重大已知和未知风险、不确定性和其他因素的影响，这些因素可能导致实际结果、绩效或成就以及事件发生的时间与此类声明所暗示的时间有重大差异，因此这些声明不应被视为对未来绩效或结果的保证。

Such risks include, without limitation, the risks associated with the process of discovering, developing, manufacturing and commercializing drugs that are safe and effective for use as human therapeutics and other risks, including the ability of publicly disclosed preliminary clinical trial data to support continued clinical development and regulatory approval for specific treatments, in each case as described in Xencor's public securities filings.

此类风险包括但不限于与发现、开发、制造和商业化安全有效的人类治疗药物过程相关的风险和其他风险，包括公开披露的初步临床试验数据支持持续临床开发和特定治疗的监管批准的能力，在每种情况下，如Xencor的公共证券文件所述。

For a disc.

对于光盘。