Leveraging doxorubicin immune-modulation, blood-brain barrier opening, and personalized medicine for effective immunotherapy in glioblastoma. A mechanistic approach and pharmacokinetic trial.

摘要 尽管临床前的承诺和偶尔的长期（或长期）肿瘤生长控制的患者子集，抗PD1， 检查点阻断（aPD 1）未能改善胶质母细胞瘤（GBM）的结果。未能证明A 抗PD1抗体（aPD1）的益处可能是由于1）免疫抑制微环境， 免疫原性肿瘤细胞; 2）aPD 1穿透血脑屏障（BBB）不足，不能 到达瘤周脑中的浸润肿瘤细胞;和3）GBM的分子异质性。这里我们 系统地应对这些挑战。我们的目标是引起对Balstilimab的强有力的抗肿瘤反应。 （Bio），一种新型aPD 1抗体，通过低剂量的阿霉素调节免疫应答， 以前被展示过。为了让药物充分渗透组织，我们将暂时破坏血脑 通过颅骨植入式超声装置（SonoCloud-9）与静脉内微泡联合进行屏障 (US/MB）。在我们正在进行的研究和临床试验中，我们已经证明了这种方法的可行性，包括 增强和非增强组织的靶向活检并测量药物组织分布。最后，我们的目标 在确定分子特征，将允许预测从aPD1免疫治疗的好处，基于 我们先前的工作，其中我们已经鉴定了MAPK活化（pERK染色）作为推定的生物标志物。我们将首先 改进临床前模型中DOX和aPD 1给药的顺序。第二，为了核查和 为了优化，我们将在我们试验的导入期治疗一些试点患者。第三，优化的方案将是 在将接受DOX和aPD 1 Balstilimab治疗的复发性GBM患者中进行的多队列研究中进行了测试 (DOX+ aPD 1）。主要终点是切除标本和/或外周组织中的肿瘤免疫应答。 免疫应答，增强和非增强脑组织中的药物浓度（ 时间和安全性。临床结局和生物标志物是次要终点。4个患者队列 将在DOX/aPD 1治疗在不同时间点开始的情况下进行检查：诱导（新辅助治疗， 切除）;或术中切除时，分别使用和不使用US/MB。非干预性标准， 护理组将作为对照。我们的建议有3个具体目标：SA1：表征和优化的效果 DOX + aPD 1对GBM中抗肿瘤免疫的影响。SA 2：确定US/MB对 人脑中的DOX + aPD 1和GBM中的抗肿瘤免疫应答。SA3：调查肿瘤是否 pERK/MAPK活化预测GBM对DOX + aPD 1的应答。成功完成将决定i） DOX和aPD 1的免疫调节价值; ii）诱导（切除前）治疗和体内治疗的价值 iii）BBB开放对于aPD 1功效的值（或其不存在）; 和iv）pERK是否预测应答并鉴定将从治疗中获益的患者。

ABSTRACT Despite preclinical promise and occasional long(er) term tumor growth control in subsets of patients, anti-PD1 checkpoint blockade (aPD1) has failed to improve outcome in glioblastoma (GBM). The failure to demonstrate a benefit to an anti-PD1 antibody (aPD1) may be due to 1) an immunosuppressive microenvironment with few immunogenic tumor cells; 2) insufficient aPD1 penetration across the blood-brain barrier (BBB), which fail to reach the infiltrating tumor cells in the peritumoral brain; and 3) molecular heterogeneity of GBM. Here we systematically address each of these challenges. We aim to elicit robust anti-tumoral response to Balstilimab (Agenus Bio), a novel aPD1 antibody by modulating the immune response by low doses of doxorubicin as has been shown previously. To allow for adequate drug tissue penetration, we will transiently disrupt the blood-brain barrier by a skull implantable ultrasound device (SonoCloud-9) in association with intravenous microbubbles (US/MB). In our ongoing research and clinical trials we have shown the feasibility of this approach including targeted biopsies of enhancing and non-enhancing tissue and measure drug tissue distribution. Lastly, we aim at identifying molecular characteristics that will allow to predict a benefit from aPD1 immunotherapy based on our prior work where we have identified MAPK activation (pERK staining) as a putative biomarker. We will firstly refine the sequence of DOX & aPD1 administration in preclinical models. Second, for verification and optimization we will treat a few pilot patients in the lead-in phase of our trial. Third, the optimized regimen will be tested in a multi-cohort study in patients with recurrent GBM who will be treated by DOX and the aPD1 Balstilimab (DOX+aPD1). Primary endpoints are tumor immune response in the resection specimen and/or peripheral immune response, drug concentrations in enhancing and non-enhancing brain tissue (targeted biopsies at the time of resection) and safety. Clinical outcome and biomarkers are secondary endpoints. Four cohorts of patient will be examined where DOX/aPD1 treatment starts at different time points: Induction (neoadjuvant, prior to resection); or intraoperatively upon resection, each with and without US/MB. A non-interventional standard of care cohort will serve as control. Our proposal has 3 specific aims: SA1: Characterize & optimize the effect of DOX + aPD1 on anti-tumoral immunity in GBM. SA2: Determine the effect of US/MB on the concentration of DOX + aPD1 in the human brain and anti-tumoral immune response in GBM. SA3: Investigate whether tumor pERK/MAPK activation predicts GBM response to DOX + aPD1. Successful completion will determine the i) value of immune modulation by DOX and aPD1; ii) the value of induction (pre-resection) treatment and in vivo evaluation of anti-tumor immune response; iii) the value (or absence thereof) of BBB-opening for aPD1 efficacy; and iv) whether pERK predicts response and identifies patients that will benefit from treatment.