Lymphocyte and inflammatory cytokine markers of response in the first-in-human combination of anti-PD-1 mAb and IL-15/IL-15Ra complexes and investigation of mediators of anti-tumor immune responses

由于PD-1疗法仅使大约五分之一的非小细胞肺癌患者受益，因此有很大的 需要改进对这种疾病的免疫治疗。一种独特的免疫疗法，IL-2，可以产生完全 黑色素瘤和肾癌的反应。由于常见的危及生命的毒性，IL-2的使用受到限制。 IL-2的替代品是IL-15/IL-15Rα复合体。ALT-803是一种临床级IL-15/IL-15Rα复合体， 强大的IL-15应答CD8+淋巴细胞和自然杀伤(NK)细胞的超级激动剂 与IL-2相比，安全性更高。联合ALT-803和抗PD-1单抗的临床前研究表明 显著的抗肿瘤作用与CD8+T细胞和NK细胞的扩增和产生 炎性细胞因子如IL-6和干扰素γ的表达。我们已经和一位研究人员将这种疗法转移到了诊所- 启动了人类首个Ib/II期试验，测试了临床假说：添加IL-15/IL-15Rα复合体(ALT- 803)抗PD1单抗(Nivolumab)治疗非小细胞肺癌(NCT02523469)安全有效。到目前为止，有11名患者 用三个高活性剂量水平(6、10、15微克/公斤SC，15为最高计划剂量)治疗 零观察剂量限制毒性(DLT)和CD8+T细胞和NK细胞的良好激活并增加 血清IL-6和干扰素γ。此应用程序的目标是确定机械基础和预测因素 对这一有希望的组合方法的响应使用我们独特的试验衍生样本库和 强大的临床前肺肿瘤模型。我们推测，IL-15/IL-15Rα复合体与抗PD- 1单抗通过增强肿瘤反应的扩增和功能激活而增强抗肿瘤效果 CD8+淋巴细胞和NK细胞，并诱导炎性细胞因子如IL-6和干扰素γ 与抗肿瘤疗效有关。我们进一步假设增强抗肿瘤疗效将取决于效应器 淋巴细胞(CD8+和NK，而不是CD4+)，并与细胞因子(IL-6和干扰素γ)相关。具体目标1：使用 我们将进行NK和CD8+T细胞的高维表征 最多116名患者的纵向PBMC样本的隔室。我们将对其进行TCR测序 扩增T细胞以确定它们是否来自肿瘤。我们还将进行65-plex血清 对纵向获取的样本进行细胞因子/趋化因子分析，以确定新的血清生物标志物。我们会 淋巴细胞和血清细胞因子/趋化因子参数的变化与临床疗效的关系。特定的 目的2：我们将使用我们的Lewis肺癌(LLC)小鼠模型来为我们未来的临床工作提供信息 抗PD-1单抗与IL-15/sIL-15Rα复合物的结合首先，我们将鉴定细胞和分子 通过对有效和无效的纵向分析确定与治疗结果相关的标记物 老鼠。其次，我们将使用抗体介导的淋巴细胞亚群耗尽或 细胞因子。最后，我们将评估交替给药和计划对关键效应者种群的影响，以及 同时将抗CTLA-4单抗治疗与我们的治疗相结合。

Because PD-1 therapies only benefit approximately 1 in 5 patients with NSCLC, there is a great need to improve immunotherapy for this disease. A distinct form of immunotherapy, IL-2, can yield complete responses in melanoma and renal cell carcinoma. Use of IL-2 is limited due to common life-threatening toxicity. An alternative to IL-2 is IL-15/IL-15Rα complexes. ALT-803 is a clinical grade IL-15/IL-15Rα complex and powerful super-agonist for IL-15 responsive CD8+ lymphocytes and natural killer (NK) cells with dramatically improved safety compared with IL-2. Preclinical studies combining ALT-803 with anti-PD-1 mAb demonstrate remarkable anti-tumor efficacy associated with expansion of both CD8+ T cells and NK cells, and the production of inflammatory cytokines such as IL-6 and IFNγ. We have moved this therapy into the clinic with an investigator- initiated, first-in-human, phase Ib/II trial testing the clinical hypothesis that adding IL-15/IL-15Rα complexes (ALT- 803) to anti-PD1 mAb (nivolumab) is safe and efficacious in NSCLC (NCT02523469). To date 11 patients have been treated with three highly active dose levels (6, 10, 15 mcg/kg SC, 15 being the highest planned dose) with zero observed dose limiting toxicities (DLTs) and excellent activation of CD8+ T cells and NK cells and increases in serum IL-6 and IFNγ. The goal of this application is to determine the mechanistic basis and predictors of response for this promising combinatorial approach using our unique bank of trial-derived samples and a powerful preclinical lung tumor model. We hypothesize that the addition of IL-15/IL-15Rα complexes to anti-PD- 1 mAb augments anti-tumor efficacy through enhanced expansion and functional activation of tumor-reactive CD8+ lymphocytes and NK cells and that the induction of inflammatory cytokines such as IL-6 and IFNγ will be associated with anti-tumor efficacy. We further hypothesize enhanced anti-tumor efficacy will depend on effector lymphocytes (CD8+ and NK but not CD4+) and correlate with cytokines (IL-6 and IFNγ). Specific Aim 1: Using state-of-art mass cytometry we will perform the high-dimension characterization of both NK and CD8+ T cell compartments from longitudinal PBMC samples of up to 116 patients. We will perform TCR sequencing on expanded T cells to determine if they originate from tumor. We will also perform 65-plex serum cytokine/chemokine analysis of longitudinally acquired samples to identify novel serum biomarkers. We will associate changes in lymphocyte and serum cytokines/chemokines parameters with clinical response. Specific Aim 2: We will use our Lewis lung carcinoma (LLC) mouse model to inform our future clinical efforts with the combination of anti-PD-1 mAb and IL-15/sIL-15Rα complexes. First, we will identify cellular and molecular markers that correlate with treatment outcome using longitudinal analysis of responding and non-responding mice. Second we will validate critical pathways using antibody-mediated depletion of lymphocyte subsets or cytokines. Finally, we will evaluate the effects of alternate dosing and schedule on key effector populations, and also integrate anti-CTLA-4 mAb therapy into our treatment.