MGMT

前言在过去的几十年中，对DNA损伤反应（DDR）途径的理解不断加深，拓宽了肿瘤学的治疗领域。越来越清楚的是，DNA损伤反应缺陷导致的细胞基因组不稳定性导致了癌症的发生。另一方面，这些缺陷也可以作为一个治疗机会。越来越多的DDR靶向药物已迅速扩展到参与DDR途径的多个成员的抑制剂，包括PARP、ATM、ATR、CHK1、WEE1和DNA-PK。目前，这些DDR成分的抑制剂，其中一些正处于临床研究中。此外，新的证据表明DDR抑制剂对传统癌症治疗的敏感性，以及DDR途径和免疫检查点抑制剂（ICI）反应之间的相关性，这些都促进基于DDR抑制剂的联合治疗。靶向DNA修复途径的药物正在肿瘤治疗领域显示出越来越大的作用。DNA损伤与DNA损伤反应为了保持基因组的完整性，复杂的DNA修复系统被用来对抗各种形式的DNA损伤，这些机制被称为DNA损伤反应。DDR通路分为三个功能上相互交织的部分：检测DNA损伤的传感器、触发信号级联的信号转换器和阻碍DNA修复的效应器。这些途径不是相互排斥的过程，而是相互协调，形成DNA修复的精确调控网络。             碱基切除修复（BER）和核苷酸切除修复（NER）所有生物体的基因组都在不断地经历微妙的变化，这是由于内源性产生的各种基因毒物，如活性氧（ROS）、电离辐射以及烷基化剂等环境损伤所致。DNA中的大多数细微变化，如单链断裂（SSB），都是通过BER途径修复的。BER首先由受损的碱基启动，然后切除碱基并用新合成的DNA替换。然后，脱嘌呤/脱嘧啶核酸内切酶（APE）切割AP位点，在损伤位点形成3′OH末端。最后，DNA聚合酶和DNA连接酶在去除损伤碱基产生的核苷酸缺口处被招募，从而封闭缺口。BER负责修复小损伤，而使DNA螺旋结构变形的较大的双链断裂（DSB）则需要NER途径修复。NER机制涉及一种关键蛋白质，即切除修复交叉互补蛋白1（ERCC1），它会清除断裂点附近的DNA，然后用正常的DNA复制进行替换。同源重组（HR）和非同源末端连接（NHEJ）在哺乳动物细胞中，HR和NHEJ是修复DSB的两条主要途径。由于同源姐妹染色单体是新DNA合成所需的模板，HR途径可以在S/G2细胞周期阶段修复DSB，而NHEJ在除M期外的所有细胞周期阶段都是活跃的。HR分析来自基因组其他部分的同源序列，收集断裂位点丢失的信息。HR首先切除断裂端，随后通过Brca2和Rad51形成Rad51核蛋白丝，开始检索同源序列，并促进断裂DNA和同源模板之间形成连接分子，完成修复。NHEJ比HR更简单一些，直接将断裂端重新连接在一起。NHEJ所需的基本因子是由Ku70/Ku80和DNA依赖性蛋白激酶的催化亚单位（DNA-PKcs）组成的异二聚体，其识别DSB并促进NHEJ的下游信号因子，如XRCC4、XLF和DNA连接酶IV。虽然NHEJ机制较为简单，但有时会导致重排，而HR被认为不会产生错误。除HR和NHEJ外，一种DSB修复途径与这两个主要DSB修复途径具有相似的机制，但在遗传上不同，称为替代末端连接（a-EJ）途径。a-EJ途径既可以与HR共享类似的起始过程，也可以与NHEJ一样组成无同源模板的DNA末端连接因子。目前，越来越多的研究开始关注a-EJ通路作为NHEJ或HR活性受损癌细胞的潜在治疗靶点。错配修复（MMR）除了暴露于基因毒素的细胞所产生的损伤外，DNA损伤也可能来自异常的DNA处理。针对复制相关错误的DNA修复途径称为MMR。在DNA合成过程中，MMR纠正核苷酸错误整合，从而防止分裂细胞中永久性的DNA改变。因此，基因突变或表观遗传沉默导致的MMR缺陷可能导致自发突变的发生率增加，这通常与遗传性和散发性癌症有关。跨损伤合成与模板置换DNA损伤耐受性（DDT）作为修复复制停滞DNA损伤的一种基本旁路机制，允许DNA复制穿过阻碍元件。跨损伤合成（TLS）是两种不同的DDT模式之一，取决于一种特殊的TLS聚合酶的功能，而不是复制性DNA聚合酶，其可以直接跨过损伤部位复制。由于TLS聚合酶的校对活性不足，TLS机制是容易出错的，这增加了突变的风险。毫不奇怪，TLS是细胞突变的主要来源。相反，DDT的另一种模式，即模板置换（TS），涉及在姐妹染色单体上重组到同源DNA模板，这类似于HR过程，被认为比TLS更准确。TLS和TS的修复活动开始于复制叉之后，这表明它们可能发生在DNA复制期间或之后，TS开始于S期早期，TLS开始于S期晚期。范可尼贫血（FA）途径范可尼贫血是一种罕见的遗传病，由范可尼基因的双等位基因突变引起，受影响的患者伴有对DNA损伤的反应不足。范科尼贫血已被确定为一种DNA修复途径，可清除阻碍DNA复制和转录的屏障，即DNA链间交联（ICL）。ICL可由醛类在多种代谢反应（如脂质过氧化和乙醇代谢）和化疗（如铂）期间形成。而链内交联通过NER途径修复，而ICL主要通过FA途径修复。通过UHRF1蛋白和FANCM–MHF1–MHF2复合物检测ICL后，FA核心复合物被招募到染色质中，并单泛素化底物FANCI和FANCD2。泛素化FANCD2-I为各种DNA内切酶招募支架蛋白，从而完成对交联处DNA的识别和核苷酸的切除，从而得到适合重组修复的DNA底物。O6-甲基鸟嘌呤-DNA甲基转移酶途径众所周知，DNA甲基化剂能够抑制DNA甲基化并产生广泛的DNA加合物，如O6-甲基鸟嘌呤（O6MeG）和O4-甲基胸腺嘧啶，这可能导致碱基错配和随后的点突变。其中，O6MeG被认为是甲基化剂诱导的DNA加合物的主要来源，可导致突变和致癌。O6MeG可以通过O6-甲基鸟嘌呤-DNA甲基转移酶（也称为MGMT）在单步自杀反应中修复。MGMT将受损鸟嘌呤O6位点的甲基转移到半胱氨酸残基，从而防止基因突变。可以想象，MGMT降低了烷化剂在癌细胞中的作用，可能导致化疗耐药。MGMT启动子的甲基化会阻碍其转录，因此可以用来提高细胞对烷化剂的敏感性。DDR治疗应用的机制与正常细胞相比，肿瘤细胞对DNA损伤敏感性增加的潜在机制在于三个主要方面：至少一条DDR途径的缺陷、复制应激的升高和内源性DNA损伤的增加。DDR缺陷尽管DDR缺陷与癌症的发生和发展有关，但DDR途径中的缺陷也为靶向肿瘤细胞提供了治疗机会。携带DDR缺陷的肿瘤细胞导致基因组不稳定性增强，并依赖剩余的DDR途径生存。作为一种治疗方法，剩余DNA修复途径的组合靶向产生了一种被称为“合成致死”的概念。合成致死的概念基于两个同时发生的功能丧失遗传事件，其中任何一个单独都不会导致损伤，而是共同作用导致细胞死亡。当癌细胞特有的DDR途径发生一种基因改变时，由DDR抑制剂引起的第二种功能丧失事件将在不影响正常细胞的情况下对癌细胞合成致死。复制应激真核细胞复杂的DNA复制系统在细胞分裂过程中受到细胞周期中各种蛋白质的严格调控。许多DNA核苷酸需要精确聚合以确保细胞内稳态。阻碍或终止复制叉进展的内源性或外源性障碍激活保守的细胞反应途径，称为复制应激。复制应激的分子机制是DNA聚合酶的进展停滞和随后DNA聚合与DNA解旋酶的解偶联。诱导复制应激的一个例子是G1/S细胞周期检查点缺陷，其原因可能是pRb功能丧失、CDKN2A缺失或细胞周期蛋白D1或细胞周期蛋白E扩增。 内源性DNA损伤一些内源性性DNA损伤是中性pH条件下低浓度氢离子和氢氧根离子的作用造成的，如脱嘌呤和脱嘧啶作用。细胞内环境对于染色体DNA来说，还具有其他危险，其中最严重的来自氧化过程，在线粒体产生的一些中间产物，如ROS，可能会从线粒体渗出，进入细胞质。这样的中间产物包括超氧离子、过氧化氢和羟自由基。在肿瘤代谢中，低PH值、缺氧和高水平的ROS在肿瘤微环境（TME）中普遍存在。靶向DNA修复途径的抑制剂目前利用DDR缺陷的抗癌策略在很大程度上是通过开发抑制DNA修复过程中分子的靶向药物来解决的。聚ADP-核糖聚合酶（PARP）抑制剂PARP抑制剂的发展是合成致死的典型代表。PARP1和PARP2是关键的DDR酶，通过带负电荷的聚ADP-核糖（PAR）链修饰靶蛋白，感知DNA损伤并传递信号。PARP1与受损DNA结合后的结构变化激活其催化功能，促进DNA修复效应分子的招募和DNA损伤部位周围染色质的结构重塑，而染色质的动态重塑将在很大程度上影响DNA修复的效率。                        鉴于PARP在促进DNA有效修复中的关键作用，PARP抑制剂可以选择性地杀死同源重组缺陷的肿瘤细胞。PARP抑制剂是BRCA突变肿瘤的一种很有前途的治疗策略。聚ADP-核糖水解酶（PARG）抑制剂PARG通过在DNA损伤后水解PAR核糖键来逆转PARP酶的作用。同样，PARG在DNA复制和修复中的积极作用导致PARG缺陷细胞对DNA损伤剂的敏感性增加。尽管大量研究表明PARP抑制剂与合成致死率之间存在相关性，但对PARG抑制剂治疗机制的研究却相对滞后。据报道，乳腺癌细胞中HR蛋白（如BRCA1/2）的缺失可刺激PARG抑制细胞的合成致死性，PARG抑制剂COH34可诱导BRCA突变或对奥拉帕利耐药的卵巢癌和乳腺癌细胞死亡。然而，在其他癌细胞中报告了相互矛盾的结果。在六个测试的乳腺癌细胞系中，只有一个BRCA缺陷的细胞系对PARG抑制剂PDD00017273敏感，而五个细胞系对PDD00017273（包括BRCA突变的细胞系）无效。共济失调毛细血管扩张突变蛋白（ATM）抑制剂DDR信号级联由一系列蛋白磷酸化驱动，ATM、ATR和DNA-PKs是参与该过程的关键激酶。被DNA双链断裂激活，ATM被MRE11-RAD50-NBS1（MRN）复合物招募到DSB位点。ATM底物包括p53、CHK1和CHK2，它们的磷酸化将导致S内或G2/M细胞周期阻滞。尽管ATM在DNA修复等多种分子过程中起着典型作用，但它也具有非典型功能，包括剪接体置换。ATM被认为是肿瘤抑制因子，ATM缺陷或突变在实体瘤和B细胞淋巴瘤中比较常见。ATM突变可能导致共济失调毛细血管扩张症，这是一种神经退行性疾病，其容易导致癌症。目前有几种ATM抑制剂正在研究用于癌症治疗。共济失调毛细血管扩张症和Rad3相关蛋白（ATR）抑制剂与由DSB触发的ATM不同，ATR被复制蛋白A（RPA）包裹的单链DNA激活并被招募。单链DNA可以通过DSB的核溶解处理以及复制DNA解旋酶与DNA聚合酶的解偶联产生。细胞内ATR信号涉及一系列下游分子的磷酸化，触发广泛的反应，包括阻断细胞周期检查点、DDR和细胞凋亡。与其他DDR蛋白如PARP相比，ATR抑制剂的开发相对滞后。原因可能包括ATR分子的大尺寸和对其晶体结构缺乏了解。此外，其在所有PIKK中的高度同源活性位点以及对共激活蛋白的需求进一步限制了其药物设计。CHK1抑制剂检查点激酶CHK1通过磷酸化和招募一系列调节蛋白，积极参与ATR和ATM启动的DNA损伤反应。CHK1通过磷酸化CDC25A来调节S期内检查点，导致CDC25A降解，随后S期细胞周期蛋白依赖性激酶2（CDK2）活性降低，CHK1对CDC25C和WEE1的磷酸化调节有丝分裂和G2/M检查点。此外，CHK1还磷酸化Thr-309上的RAD51，促进其在HR期间与BRCA2的相互作用。CHK1水平升高与更差的预后、疾病复发和治疗抵抗相关，这进一步支持CHK1抑制的治疗潜力。WEE1抑制剂作为对DNA损伤的反应，激活的ATR使Chk1磷酸化，Chk1又使WEE1和CDC25磷酸化。与活性被磷酸化抑制的CDC25相比，WEE1被激活，然后磷酸化下游CDK1上的Tyr15和Thr14以抑制其活性，导致G2/M周期阻滞，为DNA损伤修复留出时间。此外，通过磷酸化CDK1上的Tyr15，WEE1还可以在DNA复制完成之前阻止S期向G2期的进展。虽然WEE1抑制剂的原理是明确的，但其临床应用受到其治疗窗口的限制。目前，大多数临床研究集中于WEE1抑制与化疗药物的联合应用。DNA-PK抑制剂DNA依赖性蛋白激酶是一个由DNA激活的丝氨酸/苏氨酸蛋白激酶，大量表达在几乎所有哺乳动物的细胞中。DNA-PK是DNA修复的关键蛋白激酶， 参与了NHEJ的过程 。在各种肿瘤类型（包括胃肠道癌、肺癌和肝细胞癌）中都观察到DNA-PK表达上调，并且与较高的肿瘤分级和不良预后相关。DNA-PK抑制剂的开发主要集中在DNA-PKcs的催化活性上，而新的抗DNA-PKcs方法，如DNA-PKcs抑制性microRNA或靶向Ku异二聚体的抑制剂，则基于ATP结合位点的同源模型。目前，大多数DNA-PK抑制剂的临床研究集中在与癌症化疗或放疗联合使用的效果。小结细胞对DNA损伤的反应是一个复杂的过程，涉及各种信号网络和蛋白质，它们在特定的癌症类型中被差异激活或失活。肿瘤中增加的复制应激和DNA修复缺陷为我们治疗癌症提供了机会，使得癌细胞比正常细胞更容易受到DDR抑制。目前，以PARP抑制剂为典型的靶向DDR途径的药物已经走向临床应用，并且在肿瘤治疗中展现出令人鼓舞的前景。进一步，确定这些DDR抑制剂的最佳剂量、组合和时间表，减少不良反应，更理想地提高疗效将是未来的方向。此外，对每一种肿瘤进行表征，以确定其失控的DDR成分的具体特征，将有助于癌症患者的个性化治疗。参考文献：1.  Targeting DNA repair pathway in cancer:Mechanisms and clinical application. MedComm (2020). 2021 Dec; 2(4):654–691.声明：发表/转载本文仅仅是出于传播信息的需要，并不意味着代表本公众号观点或证实其内容的真实性。据此内容作出的任何判断，后果自负。若有侵权，告知必删！长按关注本公众号   粉丝群/投稿/授权/广告等请联系公众号助手 觉得本文好看，请点这里↓

Reported the First-Ever Durable Persistence of an Allogeneic Cellular Therapy from a Phase 1 Study of INB-100 in Leukemia where 100% of Evaluable Patients (n=10) Treated Remained in Remission, including six Patients Alive and Progression Free Past 12 Months Presented Positive Results from a Phase 1 Study in Newly Diagnosed Glioblastoma (GBM) Demonstrating All Patients Treated with INB-200 Exceeded Progression-Free Survival (PFS) of Seven Months at the Society for Neuro-Oncology (SNO) 28th Annual MeetingAppointed Dr. Corinne Epperly, M.D., M.P.H. to Board of DirectorsClosed Private Placement in December 2023 with Initial Gross Proceeds of $14.4 Million to Provide Cash Runway into 1Q 2025 NEW YORK, March 14, 2024 (GLOBE NEWSWIRE) -- IN8bio, Inc. (Nasdaq: INAB), a clinical-stage biopharmaceutical company developing innovative gamma-delta T cell therapies, today reported financial results and business highlights for the fourth quarter and full-year ended December 31, 2023. “IN8bio entered 2024 with significant momentum behind the company,” said William Ho, CEO and co-founder of IN8bio. “Despite the difficult environment in 2023, the IN8bio team executed operationally and successfully advanced our programs. We presented positive data across our major clinical programs in leukemia and GBM, broadened our clinical portfolio, and strengthened our financial position by securing funding into 1Q 2025. We presented updated data from our INB-100 study at the 65th American Society of Hematology Annual Meeting, which was the first time any allogeneic cellular therapy has reported sustained efficacy and long-term cell persistence through 365 days. This showcases the potential of gamma-delta T cells to provide long-term durable remissions for patients with leukemia. We believe that IN8bio is well-positioned for significant near- and long-term catalysts as we advance our pipeline of gamma-delta T cell therapies to potentially extend survival in some of the most aggressive forms of cancer.” Business Highlights and Recent Developments Announced positive INB-100 data at the 65th American Society of Hematology (ASH) Annual Meeting & Exposition demonstrating that 100% of evaluable leukemia patients (n=10) treated remained alive, progression-free, and in durable complete remission (CR) as of November 3, 2023. The data showed long-term in-vivo expansion and persistence of allogeneic gamma-delta T cells 365 days following a single administration of INB-100. The study demonstrated the first-ever durable persistence of an allogeneic cellular therapy.Reported positive data on INB-200 at the 28th SNO Annual Meeting. All patients who completed mandated doses surpassed a median PFS of seven months, exceeded the standard-of-care median PFS of four to seven months, with one patient in Cohort 2 remaining alive and progression free past 28.5 months as of October 20, 2023. In addition, most patients exceeded the expected PFS based on their age and methylguanine-DNA methyltransferase (MGMT) status of their tumors.Announced a private placement totaling up to $46.9 million in potential gross proceeds. The initial closing of $14.4 million is expected to support operational execution and extended the Company’s cash runway into 1Q 2025 with the potential for up to $32.5 million in additional capital at increasing valuations, subject to certain conditions.Initiated enrollment for the Phase 2 study of INB-400 in newly diagnosed GBM.Announced publication in Frontiers in Immunology on IN8bio’s DeltEx Drug Resistant Immunotherapy (DRI) as a rational therapeutic approach to newly diagnosed glioblastoma titled, “Adoptive Cell Therapy for High Grade Gliomas using Simultaneous Temozolomide and Intracranial MGMT-Modified γδ T cells Following Standard Post-Resection Chemotherapy and Radiotherapy: Current Strategy and Future Directions.”Appointed Dr. Corinne Epperly, M.D., M.P.H., an internationally recognized immuno-oncology and cell therapy executive with 20 years of experience, to the Board of Directors. Upcoming Anticipated Pipeline Milestones and Events INB-100: Enroll an additional 10 patients in an expansion cohort at the recommended Phase 2 dose (RP2D) and report Phase 1 long-term follow-up results at multiple medical meetings throughout 2024; potentially submit investigational new drug (IND) application for Phase 3 randomized control trial in 2024.INB-200: Report Phase 1 long-term follow up results at multiple medical meetings in 2024.INB-300: Present additional preclinical data demonstrating proof-of-concept for the nsCAR platform targeting CD33 and CD123 at the American Association for Cancer Research (AACR) Annual Meeting in April 2024.INB-400: Dose first patient and treat up to 15 patients at multiple sites across the United States in the Phase 2 trial in newly diagnosed GBM; potentially submit IND for Phase 1b allogeneic gamma-delta T cell study in relapsed GBM in 2024. Fourth Quarter and Full Year 2023 Financial Highlights Research and Development (R&D) expenses: R&D expenses were $4.5 million for the three months ended December 31, 2023, compared to $4.0 million for the comparable prior year period. R&D expenses were $16.8 million for the year ended December 31, 2023, compared to $14.1 million in the prior year. The increase in R&D expenses was primarily due to increased personnel-related costs, including salaries, benefits, and non-cash stock-based compensation due to increased headcount, as well as increased third-party clinical trial-related activities for the INB-100 and INB-200 programs. The increase was partially offset by a reduction in contract research organization expenses for INB-400 related to the IND filing in the prior year.General and administrative (G&A) expenses: G&A expenses were $3.1 million for the three months ended December 31, 2023, compared to $3.9 million for the comparable prior year period. G&A expenses were $13.5 million for the year ended December 31, 2023, compared to $14.5 million in the prior year. The decrease in G&A expenses was primarily due to cost savings related to D&O insurance premiums and reductions in professional services.Net loss: The company reported a net loss of $7.6 million, or $0.22 per basic and diluted common share, for the three months ended December 31, 2023, compared to a net loss of $7.8 million, or $0.32 per basic and diluted common share, for the comparable prior year period. For the year ended December 31, 2023, net loss was $30.0 million, or $1.00 per basic and diluted common share, compared to a net loss of $28.5 million, or $1.36 per basic and diluted common share, for the prior year.Cash position: As of December 31, 2023, the Company had cash of $21.3 million, compared to $18.2 million as of December 31, 2022. About IN8bio IN8bio is a clinical-stage biopharmaceutical company developing gamma-delta T cell-based immunotherapies for cancer patients. Gamma-delta T cells are a specialized population of T cells that possess unique properties, including the ability to differentiate between healthy and diseased tissue. The company’s lead program INB-400 is in a Phase 2 trial in glioblastoma multiforme (GBM). Additional programs include Phase 1 trials in solid and hematologic tumors, including INB-200 for GBM and INB-100 for patients with hematologic malignancies undergoing transplantation. For more information about IN8bio, visit www.IN8bio.com. Forward Looking StatementsThis press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as “aims,” “anticipates,” “believes,” “could,” “estimates,” “expects,” “forecasts,” “goal,” “intends,” “may,” “plans,” “possible,” “potential,” “seeks,” “will” and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding extending IN8bio’s cash runway into January 2025; IN8bio’s ability to receive additional capital from the December 2023 private placement and the corresponding impact on the company’s cash runway; IN8bio’s ability to achieve significant near- and long-term growth; IN8bio’s ability to advance its pipeline of gamma-delta T cell therapies to potentially extend survival in some of the most aggressive forms of cancer; the timing of initiation, progress and scope of clinical trials for IN8bio’s product candidates, including INB-100, INB-200, INB-300 and INB-400; and IN8bio’s ability to achieve anticipated milestones, including expected data readouts from its trials, enrollment of additional patients in its clinical trials, advancement of clinical development plans and submission of INDs. IN8bio may not actually achieve the plans, intentions or expectations disclosed in these forward-looking statements, and you should not place undue reliance on these forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including: risks to site initiation, clinical trial commencement, patient enrollment and follow-up, as well as IN8bio’s ability to meet anticipated deadlines and milestones, presented by public health crises as well as rising inflation and regulatory developments; uncertainties inherent in the initiation and completion of preclinical studies and clinical trials and clinical development of IN8bio’s product candidates; the risk that IN8bio may not realize the intended benefits of its DeltEx platform; availability and timing of results from preclinical studies and clinical trials; whether the outcomes of preclinical studies will be predictive of clinical trial results; whether initial or interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; the risk that trials and studies may be delayed and may not have satisfactory outcomes; potential adverse effects arising from the testing or use of IN8bio’s product candidates; expectations for regulatory approvals to conduct trials or to market products; IN8bio’s reliance on third parties, including licensors and clinical research organizations; and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, are described in greater detail in the section entitled “Risk Factors” in our Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on November 9, 2023, as well as in other filings IN8bio may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and IN8bio expressly disclaims any obligation to update any forward-looking statements contained herein, whether because of any new information, future events, changed circumstances or otherwise, except as otherwise required by law. IN8BIO, INC.Balance Sheets (In thousands, except share and per share data) December 31, December 31, 2023 2022 Assets Current assets Cash$21,282 $18,182 Prepaid expenses and other current assets 3,343 4,052 Total Current Assets 24,625 22,234 Non-current assets Property and equipment, net 3,514 4,397 Construction in progress 182 29 Restricted cash 256 252 Right-of-use assets - finance leases 1,364 1,691 Right-of-use assets - operating leases 3,513 4,181 Other non-current assets 255 255 Total Non-Current Assets 9,084 10,805 Total Assets$33,709 $33,039 Liabilities and Stockholders' Equity Liabilities Current liabilities Accounts payable$924 $2,091 Accrued expenses and other current liabilities 2,955 2,342 Short-term finance lease liability 694 682 Short-term operating lease liability 820 707 Total Current Liabilities 5,393 5,822 Long-term finance lease liability 525 811 Long-term operating lease liability 2,854 3,674 Total Non-Current Liabilities 3,379 4,485 Total Liabilities 8,772 10,307 Commitments and Contingencies Stockholders' Equity Preferred stock, par value $0.0001 per share; 10,000,000 shares authorized at December 31, 2023 and 2022. No shares issued and outstanding — — Common stock, par value $0.0001 per share; 490,000,000 shares authorized at December 31, 2023 and 2022; 43,287,325 and 24,545,157 shares issued and outstanding at December 31, 2023 and 2022, respectively 4 3 Additional paid-in capital 116,152 83,941 Accumulated deficit (91,219) (61,212)Total Stockholders' Equity 24,937 22,732 Total Liabilities and Stockholders' Equity$33,709 $33,039 IN8BIO, INC.Statements of Operations(In thousands, except share and per share data) Year EndedDecember 31, 2023 2022 Operating expenses: Research and development$16,827 $14,062 General and administrative 13,510 14,459 Total operating expenses 30,337 28,521 Loss from operations (30,337) (28,521)Other income 330 — Net loss$(30,007) $(28,521)Net loss per share – basic and diluted$(1.00) $(1.36)Weighted-average number of shares used in computing net loss per common share – basic and diluted 29,864,932 20,967,955 Company Contact IN8bio, Inc.Patrick McCall+1 646.600.6GDT (6438)info@IN8bio.com Investors Meru AdvisorsLee M. Sternlstern@meruadvisors.com Media Contact Kimberly HaKKH Advisors917.291.5744kimberly.ha@kkhadvisors.com

NEW YORK, Feb. 14, 2024 (GLOBE NEWSWIRE) -- IN8bio, Inc. (NASDAQ: INAB), a leading clinical-stage biopharmaceutical company developing innovative gamma-delta T cell therapies, today announced a publication in Frontiers in Immunology that reviews IN8bio’s novel approach for solid tumors, such as glioblastoma (GBM), an aggressive form of brain cancer. Cellular therapies, particularly chimeric antigen receptor T cell therapies (CAR-T), have shown promise in hematologic malignancies but have faced significant challenges when applied to solid tumors like GBM. These obstacles include rapid tumor growth, antigen heterogeneity, and limited response to current therapies. The publication, titled: “Adoptive cell therapy for high grade gliomas using simultaneous temozolomide and intracranial mgmt-modified γδ t cells following standard post-resection chemotherapy and radiotherapy: current strategy and future directions,” explains the mechanism of action behind IN8bio’s novel therapeutic approach called DeltEx Drug Resistance Immunotherapy (DRI) and the current strategy and future directions for this treatment. The INB-200 and INB-400 studies by IN8bio addresses the challenges towards targeting solid tumors by harnessing the innate immune functions of gamma-delta T cells. GBM cells constitutively express stress-associated NKG2D ligands (NKG2DL), which can be further upregulated through the DNA damage response (DDR) pathway triggered by alkylating agents like temozolomide (TMZ). “We believe our results to date represent a significant advancement in the treatment of GBM. By combining standard chemotherapy with gamma-delta T cells genetically engineered to resist the lymphodepleting effects of chemotherapy, we are creating a synergistic effect that enhances the immune response against GBM while minimizing toxicity to healthy tissues,” said Lawrence Lamb, Ph.D., Chief Scientific Officer and Co-Founder of IN8bio. “This new treatment may improve the survival and quality of life of patients with GBM by preventing tumor recurrence and enhancing the immune response to eliminate residual cancer cells.” The current standard of care for newly diagnosed GBM typically involves primary tumor resection followed by six weeks of chemoradiation therapy, succeeded by six cycles of monthly maintenance therapy with TMZ. This regimen typically yields a median progression-free survival (PFS) of 6 to 7 months and an overall survival (OS) ranging from 14 to 16 months. IN8bio‘s Phase 1 trial (INB-200) assessing the safety and efficacy of intracranial infusions of autologously derived DeltEx DRI gamma-delta T cells in addition to standard-of-care maintenance therapy suggests that the therapy is manageable with a possible improvement in PFS. In the Phase 1 study, cells from the patient are isolated, expanded and modified prior to being delivered intracranially to the tumor cavity every month in combination with maintenance TMZ. The trial assesses three different dosing regimens from a single dose delivered on cycle 1, day 1 in Cohort 1, to three doses delivered on day 1 of cycles 1-3 in Cohort 2, to six doses delivered on day 1 of cycles 1-6 in Cohort 3. All patients receive 1x107 cells per dose. The trial aims to improve PFS by targeting residual cancer cells. Of the eight patients who have completed scheduled dosing, all have exceeded the median PFS expected with standard-of-care therapy alone. IN8bio is also conducting a Phase 2 clinical trial of a genetically modified autologous gamma-delta T cell therapy (INB-400) targeting newly diagnosed GBM. The study will assess the safety, efficacy and tolerability of genetically modified DeltEx DRI cells at leading medical centers across the United States. About INB-200 INB-200 is a genetically modified autologous DRI product candidate for the treatment of solid tumors. This novel platform utilizes genetic engineering to generate chemotherapy-resistant gamma delta T cells which can be administered concurrently with standard-of-care treatment in solid tumors. This is a powerful, synergistic treatment approach enabling gamma-delta T cells to persist in the presence of chemotherapy, and maintain their natural ability to recognize, engage and kill cancer cells. INB-200 is the first genetically engineered gamma-delta T cell therapy to be administered to patients with solid tumors and our initial indication is in GBM. About INB-400 INB-400 is IN8bio’s DeltEx autologous and allogeneic DRI technology. Allogeneic INB-400 will expand the application of DRI gamma-delta T cells into other solid tumor types through the development of allogeneic DeltEx DRI technology. About IN8bio IN8bio is a clinical-stage biopharmaceutical company focused on the discovery, development and commercialization of gamma-delta T cell product candidates for solid and liquid tumors. Gamma-delta T cells are a specialized population of T cells that possess unique properties, including the ability to differentiate between healthy and diseased tissue. IN8bio’s DeltEx platform employs allogenic, autologous, iPSC and genetically modified approaches to develop cell therapies, designed to effectively identify and eradicate tumor cells. IN8bio has initiated a Phase 2 trial of INB-400 in GBM at multiple centers across the United States and has two ongoing Phase 1 trials in solid and hematologic tumors, including INB-200 for GBM and INB-100 for patients with hematologic malignancies undergoing transplantation. IN8bio also has a broad portfolio of preclinical programs focused on addressing other hematological and solid tumor cancers. For more information about IN8bio and its programs, please visit . Forward Looking Statements This press release may contain forward-looking statements made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as “aims,” “anticipates,” “believes,” “could,” “estimates,” “expects,” “forecasts,” “goal,” “intends,” “may,” “plans,” “possible,” “potential,” “seeks,” “will” and variations of these words or similar expressions that are intended to identify forward-looking statements, although not all forward-looking statements contain these words. Forward-looking statements in this press release include, but are not limited to, statements regarding the ability of CAR-T cellular therapies to treat hematologic malignancies and GBM; the ability of the INB-200 study (i) to present a significant advancement in the treatment of GBM, (ii) create a synergistic effect that enhances the immune response against GBM while minimizing toxicity to healthy tissues and (iii) improve the survival and quality of life of patients with GBM by preventing tumor recurrence and enhancing the immune response to eliminate residual cancer cells; the ability of IN8bio’s Phase 1 trial in INB-200 to improve PFS by targeting residual cancer cells; and extending IN8bio’s cash runway into 2025; IN8bio’s ability to extend runway upon receipt of additional capital from the December 2023 private placement; IN8bio’s ability to raise additional capital from the December 2023 private placement; IN8bio’s ability to advance its work in other solid tumor indications; the potential for INB-400 to treat GBM; the timing of initiation, progress and scope of clinical trials for IN8bio’s product candidates, including INB-100, INB-200 , INB-300 and INB-400; and IN8bio’s ability to achieve anticipated milestones, including expected data readouts from its trials, enrollment of additional patients in its clinical trials and advancement of clinical development plans. IN8bio may not actually achieve the plans, intentions or expectations disclosed in these forward-looking statements, and you should not place undue reliance on these forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in these forward-looking statements as a result of various factors, including: risks to site initiation, clinical trial commencement, patient enrollment and follow-up, as well as IN8bio’s ability to meet anticipated deadlines and milestones, presented by public health crises as well as rising inflation and regulatory developments; uncertainties inherent in the initiation and completion of preclinical studies and clinical trials and clinical development of IN8bio’s product candidates; the risk that IN8bio may not realize the intended benefits of its DeltEx platform; availability and timing of results from preclinical studies and clinical trials; whether the outcomes of preclinical studies will be predictive of clinical trial results; whether initial or interim results from a clinical trial will be predictive of the final results of the trial or the results of future trials; the risk that trials and studies may be delayed and may not have satisfactory outcomes; potential adverse effects arising from the testing or use of IN8bio’s product candidates; expectations for regulatory approvals to conduct trials or to market products; IN8bio’s reliance on third parties, including licensors and clinical research organizations; and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, are described in greater detail in the section entitled “Risk Factors” in our Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission (SEC) on November 9, 2023, as well as in other filings IN8bio may make with the SEC in the future. Any forward-looking statements contained in this press release speak only as of the date hereof, and IN8bio expressly disclaims any obligation to update any forward-looking statements contained herein, whether because of any new information, future events, changed circumstances or otherwise, except as otherwise required by law. Company Contact IN8bio, Inc. Patrick McCall +1 646.600.6GDT (6438) info@IN8bio.com Investors Argot Partners IN8bio@argotpartners.com Media Contact Kimberly Ha KKH Advisors 917-291-5744 kimberly.ha@kkhadvisors.com