作者: Vetter, Tatyana A ; Cormet-Boyaka, Estelle ; Rayner, Rachael E. ; Kim, Sun Hee ; Vaidyanathan, Sriram ; Suarez, Carlos J ; Kanke, Karen L. ; Vetter, Tatyana A. ; Kanke, Karen L ; Stack, Jacob T. ; Stack, Jacob T ; Nouri, Reza ; Suarez, Carlos J. ; Rayner, Rachael E

Cystic fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Although many people with CF (pwCF) are treated using CFTR modulators, some are non-responsive due to their genotype or other uncharacterized reasons. Autologous airway stem cell therapies, in which the CFTR cDNA has been replaced, may enable a durable therapy for all pwCF. Previously, CRISPR-Cas9 with two AAVs was used to sequentially insert two-halves of the CFTR cDNA and an enrichment cassette into the CFTR locus. However, the editing efficiency was <10% and required enrichment to restore CFTR function. Further improvement in gene insertion may enhance cell therapy production. To improve CFTR cDNA insertion in human airway basal stem cells (ABCs), we evaluated the use of the small molecules AZD7648 and ART558, which inhibit non-homologous end-joining (NHEJ) and micro-homology mediated end-joining (MMEJ). Adding AZD7648 alone improved gene insertion by 2- to 3-fold. Adding both ART558 and AZD7648 improved gene insertion but induced toxicity. ABCs edited in the presence of AZD7648 produced differentiated airway epithelial sheets with restored CFTR function after enrichment. Adding AZD7648 did not increase off-target editing. Further studies are necessary to validate if AZD7648 treatment enriches cells with oncogenic mutations.

2024-11-01·SURGERY

Overexpression of human DNA polymerase theta is a biomarker of aggressive and DNA repair-deficient papillary thyroid cancers

Article

作者: Gillanders, William ; Othoum, Ghofran ; Goedegebuure, S Peter ; Yeager, Ashley ; Olson, John A ; Brown, Taylor C ; Maher, Christopher A ; Chernock, Rebecca ; Frye, C Corbin ; Bhardwaj, Priya ; Azimzadeh, Pedram ; Liu, Jingxia ; Xu, Yifei ; Tennant, Lena

BACKGROUND:

DNA polymerase theta (POLQ) is an enzyme that repairs double-strand DNA breaks. POLQ is overexpressed in several cancer types, and increased expression is associated with a poor prognosis. Ablating POLQ function in vitro increases drug sensitivity to agents that cause double-strand DNA breaks, including chemotherapies and ionizing radiation. POLQ's role in thyroid cancer remains poorly understood.

METHODS:

Expression of POLQ and other genes of interest were analyzed in 513 papillary thyroid cancers (505 primary tumors and 8 metastatic lesions) and 59 normal thyroid samples available in the Cancer Genome Atlas. The Cancer Genome Atlas RNA and DNA sequencing data were queried with the Xena platform. The Recombination Proficiency Score was calculated to assess DNA repair efficiency. Other signaling events associated with thyroid tumorigenesis and clinical outcomes were analyzed. Univariate and multivariate analyses were performed. Treatment with the POLQ inhibitors ART558 and Novobiocin tested the effect of POLQ inhibition on in vitro thyroid cancer growth.

RESULTS:

POLQ expression was increased in papillary thyroid cancers compared to normal thyroid tissue (P < .05). POLQ expression levels were inversely correlated with Recombination Proficiency Score levels (P < .05). POLQ expression was highest in tall cell papillary thyroid cancers and in metastases. Higher POLQ expression was also associated with dedifferentiation, BRAF signaling, and shorter progression-free intervals (P < .05). Treatment with POLQ inhibitors decreased in vitro thyroid cancer growth (P < .05).

CONCLUSION:

These findings suggest that increased POLQ expression could serve as a valuable clinical marker and a potential therapeutic target in the treatment of thyroid cancer.

2024-11-01·RADIOTHERAPY AND ONCOLOGY

Talazoparib enhances resection at DSBs and renders HR-proficient cancer cells susceptible to Polθ inhibition

Article

作者: Sun, Yanjie ; Hessenow, Razan ; Mladenov, Emil ; Guberina, Maja ; Iliakis, George ; Soni, Aashish ; Stuschke, Martin ; Lin, Xixi

BACKGROUND AND PURPOSE:

The PARP inhibitor (PARPi), Talazoparib (BMN673), effectively and specifically radiosensitizes cancer cells. Radiosensitization is mediated by a shift in the repair of ionizing radiation (IR)-induced DNA double-strand breaks (DSBs) toward PARP1-independent, alternative end-joining (alt-EJ). DNA polymerase theta (Polθ) is a key component of this PARP1-independent alt-EJ pathway and we show here that its inhibition can further radiosensitize talazoparib-treated cells. The purpose of the present work is to explore mechanisms and dynamics underpinning enhanced talazoparib radiosensitization by Polθ inhibitors in HR-proficient cancer cells.

METHODS AND MATERIALS:

Radiosensitization to PARPis, talazoparib, olaparib, rucaparib and veliparib was assessed by clonogenic survival. Polθ-proficient and -deficient cells were treated with PARPis and/or with the Polθ inhibitors ART558 or novobiocin. The role of DNA end-resection was studied by down-regulating CtIP and MRE11 expression using siRNAs. DSB repair was assessed by scoring γH2AX foci. The formation of chromosomal abnormalities was assessed as evidence of alt-EJ function using G₂-specific cytogenetic analysis.

RESULTS:

Talazoparib exerted pronounced radiosensitization that varied among the tested cancer cell lines; however, radiosensitization was undetectable in normal cells. Other commonly used PARPis, olaparib, veliparib, or rucaparib were ineffective radiosensitizers under our experimental conditions. Although genetic ablation or pharmacological inhibition of Polθ only mildly radiosensitized cancer cells, talazoparib-treated cells were markedly further radiosensitized. Mechanistically, talazoparib shunted DSBs to Polθ-dependent alt-EJ by enhancing DNA end-resection in a CtIP- and MRE11-dependent manner - an effect detectable at low, but not high IR doses. Chromosomal translocation analysis in talazoparib-treated cells exposed to Polθ inhibitors suggested that PARP1- and Polθ-dependent alt-EJ pathways may complement, but also back up each other.

CONCLUSION:

We propose that talazoparib promotes low-dose, CtIP/MRE11-dependent resection and increases the reliance of irradiated HR-proficient cancer cells, on Polθ-mediated alt-EJ. The combination of Polθ inhibitors with talazoparib suppresses this option and causes further radiosensitization. The results suggest that Polθ inhibition may be exploited to maximize talazoparib radiosensitization of HR-proficient tumors in the clinic.

项与 ART-558 相关的新闻（医药）

2024-08-09

·CPHI制药在线

圣域生物SYN818片IND获FDA批准，浅谈Polθ抑制剂研究进展

关注并星标CPHI制药在线近日，杭州圣域生物（SynRx Therapeutics）自主研发的创新药物SYN818片的新药临床试验申请（IND）获得美国FDA的许可，即将启动1期临床试验。就在几日前，SYN818片在中国的IND申请也获得国家药监局药品评审中心（CDE）的受理。 SYN818是由圣域生物自主研发的一款新型小分子抑制剂化合物。该药物通过精准靶向DNA聚合酶θ（Polθ），有效抑制肿瘤细胞的DNA损伤修复，从而有选择性的杀死肿瘤细胞。临床前研究显示，SYN818能够高效抑制Polθ蛋白活性，阻断MMEJ修复通路，与同源重组缺陷（HRD）存在联合致死效果，从而发挥抗肿瘤作用。同时，它在体内外研究中也表现出与PARPi的显著联合增效作用。SYN818在临床前研究中表现出强效抗肿瘤活性、优异的药代动力学性质，以及良好的安全性，未观察到显著的血液毒性。根据临床前研究数据，SYN818作为一个Polθ抑制剂具有潜在“best-in-class”的特征。SYN818不仅对HRD肿瘤细胞具有单独成药的潜力，还具有与PARP抑制剂、放化疗、抗体偶联药物等联合用于多种肿瘤治疗的潜质，有望降低现有治疗方案的临床毒性、克服耐药，具有广阔的临床开发前景。此外，圣域生物的另一款处于临床前阶段的高潜力Polθ抑制剂也在今年4月举办的美国癌症研究协会年会（AACR 2024）上亮相，其与PARP抑制剂联用具有强大的协同作用，亦可能单独治疗HR通路缺陷的患者。在非临床研究阶段，SYX1097展现了出色的动物体内疗效，优良的药代动力学特征及理想的安全性表现，在较高剂量下亦未见明显血液毒性，从而揭示了宽广的治疗窗。合成致死靶点之Polθ Polθ是DNA聚合酶A家族成员之一，由哺乳动物细胞中的POLQ基因编码，具有N端解旋酶样结构域和C端DNA聚合酶结构域，通过非结构中心结构域分离开。Polθ是MMEJ途径的重要组成部分，作为效应蛋白参与DNA双链断裂修复。MMEJ生化步骤中，Polθ解旋酶活性促进含有微同源性(互补DNA序列的短片段)的ssDNA退火，Polθ聚合酶活性完成DNA合成填充切除的缺口。在具有功能性HR修复途径的正常细胞中，Polθ参与的MMEJ途径是不活跃的，其对DSB修复的影响有限。HR和MMEJ途径共享相同的底物，同源重组缺陷(HRD)的肿瘤细胞存活会高度依赖MMEJ介导的DNA修复。因此，在HRD肿瘤中抑制Polθ可以诱发合成致死。此外，PARP作为损伤感应器与Polθ作为效应蛋白均参与HR受损后的MMEJ后备修复通路，由于其不同的作用机制，PARPi和Polθ抑制剂联合治疗可能在HR缺陷肿瘤中具有协同作用；另外，尽管PARPi单药治疗在BRCA突变的癌症中观察到了显著的临床获益，但相当一部分患者产生原发性(＞40％)和继发性耐药，因此需要新的治疗策略来克服PARP的耐药性，以及利用其他的DNA修复缺陷新途径。鉴于Polθ在正常组织中的几乎不表达，但在乳腺癌、卵巢癌、头颈肿瘤和肺癌等多种肿瘤中高表达，而这些瘤种中又普遍存在同源重组修复缺陷, Polθ被认为是合成致死药物研发的潜力靶点。 Polθ抑制剂：Artios、IDEAYA领衔，国内紧跟脚步目前，Polθ已经被证实与肿瘤的形成、肿瘤细胞放射治疗的敏感性以及患者预后有关。全球药企针对该靶点有多款新药在研，在研Polθ抑制剂进展缓慢，最快处于1/2期临床，大多处于临床前阶段。从布局企业来看，Polθ抑制剂研发企业并不多，且相对集中。 Artios Pharma是Polθ领域的大玩家，ART4215是Artios开发的一种选择性的口服生物可利用的POLQ聚合酶结构域小分子抑制剂，也是全球首个Polθ抑制剂，2022年已启动ART4215联合PARP抑制剂他拉唑帕利治疗BRCA缺陷型乳腺癌的2期研究。来自第一阶段的剂量组初步数据表明，ART4215具有良好的耐受性。此外，Artios还布局2款Polθ抑制剂，ART6043处于临床1/2期；ART558和ART812处于临床前。 IDEAYA Biosciences是一家致力于突破合成致死领域技术困境的创新企业。2020年6月，IDEAYA Biosciences和葛兰素史克公司（GSK）宣布在“合成致死”领域建立战略合作伙伴关系，而这一战略合作伙伴关系包含IDEAYA Biosciences的三个合成致死研发项目，分别靶向MAT2A、Polθ和Werner解旋酶。 GSK101（IDE705）是一种潜在首创Polθ小分子抑制剂。临床前研究显示，在BRCA突变模型中，GSK101联用niraparib与单药相比，能产生更深入、更持久的抗肿瘤作用。去年8月，该药在美国获批1/2期临床，评估其联合GSK的PARP小分子抑制剂niraparib治疗携带BRCA或其他同源重组（HR）突变或同源重组缺陷（HRD）肿瘤的效果。此外，有研究指出一种在20世纪50年代发现的抗生素新生霉素（novobiocin，NVB）也是一种人类DNA聚合酶Polθ的抑制剂，能有效地杀死携带同源重组（HR）DNA修复缺陷的肿瘤细胞，更加令振奋的是，这种杀伤能力对那些对PARP抑制剂产生耐药的肿瘤细胞也有效。2023年1月，美国食品和药物管理局（FDA）批准Novobiocin用于携带BRCA2或BRCA1基因突变的癌症患者的临床试验。除了圣域生物，国内药企如先声药业也积极布局了该靶点，已经有2款Polθ抑制剂处于临床前阶段，分别为SIM0508和SS008871。其中，SIM0508能够抑制HR缺陷的BRCA2-/-DLD-1细胞的增殖，并显示出DLD-1亲本细胞和非恶性细胞的>125倍选择性，SIM0508片的临床试验申请在今年6月已获得CDE受理。另一款Polθ抑制剂SS008871和奥拉帕尼的组合能进一步导致肿瘤消退，且在人类造血干细胞等体外试验中没有出现明显的造血毒性风险，具有良好的安全性。参考文献： 1.Zhou, J., et, al. (2021). A first-in-class polymerase theta inhibitor selectively targets homologous-recombination-deficient tumors. Nature Cancer. Doi:10.1038/s43018-021-00203-x. 2.《实力靶点Polθ：潜力迸发，巨头入局》.医药魔方.2021-08-12 3.各企业官网 END 【智药研习社直播预告】来源：CPHI制药在线声明：本文仅代表作者观点，并不代表制药在线立场。本网站内容仅出于传递更多信息之目的。如需转载，请务必注明文章来源和作者。投稿邮箱：Kelly.Xiao@imsinoexpo.com ▼更多制药资讯，请关注CPHI制药在线▼ 点击阅读原文，进入智药研习社~

临床申请AACR会议临床1期

100 项与 ART-558 相关的药物交易

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