Development of a Companion Diagnostic Assay for Detection of ADAM8-Positive Cancers

乳腺癌(BRCA)每年导致全球约685,000名妇女死亡。而使用激素的患者 受体(HR)和人表皮生长因子受体-2(HER2)驱动的癌症(HR+和/或HER2+) 虽然他们受益于内分泌和HER2靶向治疗，但他们仍然占死亡人数的大多数。这个 HR和HER2阴性(HR-/HER2-)亚型，也被称为三阴性乳腺癌(TNBC)，是最常见的 攻击性更强，治疗更具挑战性，导致约25%的死亡，尽管发病率要低得多。 迫切需要更有效的治疗方法。我们鉴定了细胞表面蛋白ADAM8是一个独立的 BRCA患者预后不良的标志，也是肿瘤生长和扩散的驱动力。使用ADAM8阳性(ADAM8+) TNBC小鼠模型，我们证明了基于抗体(Ab)的靶向ADAM8是一种有效的治疗(TX)方法 战略[1]。原代TNBCs的初步免疫组织化学(IHC)显示仅有一部分是ADAM8+ (17/50或34%)，建议需要诊断(Dx)以确定哪些患者可以受益于靶向 心理治疗。我们推出了Adecto制药公司，以开发Dx和Tx产品，以改善 ADAM8+癌症患者。ADP2，我们的顶级TX抗体，减少了先前存在的TNBC增长和扩散，改善了 提高存活率，并增强对标准护理化疗的反应。ADP2成功人性化， 领先候选人(AD100)在支持IND的研究之前被选中。AD100方案可能会显著改善 BRCA治疗。在这里，我们建议开发一种基于IHC的用于ADAM8+癌症的Dx作为AD100的伴侣 或者是一个独立的预后指标，用于识别进展性疾病的高风险患者。目前，没有 DX用于检测这些肿瘤。使用一组高度特异的抗ADAM8单抗(MAbs)和 第一阶段SBIR基金，我们(I)优化了IHC条件，并确定ADP2为铅Dx抗体；(Ii)开发了乳房 染色/记分控制细胞系微阵列(CCM)，其中3个细胞系表达低、中、高ADAM8，以及 分析患者来源的异种移植样本；(Iii)验证IHC试验和CCM，并建立ADAM8 主要BRCA样本中的评分系统(完成了所有建议的目标)。与早先的发现一致， ADP2-IHC显示36.1%的TNBCs(22/61)为ADAM8+，而非TNBC-BrCas的出乎意料的是32.8% (115/351)。一项对HR+/HER2-亚型的10年年龄调整分析显示，样本量最大 ADAM8评分与较差的存活率相关，为这项检测的预后应用提供了早期支持。在这 针对第二阶段的应用，我们建议：1)改进ADP2测定，以允许准确地表征 ASCO/CAP指南中任何BRCA样本中的ADAM8；2)验证ADAM8阳性率并研究 检测在BRCA中的预后价值；3)用TNBC检测AD100反应的预测价值 和HR+/HER2-小鼠模型；4)由临床Dx承包商完成CLIA分析验证。成功 完成拟议的AIMS将导致采用CLIA标准操作规程的ADAM8 IHC分析 准备在未来的临床试验中进行测试。

Breast cancer (BrCa) leads to ~685,000 deaths in women yearly worldwide (WHO). While patients with Hormone Receptor (HR) and Human Epidermal Growth Factor Receptor-2 (HER2)-driven cancers (HR+ and/or HER2+) have benefited from endocrine and HER2-targeted therapies, they still account for the majority of deaths. The HR and HER2 negative (HR-/HER2-) subtype, also known as Triple-negative breast cancer (TNBC), is the most aggressive and even more challenging to treat, leading to ~25% of deaths, despite a much lower incidence. More effective therapies are urgently needed. We identified the cell surface protein ADAM8 as an independent marker of poor BrCa patient outcome and a driver of tumor growth and spread. Using ADAM8-positive (ADAM8+) TNBC mouse models, we showed antibody (Ab)-based targeting of ADAM8 is an effective therapeutic (Tx) strategy [1]. Preliminary immunohistochemistry (IHC) of primary TNBCs revealed only a subset are ADAM8+ (17/50 or 34%), suggesting a diagnostic (Dx) will be needed to identify patients who can benefit from targeted therapy. We launched Adecto Pharmaceuticals to develop Dx and Tx products to improve the outcome of patients with ADAM8+ cancers. ADP2, our top Tx Ab, reduces pre-existing TNBC growth and spread, improves survival, and enhances response to standard-of-care chemotherapy. ADP2 was successfully humanized, and a lead candidate (AD100) selected ahead of IND-enabling studies. AD100 regimens could dramatically improve BrCa treatment. Here, we propose to develop an IHC-based Dx for ADAM8+ cancers as a companion to AD100 or a standalone prognostic for identification of patients at high risk of progressive disease. Currently, there is no Dx for detection of these tumors. Using a panel of highly specific anti-ADAM8 monoclonal Abs (mAbs) and Phase 1 SBIR funds, we (i) optimized IHC conditions and identified ADP2 as lead Dx Ab; (ii) developed a breast staining/scoring control cell line microarray (CCM) with 3 lines expressing low, medium or high ADAM8, and analyzed patient-derived xenograft samples; (iii) validated IHC assay and CCM, and established an ADAM8 scoring system, in primary BrCa samples (which completed all proposed aims). Consistent with earlier findings, ADP2 IHC showed 36.1% of TNBCs (22/61) were ADAM8+, and unexpectedly 32.8% of non-TNBC BrCas (115/351). A 10-year age-adjusted analysis of the HR+/HER2- subtype, with largest sample size, revealed ADAM8 score associated with poor survival, providing early support for a prognostic use of this assay. In this Direct to Phase 2 application, we propose to: 1) refine the ADP2 assay to permit accurate characterization of ADAM8 in any BrCa sample within ASCO/CAP guidelines; 2) verify ADAM8 positivity rates and study the prognostic value of the assay in BrCa; 3) test the predictive value of the assay for AD100 response using TNBC and HR+/HER2- mouse models; 4) complete CLIA validation of the assay by a clinical Dx contractor. Successful completion of the proposed aims will result in an ADAM8 IHC assay with CLIA standard operating protocols ready for testing in future clinical trials.