IL-15

外源性细胞因子工程化被认为是增强抗肿瘤T细胞免疫的解决方案之一。常见细胞因子对CAR-T细胞的作用包括：细胞因子对CAR-T细胞特性的影响IL-2增强增殖和效应能力IL-7延长潜在寿命，提高效应功能的持久性IL-9维持T细胞干性，增强效应功能IL-15延长细胞寿命IL-8增强T细胞向肿瘤迁移的能力IL-10通过代谢重编程恢复耗竭T细胞功能IL-12直接上调细胞毒性，调节免疫抑制TMEIL-18增强效应功能，重塑TMEIL-23提高效应功能，减少耗竭表型IL-33调节TMEIL-36γ增强细胞毒性，调节TMEIL-37恢复耗竭T细胞功能在实际开发应用中，把握共表达细胞因子的安全性和有效性依然是一个挑战。近期还是有一些相关研究团队继续关注着细胞因子CAR结构的开发。IL-4IL-4是肿瘤细胞在TME中释放的细胞因子，可以通过与T细胞表面的IL-4受体结合来对抗T细胞效应功能。通过转化细胞因子受体CAR(ICR)是抑制这种免疫抑制作用的常见方法，IL-7和IL-21通常是对应转化细胞因子的选择。华师大的研究团队近期则设计了一款4/15NKG2D-CAR，由基于NKG2D的嵌合抗原受体组成，IL-4R作为细胞外结构域共表达，IL-15R作为跨膜和细胞内结构域共表达，从而将IL-4R抑制信号转化为下游的IL-15R激活信号。(doi:10.1016/j.biopha.2023.115740.)4/15NKG2D-CAR-T在小鼠模型中表现出提高细胞毒性、增殖水平、存活率、未分化表型比例等抗肿瘤作用。IL-7(doi:10.1007/s10565-023-09821-w)研究人员设计了一款GPC3-7-19-CAR-T细胞用于治疗HCCs。杀伤效率是单纯GPC3-CAR-T细胞的1.5-2倍。在小鼠实验中表现出提高浸润CD4+ T细胞亚群比例、募集更成熟的DCs、减少PMN-MDSC和Treg细胞浸润，从而诱导TME重塑。该CAR-T在1例GPC3+ 晚期HCC患者身上展开了临床试验。结果显示，CAR-T治疗后，淋巴结节明显缩小，CT扫描显示CAR-T注射后56天患者纵隔淋巴囊萎缩，CD8+ T细胞的比例(67.9%)远高于基线(16.6%)。采用的患者来源CAR-T细胞阳性率为69%。IL-10IL-10在肿瘤发展和发病机制中的作用似乎是自相矛盾的。IL-10本身具有强大的抗肿瘤作用，通过免疫依赖性机制抑制转移，包括抑制浸润性巨噬细胞和血管生成因子以及激活CD8 + T细胞CTL。但同时，研究也报道了TAM产生的IL-10可以通过抑制APC的功能并随后阻断T细胞效应功能，来减弱抗肿瘤反应。矛盾的IL-10(doi:10.1038/s41587-023-02060-8)2024年1月浙江大学/唐力教授团队合作研究开发了一款表达IL-10的CAR-T，在小鼠实验中表现出能够维持线粒体健康、促进OXPHOS代谢等代谢重编程功能，实现肿瘤的消除。据称该CAR-T已经展开IIT临床试验，至少已有11名复发难治性淋巴瘤或复发难治性急性白血病患者达到完全缓解，CR接近100%。重新认识IL-10：提升CAR-T的CR至100%IL-13Rα2IL-13Rα2则和其他细胞因子的使用不同，其主要是因为在肿瘤上特异性表达而被当做靶点。1.(doi:10.1038/s41591-024-02893-z)近期野马生物/希望之城公布了其IL13Rα2靶向CAR-T MB-101的1期临床数据。所有患者的中位总生存期（中位OS）为8个月，高于复发胶质母细胞瘤的6个月预期生存期，而五项细分亚组中，最大剂量第五组OS达10.2个月。(只剩6个月时，他敲响了CAR-T的门)2.(doi:10.1038/s41591-024-02893-z)同期，吉利德/宾法大学也公布了其靶向EGFR和IL13Rα2的鞘内二价CAR T细胞同样治疗复发性胶质母细胞瘤的1期试验中期结果。该CAR-T会在过表达(EGFR扩增)和/或EGFR胞外结构域突变而发生EGFR 激活失调时激活。接受治疗的6名患者的中位随访时间为2.5个月，所有 6 名患者都观察到增强肿瘤大小的减小，部分肿瘤消退维持在第 +28 天及以后。然而，没有一个达到RANO标准的客观反应标准。IL-15(doi:10.3389/fimmu.2023.1165404)2023年信达生物与苏州大学合作设计的一款H9 CAR-IL15 T细胞，旨在解决其Claudin18.2 CAR-T疗法的长期持久性问题。小鼠 IL-15 修饰赋予肿瘤脉管系统靶向 CAR-T 细胞增强的效应器功能、植入和重编程TME能力，从而在免疫功能正常的小鼠中更好地控制肿瘤。其结果显示，在体外实验中，mIL-15对CAR-T细胞杀伤活性的明显影响仅保持较短时间，在超过三轮刺激后消失，可能和IL-15浓度不足相关。尽管IL-15在体外试验中对CAR-T细胞的总体影响通常不显著，但其在体内的作用是显著的。即使没有淋巴细胞清除预处理，H9 CAR-IL15 T细胞仍然产生明显的肿瘤抑制作用，而未修饰的CAR-T细胞几乎没有效果，从而有机会降低淋巴细胞清除方案造成的毒性作用。IL-24(doi:10.1038/s41416-024-02601-1)IL-24主要是通过靶向肿瘤细胞的干性来影响免疫细胞的疗效，可以通过多种途径特异性诱导肿瘤细胞凋亡，包括DNA损伤、SARI诱导、AIF、ATM和beclin-1轴。同时IL-24还可促进T细胞活化、中枢记忆分化和增殖，但不影响其凋亡。郑州大学研究人员通过构建IL-24 CAR-T细胞，旨在通过IL-24影响抗原丢失的肿瘤细胞对CAR-T的耐药性。体内模型显示，分泌IL-24的CAR-T细胞能更好地控制晚期肿瘤和复发。小结目前很多细胞因子CAR-T都能在安全性方面有较好表现，但实际有效性还是参差不齐的。其他参考文献：Shi H,et al.(2023) IL-15 armoring enhances the antitumor efficacy of claudin 18.2-targeting CAR-T cells in syngeneic mouse tumor models. Front. Immunol. 14:1165404. doi: 10.3389/fimmu.2023.1165404

点击上方的 行舟Drug ▲ 添加关注前言迄今为止，与传统的抗癌治疗策略相比，免疫治疗被认为是最有前景的全身性肿瘤治疗方法，其中，单克隆抗体因其特异性靶向分子的能力，已成为癌症治疗中一种关键而有效的治疗方式。然而，由于肿瘤复杂的疾病发病机制，针对单一靶点的单克隆抗体往往不足以表现出足够的治疗效果。因此，针对多个靶点的双特异性抗体（bsAbs）应运而生，它的发展改变了肿瘤免疫治疗的领域。目前，人们正在研究越来越多的针对癌症治疗的不同类型的bsAbs。这些类型包括双靶向抑制剂，其作用于不同水平的肿瘤增殖、血管形成和转移；以及双特异性抗体偶联药物、T细胞结合器、双特异性自然杀伤细胞接合器（NKCE）和先天免疫细胞接合器。其他类型还包括双特异性免疫检查点抑制剂（CPI）、共刺激bsAbs和融合蛋白、具有联合检查点抑制和共刺激特征的bsAbs、在肿瘤微环境（TME）中特异性激活的bsAb，以及将过继T细胞治疗和治疗性抗体相结合的新方法。目前，有300多项临床试验涉及200多种不同的双特异性抗体分子，其中约75%用于治疗实体瘤，25%用于治疗血液系统恶性肿瘤。有10种bsAb药物已被批准用于癌症治疗，其中9种在美国和/或欧洲获得批准，cadonilimab在中国获得批准。到目前为止，临床中开发的很大一部分bsAbs已经处于后期阶段（II期和III期）。另外，可以发现，治疗实体瘤的bsAbs主要由免疫调节剂主导，包括双CPI（约45%）和TCE（约33%），其次是靶向双途径、ICEs和ADC的bsAb。bsAb的发展史BsAbs最初的概念是由AlfredNisonof在20世纪60年代首次提出的。他将两个不同的抗原结合位点结合在一个分子中，并从抗牛γ球蛋白和抗卵清蛋白单价片段的混合物中获得了一个具有双重特异性的F(ab’)2分子。1975年，Köhler和Milstein发明了杂交瘤技术，最终解决了生产单克隆抗体的问题，开启了单克隆抗体治疗的新时代。1983年，Milstein和Cuello开创了quadroma技术，该技术基于分泌Abs混合物的两种不同杂交瘤细胞系的体细胞融合，包括具有双重特异性的鼠IgG形式的bsAb。然而，bsAb的低产率以及难以从密切相关的错配副产物中纯化所需的Ab是一个重大问题。1988年，James Huston和他的同事发明了单链抗体片段（scFv），它最大限度地减少了复性问题，例如不正确的结构域配对或聚集。1996年，Genentech的科学家们利用重组DNA技术发明了knob-into-hole技术，克服了Quadrome技术的局限性。通过在人类IgG的CH3结构域之间的界面突变选定的氨基酸，可以减少IgG重链的错配。这种技术利用更有利的蛋白质相互作用，最终可以形成高达90%的正确双特异性重链配对。随后，随着抗体工程和生物学的进展，bsAb的不同概念和结构正在不断演变。靶向双受体抑制的bsAb许多参与细胞信号传导的细胞表面蛋白，如RTK和相关受体，是基于抗体治疗的有效靶点。尽管靶向一个确定的信号受体的抗体治疗是非常有效的，但疾病相关表型通常由不止一种途径触发。这种冗余允许细胞通过使用其他补偿信号通路，从而耐受药物的生长抑制或细胞毒性诱导。同时调节不同疾病相关信号受体或通路的bsAbs可以减少或克服这一限制。Amivantamab（JNJ-61186372）靶向EGFR和肝细胞生长因子受体（MET），两种受体都能触发非小细胞肺癌（NSCLC）的增殖。因此，阻断两种受体比仅阻断一种途径能够更有效地抑制NSCLC的生长。Amivantamab已被FDA批准用于治疗携带EGFR外显子20插入突变的NSCLC亚型。一项随机III期研究的数据显示，在这部分患者中，与单独化疗相比，Amivantamab联合化疗具有显著优越性。另外一些针对肿瘤不同第二靶点的EGFR的bsAbs也正在临床开发中。例如，petosemtamab（MCLA-158）靶向EGFR和LGR5，LGR5是一种癌症干细胞相关的细胞表面受体。Petosemtamab目前正在包括晚期头颈部鳞状细胞癌在内的实体瘤患者的I/II期试验中进行评估（NCT03526835）。靶向配体受体抑制的bsAbbsAbs可以同时阻断两种不同的配体，或者是配体和受体的组合。VEGF和血管生成素2（ANG2）的双重靶向作用分别阻断VEGFR和血管生成因子1受体（TIE2）的激活，这两种途径涉及血管生成。vanucizumab，一种靶向VEGFA和ANG2的bsAb，在临床前模型中与化疗联合显示出抗肿瘤、抗血管生成和抗转移作用。BI836880是一种三特异性纳米抗体融合蛋白，由三个靶向VEGFA、ANG2和HSA的纳米抗体组成，后者可延长其血清半衰期。目前正在头颈部鳞状细胞癌、NSCLC和其他实体瘤患者的I期研究中进行评估。此外，靶向VEGF可以进一步设计成联合靶向肿瘤细胞上的PD-L1或T细胞上的PD-1，从而将抗血管生成与肿瘤免疫学方法联系起来。例如靶向PD1和VEGF的ivonescimab（AK112），其目前已在中国获批用于。其他bsAbs靶向PDL1和VEGF，包括PM8002，该药物正在NSCLC患者的II/III期研究（NCT05756972）中进行评估。靶向受体激活的bsAb许多抗肿瘤反应是通过激活细胞表面受体介导的，包括通过诱导细胞凋亡的免疫反应或细胞死亡。其中一种方法是靶向递送受体激活配体，如生长因子、细胞因子和（共）免疫刺激配体，将其融合到抗体或抗体片段中，以诱导局部或组织特异性激动活性，从而诱导细胞反应。越来越多的这种抗体-配体融合蛋白正在进入临床试验。受体激活也可以使用激动性抗体来实现。针对靶抗原和肿瘤坏死因子超家族（TNFRSF）成员的bsAbs已被证明是具有强大活性和肿瘤选择性的激动分子。RG7386（RO6874813）是一种四价bsAb，靶向癌症相关成纤维细胞上的FAPα和DR5，在具有FAPα间质表达的小鼠模型中具有效和选择性的肿瘤细胞杀伤，并已进入临床测试。此外，BI905711，一种靶向DR5和CDH17的四价双特异性IgG-scFv融合蛋白，目前处于I期临床研究中。靶向递送有效载荷的bsAb存在两种概念上不同的方法来利用bsAbs靶向递送有效载荷，如细胞毒性药物或放射性药物。第一种方法，预靶向治疗，使用bsAb的一个臂特异性靶向肿瘤细胞，另一个臂随后捕获有效载荷到肿瘤细胞。GD2 x DOTA是一种识别GD2的bsAb，并捕获放射性有效载荷177Lu-DOTA，其在TME中组装。在没有四聚化的情况下，由于半衰期，它会被迅速从外围清除。然而，到目前为止，临床试验中很少有bsAbs利用这种MoA，这可能是因为放射性预靶向涉及复杂的导流，限制了其普遍适用性。第二种方法通过递送偶联到双特异性抗体上的细胞毒性有效载荷，实现肿瘤细胞的特异性靶向。目前，bsADC已成为肿瘤药物开发的热点，已有多款bsADC进入临床开发，如ZW49、REGN5093、BL-B01D1等。靶向癌症免疫治疗的bsAb癌症免疫疗法中使用的大多数bsAbs通过T细胞驱动的天然或内源性免疫发挥作用，包括免疫检查点抑制（CPIs）效应细胞接合器（包括TCE和ICEs）以及共刺激性bsAb。双免疫检查点抑制许多抑制免疫检查点的单特异性抗体，如CTLA4或PD-1/PDL-1，已被批准用于癌症免疫疗法。将检查点抑制性抗体疗法扩展到bsAbs可以减少不期望的副作用，并增强疗效。大多数双免疫检查点抑制剂靶向PD-1/PD-L1轴和其他免疫抑制分子，如CTLA-4、TIM-3、LAG-3或TIGIT。MEDI5752（PD-1×CTLA-4）抑制PD-1+激活的T细胞中CTLA-4的功能，诱导PD-1的快速内化和降解。与PD-1和CTLA-4单抗联合治疗相比，MEDI5752的活性显著增强。针对其他检查点分子的双功能性抑制剂，包括LAG-3和TIGIT，也正在开发中。效应细胞接合器细胞接合器连接两种不同类型的细胞，主要是肿瘤细胞和T/NK细胞，以诱导肿瘤细胞溶解。细胞接合器由TAA靶向部分和效应细胞识别部分组成，并进一步分为T细胞接受器和NK细胞接受器。T细胞接合器利用TAA和TCR成分（主要是CD3），它们连接肿瘤细胞和T细胞，绕过TCR-MHC-I相互作用。因此，无论抗原特异性如何，T细胞结合器都会触发T细胞活化，产生包括穿孔素和颗粒酶在内的细胞毒性分子，以杀伤肿瘤细胞。BiTE是T细胞结合器的一种形式，通过靶向TAA和CD3的单链抗体将肿瘤细胞和T细胞结合，用于T细胞介导的肿瘤细胞杀伤。靶向CD19和CD3的blinatumomab是临床上典型的BiTE，2014年，blinatumomab成为第一个被FDA批准的BsAb，用于治疗ALL患者，在随后的几年里，blinatumomab的治疗范围进一步拓宽，2018年，FDA批准其用于首次或第二次完全缓解后MRD≥0.1%的pre-B ALL患者群体的治疗。目前，超过60例BiTE形式的双抗正在进行I/II期临床试验。NK细胞接合器将CD16A+NK细胞重定向至肿瘤细胞，诱导NK细胞活化。与BiTE相比，NK细胞接受者表现出较少的不良反应，如细胞因子释放综合征（CRS）和神经毒性。多种细胞毒性受体可激活NK细胞：CD16（FcγRIII）、天然细胞毒性受体（NCR；NKp30、NKp44、NKp46）、C型凝集素样受体NKG2D（CD314）和CD94/NKG2C。最近，抗CD30×CD16A的NK细胞接合器（AFM13）在AACR 2022的报告中展示了不俗的抗肿瘤效果。共刺激bsAbs高效、持久和局部受限的抗肿瘤免疫反应需要共刺激和共抑制信号来严格调节细胞毒性T细胞、自然杀伤细胞和巨噬细胞的激活、分化和维持。TNFRSF家族的成员（如4-1BB、CD40、OX40、GITR、CD27或CD30）以及CD28免疫球蛋白超家族（如CD28、CTLA4、PD-1、ICOS、BTLA)及其相应的配体在介导免疫调节信号中发挥着重要作用。靶向这些免疫调节途径可以增强免疫治疗。PRS-343（cinrebafusp），是一种针对HER2和4-1BB的四价bsAb，在IND研究中其耐受性良好，没有明显和相关的药物相关毒性；在接受有效剂量治疗的患者中（n=33），12%的患者达到ORR，包括1个CR，疾病控制率（DCR）为52%。bsAbs中通过4-1BB进行肿瘤选择性共刺激的其他靶点还包括EGFR、PSMA、CLDN18.2、B7H4、CEACAM5、HER2、PD-L1和FAP。此外，十多种针对PD-L1和4-1BB的不同bsAbs处于I期或II期试验中。bsAb的新概念bsAbs的领域仍在进一步探索和扩展技术和应用，可能提供目前正在开发的bsAb尚未解决的治疗概念。三特异性TCE共刺激信号可以与双特异性TCE组合以促进更加有效的T细胞活化。这样的三特异性TCE目前正在针对TAA和CD3的临床试验中，并且进一步包含抗CD28结合位点。SAR443216是一种针对HER2×CD3×CD28的三特异性抗体，能够强力激活CD4+和CD8+T细胞，诱导T细胞增殖、细胞因子和颗粒酶B的释放，以及T细胞介导的对表达HER2的肿瘤细胞的杀伤，其目前处于I期临床研究中。在类似的方法中，SAR442257是另一种CD38×CD3×CD28的三特异性抗体。前药方法一种新兴的方法是在肿瘤处选择性激活的前药，产生具有高度肿瘤特异性功能的bsAbs。前药转化为功能性bsAbs可以通过环境触发因素如肿瘤相关蛋白酶来实现。双重肿瘤靶向的另一种前药方法依赖于来自两个具有分裂CD3ε结合部分的肿瘤特异性组装。这些分子需要被设计为非活性的独立实体并在循环中，使得它们仅在肿瘤抗原结合和随后的原位组装时被激活。PROTAC bsAbs另一个新兴概念和新的MoA利用bsAbs通过靶向降解来抑制增殖相关过程。类似于双特异性或多特异性小分子蛋白水解靶向嵌合体（PROTACs），bsAbs可被设计为触发参与癌症发展或进展的表面蛋白的内化和随后的降解。这样的bsAbs同时与靶向降解的蛋白质和降解的因子结合，并触发内化，如膜上的E3泛素连接酶或转铁蛋白受体。目前，抗体-PROTAC概念仍处于早期开发阶段，迄今为止还没有进入临床研究。bsAb递送bsAb开发中另一个重要的新兴概念是bsAb的局部产生和随后的局部递送，如通过脂质纳米颗粒介导的mRNA递送的CLDN6 TCE、溶瘤病毒或包括CAR-T细胞在内的基因治疗方法。细胞因子模拟抗体最后，bsAbs也可以作为细胞因子模拟物或所谓的合成细胞因子激动剂。scFvs或基于单域抗体VHH的方法可以通过模拟IL-2或IL-15、IL-18、I型干扰素和IL-10来有效地触发细胞因子信号传导。这种基于抗体的细胞因子模拟物可能在癌症免疫疗法中具有各种应用。小结bsAbs领域最近取得了实质性进展，到2023年底，已有十几种bsAbs获得批准，许多不同的方法正在临床上进行测试。尽管如此，由于癌症的异质性和适应性，这些方法中的任何一种都不太可能成为普遍的癌症免疫疗法。相反，抗体需要针对某些应用量身定制，并将依赖于与其他方法的结合，以最大限度地提高其疗效和安全性。在不久的将来，多特异性抗体疗法的发展可能会在以下四个领域出现增长：针对具有明确依赖性的肿瘤相关RTK的bsAbs；用于以增加的选择性靶向肿瘤的bsADC；用于靶向降解适用于各种途径的细胞表面蛋白的双特异性PROTAC；以及用于癌症免疫疗法的多特异性抗体。与其他治疗癌症的药物一样，通过改进的诊断方法和新的开发模式，将bsAbs和多特异性抗体疗法应用于早期患者，对于实现治愈癌症患者的目标至关重要。参考文献：1. The present and future of bispecific antibodies for cancer therapy. Nat Rev Drug Discov.2024 Mar 6.2. Development of Bispecific Antibody for CancerImmunotherapy: Focus on T Cell Engaging Antibody. Immune Netw. 2022 Feb; 22(1): e4.文章信息源于公众号小药说药，登载该文章目的为更广泛的传递行业信息，不代表赞同其观点或对其真实性负责。文章版权归原作者及原出处所有，文章内容仅供参考。本网拥有对此声明的最终解释权，若无意侵犯版权，请联系小编删除。学如逆水行舟，不进则退；心似平原走马，易放难收。行舟Drug每日更新 欢迎订阅+医药大数据|行业动态|政策解读

$40.9 million cash balance at the end of 2023 expected to provide cash runway into 2H 2025 Completed enrollment of Phase 2 clinical study of EQ101 in alopecia areata: topline data expected in Q2 2024 Presented positive data from Phase 1b EQUALISE study of itolizumab in lupus nephritis patients at American Society of Nephrology (ASN) & American College of Rheumatology (ACR) meetings Ono Pharmaceutical option exercise decision for itolizumab expected in 2H 2024 LA JOLLA, Calif.--(BUSINESS WIRE)-- Equillium, Inc. (Nasdaq: EQ), a clinical-stage biotechnology company leveraging a deep understanding of immunobiology to develop novel therapeutics to treat severe autoimmune and inflammatory disorders, today announced financial results for the fourth quarter and full year 2023, as well as corporate and clinical highlights. “The past year we have been focused on clinical execution that has set up the potential milestones we have in front of us in 2024,” said Bruce Steel, chief executive officer at Equillium. “The Phase 1b EQUALISE study of itolizumab in patients with lupus nephritis is now complete. We presented positive data from this study at the annual meetings of both ASN and ACR in the fourth quarter last year and we expect to deliver the topline data to our partner Ono in the coming weeks. We expect to announce the results of the interim review by the data monitoring committee of our Phase 3 EQUATOR study of itolizumab in patients with acute graft-versus-host disease in the third quarter, which would represent the final data deliverable to trigger Ono’s option exercise period, which will expire three months following such deliverables. If Ono exercises their option to acquire our rights to itolizumab we would receive an exercise payment of approximately $331 million, which would significantly extend our cash runway beyond the second half of 2025 - our current guidance - and we would remain eligible to receive approximately $101 million in additional milestone payments. “Our lead multi-cytokine inhibitor, EQ101, a first in class, tri-specific inhibitor targeting IL-2, IL-9 and IL-15, has completed enrollment in a Phase 2 study for the treatment of moderate to severe alopecia areata. There remains a large unmet medical need for safer alternatives to JAK inhibitors, which carry black-box warnings and are today the only approved class of drugs to treat alopecia areata patients. This is the first study in which EQ101 has been tested in alopecia areata patients, where we are looking for signs of clinical activity above historically low observed placebo responses. We’re pleased to have completed enrollment of this study and look forward to announcing topline data in the second quarter this year.” “In addition to clinical execution, we have also focused efforts on advancing the rest of our novel multi-cytokine inhibitor programs,” said Steve Connelly, chief scientific officer at Equillium. “EQ302, our first-in-class, bi-specific inhibitor of IL-15 and IL-21, is a second-generation peptide with improved potency that is orally deliverable and stable in the gut. We believe this represents a compelling product pro positioned to target gastrointestinal indications including celiac disease, inflammatory bowel disease, and eosinophilic esophagitis. We look forward to advancing this program towards the clinic.” Q4 2023 Highlights: Presented positive data from the Phase 1b EQUALISE study of itolizumab in lupus nephritis patients at the annual meetings of both ASN and ACR. The presentations highlighted a well-tolerated safety pro data that demonstrated high complete and partial response rates with rapid and deep reductions in urine protein creatinine ratios in highly proteinuric patients when itolizumab was added to mycophenolate mofetil and corticosteroids. Hosted an Analyst & Investor Day featuring Arash Mostaghimi, MD, MPA, MPH, associate professor of dermatology at Harvard Medical School, that highlighted Equillium’s pipeline, the multi-cytokine platform and clinical-stage multi-cytokine inhibitors, with a focus on EQ101, currently in a Phase 2 clinical study for moderate to severe alopecia areata. Announced a presentation at the 18th Annual Peptide Therapeutics Symposium highlighting EQ302, a first-in-class, second generation, orally deliverable multi-cytokine inhibitor targeting IL-15 and IL-21. The presentation outlined the origins of EQ302 from its parent peptide and data illustrating that adding hydrocarbon staples to the peptide conferred increased stability in the gastrointestinal tract while retaining its cytokine inhibitory properties. Anticipated Upcoming Milestones: EQ101: Phase 2 clinical study in subjects with moderate to severe alopecia areata – topline data anticipated in Q2 2024 Itolizumab: EQUALISE lupus nephritis topline data to Ono anticipated in the coming weeks; EQUATOR acute graft-versus-host disease interim review anticipated in Q3 2024 Ono option exercise decision anticipated in 2H 2024 Fourth Quarter and Full Year 2023 Financial Results Revenue for the fourth quarter of 2023 was $9.2 million, compared with $15.8 million for the same period in 2022. For the full year of 2023, revenue was $36.1 million, compared with $15.8 million for the full year of 2022. Revenue in 2023 and 2022 consisted entirely of itolizumab development funding and amortization of the upfront payment from Ono resulting from the Asset Purchase Agreement with Ono executed in December 2022, which included such development funding retroactive to the beginning of the third quarter of 2022. Research and development (R&D) expenses for the fourth quarter of 2023 were $9.2 million, compared with $8.5 million for the same period in 2022. For the full year of 2023, R&D expenses were $37.0 million, compared with $37.5 million for the full year of 2022. The nominal year-over-year decrease in R&D expenses was driven by a decrease in non-clinical research expenses and lower employee compensation and benefits, which were partially offset by increased clinical development expenses, primarily driven by the EQUATOR, EQ101 and EQ102 clinical studies. General and administrative (G&A) expenses for the fourth quarter of 2023 were $3.2 million, compared with $5.2 million for the same period in 2022. For the full year of 2023, G&A expenses were $13.6 million, compared with $17.2 million for the full year of 2022. The year-over-year decrease was driven by decreased legal expenses primarily related to 2022 business development activities, lower employee compensation and benefits, and lower consulting and general overhead expenses, which were partially offset by greater audit and tax related professional fees. Net loss for the fourth quarter of 2023 was $2.3 million, or $(0.07) per basic share and diluted share, compared with net income of $2.8 million, or $0.08 per basic and diluted share for the same period in 2022. Net loss for the full year of 2023 was $13.3 million, or $(0.38) per basic and diluted share, compared with a net loss of $62.4 million, or $(1.85) per basic and diluted share for the full year of 2022. The decrease in net loss for the full year of 2023 compared to the full year of 2022 was primarily due to lower operating expenses driven by the non-cash in-process R&D expense related to the acquisition of Bioniz Therapeutics, Inc. in 2022 and lower G&A expenses, greater revenue related to the Ono partnership, greater income on investments, and less interest expense due to the retirement of our former debt facility, which was partially offset by greater income tax expense. Cash, cash equivalents and short-term investments totaled $40.9 million as of December 31, 2023, compared to $71.0 million as of December 31, 2022. Net cash used in operating activities in the fourth quarter was $5.7 million. Equillium believes that its cash, cash equivalents and short-term investments on the balance sheet as of December 31, 2023, will be sufficient to fund its currently planned operations into the second half of 2025, assuming no further repurchases under our stock repurchase program. About Multi-Cytokine Platform and Multi-Cytokine Inhibitors EQ101 & EQ302 Our proprietary multi-cytokine platform generates rationally designed composite peptides that selectively block key cytokines at the shared receptor level targeting pathogenic cytokine redundancies and synergies while preserving non-pathogenic signaling. This approach is expected to avoid the broad immuno-suppression and off-target safety liabilities that may be associated with other therapeutic classes, such as Janus kinase inhibitors. Many immune-mediated diseases are driven by the same combination of dysregulated cytokines, and we believe identifying the key cytokines for these diseases will allow us to target and develop customized treatment strategies for multiple autoimmune and inflammatory diseases. Current platform assets include EQ101, a clinical stage, first-in-class, selective, tri-specific inhibitor of IL-2, IL-9, and IL-15 for intravenous and subcutaneous delivery and EQ302, a preclinical stage, first-in-class, selective, bi-specific inhibitor of IL-15 and IL-21 for oral delivery. About Itolizumab Itolizumab is a clinical-stage, first-in-class anti-CD6 monoclonal antibody that selectively targets the CD6-ALCAM signaling pathway to downregulate pathogenic T effector cells while preserving T regulatory cells critical for maintaining a balanced immune response. This pathway plays a central role in modulating the activity and trafficking of T cells that drive a number of immuno-inflammatory diseases. About Equillium Equillium is a clinical-stage biotechnology company leveraging a deep understanding of immunobiology to develop novel therapeutics to treat severe autoimmune and inflammatory disorders with high unmet medical need. The company’s pipeline consists of the following novel first-in-class immunomodulatory assets and product platform targeting immuno-inflammatory pathways. EQ101: a selective tri-specific cytokine inhibitor targeting IL-2, IL-9, and IL-15; currently under evaluation in a Phase 2 proof-of-concept clinical study of patients with alopecia areata being conducted in Australia and New Zealand by Equillium’s Australian subsidiary as the trial sponsor. EQ302: an orally delivered, selective bi-specific cytokine inhibitor targeting IL-15 and IL-21; currently in pre-clinical development. The multi-cytokine platform: generates rationally designed composite peptides that selectively block key cytokines at the shared receptor level targeting pathogenic cytokine redundancies and synergies while preserving non-pathogenic signaling. Itolizumab: a monoclonal antibody that targets the CD6-ALCAM signaling pathway which plays a central role in the modulation of effector T cells; currently under evaluation in a Phase 3 clinical study of patients with acute graft-versus-host disease (aGVHD) and a Phase 1b clinical study of patients with lupus/lupus nephritis. Equillium acquired rights to itolizumab through an exclusive partnership with Biocon Limited and has entered a strategic partnership with Ono Pharmaceutical Co., Ltd., for the development and commercialization of itolizumab under an option and asset purchase agreement. For more information, visit . ____________________________ 1 Option exercise payment is denominated in Japanese yen (5 billion) and subject to currency exchange rates at the time of payment. Forward Looking Statements Statements contained in this press release regarding matters that are not historical facts are “forward-looking Statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the use of words such as “anticipate”, “believe”, “could”, “continue”, “expect”, “estimate”, “may”, “plan”, “outlook”, “future” and “project” and other similar expressions that predict or indicate future events or trends or that are not statements of historical matters. These statements include, but are not limited to, statements regarding Equillium’s plans for developing EQ101, EQ302 and itolizumab and the expected timeline for results from clinical studies, anticipated upcoming milestones, the timing for triggering Ono’s option period and for receiving Ono’s option decision, the potential impacts of Ono’s option exercise decision, the timing for an IND submission for EQ302, the fluctuation of the foreign exchange rate, Equillium’s cash runway, and the potential benefits of Equillium’s product candidates. Because such statements are subject to risks and uncertainties, many of which are outside of Equillium’s control, actual results may differ materially from those expressed or implied by such forward-looking statements. Risks that contribute to the uncertain nature of the forward-looking statements include: Equillium’s ability to execute its plans and strategies; risks related to performing clinical and pre-clinical studies; whether the results from clinical and pre-clinical studies will validate and support the safety and efficacy of Equillium’s product candidates; changes in the competitive landscape; risks related to Ono’s financial condition and decision to exercise its option, if ever to purchase itolizumab or terminate the asset purchase agreement; uncertainties related to Equillium’s capital requirements; and having to use cash in ways or on timing other than expected and the impact of market volatility on cash reserves. These and other risks and uncertainties are described more fully under the caption "Risk Factors" and elsewhere in Equillium's filings and reports, which may be accessed for free by visiting the Securities and Exchange Commission’s website and on Equillium’s website under the heading “Investors.” Investors should take such risks into account and should not rely on forward-looking statements when making investment decisions. All forward-looking statements contained in this press release speak only as of the date on which they were made. Equillium undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made, except as required by law. Equillium, Inc. Condensed Consolidated Balance Sheets (In thousands) (unaudited) December 31, 2023 2022 Assets Cash, cash equivalents and short-term investments $ 40,866 $ 71,023 Accounts receivable 3,735 2,838 Prepaid expenses and other assets 5,133 3,369 Operating lease right-of-use assets 796 1,191 Total assets $ 50,530 $ 78,421 Current liabilities Accounts payable and other current liabilities $ 11,844 $ 17,338 Current portion of deferred revenue 15,729 14,700 Total current liabilities 27,573 32,038 Long-term deferred revenue - 10,378 Other long-term liabilities 384 4,063 Total liabilities 27,957 46,479 Total stockholders' equity 22,573 31,942 Total liabilities and stockholders' equity $ 50,530 $ 78,421 Equillium, Inc. Condensed Consolidated Statements of Operations (In thousands, except share and per share data) (unaudited) Three Months Ended December 31, Year Ended December 31, 2023 2022 2023 2022 Revenue $ 9,211 $ 15,759 $ 36,084 $ 15,759 Operating expenses: Research and development 9,183 8,525 37,039 37,547 Acquired in-process research and development - - - 23,049 General and administrative 3,228 5,192 13,567 17,239 Total operating expenses 12,411 13,717 50,606 77,835 (Loss) income from operations (3,200 ) 2,042 (14,522 ) (62,076 ) Other income (expense), net 874 731 1,767 (352 ) Net (loss) income before income tax expense (2,326 ) 2,773 (12,755 ) (62,428 ) Income tax expense 16 - 580 - Net (loss) income $ (2,342 ) $ 2,773 $ (13,335 ) $ (62,428 ) Net (loss) income per common share, basic and diluted $ (0.07 ) $ 0.08 $ (0.38 ) $ (1.85 ) Weighted-average number of common shares outstanding, basic and diluted 35,153,124 34,366,926 34,726,384 33,727,945