CXCL10

Advanced OTX-2002 in MYCHELANGELO™ I trial; initial cohorts demonstrated encouraging disease control rate in late-stage HCC patientsEstablished a research collaboration with Novo Nordisk to develop an epigenomic controller for obesity, expanding the pipeline into the cardiometabolic space Announced strategic prioritization to focus resources on potential near-term value drivers, support long-term growth, and extend cash runway into Q1 2025 CAMBRIDGE, Mass., March 28, 2024 (GLOBE NEWSWIRE) -- Omega Therapeutics, Inc. (Nasdaq: OMGA) (“Omega”), a clinical-stage biotechnology company pioneering the development of a new class of programmable epigenomic mRNA medicines, today announced financial results for the fourth quarter and full year ended December 31, 2023, and a strategic prioritization initiative to focus resources on near-term milestones to support long-term shareholder value. “2023 was an important year for Omega where we executed to plan and demonstrated clinical validation of an epigenomic controller to regulate c-MYC in humans for the first time. These proof-of-platform clinical data, coupled with our research collaboration with Novo Nordisk in obesity, support the ability of the OMEGA platform to potentially address epigenomic regulation of almost all human genes across broad therapeutic areas including cancer, cardiometabolic conditions and liver regeneration,” said Mahesh Karande, President and Chief Executive Officer of Omega Therapeutics. “Initial clinical data from our ongoing Phase 1/2 MYCHELANGELO I trial of OTX-2002 demonstrated controlled modulation of MYC expression levels, one of the most challenging gene targets in oncology, and an encouraging disease control rate and stable disease in heavily pre-treated, late-stage HCC patients. We are within what we believe is a clinically meaningful dose range and, as we continue to see a promising safety profile for OTX-2002, have recently opened enrollment of Cohort 5. We look forward to sharing additional updates from this program throughout 2024.” “Today we also announced a strategic prioritization, implemented to ensure we have sufficient resources to advance our lead program and maximize near- and long-term value creation from our platform. As part of this initiative, we are taking difficult but necessary actions to streamline our team and optimize our R&D efforts and cost structure to extend our cash runway into the first quarter of 2025. These changes will unfortunately affect a number of our colleagues, and we are grateful for their dedication and contributions to our mission,” continued Mr. Karande. “As we sharpen our focus, we look forward to the opportunities ahead to generate meaningful clinical data for OTX-2002, continue to demonstrate the broad potential of our platform, and establish additional partnerships. We remain steadfast in our mission to pioneer a new class of programmable epigenomic mRNA medicines to transform the treatment of a broad range of diseases.” Recent Highlights and Key Anticipated Milestones Development Pipeline and Platform Advanced the Phase 1/2 MYCHELANGELO™ I clinical trial evaluating OTX-2002 in patients with hepatocellular carcinoma (HCC): OTX-2002 continues to advance in monotherapy dose escalation.As of March 24, 2024, data from the first three cohorts (0.02 mg/kg – 0.06 mg/kg) showed: OTX-2002 continued to be generally well tolerated, with no dose-limiting toxicities observed.Consistent dose-dependent pharmacokinetics with no drug accumulation observed following repeat doses.All patients demonstrated controlled modulation and downregulation of MYC mRNA expression, an important oncogene regulating cell function and cell death.The interim disease control rate (DCR) for the target population of HCC patients was 80%, reflecting 4 out of 5 efficacy-evaluable patients having a best overall response of stable disease. These patients had an average of three or more previous therapies and entered the trial with a life expectancy of less than 12 weeks. The DCR for patients with non-HCC solid tumors in the trial (n=5) was 40%, indicating the potential specificity of OTX-2002 for HCC. The Company continues to evaluate patients with HCC in Cohort 4 at the 0.12 mg/kg dose level, which recently cleared the 28-day dose limiting toxicity (DLT) window. Based on preclinical experience and modeling, Omega believes this dose level is within the expected active dose range. In March 2024, the Company opened enrollment for Cohort 5 at a dose level of 0.3 mg/kg.Omega expects to report additional updated clinical data from monotherapy dose escalation in mid-2024.The Company plans for expansion into monotherapy and combination settings in mid-2024. Announced research collaboration with Novo Nordisk to develop a novel therapeutic for obesity management: The collaboration will leverage Novo Nordisk’s expertise in research and development within cardiometabolic diseases and Omega’s proprietary platform technology to develop an epigenomic controller designed to enhance metabolic activity.Unlike traditional approaches focused on appetite suppression, the program aims to leverage precision epigenomic control to enhance thermogenesis, a naturally occurring metabolic process that burns calories.Under the terms of the agreement, Novo Nordisk will reimburse all R&D costs and has the right to select one target to advance for clinical development. Omega and Flagship’s Pioneering Medicines are eligible to receive up to $532 million in upfront, development and commercial milestone payments, as well as tiered royalties on annual net sales of a licensed product, which will be split equally between the parties. Continued to advance and expand OMEGA platform capabilities: Presented new preclinical data supporting the breadth of Omega’s platform capabilities, including bidirectional and multiplexed epigenomic control of gene expression in liver inflammation and fibrosis at the American Association for the Study of Liver Diseases’ (AASLD) The Liver Meeting® 2023. A HNF4A-targeting epigenomic controller led to a durable increase in HNF4α expression, preferential upregulation of HNF4α P1 promoter isoforms, and reduced key measures of fibrosis both in vitro and in vivo, supporting this development candidate’s potential for the treatment of fibrotic liver disease.In preclinical models, liver-specific multiplexed targeting of CXCL9, CXCL10 and CXCL11 via an epigenomic controller led to a significant reduction in T-cell migration, a critical driver of inflammation-induced liver injury, supporting the potential of this approach as a novel treatment for inflammatory liver diseases. Corporate Announced cost reduction and strategic prioritization initiative to maximize near- and long-term value creation opportunities: Following a strategic review, the Company has focused its pipeline and reduced overall headcount by approximately 35%. These fiscally disciplined actions are expected to extend the Company’s cash runway into Q1 2025.Positions the Company to achieve key clinical data readouts from the monotherapy dose escalation and dose expansion stages of the MYCHELANGELO I clinical trial.The Company will prioritize certain preclinical programs and platform efforts: Prioritized preclinical programs include OTX-2101 for non-small cell lung cancer (NSCLC), the HNF4A program in liver regeneration, and development of an epigenomic controller for obesity in collaboration with Novo Nordisk.Core work on platform biology, epigenomic controllers, and characterization of LNP delivery to the lung and other tissues will continue. An updated corporate presentation is available on the Investors section of the Company’s website at https://ir.omegatherapeutics.com/. Fourth Quarter and Full Year 2023 Financial Results As of December 31, 2023, the Company had cash, cash equivalents and marketable securities totaling $73.4 million, which is expected to fund operations into Q1 2025. Research and development (R&D) expenses for the fourth quarter of 2023 were $15.5 million, compared to $26.0 million for the fourth quarter of 2022. R&D expenses for 2023 were $77.2 million compared to $81.2 million in 2022. The $4.0 million decrease in R&D expenses in 2023 compared to 2022 was primarily due to lower external research and manufacturing costs, consulting and professional fees, and lab expenses, partially offset by an increase in personnel-related expenses, including stock-based compensation to support business growth, and facilities and other costs. General and administrative (G&A) expenses for the fourth quarter of 2023 were $6.2 million, compared to $5.7 million for the fourth quarter of 2022. G&A expenses for 2023 were $26.2 million, compared to $23.7 million in 2022. The $2.5 million increase in G&A expenses in 2023 compared to 2022 was primarily due to higher professional and consulting fees, and facilities and other administrative costs. Net loss for the fourth quarter of 2023 was $20.2 million, compared to $30.8 million for the fourth quarter of 2022. Net loss for the year ended December 31, 2023, was $97.4 million, compared to a net loss of $102.7 million for the year ended December 31, 2022. The decrease in net loss for 2023 compared to 2022 was primarily due to decreases in R&D expenses. About Omega Therapeutics Omega Therapeutics is a clinical-stage biotechnology company pioneering the development of a new class of programmable epigenomic mRNA medicines to treat or cure a broad range of diseases. By pre-transcriptionally modulating gene expression, Omega’s approach enables precision epigenomic control of nearly all human genes, including historically undruggable and difficult-to-treat targets, without altering native nucleic acid sequences. Founded in 2017 by Flagship Pioneering following breakthrough research by world-renowned experts in the field of epigenetics, Omega is led by a seasoned and accomplished leadership team with a track record of innovation and operational excellence. The Company is committed to revolutionizing genomic medicine and has a pipeline of therapeutic candidates derived from its OMEGA platform spanning oncology, regenerative medicine, and multigenic diseases including inflammatory and cardiometabolic conditions. For more information, visit omegatherapeutics.com, or follow us on X and LinkedIn. About the OMEGA Platform The OMEGA platform leverages the Company’s deep understanding of gene regulation, genomic architecture and epigenetic mechanisms to design programmable epigenomic mRNA medicines that precisely target and modulate gene expression at the pre-transcriptional level. Combining world-class data science capabilities with rational drug design and customized delivery, the OMEGA platform enables control of fundamental epigenetic processes and reprogramming of cellular physiology to address the root cause of disease. Omega’s modular and programmable mRNA medicines, called epigenomic controllers, target specific genomic loci within insulated genomic domains with high specificity to durably tune single or multiple genes to treat and cure diseases through unprecedented precision epigenomic control. Forward-Looking Statements This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. All statements contained in this press release that do not relate to matters of historical fact should be considered forward-looking statements, including without limitation statements regarding the timing, progress and design of our ongoing Phase 1/2 MYCHELANGELOTM I clinical trial and our preclinical studies, as well as the timing of announcements of data related thereto; the potential of the OMEGA platform to engineer programmable epigenomic mRNA therapeutics that successfully regulate gene expression by targeting insulated genomic domains; expectations surrounding the potential of our product candidates, including OTX-2002 and OTX-2101; expectations regarding our pipeline, including trial design, initiation of preclinical studies and advancement of multiple preclinical development programs in oncology, immunology, regenerative medicine, and select monogenic diseases; potential franchise opportunities; our anticipated cash runway into the first quarter of 2025; our prioritization of certain preclinical programs and platform efforts; and our plans to ensure that we have sufficient resources to advance our lead program, support long term growth, and accomplish our mission. These statements are neither promises nor guarantees, but involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements, including, but not limited to, the following: the novel technology on which our product candidates are based makes it difficult to predict the time and cost of preclinical and clinical development and subsequently obtaining regulatory approval, if at all; the substantial development and regulatory risks associated with epigenomic controllers due to the novel and unprecedented nature of this new category of medicines; our limited operating history; the incurrence of significant losses and the fact that we expect to continue to incur significant additional losses for the foreseeable future; our need for substantial additional financing; our investments in research and development efforts that further enhance the OMEGA platform, and their impact on our results; uncertainty regarding preclinical development, especially for a new class of medicines such as epigenomic controllers; potential delays in and unforeseen costs arising from our clinical trials; the fact that our product candidates may be associated with serious adverse events, undesirable side effects or have other properties that could halt their regulatory development, prevent their regulatory approval, limit their commercial potential, or result in significant negative consequences; the impact of increased demand for the manufacture of mRNA and LNP based vaccines to treat COVID-19 on our development plans; difficulties manufacturing the novel technology on which our epigenomic controller candidates are based; our ability to adapt to rapid and significant technological change; our reliance on third parties for the manufacture of materials; our ability to successfully acquire and establish our own manufacturing facilities and infrastructure; our reliance on a limited number of suppliers for lipid excipients used in our product candidates; our ability to advance our product candidates to clinical development; and our ability to obtain, maintain, enforce and adequately protect our intellectual property rights. These and other important factors discussed under the caption “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2023, and our other filings with the SEC, could cause actual results to differ materially from those indicated by the forward-looking statements made in this press release. Any such forward-looking statements represent management’s estimates as of the date of this press release. While we may elect to update such forward-looking statements at some point in the future, we disclaim any obligation to do so, even if subsequent events cause our views to change. Omega Therapeutics, Inc.Consolidated statements of operations and comprehensive loss (Unaudited, In thousands except share and per share data) Three Months Ended December 31, Year Ended December 31, 2023 2022 2023 2022 Collaboration revenue from related party$989 $735 $3,094 $2,073 Operating expenses: Research and development 15,531 25,968 77,169 81,167 General and administrative 6,157 5,734 26,186 23,672 Total operating expenses 21,688 31,702 103,355 104,839 Loss from operations (20,699) (30,967) (100,261) (102,766)Other income (expense), net: Interest income, net 487 248 2,810 222 Other income (expense), net (2) (107) 23 (157)Total other income, net 485 141 2,833 65 Net loss$(20,214) $(30,826) $(97,428) $(102,701)Net loss per common stock attributable to common stockholders, basic and diluted$(0.37) $(0.64) $(1.80) $(2.14)Weighted-average common stock used in net loss per share attributable to common stockholders, basic and diluted 55,143,137 47,895,083 54,010,996 47,880,819 Comprehensive loss: Net loss$(20,214) $(30,826) $(97,428) $(102,701)Other comprehensive income (loss): Unrealized gain (loss) on marketable securities 72 438 465 (417)Comprehensive loss$(20,142) $(30,388) $(96,963) $(103,118) Omega Therapeutics, Inc.Condensed Consolidated Balance Sheets(Unaudited, In thousands) December 31, December 31, 2023 2022 Assets Cash and cash equivalents$68,443 $70,615 Marketable securities 4,986 54,063 Other assets 130,937 21,320 Total assets$204,366 $145,998 Liabilities and stockholders’ equity Liabilities$146,350 $40,027 Stockholders’ equity 58,016 105,971 Total liabilities and stockholders’ equity$204,366 $145,998

导读：2020年，Moderna研究团队在Clinical Cancer Research（1区, 影响因子11.5）发表文章：《Intratumoral IL-12 mRNA Therapy Promotes TH1 Transformation of the Tumor Microenvironment》。研究者开发了一种IL-12 mRNA-LNP瘤内注射制剂，用于治疗实体瘤，在细胞、多种小鼠模型和肿瘤患者立体培养物中证实了IL-12 mRNA-LNP具有强效的抗肿瘤活性。上篇文章，菌菌对IL-12 mRNA-LNP的序列特征和体内外验证结果进行了详细解读：【耀文解读】Moderna:IL-12 mRNA-LNP蛋白替代疗法序列设计与验证、【耀文解读】一文读懂|IL-12 mRNA蛋白替代疗法实体瘤研究进展。今天，我们将继续剖析其抗肿瘤作用机制，包括同源肿瘤小鼠模型、人源异种移植小鼠模型和患者肿瘤切除样品。01背景介绍MEDI1191是Moderna与阿斯利康联合开发的一款IL-12 mRNA-LNP药物。MEDI1191的序列特征为：优化后的人源IL-12b 和 IL-12a 序列通过多肽连接，并且在IL-12 mRNA的3′ UTR 中掺入了一个 miR122 结合位点，以抑制肝细胞中IL-12的产生，而不影响癌细胞的水平。研究人员先后将IL-12 mRNA-LNP转化结直肠MC38肿瘤细胞、以及负荷不同肿瘤（A20、MC38-S 和 MC38-R）的小鼠模型，验证了IL-12的抗肿瘤活性。另一点需注意的是，由于人源IL12p70在小鼠体内没有生物学活性，因此研究者设计了小鼠(m) IL12 mRNA用于小鼠模型。紧接着，研究者剖析了MEDI1191抗肿瘤的作用机制，结果见下文所述：02IL-12mRNA-LNP的抗肿瘤机制研究2.1 CD8+T细胞对于mIL-12 mRNA最佳抗肿瘤活性是必需的在MC38-R荷瘤小鼠中，给药 7 天后，mIL-12 mRNA 诱导肿瘤浸润 CD8+T细胞呈剂量依赖性增加。mIL-12 mRNA 不会改变肿瘤 FoxP3-CD4+细胞或 FoxP3+ CD4+（Treg）细胞数量。因此，在单剂量 0.05 μg 或 0.5 μg mIL-12 mRNA 后 7 天，观察到 CD8+T细胞与 Treg 细胞比例呈剂量依赖性增加。为了进一步研究 mIL-12 mRNA 对 MC38-R TME 的影响，转录组数据显示，给药后 7 天与 T 细胞谱系丰度相关的转录产物显著增加。与免疫系统完整的小鼠相比，CD8+T细胞耗竭显著降低了mIL-12 mRNA 在MC38-R荷瘤小鼠中的抗肿瘤活性。mIL-12 mRNA 仍然延迟 CD8+T细胞耗竭耗竭小鼠中的肿瘤生长，但 mIL-12 mRNA无法诱导任何的CR。相反，CD4+T 细胞耗竭对mIL-12 mRNA 抗肿瘤活性没有影响。这些数据表明，CD8 +T 细胞依赖性适应性免疫是 mIL-12 mRNA 在MC38-R荷瘤小鼠模型中发挥最佳抗肿瘤活性所必需的。2.2 mIL-12 mRNA 抗肿瘤免疫依赖于IFNγIL-12 的许多已知作用都依赖于激活的 NK 和 T 细胞释放的IFNγ。在注射mIL-12 mRNA 24小时内，激活的NK和NKT细胞（激活标记物CD69增加百分比）呈现剂量依赖性，相反，没有观察到MC38-R 肿瘤内 CD4 +或 CD8+T 细胞的早期激活。给药后7天，肿瘤中的NK细胞数量没有变化，相反，NKT细胞数量出现轻微但显著的增加。MC38-R 荷瘤小鼠中，给药后 24 小时内肿瘤 NK 激活，肿瘤和血浆 IFNγ 水平呈剂量依赖性增加。在 A20 荷瘤小鼠中也观察到类似的 IFNγ 水平的剂量依赖性增加。为了更直接地确定 IFNγ 在 mIL-12 mRNA 抗肿瘤免疫反应中的作用，在给予单次瘤内剂量的 mIL-12 mRNA 之前，用 IFNγ 阻断抗体治疗 MC38-R 荷瘤小鼠。阻断 IFNγ 完全消除了该模型中 mIL-12 mRNA 的抗肿瘤活性。由于 NK 细胞激活有可能导致 IFNγ 释放和肿瘤细胞细胞毒性，因此，在 MC38-R 模型中研究了 NK 和 NKT 细胞耗竭对 mIL-12 mRNA 诱导的 IFNγ 表达和抗肿瘤活性的影响。用抗 NK1.1 消除 NK 和 NKT 细胞导致小鼠外周 IFNγ 对 mIL-12 mRNA 的反应小幅但显著降低。然而，NK细胞和NKT细胞的消耗对该模型中的mIL-12 mRNA抗肿瘤活性没有统计学上的显著影响。MC38-R 荷瘤小鼠给药后 7 天，mIL-12 mRNA 诱导 TH1 TME 转化，表现为TH1 免疫反应基因上调，成熟DC细胞的早期增加（包括 CD103+ 和 CD8 + 交叉呈递 DC 亚群）以及与 DC 丰度和抗原呈递相关的基因表达增加。重要的是，对照 mRNA 不会诱导非特异性 DC 激活。对 MC38-R 肿瘤转录组数据的其他通路分析揭示了 mIL-12 mRNA 给药后 7 天 TME 转化的广泛程度，涉及T细胞和NK细胞激活基因、细胞因子和趋化因子、补体因子以及与细胞外基质（ECM）调节和脂质代谢相关的基因表达增加。给药后 7 天，MC38-R 肿瘤转录组的广泛变化与 mIL-12 mRNA 在该时间点诱导的肿瘤生长的显著抑制密切相关。2.3 mIL-12 mRNA 与PD-L1阻断剂联用，增强抗肿瘤效果IFNγ 是肿瘤和骨髓细胞上 PD-L1 表达的有效诱导剂。因此，研究者试图确定肿瘤内 mIL-12 mRNA 是否会在同源小鼠肿瘤模型的肿瘤微环境中诱导 PD-L1 表达。事实上，给药后 7 天，mIL-12 mRNA会使得MC38-R 肿瘤中免疫浸润细胞的 PD-L1 表达增加。流式细胞术分析显示，肿瘤浸润性 CD11b+骨髓细胞和 CD11b+Ly6C hi单核细胞上的 PD-L1 表达增加，但是，在任何时间点均未检测到 MC38-R 肿瘤细胞上 的PD-L1 表达发生显著变化。在肿瘤总 CD11b +骨髓细胞中，低剂量 mIL-12 mRNA 仅在给药后 24 小时和给药后 72 小时诱导 PD-L1，并且这些细胞上的 PD-L1 水平在药后 7 天已恢复至基线。相反，0.05和0.5μg mIL-12 mRNA均增加了肿瘤中Ly6Chi单核细胞上的PD-L1表达，并且这种增加从给药后24小时持续到7天。CD11b +骨髓区室包括中性粒细胞、单核细胞、巨噬细胞、MDSC 和一些 DC。与其他 CD11b + 骨髓细胞群体相比，Ly6Chi 单核细胞/mMDSC 亚群上的 PD-L1 表达更持久，这可能反映了 mMDSC 更强的抑制功能。在 MC38-R 荷瘤小鼠的血液中，给药 24 小时后，mIL-12 mRNA 也会诱导 Ly6Chi 单核细胞上的 PD-L1 表达，并且这种对 PD-L1 的诱导表达在 IFNγ- 阻断抗体存在下会被显著抑制。由于 PD-L1 与 PD-1 的相互作用可以抑制抗肿瘤免疫，因此在携带已建立的 MC38-R 肿瘤的动物中研究了 PD-L1 阻断剂对 mIL-12 mRNA 抗肿瘤活性的影响。与单独使用相同剂量的 mIL-12 mRNA 相比，PD-L1阻断剂与单剂量 0.5 或 5 μg mIL-12 mRNA 的联用可显著改善总体存活率并增加了 CR 小鼠数量。此外，与单剂量 mIL-12 mRNA +抗 PD-L1 组合相比，每周三剂 mIL-12 mRNA +抗 PD-L1 组合的生存率改善趋势不显著。与抗 PD-L1 +单剂量 mIL-12 mRNA 组合（8/15 CR，80%）相比，抗 PD-L1 +三剂 mIL-12 mRNA 组合也导致更多 CR（12/15 CR，80%）。接下来，研究者对抗 PD-L1 增强 MC38-R 荷瘤小鼠 mIL-12 mRNA 抗肿瘤活性的机制。通过用 MC38 免疫显性逆转录病毒抗原肽 p15E 重新攻击脾细胞来量化脾肿瘤肽反应性 T 细胞的频率。给药后 7 天，单独的 mIL-12 mRNA 扩增了脾脏中的肿瘤反应性 T 细胞，但与 mIL-12 mRNA 单一疗法治疗的动物相比，抗 PD-L1 与 mIL-12 mRNA 联合并没有进一步扩增这些细胞。然而，与单独使用抗 PD-L1或 mIL-12 治疗相比，mIL-12 mRNA 与抗 PD-L1 组合确实显著增加了浸润肿瘤的 CD8+T细胞数量。特别是，在给药后 7 天，在用 0.5 μg mIL-12 mRNA 加抗 PD-L1 治疗的 8 只动物中，有 4 只在完全坏死的肿瘤核心周围检测到密集的 CD8+ 免疫浸润。在大多数具有 mIL-12 mRNA +抗 PD-L1 的 CR 动物中，在动物的另一侧再次植入 MC38-R 细胞后，没有观察到肿瘤生长。总之，这些数据表明，PD-L1 阻断增强了 CD8 +T 细胞向 MC38-R 肿瘤的募集，以及 CD8 +T 细胞介导的 mIL-12 mRNA 响应的肿瘤裂解。B16F10-AP3 模型是一种具有最小免疫浸润的 PD-L1 阻断抗性黑色素瘤肿瘤模型。在此模型中，单剂量的 mIL-12 mRNA 转化了 TME，激活 NK 细胞和 DC，增加 CD8+T 细胞浸润和 CD8 +T 细胞与 Treg 的比率，诱导 IFNγ 释放，并另外增加肿瘤、骨髓和细胞上的 PD-L1 表达。在B16F10-AP3 模型中，与对照 mRNA 相比，注射单剂量 0.5 μg mIL-12 mRNA 显著提高小鼠存活率。与 mIL-12 mRNA 相比，注射mIL-12 mRNA +抗 PD-L1 对小鼠存活率和 CR 数量有着非常明显的增加趋势。然而，在 B16F10-AP3 模型中，无论是单独的 mIL-12 mRNA 还是 mIL-12 mRNA+αPD-L1 组合都不能扩增脾肿瘤肽反应性 T 细胞（Trp2 或 p15E 肽），这表明相比在MC38-R 荷瘤小鼠中， mIL-12 mRNA 在B16F10-AP3小鼠模型中诱导抗肿瘤免疫的效率较低。2.4 膜结合型mIL-12 mRNA抗肿瘤活性在MC38-S 双侧肿瘤小鼠中，注射单独使用肿瘤内 mIL-12 mRNA 或者与抗 PD-L1 联合使用，可以促进远端未治疗肿瘤的消退。与注射同种型抗体+ 5 μg 对照 mRNA 治疗的小鼠比，单次注射 0.5 μg 较低剂量的 mIL-12 mRNA 可诱导 3/20 只动物中治疗和远端肿瘤发生完全消退（双侧 CR），并显著提高总体存活率。与 0.5 μg mIL-12 mRNA 相比，较高的 5 μg mIL-12 mRNA 剂量可显著诱导更高的总生存率和更多数量的 CR。相比之下，与单独使用相同剂量的 mIL-12 mRNA 相比，注射αPD-L1 抗体+0.5 或 5 μg mIL-12 mRNA 的组合显著改善小鼠总体存活率。在同源荷瘤小鼠中，瘤内注射mIL-12 mRNA会诱导局部肿瘤mIL-12p70表达，并且外周mIL-12p70会有所增加。为了研究局部IL-12p70单独驱动远端肿瘤部位消退的能力，我们使用编码膜结合型mIL-12p70的mRNA来限制外周mIL-12p70的分泌。相对于分泌型IL-12mRNA，膜结合型mIL-12-mRNA编码的12p70释放到Hela细胞培养物上清液中的量非常低，并且同样会刺激共培养的小鼠 CD8 +T 细胞的 IFNγ 释放。在携带双侧 MC38-S 肿瘤的小鼠中，通过瘤内递送栓系 mIL-12 mRNA，导致 4/20 只小鼠接受治疗的肿瘤和远端肿瘤完全消退（双侧 CR）。与用分泌型 mIL-12 mRNA 处理的动物相比，在注射膜结合型mIL-12 mRNA 小鼠中，检测到循环 mIL-12p70 的增幅最小，同时，血浆中IFNγ诱导也大大降低。这些数据表明，在循环 mIL-12p70 水平不增加的情况下，局部肿瘤 mIL-12p70 表达可以诱导远端肿瘤部位的消退。2.5 MEDI1191在PDX模型中编码分泌人L12p70MEDI1191 编码人源L12p70 蛋白，诱导人单核细胞来源的巨噬细胞和 16 种人肿瘤细胞系中剂量依赖性的 hIL-12p70 释放。体外肿瘤细胞系之间分泌释放的hIL-12p70 产量差异显著，而来自不同供体的单核细胞来源的巨噬细胞之间的 hIL-12p70 产量非常一致。在人CD8+T细胞 IFNγ 释放测定中，MEDI1191编码的hIL-12p70 活性与重组异二聚体 hIL-12p70 的活性相当。左图: MEDI1191诱导16种人肿瘤细胞系中剂量依赖性的 hIL-12p70 释放右图: 用重组重组异二聚体hIL-12p70或者源自MEDI1191转染Hela细胞上清中的hIL-12p70刺激人CD8+T细胞 ，测定IFNγ分泌水平在ME12057黑色素瘤和HN5111 HNSCC（头颈鳞状细胞癌）PDX 模型中，瘤内 MEDI1191诱导肿瘤和血浆 hIL-12p70 浓度呈剂量依赖性增加。在所有四种 PDX 模型（2种黑色素瘤模型ME12057/ME12058和2种头颈鳞状细胞癌HN5111/HN5116）中，0.5 μg MEDI1191 给药6 小时后，肿瘤或血浆 hIL-12p70 水平没有观察到显著差异，给药24 小时后 ，HN5116 HNSCC 荷瘤小鼠肿瘤和血浆中的 hIL-12p70 水平显著低于其他模型。2.6 MEDI1191改变肿瘤微环境收集手术切除后的患者肿瘤新鲜样本进行振动切片，并在存在 MEDI1191 或对照 mRNA 的情况下在空气/介质界面处进行体外培养。在所有测试患者肿瘤切片培养物中，MEDI1191 编码释放的hIL-12p70呈现剂量依赖性。同时，MEDI1191 还诱导剂量依赖性分泌IFNγ 和 CXCL10 。虽然 MEDI1191 诱导每个测试患者肿瘤释放 hIL-12p70，但患者肿瘤切片之间的 IFNγ 和 CXCL10 释放变化更大。对来自接受过治疗的结直肠腺癌(CRC)、结直肠肝转移(CRLM)和子宫内膜癌(UCEC)患者的离体培养肿瘤切片上清液中的IL-12p70 (A)、IFNγ(B)和CXCL10(C)进行定量。对振动切片后立即固定的患者肿瘤切片中的 NK 细胞和 T 细胞密度通过 IHC 进行定量。未观察到患者肿瘤切片 IFNγ 释放与T 细胞浸润基线之间的相关性。然而，患者肿瘤切片急性IFNγ释放和NK细胞浸润基线之间呈现正相关。用 MEDI1191 处理的患者肿瘤切片的 NanoString 转录组分析显示，与对照 mRNA 处理的肿瘤切片相比，TH1 反应基因的表达显著增加。值得注意的是，在 MEDI1191 治疗的患者肿瘤切片和 mIL-12 mRNA 治疗的 MC38-R 肿瘤中，IFNG、STAT1 和 GBP2 表达均上调。03总结在多种肿瘤模型中，单次瘤内剂量的鼠源IL-12 mRNA诱导肿瘤消退。这既是 CD8 +T 细胞依赖性的，也是IFNγ依赖性的，并且与特征TH1免疫反应基因的上调相关，从而与TH1 TME转化相关。在PD-L1耐药模型中，PD-L1阻断增强了小鼠 IL-12 mRNA诱导的抗肿瘤免疫。小鼠IL-12 mRNA 也驱动未注射的远端病变消退，抗 PD-L1增强了这种反应。在循环 IL-12 没有增加的情况下，编码膜系小鼠IL-12的mRNA的瘤内递送诱导了未经治疗的病变的消退，支持了局部 IL-12 可以诱导针对远端病变的全身抗肿瘤免疫反应的假设。最后，他们还发现在离体患者肿瘤切片培养中，人IL-12 mRNA （MEDI1191）诱导剂量依赖性 IL-12 产生、IFNγ表达和TH1 TME 转化。总之，这项研究为MEDI1191 (IL-12 mRNA-LNP) 的开发提供了支持，使其可作为一种潜在的新型治疗方法，无论是单独使用还是与PD-L1/PD-1 检查点抑制剂联合使用，用于治疗浅表和深层实体瘤 。参考文献：Hewitt SL, Bailey D, Zielinski J, et al. Intratumoral IL12 mRNA Therapy Promotes TH1 Transformation of the Tumor Microenvironment. Clin Cancer Res. 2020 Dec 1;26(23):6284-6298. doi: 10.1158/1078-0432.CCR-20-047.识别微信二维码，添加生物制品圈小编，符合条件者即可加入生物制品微信群！请注明：姓名+研究方向！版权声明本公众号所有转载文章系出于传递更多信息之目的，且明确注明来源和作者，不希望被转载的媒体或个人可与我们联系(cbplib@163.com)，我们将立即进行删除处理。所有文章仅代表作者观点，不代表本站立场。

该研究发现，瘤内注射CXCL9/10工程化树突状细胞（CXCL9/10-DC），增强了肿瘤微环境（TME）中的T细胞浸润和活化，在多个同源小鼠非小细胞肺癌模型中产生了有效的肿瘤抑制作用。 加州大学洛杉矶发现 Bin Liu、Steven Dubinett 等人在 Cell 子刊 Cell Reports Medicine 上发表了题为：CXCL9/10-engineered dendritic cells promote T cell activation and enhance immune checkpoint blockade for lung cancer 的研究论文。 该研究使用慢病毒载体构建了表达CXCL9和CXCL10的工程化树突状细胞（CXCL9/10-DC），瘤内注射CXCL9/10-DC能够增强肿瘤微环境中的T细胞浸润和激活，有效抑制小鼠非小细胞肺癌模型的肿瘤发展，瘤内注射CXCL9/10-DC与免疫检查点阻断（ICB）疗法结合，克服了治疗耐药性并建立了全身肿瘤特异性免疫。 这项研究提供了对CXCL9/10-DC介导的宿主免疫激活的机制理解，并支持瘤内注射CXCL9/10-DC的临床转化，以增强ICB疗法在非小细胞肺癌中的疗效。 趋化因子是招募T细胞进入肿瘤微环境的必不可少的可溶性介质。CXCL9和CXCL10（CXCL9/10）是干扰素γ（IFN-γ）诱导的趋化因子，主要由肿瘤内CD103+树突状细胞和肿瘤相关巨噬细胞分泌。 CXCL9/10通过CXCR3信号促进CXCR3+效应T细胞的肿瘤浸润，包括1型T细胞辅助细胞和CD8+细胞毒性T淋巴细胞。除了促进效应T细胞浸润到肿瘤中外，CXCL9/CXCL10/CXCR3信号级联是最佳T细胞激活所必需的。CXCL9表达是癌症患者对ICB反应的最强预测因子之一，此外，肿瘤活检中CXCL9、CXCL10和/或CXCR3的高表达与接受ICB治疗的患者总体生存率的改善相关。这些发现强调了CXCL9/10在肿瘤微环境中作为ICB诱导的抗肿瘤免疫介质的重要作用。 树突状细胞（DC）原位疫苗已成为克服ICB耐药的有前途的方法。瘤内疫苗接种为树突状细胞提供了获得所有可用肿瘤抗原的能力，以促进广泛的抗肿瘤T细胞反应。在临床前研究中，基因修饰的树突状细胞疫苗可以分泌趋化因子，调节肿瘤微环境中的可溶性介质和细胞介质，以促进良好的抗肿瘤反应。 值得注意的是，细胞因子基因工程化树突状细胞作为表达载体的表现优于成纤维细胞，强调了树突状细胞的抗原呈递功能对于最佳疗效的重要性。鉴于CXCL9/10在促进T细胞介导的抗肿瘤免疫反应中的关键作用，研究团队评估了CXCL9/10工程化树突状细胞（CXCL9/10-DC）原位疫苗在小鼠非小细胞肺癌（NSCLC）模型中增强免疫检查点阻断（ICB）疗法的效果。 该研究发现，瘤内注射CXCL9/10工程化树突状细胞（CXCL9/10-DC），增强了肿瘤微环境（TME）中的T细胞浸润和活化，在多个同源小鼠非小细胞肺癌模型中产生了有效的肿瘤抑制作用。瘤内注射CXCL9/10-DC的抗肿瘤效果依赖于CD4+T细胞和CD8+T细胞以及CXCR3介导的T细胞转运和淋巴结中的T细胞输出。 瘤内注射CXCL9/10-DC克服了低肿瘤突变负荷的Lkb1缺陷Kras突变小鼠非小细胞肺癌模型对PD-1/PD-L1阻断的耐药性。此外，瘤内注射CXCL9/10-DC增强了高肿瘤突变负荷的Lkb1缺陷，Kras突变小鼠NSCLC模型对PD-1/PD-L1阻断的相对中等疗效，导致部分肿瘤完全消灭并建立了肿瘤特异性免疫记忆。 这些发现为瘤内注射CXCL9/10-DC作为克服耐药性和增强非小细胞肺癌ICB免疫治疗临床疗效的潜在临床转化提供了证据。