Small Molecule Tyrosine Kinase Inhibitors Research Articles

The efficacy and safety of anlotinib combined with bevacizumab in treatment of recurrent isocitrate dehydrogenase wildtype glioblastoma: A retrospective analysis.

e14028 Background: Glioblastoma (GBM) is the most common and aggressive malignant primary brain tumor with a 5-year survival rate of 5%. There is no standard and effective treatment for recurrent GBM. Angiogenesis is recognized as a key event in the progression of GBM. Bevacizumab as an anti-angiogenic monoclonal antibody has been recommended by NCCN guidelines for recurrent GBM. Anlotinib is a small-molecule multi-target tyrosine kinase inhibitor (TKI) which has different function mechanisms and targets with bevacizumab. Therefore, we investigated the clinical efficacy and safety of anlotinib combined with bevacizumab in patients with recurrent IDH-wide type (wt) GBM on the basis of TMZ treatment. Methods: We retrospectively analyzed the clinical data of 18 patients with IDH-wt GBM in Shandong Cancer Hospital and Institute from 2019 to 2022. The primary endpoint was progression-free survival (PFS) and overall survival (OS) for combination treatment. The secondary endpoint was 6-months PFS rate, 1-year OS rate, objective response rate (ORR), disease control rate (DCR), OS and safety and toxicity profile. Results: All patients were diagnosed as WHO grade IV IDH-wt GBM and the median age of all patients was 55 years (range 39-76). Patients with recurrent GBM were first treated with anlotinib, followed by bevacizumab when patients developed progression or cerebral edema. In the overall population, the median OS for overall patients is 27 months, and the median survival time after first recurrence is 13.3 months. The median survival time of anlotinib treatment and combination treatment is 15.6 months and 12 months, respectively and the median PFS is 14.3 months and 9.1 months, respectively. The ORR for combination treatment was 27.8%, and 6-months DCR was 77.8%. The last follow-up date was October 15, 2022. By the last follow-up date, 3 patients were continuing anlotinib combined with bevacizumab treatment with no disease progression. The 6-months PFS rate was 78.9%, and the 1-year OS rate was 44.4%. The treatment-related adverse events (AEs) were shown in Table 3. The main AEs was bone marrow suppression (83.3%, 15/18), most of which were grade I and II (50%, 9). The AEs were relieved by adjusting the drug dose and symptomatic treatment. There were no treatment related deaths. Conclusions: Our study reported the clinical effect of anlotinib combined with bevacizumab treatment in recurrent GBM patients on the basis of TMZ treatment in a real-world setting. This is the first attempt to conduct dual antiangiogenic treatment in GBM patients. We demonstrate a promising result and suggest that this combination treatment may be a novel and safety treatment option for recurrent IDH-wt GBM patients.

Efficacy and safety of anlotinib in overall and disease-specific advanced gynecological cancer: A real-world study.

5608 Background: Anlotinib is a novel oral small-molecule multi-target tyrosine kinase inhibitor that has been approved for treating non-small cell lung cancer. However, its efficacy and safety among patients with advanced gynecological cancer. We conducted this study to address this issue in the real-world setting. Methods: Data from patients treated with anlotinib for persistent, recurrent or metastatic gynecological cancer including cervical, endometrial, and ovarian cancer were collected from 17 centers from August 2018. The database lock-time was on March 2022. Anlotinib was administered orally on days 1–14 every 3 weeks until disease progression, severe toxicity occurred, or death. The outcomes included objective response rate (ORR), disease control rate (DCR), and progression-free survival (PFS). Results: A total of 249 patients were analyzed, with a median follow-up of 14.46 months. The overall ORR and DCR were 28.1% (95% CI 22.6% to 34.1%), and 80.7% (95% CI 75.3% to 85.4%), respectively. Specifically, the ORR varied from 19.7% to 34.4% and the DCR differed from 81.7% to 90.0% in disease-specific advanced gynecological cancer. The median PFS was 6.1 months and ranged from 5.6 to 10.0 months in the overall and disease-specific advanced gynecological cancer, respectively. Larger cumulative dosage of anlotinib (>700 mg) was in general associated with longer PFS in the overall and disease-specific advanced gynecological cancer. The most common adverse event related to anlotinib use was pain/arthralgia (18.3%). Conclusions: In conclusion, anlotinib holds promise in treating patients with advanced gynecological cancer, such as cervical, endometrial, and ovarian cancer, with reasonable efficacy and tolerable safety.

A randomized trial of eribulin monotherapy versus eribulin plus anlotinib in patients with locally recurrent or metastatic breast cancer

Eribulin mesylate is a novel, nontaxane, microtubule dynamics inhibitor. In this study, we assessed the efficacy and safety of eribulin versus eribulin plus the oral small-molecule tyrosine kinase inhibitor anlotinib in patients with locally recurrent or metastatic breast cancer. In this single-center, open-label, phase II clinical study (NCT05206656) conducted in a Chinese hospital, patients with human epidermal growth factor receptor 2 (HER2)-negative, locally recurrent or metastatic breast cancer previously treated with anthracycline- or taxane-based chemotherapy were randomized (1 : 1) to receive eribulin alone or in combination with anlotinib. The primary efficacy endpoint was investigator-assessed progression-free survival (PFS). From June 2020 to April 2022, a total of 80 patients were randomly assigned to either eribulin monotherapy or eribulin plus anlotinib combination therapy, with 40 patients in each group. The data cut-off was 10 August 2022. The median PFS was 3.5 months [95% confidence interval (CI) 2.8-5.5 months] for eribulin and 5.1 months (95% CI 4.5-6.9 months) for eribulin plus anlotinib (hazard ratio= 0.56, 95% CI 0.32-0.98; P= 0.04). The objective response rates were 32.5% versus 52.5% (P= 0.07), respectively, and disease control rates were 67.5% versus 92.5% (P= 0.01), respectively. Patients <50 years of age, with an Eastern Cooperative Oncology Group performance status score of 0, visceral metastasis, number of treatment lines of four or more, hormone receptor negative (triple-negative), and HER2 low expression appeared to benefit more from combined treatment. The most common adverse events in both groups were leukopenia (n= 28, 70.0%, patients in the eribulin monotherapy group versus n= 35, 87.5%, patients in the combination therapy group), aspartate aminotransferase elevations (n= 28, 70.0%, versus n= 35, 87.5%), neutropenia (n= 25, 62.5%, versus n= 31, 77.5%), and alanine aminotransferase elevations (n= 25, 62.5%, versus n= 30, 75.0%). Eribulin plus anlotinib can be considered an alternative treatment option for HER2-negative locally advanced or metastatic breast cancer.

Bruton Tyrosine Kinase Inhibitor Associated Cryptococcal Meningitis Manifesting as Stroke (P1-10.002)

<h3>Objective:</h3> To highlight the appearance of fungal-related stroke on MRI and to increase awareness of opportunistic CNS infection as an etiology of cryptogenic stroke in patients receiving immunomodulatory therapies <h3>Background:</h3> Over a third of strokes are cryptogenic. Identifying the etiology of stroke is a crucial step in reducing the incidence and associated morbidity and mortality of recurrent stroke. Opportunistic CNS infection is a well-documented cause of stroke. The development and increasingly widespread use of high-efficacy immunomodulatory drugs requires vigilance for opportunistic infection and associated complications in patients receiving these drugs. <h3>Design/Methods:</h3> A case report <h3>Results:</h3> A 65-year-old gentleman with Waldenstrom’s macroglobulinemia on zanubrutinib complicated by biopsy-confirmed AHL amyloidosis, which was further complicated by cardiomyopathy, nephropathy, and recurrent pleural effusions presented with encephalopathy and was found to have multifocal acute, symmetric, subcortical strokes. There was no evidence of prior strokes or chronic small vessel disease on MRI. A comprehensive stroke work-up was unremarkable, including typical vascular risk factors within goal, negative blood cultures, normal d-dimer, normal serum viscosity, no radiographic evidence of large vessel disease, and no arrhythmia on telemetry. Echocardiogram showed bi-atrial enlargement related to cardiac amyloid, but no evidence of atrial, ventricular, or perivalvular thrombus. Lumbar puncture was performed and revealed WBC 10, RBC 9, glucose 16, and protein 154. Cryptococcal antigen was positive at a titer of 1:64. Amphotericin B and flucytosine were initiated with clinical improvement over two weeks and he was transitioned to fluconazole for maintenance therapy and prophylaxis. <h3>Conclusions:</h3> This case describes a patient treated with zanubrutinib who developed cryptococcal meningitis causing multifocal acute, symmetric, subcortical strokes. Small molecule tyrosine kinase inhibitors are associated with increased relative risk of opportunistic infection, including CNS fungal infections. Opportunistic CNS infection should be considered as a potential cause of cryptogenic stroke in patient’s receiving these drugs. <b>Disclosure:</b> Dr. Perez has nothing to disclose. Mr. Morrison has nothing to disclose. The institution of Dr. Sloane has received research support from National Center for Advancing Translational Sciences of the National Institutes of Health: KL2TR001879.

A single-arm phase II clinical trial of anlotinib combined with chemotherapy for the treatment of metastatic triple-negative breast cancer.

Anlotinib is a novel oral small-molecule tyrosine kinase inhibitor (TKI), which can inhibit angiogenesis. The purpose of this study was to evaluate the efficacy and safety of anlotinib combined with chemotherapy in patients with metastatic triple-negative breast cancer (TNBC). This phase II clinical trial included 40 patients with metastatic TNBC who had previously received anthracycline and/or taxane treatment. All patients received anlotinib combined with chemotherapy. The primary endpoint was progression-free survival (PFS). The secondary endpoints included overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR), disease control rate (DCR) and safety. During May 1, 2019 and April 30, 2022, there were 40 patients enrolled in this study. The median PFS and median OS were 8.8 months (95% confidence interval [CI] 6.5-11.1 months) and 19.0 months (95% CI, 12.1-25.9 months), respectively. The ORR, CBR and DCR were 40.0% (16/40), 85.0% (34/40) and 95.0% (38/40), respectively. Cox univariate and multivariate analyses demonstrated that having more than 3 metastatic sites (p = 0.001; p = 0.020) was an independent and meaningful unfavorable prognostic factor for PFS. 37.5% of patients had grade 3 to 4 treatment-related adverse events (TRAEs). The grade 3 to 4 TRAEs included neutropenia (22.5%), leukopenia (20.0%), secondary hypertension (10.0%), hand-foot syndrome (5.0%), vomiting (5.0%), proteinuria (5.0%) and thrombocytopenia (2.5%). None of the patients withdrew from the study or died due to TRAEs. In this single-arm study, the treatment of metastatic TNBC with anlotinib combined with chemotherapy showed certain efficacy, and its toxicity was acceptable.

Membrane fusion-mediated delivery of small-molecule HER2 tyrosine kinase inhibitor for effective tumor chemosensitization

Although nanocarriers have been widely applied in the delivery of anticancer drugs, many commercialized anticancer nanodrug systems still suffer from the problem of being easily trapped by lysosomes, which severely limits the drug delivery efficiency of a nanodrug system. Meanwhile, in drug-resistant tumors, the efflux of anticancer therapeutic drugs via the drug efflux transporters on the plasma membrane of cancer cells can significantly decrease the intracellular drug concentration and lead to the failure of the drug treatment. Here, we developed a small-molecule tyrosine kinase inhibitor (TKI)- and doxorubicin (Dox, a common anticancer drug)-loaded membrane fusion liposome (MFL) (termed Dox@Lapa-MFL) to achieve tumor cell membrane fusion-mediated drug delivery and enhanced chemotherapy of drug-resistant tumor. MFL could deliver drugs in a membrane fusion manner, circumventing the capture by lysosomes. Lapatinib, as the TKI doped in the MFL, could inhibit the efflux of Dox by ATP-binding cassette transporters (ABC transporters), further promoting the intracellular Dox accumulation. As a result, Dox achieved effective killing of drug-resistant tumors under the dual effect of MFL and lapatinib. To the best of our knowledge, it is the first example that employs membrane fusion-mediated TKI delivery for achieving tumor chemosensitization with good biosafety. This work presents an efficient and easily achievable strategy for treating drug-resistant tumors, which may hold promise for clinical applications.

Abstract 561: Development of competing and non-competing fully human internalizing anti-Her2 monoclonal antibodies

Abstract The human epidermal growth factor receptor (HER) family of receptors has been implicated in several human cancers. Among them, HER2 is overexpressed in several cancers with or without gene amplification with prognostic and predictive implications. In 15-30% of breast cancers, HER2 overexpression and amplification are associated with shorter disease-free and overall survivals along with resistance to hormonal agents as well as increased risk of brain metastasis. Two types of HER2 targeting have been developed: anti-HER2 monoclonal antibodies and small molecule tyrosine kinase inhibitors. Trastuzumab is a humanized anti-HER2 monoclonal antibody that binds to domain IV of HER2 extracellular segment and blocks its signaling. It is the first therapeutic antibody targeting Her2 overexpression approved by the FDA. More recently, two antibody drug conjugates using trastuzumab have been approved: Ado-Trastuzumab-Emtansine (Kadcyla) consisting of trastuzumab conjugated to the drug mertansine DM1 and fam-trastuzumab-deruxtecan-nhki (Enhertu to deliver the topoisomerase inhibitor deruxtecan. We are reporting here the development of fully human internalizing anti-Her2 antibodies that compete or not with trastuzumab for binding to Her2. These antibodies have been developed by immunizing fully human (TC-Mab mouse) mice with recombinant Her2 protein. After production of hybridoma secreting fully human immunoglobulins, the screening process included inhibition of binding of trastuzumab to Her2 by enzyme linked immunoassay and by Octet epitope binning as well as internalization assay. Several internalizing antibodies able to compete or not with trastuzumab and with high affinity (Kd ranging from 10−9 M to 10−12 M) were selected. They were next investigated for their ability to deliver a cytotoxic payload in HER2 overexpressing cells breast cancer cells such as SKBR3, BT474 and AU565. Two antibodies: one competing with trastuzumab and the other one non-competing were further characterized. Data related to these antibodies’ biochemical characteristics as well as their ability to inhibit proliferation in vitro and in vivo in mouse xenografts studies will be presented here. In conclusion, the use of fully human mice in our laboratory provides a powerful and attractive approach to develop fully human monoclonal antibodies against cancer targets allowing to by-pass the need for humanization and affinity maturation of antibodies. Citation Format: Ginette Serrero, Binbin Yue, Jianping Dong, Chun Dong, Jun Hayashi. Development of competing and non-competing fully human internalizing anti-Her2 monoclonal antibodies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 561.

Abstract 5675: Discovery and development of an asymmetric IgG-like bispecific antibody targeting EGFR and c-MET, engineered through H-H and H-L chain charge-based heterodimerization

Abstract Background: Lung cancer remains the leading cause of cancer mortality and is the most commonly diagnosed cancer with an estimated 2.2 million cases per year. EGFR, a tyrosine kinase receptor, plays a central role in cellular proliferation, survival, differentiation, and migration. Gain-of-function somatic mutations of EGFR significantly drives disease progression. Small molecule tyrosine kinase inhibitors (TKIs), designed to inhibit EGFR signaling specific to these mutations (e.g., L858R and E19del etc.), have achieved excellent clinical outcomes. However, patients carrying TKI-insensitive mutations (e.g., E20ins) and/or those with disease progression after TKI treatment, by the upregulation of complementary signaling pathways (HGF/c-MET, etc.), remain an unmet medical need. Here, we report the discovery of a fully-human afucosylated anti-EGFR x cMET IgG-like bispecific antibody (PM1080). Methods: PM1080 was generated by introducing unique mutations to the CH1-CL domains of each binding arm to promote correct HC-LC pairing. KIH mutations were also introduced to each CH3 domain to support HC-HC heterodimerization and generate an IgG-like bispecific with one arm binding to EGFR and the other to cMET. PM1080 was expressed via a four-chain expression system in CHO cells carrying a fut8−/− knockout to generate afucosylated molecules with enhanced ADCC activity. Results: Through monovalent affinity measurements, PM1080 interacted with EGFR at single digit nanomolar affinity and at sub-nanomolar affinity to c-MET. PM1080 preferentially bound to EGFR/c-MET double-positive cells rather than EGFR single-positive cells. PM1080 blocked both EGF/EGFR and HGF/c-MET signals via physical blockade of the interaction between EGF/HGF to their corresponding receptors and induced EGFR/c-MET internalization and degradation from the cell surface. Through intricate engineering, PM1080 was expressed via a four-chain system and produced as an afucosylated antibody with significantly improved ADCC function. PM1080 induced potent anti-tumor efficacy against EGFR/c-MET-positive tumor cells as a single agent. Importantly, PM1080 induced anti-tumor activity regardless of EGFR mutations at the intracellular signaling domain, and thus may serve as a promising combinational agent to TKI therapies. As expected, synergistic anti-tumor activity was observed when PM1080 was combined with either 1st or 3rd generation TKIs in both in vitro and in vivo models. Conclusion: PM1080, a bispecific antibody targeting EGFR &amp; c-MET was discovered for cancer treatment. PM1080 displayed potent anti-tumor efficacy either as a single agent or in combination with EGFR TKIs. Preclinical PK and toxicity studies have been conducted to support future first-in-human studies. Citation Format: Ping Wang, Weifeng Huang, Zhenting Zhao, Xiaoniu Miao, Shaogang Peng, Chao Wang, Yao Yan, Tiantian Dong, Andy Tsun, Yingda Xu, Xiaolin Liu, Luo Yi. Discovery and development of an asymmetric IgG-like bispecific antibody targeting EGFR and c-MET, engineered through H-H and H-L chain charge-based heterodimerization. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5675.

Abstract 5054: The study of synergy mechanism between surufatinib and vinorelbine in the treatment of non-small cell lung cancer

Abstract Background: The incidence and mortality rate of lung cancer ranks first among malignant tumors. Non-small cell lung cancer (NSCLC) is the most common pathological type of lung cancer. Combined use of targeted therapy can enhance the efficacy of chemotherapy drugs while reduce the related side effects in clinical practice. Surufatinib is a potent, small-molecule tyrosine kinase inhibitor (TKI), selectively targeting VEGF receptors (VEGFR) 1, 2, and 3, Fibroblast growth factor receptor 1 (FGFR1), and CSF-1R, which simultaneously prevents tumor angiogenesis and tumor immune evasion. Our clinical study (NCT04922658) has showed the promising effect and safety of surufatinib plus vinorelbine in NSCLC patients, but the potential mechanism is still to be revealed. Herein, tumor-bearing models and cancer cell culture platform would be established for further studying, which may shed light on the synergy mechanism between surufatinib and vinorelbine, and guide the clinical treatment ultimately. Methods: Subcutaneous tumorigenesis in nude mice were successfully established, and then treated with related experimental drugs. The tumor size was observed and CD31 expression of tumor tissue was measured using immunohistochemical analysis. In vitro study, the A549 and PC9 cell multiplication capacities were measured by CCK8 assay and plate cloning assay. The abilities of cancer cell migration and apoptosis were detected using cell scratch assay and flow cytometry kit, respectively. Results: Monotherapy with surufatinib or vinorelbine showed a moderate tumor suppression, whereas the combination therapy of surufatinib and vinorelbine showed the remarkable inhibition of tumor growth in vivo. Surufatinib and the combination therapy obviously decreased the expression of CD31 in tumor issue which might cause the anti-angiogenesis. Monotherapy with surufatinib or vinorelbine significantly inhibited the proliferation of lung cancer cells (A549 cells and PC9 cells) in a concentration-dependent manner, and surufatinib could memorably promote the anti-proliferation activity of vinorelbine. As a result, combination therapy of surufatinib and vinorelbine distinctly inhibited lung cancer cell proliferation when compared with monotherapy with vinorelbine. Consistently, the synergistic effects of surufatinib plus vinorelbine were also observed in cell migration and apoptosis analysis. Conclusions: Synergistic effect of surufatinib and vinorelbine resulted in a conspicuous tumor regression, which is consistent with the clinical observation. In a depth data analysis, surufatinib enhanced the antitumor activity of vinorelbine probably by inhibiting tumor cell proliferation and migration, suppressing tumor angiogenesis and promoting tumor apoptosis in NSCLC patients. Citation Format: Xiaoran Wu, Yanfang Zheng, Lingyu Qin, Ying Li, Zhongjian Yu, Xiongjie Zhu, Rui Cai, Feiyu Niu, Yan Yuan, Peng Jiang, Shaoshi Wen, Xing Lv, Jiancai Zhou. The study of synergy mechanism between surufatinib and vinorelbine in the treatment of non-small cell lung cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5054.

Abstract 6202: 6-Phosphofructo-2-kinase in regulating DNA damage and repair in EGFR-driven lung cancer

Abstract Activating mutations of epidermal growth factor receptor (mutEGFR) are established drivers of lung tumor development, aggressiveness, and resistance to targeted therapies. While targeting mutEGFR with small-molecule tyrosine kinase inhibitors (EGFR-TKIs) dramatically improved progression-free survival in patients with non-small cell lung cancers (NSCLCs), intrinsic or acquired resistance to TKI therapy limits the duration of an effective response to TKIs. Alteration in DNA damage response (DDR) plays a vital role in genomic stability and cancer progression and helps cells to escape apoptosis, limiting the efficacy of targeted therapies. Interestingly, lung cancer cells exposed to EGFR-TKIs demonstrate attenuated glycolytic flux - one of the major providers of precursors for de novo nucleotide synthesis. A key regulator of glycolysis is the enzyme 6-phosphofructo-2-kinase (PFKFB3). PFKFB3 synthesizes fructose 2,6-bisphosphate (F2,6BP), which is a potent allosteric activator of the glycolytic rate-limiting enzyme, 6-phosphofructo-1-kinase (PFK1). Accordingly, F2,6BP controls flux throughout the entire glycolytic pathway. In preliminary studies, we provide evidence that PFKFB3 plays multiple roles in regulating the efficacy of DDR in lung cancer cells exposed to EGFR-TKIs. We show that PFKFB3 is required for EGFR-driven glucose metabolism, which provides a list of intermediates utilized in nucleotide synthesis. PFKFB3 regulates the expression of ribonucleotide reductase small subunit M2 (RRM2) of the ribonucleotide reductase (RNR), which is important for de novo onsite synthesis of deoxynucleotide triphosphate (dNTP) during DNA replication and repair. Moreover, a PFKFB3 inhibitor, PFK-158, increases oxidative stress in mutEGFR lung cancer cell lines and, as a result, promotes DNA damage. Importantly, we found that PFKFB3 plays an important role in the chromatin binding of scaffold proteins regulating the assembly of DNA repair complex. Our studies suggest that PFKFB3 plays an important role in DDR and provide a clear rationale to propose the use of PFKFB3 inhibitors in combination with EGFR inhibitors to increase the efficiency and/or overcome resistance to EGFR-TKIs. Citation Format: Nadiia Lypova, Lilibeth Lanceta, Susan Dougherty, Jason Chesney, Yoannis Imbert-Fernandez. 6-Phosphofructo-2-kinase in regulating DNA damage and repair in EGFR-driven lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6202.

Abstract 1069: A novel PAThway based RNA and DNA Integration with Tumor Organoid Testing (PATRIOTTM) platform predicts therapeutic options in cohorts with MET overexpression and CDKN2A downregulation in patients with colon and pancreatic cancers

Abstract Background: Cancer therapy has witnessed great progress over the last 50 years with advancements in diagnostic tools to enable more precise treatment. With the development of next-generation sequencing, the field of precision oncology has been expanded to tailor treatments to a patient's mutational profile, however, there is a need for additional information such as RNA Differential Expression (DE) to match more patients to potentially beneficial drugs. We have previously described our PATRIOT platform, which integrates RNA DE analysis, NGS, and high throughput patient-derived organoid models to identify new therapeutic targets. In our previous study, we tested the PATRIOT platform on a patient with predicted KRAS and IDHI inactivation resulting in inhibition of DNA damage repair pathway. Patient-derived tumor organoids showed a significant response to the suggested treatment, Olaparib, supporting the reliability of PATRIOT prediction. To further validate this platform, we interrogated the predictive efficacy of PATRIOT in cohorts of patients characterized by CDKN2A downregulation or MET overexpression. Methods: Following PATRIOT analysis, patients with predicted CDKN2A downregulation or MET overexpression consisting primarily of colon and pancreatic cancer were grouped into two cohorts. Patient-derived tumor organoids were tested for sensitivity to drugs matched to the predicted targets as single agent or in combination, using a 4-fold dilution followed by 72h viability assay. Drug cytotoxicity and Bliss Synergy were analyzed using GraphPad Prism and Combenefit. All screenings were subjected to stringent quality control measures and normalized against untreated organoids. Results: Our analysis identified patients characterized by MET overexpression suggesting crizotinib, a small-molecule tyrosine kinase inhibitor of the c-MET receptor, as sequencing-matched therapy. Tumor organoids showed sensitivity to crizotinib (IC50 5.74 M+/- 3.2), validating our initial predictions. In a separate cohort, tumor organoids generated from patients characterized by downregulation of CDKN2A were treated with Palbociclib, a CDK4/6 inhibitor. Tumor organoids showed limited response to treatment (IC50 57.75 M+/- 25.1), which has been reported in an earlier clinical trial (NCT01740427). However, recent studies have shown that Pablociclib treatment enhances cisplatin cytotoxic effect in several solid tumor models through the CDK4/6-cyclin D1-RB-E2F pathway (NCT02897375). When tumor organoids were co-treated with Palbociclib and Cisplatin, significant synergy was observed (moderate-strong). In summary, PATRIOT analysis provided bioinformatic predictions of pathway based therapeutic options that were validated using tumor organoid platforms. Citation Format: Anna Larson, Taylor Bargenquast, Sara Byron, Anish Raju, Avijit Podder, Shelby Rheinschmidt, Tithi Ghosh Halder, Samuel Sampson, Sydney Adamson, Serina Ng, Kate Gutowsky, Alexis Weston, Trason Thode, Justin Moser, Erkut Borazanci, Mohan Kaadige, Nicholas Schork, Raffaella Soldi, Sunil Sharma. A novel PAThway based RNA and DNA Integration with Tumor Organoid Testing (PATRIOTTM) platform predicts therapeutic options in cohorts with MET overexpression and CDKN2A downregulation in patients with colon and pancreatic cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1069.

Non-Small Cell Lung Cancer Treatment with Molecularly Targeted Therapy and Concurrent Radiotherapy—A Review

Lung cancer is the leading cause of death worldwide for both men and women. Surgery can be offered as a radical treatment at stages I and II and selected cases of stage III (III A). Whereas at more advanced stages, combined modalities of treatment are applied: radiochemotherapy (IIIB) and molecularly targeted treatment (small molecule tyrosine kinase inhibitors, VEGF receptor inhibitors, monoclonal antibodies, and immunological treatment with monoclonal antibodies). Combination treatment, composed of radiotherapy and molecular therapy, is increasingly employed in locally advanced and metastatic lung cancer management. Recent studies have indicated a synergistic effect of such treatment and modification of immune response. The combination of immunotherapy and radiotherapy may result in the enhancement of the abscopal effect. Anti-angiogenic therapy, in combination with RT, is associated with high toxicity and should be not recommended. In this paper, the authors discuss the role of molecular treatment and the possibility of its concurrent use with radiotherapy in non-small cell lung cancer (NSCLC).

Lung cancer management in low and middle-income countries - current challenges and potential solutions

Lung cancer is the second-most prevalent cancer and, the most common cause of cancer-related mortality throughout the world. Evidence-based strategies to decrease its incidence and mortality are being implemented in different parts of the world. Smoking cessation policies are being actively publicized to decrease the incidence of tobacco related cancers including lung cancer. Screening program for early detection of localized lung cancer which can then be targeted by a multimodality approach utilizing surgery, radiation, chemoimmunotherapy to achieve cure is now becoming the standard in several high-income countries. Precision medicine in lung cancer is booming with metastatic non-curative cancers targeted with small molecule tyrosine kinase inhibitors. However, these advancements are not available all around the world. Inequalities exist in the management of lung cancer, mostly driven by the economic differences between the countries. Raising awareness to these international barriers is pivotal for improving lung cancer related incidence and mortality.

Abstract P2-19-01: Characterization of fully human internalizing anti-HER2 monoclonal antibodies that compete with Trastuzumab for binding to HER2

Abstract The human epidermal growth factor receptor (HER) family of receptors plays a significant role in the pathogenesis of several human cancers. Among them, HER2 is overexpressed in several cancers. In particular, overexpression with or without gene amplification occurs in 15-30% of breast cancers and this has both prognostic and predictive implications. HER2 overexpression and amplification is associated with shorter disease-free and overall survivals and with resistance to certain hormonal agents as well as increased risk of metastasis to the brain. Two types of treatment targeting HER2 biological activity have been developed: anti-Her2 monoclonal antibodies and small molecule tyrosine kinase inhibitors such as lapatinib and neratinib targeting HER2 and EGFR and Afatinib targeting all HER family members. Trastuzumab is a humanized anti-HER2 monoclonal antibody that binds to domain IV of HER2 extracellular segment and blocks its signaling. It is the first therapeutic antibody targeting Her2 overexpression approved by the FDA. It is administered in combination with standard of care chemotherapy. More recently, since it was shown that Trastuzumab was an internalizing antibody, two antibody drug conjugates using trastuzumab have been approved and used in the standard of care: Ado-Trastuzumab-Emtansine (Kadcyla) consisting of trastuzumab conjugated to the drug mertansine DM1 and fam-trastuzumab-deruxtecan-nhki (Enhertu). Enhertu is another antibody drug conjugate using Trastuzumab to deliver a topoisomerase inhibitor deruxtecan. Our laboratory has been focused in developing fully human internalizing anti-Her2 antibodies that compete or not with trastuzumab for binding to Her2. These antibodies have been developed by immunizing fully human mice with recombinant Her2 protein. Human Ab producing Tc mice (TC-mAb mice) stably maintain a mouse-derived engineered chromosome containing the entire human Ig heavy and kappa chain loci in a mouse Ig knockout background. After production of hybridoma secreting fully human immunoglobulins, the screening process included inhibition of binding of trastuzumab to Her2 by enzyme linked immunoassay and by Octet epitope binning as well as internalization assay. Several internalizing antibodies with Kd ranging from 10-9 M to 10-12 M were selected. They were stratified by their ability to compete or not with trastuzumab. They were further characterized for their ability to deliver a cytotoxic payload in Her2 overexpressing cells as well as for their efficacy to inhibit proliferation, signaling and migration of Her2 overexpressing breast cancer cells. Data related to these antibodies will be presented here. In conclusion, the use of fully human TC mice in our laboratory represents an attractive approach to develop fully human monoclonal antibodies to high value cancer targets that can by-pass the need for humanization and affinity maturation of antibodies. Citation Format: Ginette Serrero, Jianping Dong, Binbin Yue, Udaya Yerramalla, Jun Hayashi. Characterization of fully human internalizing anti-HER2 monoclonal antibodies that compete with Trastuzumab for binding to HER2 [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-19-01.

Abstract P1-11-10: Reversible versus irreversible tyrosine kinase inhibitors (TKIs) combined with antibody-drug conjugates (ADCs) in HER2-positive (HER2+) breast cancer (BC) cell lines

Abstract Background: Targeting the human epidermal growth factor receptor (HER) family of tyrosine kinase receptors with small molecule TKIs lapatinib, neratinib and tucatinib, monoclonal antibodies like trastuzumab and more recently with ADCs like T-DM1 and T-DXd has resulted in improved survival rates for patients with HER2+ BC. TKIs are primarily utilised in trastuzumab-refractory disease. Neratinib, and the pan-HER TKI afatinib, bind irreversibly to all members of the HER family, while lapatinib binds reversibly to HER2 and EGFR, and tucatinib binds reversibly to HER2 alone. Previous work in our lab has shown that TKIs like lapatinib are capable of modulating tumour surface HER2 levels and increasing trastuzumab load on tumours. Thus, there is a rationale for the use of TKI/ADC combinations in HER2+ BC. Using innately trastuzumab-resistant HER2+ BC cell lines, this in vitro study aims to assess the anti-proliferative potential of HER2-targeting ADCs T-DM1 or T-DXd in combination with the TKIs afatinib, lapatinib, neratinib or tucatinib. Methods: HCC1569 and HCC1954 cells (HER2+, estrogen receptor (ER)-negative; innately trastuzumab-resistant) were grown in RPMI1640/10% FBS at 37°C and 5% CO2. The anti-proliferative effects of afatinib, lapatinib, neratinib and tucatinib; of T-DM1 and T-DXd; and of each TKI/ADC combination thereof were assessed in these cells via 5-day acid phosphatase. ADCs were obtained from Saint Vincent’s University Hospital, Dublin, and TKIs were purchased from commercial sources. Calcusyn software was used to generate IC50 values and combination index (CI) values at ED50. CI values &amp;gt; 1 represent an antagonistic combination, CI values = 1 are additive, and CI values &amp;lt; 1 are synergistic. All assays were carried out in triplicate. Results: The HCC1569 cell line was more sensitive to all four TKIs (IC50 values were 12.8 ± 0.3, 453.8 ± 47.1 nM, 4.7 ± 1.4 and 381.5 ± 37.3 nM for afatinib, lapatinib, neratinib and tucatinib respectively) compared to the HCC1954 cell line (IC50 22.3 ± 2.8, 652.4 ± 36.0, 57.0 ± 6.3 and 2365.1 ± 185.3 nM for afatinib, lapatinib, neratinib and tucatinib respectively). Despite their innate trastuzumab resistance, both cell lines displayed high sensitivity to T-DM1 (IC50 25.2 ± 8.7 ng/mL for HCC1569 and IC50 30.4 ± 3.2 ng/mL for HCC1954) and to T-DXd (IC50 16.0 ± 3.2 ng/mL for HCC1569 and IC50 36.8 ± 8.7 ng/mL for HCC1954). In both cell lines, co-treatment with ADCs and the irreversible TKIs afatinib and neratinib resulted in additive or synergistic responses, while the combination of the ADCs with the reversible TKIs lapatinib and tucatinib resulted in mild to moderate antagonism (Table 1). Conclusions: In this pre-clinical study, T-DM1 and T-DXd consistently exhibited antagonistic interactions with reversible HER2-targeting TKIs, and synergy/additivity in combination with the irreversible TKIs tested. Future work will explore the underlying mechanisms of this observed synergy and antagonism, including impacts of TKIs on HER2 expression and real-time ADC internalisation rates. Table 1. CI values +/- Std Dev for each TKI/ADC treatment combination in HCC1569 and HCC1954 cells Citation Format: Niall Ashfield, Amira F. Mahdi, Neil T. Conlon, John Crown, Denis M. Collins. Reversible versus irreversible tyrosine kinase inhibitors (TKIs) combined with antibody-drug conjugates (ADCs) in HER2-positive (HER2+) breast cancer (BC) cell lines [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P1-11-10.

Abstract P6-12-09: Retinoic acid receptor (RAR) signalling plays a role in neratinib (NER) resistance in HER2+ breast cancer (BC) cell lines

Abstract Introduction: NER is a pan-HER tyrosine kinase inhibitor (TKI) approved for the treatment of HER2+ BC in the adjuvant setting following trastuzumab and in combination with capecitabine for advanced disease. Resistance to small molecule TKIs like NER can develop in the clinic. Pre-clinical studies have highlighted that retinoic acid can inhibit BC growth and modulate HER2 signalling pathways. The RAR family of nuclear transcription factors consists of RARα, RARβ and RARγ. The synthetic retinoic acid fenretinide (FN) acts as a pan-RAR agonist, while AGN194310 (AG) acts as a pan-RAR antagonist. In order to investigate the anti-proliferative potential of co-targeting RAR and HER2 pathways in sensitive and resistant BC cell line models, we examined the effect of FN and AG in combination with NER in two HER2+, estrogen receptor-negative, trastuzumab-resistant cell lines HCC1569 and HCC1954, and their NER-resistant (NR) sub-lines HCC1569-NR and HCC1954-NR. Methods: HCC1569 and HCC1954 cell lines were cultured in RPMI/10% FCS at 370C/5% CO2. NR cell lines were generated by continuous exposure to 150nM NER for 6 months. 10 mM stock solutions of FN (H7779-Sigma), AG (SML2665-Sigma) and NER (supplied by Puma Biotechnology, Inc) were made in DMSO. Proliferation was measured as percentage growth versus DMSO control using an acid phosphatase based assay after 5 days drug exposure. The half-maximal inhibitory concentration (IC50) was calculated for each drug using CalcuSyn. The combination assays were performed using fixed ratios. The combination index (CI) values were calculated at the effective dose that inhibits 50% growth (ED50) using CalcuSyn. Values &amp;lt; 1 represent a synergistic effect, a value of 1 is additive and values &amp;gt; 1 represent an antagonistic effect. All data presented as the mean of biological triplicate experiments ± standard deviation. Results: This research found that the NR cell lines were &amp;gt;10-fold resistant to NER (HCC1569-NR IC50 0.44 ± 0.1 μM, HCC1954-NR IC50 0.198 ± 0.019 μM) compared to the parental HCC1569 (IC50 0.018 ± 0.015 μM) and HCC1954 (IC50 0.017 ± 0.001 μM) cell lines. Pan-RAR agonism by FN had a potent anti-proliferative effect in the HCC1569 (FN IC50 0.22 ± 0.02 μM) and the HCC1569-NR cell lines (FN IC50 0.28 ± 0.13 μM), with the HCC1954 and HCC1954-NR cell lines proving less sensitive (IC50 6.47 ± 1.3 μM and 1.9 ± 0.2 μM, respectively). When combined with NER, FN produced a strong antagonistic effect in the HCC1569 cell line (CI value: 15.63 ± 9.5) and a strong synergistic effect in the HCC1954 cell line (CI value: 0.42 ± 0.06). For the NR cell line models, the NER/FN combination proved synergistic (HCC1569-NR, CI value: 0.84 ± 0.46) or additive (HCC1954-NR, CI value: 0.97 ± 0.15). Next, we wanted to assess the impact of antagonising rather than activating RAR activity in our cell line models. All four cell lines were less sensitive to antagonist AG (IC50 &amp;gt;8μM for all cell lines) compared to FN. The addition of AG to NER resulted in responses diametrically opposed to the FN/NER combination. The AG/NER combination produced a strong synergistic effect in the HCC1569 cell line (CI value: 0.52 ± 0.17), an antagonistic effect in the HCC1954 cell line (CI value: 2.1 ± 0.4) and an antagonistic effect in both NR cell lines (HCC1954-NR, CI value: 2.69 ± 0.6 and HCC1569-NR, CI value: 1.58 ± 0.12). Conclusions: This pre-clinical study suggests involvement of the RAR signalling pathway in response to NER and the development of NR. Results also suggest pan-RAR agonism, rather than pan-RAR antagonism, as a potential therapeutic strategy to overcome NR. Further investigation is warranted to determine how targeting the RAR signalling pathway may assist in the treatment of HER2+ BC. Citation Format: Debbie O’Reilly, Lisa D. Eli, Alvin Wong, John Crown, Denis M. Collins. Retinoic acid receptor (RAR) signalling plays a role in neratinib (NER) resistance in HER2+ breast cancer (BC) cell lines [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-12-09.

Targeting the Epidermal Growth Factor Receptor with Molecular Degraders: State-of-the-Art and Future Opportunities.

Epidermal growth factor receptor (EGFR) is an oncogenic drug target and plays a critical role in several cellular functions including cancer cell growth, survival, proliferation, differentiation, and motility. Several small-molecule tyrosine kinase inhibitors (TKIs) and monoclonal antibodies (mAbs) have been approved for targeting intracellular and extracellular domains of EGFR, respectively. However, cancer heterogeneity, mutations in the catalytic domain of EGFR, and persistent drug resistance limited their use. Different novel modalities are gaining a position in the limelight of anti-EGFR therapeutics to overcome such limitations. The current perspective reflects upon newer modalities, importantly the molecular degraders such as PROTACs, LYTACs, AUTECs, and ATTECs, etc., beginning with a snapshot of traditional and existing anti-EGFR therapies including small molecule inhibitors, mAbs, and antibody drug conjugates (ADCs). Further, a special emphasis has been made on the design, synthesis, successful applications, state-of-the-art, and emerging future opportunities of each discussed modality.

Inhibition of the epigenetically activated miR-483-5p/IGF-2 pathway results in rapid loss of meningioma tumor cell viability

PurposeMeningioma is the most common primary central nervous system tumor often causing serious complications, and presently no medical treatment is available. The goal of this study was to discover miRNAs dysregulated in meningioma, and explore miRNA-associated pathways amenable for therapeutic interventions.MethodsSmall RNA sequencing was performed on meningioma tumor samples to study grade-dependent changes in microRNA expression. Gene expression was analyzed by chromatin marks, qRT-PCR and western blot. miRNA modulation, anti-IGF-2 neutralizing antibodies, and inhibitors against IGF1R were evaluated in a tumor-derived primary cultures of meningioma cells.ResultsMeningioma tumor samples showed high, grade-dependent expression of miR-483-5p, associated with high mRNA and protein expression of its host gene IGF-2. Inhibition of miR-483-5p reduced the growth of cultured meningioma cells, whereas a miR-483 mimic increased cell proliferation. Similarly, inhibition of this pathway with anti-IGF-2 neutralizing antibodies reduced meningioma cell proliferation. Small molecule tyrosine kinase inhibitor blockade of the IGF-2 receptor (IGF1R) resulted in rapid loss of viability of cultured meningioma tumor-derived cells, suggesting that autocrine IGF-2 feedback is obligatory for meningioma tumor cell survival and growth. The observed IGF1R-inhibitory IC50 for GSK1838705A and ceritinib in cell-based assays along with the available pharmacokinetics data predicted that effective drug concentration could be achieved in vivo as a new medical treatment of meningioma.ConclusionMeningioma cell growth is critically dependent on autocrine miR-483/IGF-2 stimulation and the IGF-2 pathway provides a feasible meningioma treatment target.

Quantitative determination of plasma cabozantinib concentration using HPLC-UV and its application to patients with renal cell carcinoma.

Cabozantinib is an oral small-molecule tyrosine kinase inhibitor that has become a standard of care for advanced renal cell carcinoma (RCC). However, cabozantinib is associated with a high rate of adverse events. Therefore, individualised cabozantinib administration and monitoring could help maximise its therapeutic efficacy and avoid serious adverse events. This study developed and validated a method to determine cabozantinib concentration in plasma using HPLC-UV. Sorafenib, an internal standard, was added to the plasma sample containing cabozantinib. A calibration curve for cabozantinib showed good linearity (R2 = 1.00), between 25 and 4,000 ng/ml. The recovery rate was above 92.1%, and the intra- and inter-day coefficients of variation were smaller than 5.2 and 6.8%, respectively. Then, we applied the method for monitoring cabozantinib blood levels in three patients with advanced RCC who were taking cabozantinib at a dose of 20, 40 or 60 mg/day. Grade 3 adverse events were more likely to occur in patients with high dosing and blood level of cabozantinib. Owing to its simplicity, the developed method can be used in general hospitals, and is expected to help maximise drug efficacy and minimise serious adverse events in many patients with RCC undergoing cabozantinib treatment.

Pyrotinib for HER2-positive metastatic breast cancer: a systematic review and meta-analysis.

Human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer patients continue to progress despite multiple anti-HER2-targeted treatments. A number of studies have found that Pyrotinib, a small-molecule pan-ErbB receptor tyrosine kinase inhibitor (TKI), is effective in treating patients with HER2-positive metastatic breast cancer. This systematic review and meta-analysis aimed to evaluate the efficacy and safety of Pyrotinib in the treatment of HER2-positive metastatic breast cancer. PubMed, Embase, Web of Science, and Cochrane Library databases were searched until February 2022. Research on HER2-positive metastatic breast cancer being treated with Pyrotinib in any line of therapy was included, both prospective and retrospective. Statistical pooling and meta-analysis of data from the included studies were performed to explore the efficacy and safety of Pyrotinib in HER2-positive metastatic breast cancer. In this meta-analysis, 23 studies were included. The overall objective response rate was 0.49 (95% CI: 0.40, 0.58) for Pyrotinib in HER2-positive metastatic breast cancer and 0.52 (95% CI: 0.32, 0.71) in those with brain metastases. The objective response rate of Pyrotinib was superior to that of other second-line therapeutics in comparison (RR =1.38, 95% CI: 1.25, 1.52), but was relatively inferior to trastuzumab emtansine (T-DM1) (RR =0.82, 95% CI: 0.36, 1.85). The combined median progression-free survivals (PFSs) for Pyrotinib in metastatic breast cancer and those with brain metastases were 8.2 (95% CI: 6.8, 9.5) months and 8.9 (95% CI: 6.2, 11.7) months, respectively. The most common adverse reaction was diarrhea with an all-grade incidence of 0.84 (95% CI: 0.74, 0.92), followed by nausea and vomiting of 0.52 (95% CI: 0.36, 0.68). In any line of treatment for HER2-positive metastatic breast cancer, the Pyrotinib-containing regimens demonstrated considerable tumor response, disease control, and survival with manageable adverse effects.