Novel Target, New Therapy: Anti- Renalase Antibody for Tumors Resistant to PD-1Inhibitors

摘要 大多数晚期癌症患者要么没有持久的反应，要么对当前的干预措施没有反应， 包括免疫肿瘤学检查点抑制剂。对于黑色素瘤，免疫治疗的主要焦点，五年 存活率显著提高，但只有40%的患者对PD-1抑制剂有反应，而且许多人出现了 随着时间的推移产生抵抗力。与CTLA-4的另一种检查点抑制剂联合使用可产生更高的响应 发生率高，但具有较高的毒副作用，而且40%的患者有耐药肿瘤。在大多数其他肿瘤中 类型，反应较少，反应持续时间较短。因此，有一个很大的 需要额外的系统性干预。在之前的研究中，包括第一阶段的拨款，该团队 确定了分泌型黄素蛋白肾酶(RNLS)作为黑色素瘤新靶点的作用，并证明了 抑制RNLS信号转导阻止肿瘤生长的概念。RNLS基因敲除小鼠也排斥这些小鼠 黑色素瘤，为肿瘤靶向RNLS提供了理论基础。此外，RNLS水平呈负相关 因此，随着患者预后的提高，RNLS在人类肿瘤、黑色素瘤细胞和/或肿瘤中的表达增加 相关巨噬细胞与生存率下降有关，包括接受抗PD-1治疗的患者- 以养生为基础。该项目开发的抗RNLS抗体(抗RNLS mAb)可作为单剂使用 对PD-1抑制剂耐药的退化小鼠黑色素瘤肿瘤。联合抗PD-1、抗RNLS 单抗具有协同作用，无明显毒性。肿瘤排斥反应由巨噬细胞和T细胞共同驱动。 在第一阶段，研制人源化的抗RNLS单抗(anti-RNLS mAb)取得了进展 作为对PD-1抑制剂耐药的肿瘤的第一临床候选药物。更多的研究已经取得了领先地位。 抗RNLS单抗(K16)。K16对两种小鼠黑色素瘤模型有效。另外，两个新的敏感和 建立了选择性ELISA法，并用于测定血浆RNLS水平和抗RNLS单抗 级别。这些将可供将来使用。在这笔拨款中，非GMP K16将被放大，并将有两只小鼠 黑色素瘤模型将被用来证实和扩大对单抗的研究。此外，药代动力学，以及 将对K16进行剂量范围和急性毒理学研究，并估计治疗指数 (所需≥为10倍)将被计算。这一项目取得了持续的成功，取得了相当大的成果。 价值，包括：1)一种新的抗癌药物靶点-RNLS的阐明和应用；2)开发 一种独特的抗癌治疗方法--抗RNLS单抗；3)显著延长和提高抗癌活性 以及检查点抑制剂的成本效益和对检查点抑制剂具有抵抗力的癌症患者。

ABSTRACT Most patients with advanced cancer either do not respond durably or do not respond to current interventions, including immune-oncology checkpoint inhibitors. For melanoma, a major focus for immunotherapies, five-year survival improved dramatically, yet only ~ 40% of patients respond to PD-1 inhibitors, and many develop resistance over time. The combination with another checkpoint inhibitor of CTLA-4 yields a higher response rate, but with a higher rate of toxicities, and > 40% of patients have resistant tumors. In most other tumor types, responses are seen less frequently, and duration of response is shorter. There is, therefore, a great need for additional systemic interventions. In prior studies, including from a Phase 1 grant, the team established the role of the secreted flavoprotein renalase (RNLS) as a new target in melanoma and proof of concept that inhibiting RNLS signaling blocks tumor growth. RNLS knock-out mice also rejected these murine melanomas, providing a rationale for targeting RNLS in tumors. Moreover, RNLS levels inversely correlate with patient outcomes, thus, increased RNLS expression in human tumors, melanoma cells and/or tumor associated macrophages are associated with decreased survival including patients treated with anti-PD-1- based regimens. Anti-RNLS antibodies (anti-RNLS mAb) developed in the project and used as single agents regressed murine melanoma tumors resistant to PD-1 inhibitors. In combination with anti-PD-1, anti-RNLS mAb showed synergy with no apparent toxicity. Tumor rejection was driven by both macrophages and T cells. In Phase I progress was made towards developing a humanized anti-RNLS monoclonal Ab (anti-RNLS mAb) as a 1st in class clinical candidate for tumors resistant to PD-1 inhibitors. Additional studies have yielded a lead anti-RNLS mAb (K16). K16 was effective in two murine melanoma models. Also, two new sensitive and selective ELISA assays were developed and used to: measure plasma RNLS levels and anti-RNLS mAb levels. These will be available for future use. In this grant, non GMP K16 will be scaled up and two murine melanoma models will be used to confirm and extend studies of the mAb. Additionally, pharmacokinetic, and dose-ranging and acute toxicology studies on K16 will be performed and an estimate of a therapeutic Index (≥10x desired) will be calculated. The outcomes from this project, with continuing success, have considerable value, including: 1) elucidation and utility of a new and novel anticancer drug target - RNLS; 2) development of a unique anticancer therapy—anti-RNLS mAb; 3) significantly extending and improving the anticancer activity and cost effectiveness of checkpoint inhibitors and in checkpoint inhibitor resistant cancer patients.