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治疗仅使约1/5的NSCLC患者受益，因此存在很大的风险。 需要改进这种疾病的免疫疗法。一种不同形式的免疫疗法IL-2可以产生完全的 在黑色素瘤和肾细胞癌中的反应。由于常见的危及生命的毒性，IL-2的使用受到限制。 IL-2的替代物是IL-15/IL-15 R α复合物。ALT-803是一种临床级IL-15/IL-15 R α复合物， 对IL-15应答性CD 8+淋巴细胞和自然杀伤（NK）细胞的强效超级激动剂， 与IL-2相比，安全性更高。联合ALT-803与抗PD-1 mAb的临床前研究表明， 显著的抗肿瘤功效与CD 8 + T细胞和NK细胞的扩增相关， 炎性细胞因子如IL-6和IFNγ。我们已经把这个疗法带到了诊所，有一个调查员- 启动的首次人体试验，Ib/II期试验，测试了加入IL-15/IL-15 R α复合物（ALT- 803)抗PD 1 mAb（nivolumab）在NSCLC中安全有效（NCT 02523469）。迄今为止，已有11名患者 接受三种高活性剂量水平（6、10、15 mcg/kg SC，15为最高计划剂量）治疗， 零观察到的剂量限制性毒性（DLT）和优异的CD 8 + T细胞和NK细胞活化， 血清IL-6和IFNγ水平。该应用程序的目标是确定的机制基础和预测 响应这种有前途的组合方法，使用我们独特的银行的试验衍生样品和 强大的临床前肺肿瘤模型。我们假设，在抗PD-1抗体中加入IL-15/IL-15 R α复合物， 1 mAb通过增强肿瘤反应性细胞因子的扩增和功能活化来增强抗肿瘤功效 CD 8+淋巴细胞和NK细胞，并且炎性细胞因子如IL-6和IFNγ的诱导将被抑制。 与抗肿瘤功效相关。我们进一步假设增强的抗肿瘤功效将取决于效应子 淋巴细胞（CD 8+和NK，而不是CD 4+），并与细胞因子（IL-6和IFNγ）相关。具体目标1：使用 我们将使用最先进的质谱细胞仪对NK和CD 8 + T细胞进行高维表征。 来自多达116名患者的纵向PBMC样品的区室。我们将进行TCR测序， 扩增的T细胞，以确定它们是否来自肿瘤。我们还将进行65重血清 细胞因子/趋化因子分析纵向获得的样品，以鉴定新的血清生物标志物。我们将 将淋巴细胞和血清细胞因子/趋化因子参数的变化与临床反应相关联。具体 目的2：我们将使用我们的刘易斯肺癌（LLC）小鼠模型，为我们未来的临床工作提供信息。 抗PD-1 mAb和IL-15/sIL-15 R α复合物的组合。首先，我们将识别细胞和分子 使用响应和非响应的纵向分析与治疗结果相关的标志物 小鼠其次，我们将使用抗体介导的淋巴细胞亚群耗竭或 细胞因子最后，我们将评估交替给药和给药方案对关键效应群体的影响， 我们还将抗CTLA-4 mAb疗法整合到我们的治疗中。

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.