Multiple Tyrosine Kinase Inhibitor Research Articles

A phase 1b multitumor cohort study of cabozantinib plus atezolizumab in advanced solid tumors (COSMIC-021): Results of the colorectal cancer cohort.

121 Background: Cabozantinib, a multiple receptor tyrosine kinase inhibitor, promotes an immune-permissive environment which may enhance the activity of immune checkpoint inhibitors. COSMIC-021 (NCT03170960) is evaluating the combination of cabozantinib with atezolizumab, an anti-PD-L1 inhibitor, in patients with advanced solid tumors. Outcomes in patients (pts) with metastatic colorectal cancer (mCRC) previously treated with fluoropyrimidine-containing therapy are presented. Methods: Pts with mCRC and an ECOG PS of 0–1 who progressed during or following systemic chemotherapy including fluoropyrimidine plus oxaliplatin or irinotecan were eligible. Up to 2 prior lines of anti-cancer therapy including EGFR-targeted therapy were allowed. Microsatellite instability high (MSI-H) and/or mismatch repair (MMR)-deficient pts were excluded. Pts received cabozantinib 40 mg PO QD plus atezolizumab 1200 mg IV Q3W. The primary endpoint was objective response rate (ORR) per RECIST 1.1 by investigator. Other endpoints included safety, duration of response (DOR), progression-free survival (PFS), and overall survival (OS). CT/MRI scans were performed Q6W for the first year and Q12W thereafter. Results: 31 pts received cabozantinib plus atezolizumab (median age, 60 y [range 31, 79]; male, 58%; ECOG PS 1, 61%; 2 prior lines of therapy, 71%; prior EGFR inhibitor, 16%; ≥3 tumor sites, 52%; tumors in left colorectum, 71%). Median follow-up was 28.1 mo (range, 24.2, 31.3) as of July 21, 2021. Cabozantinib plus atezolizumab demonstrated clinical activity in pts with mCRC (Table). Patients with wild-type RAS (n = 12) had numerically longer PFS and OS and higher ORR vs those with mutations (n = 19) (Table). Treatment-related adverse events (TRAEs) of any grade occurred in 28 (90%); the most common were diarrhea (52%), fatigue (42%), and nausea (35%). Grade 3-4 TRAEs occurred in 16 (52%); the most common were hypertension (10%), fatigue (6%), and lipase increased (6%); no Grade 5 events were reported. Conclusions: Cabozantinib plus atezolizumab demonstrated encouraging clinical activity with manageable toxicity in pts with previously treated advanced non-MSI-H/MMR-proficient CRC. Clinical trial information: NCT03170960. [Table: see text]

Real-world Treatment Patterns and Reasons for Therapy Selection in Patients with Advanced Hepatocellular Carcinoma in US Oncology Practices.

BackgroundThe treatment landscape for advanced hepatocellular carcinoma (aHCC) is rapidly expanding beyond tyrosine kinase inhibitors (TKIs) in the first-line (1L) setting, with multiple TKIs and immune-checkpoint inhibitors (ICIs) now being evaluated in combination. Real-world evidence describing current treatment patterns and reasons for 1L and 2L treatment selection in aHCC is sparse.Patients and MethodsA retrospective cohort study with a cross-sectional survey element was conducted using Cardinal Health’s Oncology Provider Extended Network. U.S. medical oncologists identified adult aHCC patients initiating 1L systemic therapy between January 1, 2017 and July 31, 2019 and abstracted data from patient medical records. Data included provider characteristics, patient demographics and clinical characteristics, treatment regimens, and physician rationale for treatment regimen choice.ResultsA total of 44 medical oncologists provided data on 284 aHCC patients. The median age at 1L initiation was 61.5 years, and the majority were male (78%) and white (66%). Nearly half (47%) initiated 1L treatment in 2019, 34% were ECOG performance status 2+, and 63% were Child-Pugh Class B/C. Among the 284 aHCC patients, TKIs were used by 94% of patients in the 1L setting, comprised predominantly of sorafenib (54%) and lenvatinib (38%). ICIs were most common among the 90 patients (66%) who received 2L treatment.ConclusionIn the community-oncology practice setting, nearly all aHCC patients received sorafenib or lenvatinib in the 1L setting, while the majority of patients received an ICI in the 2L setting. With recent ICI approvals in aHCC, this marks the beginning of an increased use of ICIs in the 1L setting.

Management of Oligoprogression in Patients with Metastatic NSCLC Harboring ALK Rearrangements.

Simple SummaryThe growing efficacy and availability of new targeted systemic therapies have markedly improved the prognosis of metastatic lung cancer patients harboring ALK rearrangements. The use of effective targeted therapies capable of maintaining a prolonged control of disease, for as long as possible, is paramount to ensure the best survival outcomes. In this regard, in cases of oligoprogression, “beyond progression” systemic treatment added to local ablative therapies is considered a feasible option in an attempt to improve the quality and quantity of patients’ lives, even if based on retrospective data. Certainly, treatment of ALK rearranged lung cancer patients with oligoprogressive disease must be individualized and based on multidisciplinary decisions. Above all, when further molecular targeted therapies are available, options must always be evaluated, especially in case of cerebral progression. In this review, we provide an updated and comprehensive overview of the main treatment strategies in cases of ALK rearranged oligoprogression.Personalized treatment based on driver molecular alterations, such as ALK rearrangement, has revolutionized the therapeutic management of advanced oncogene-addicted NSCLC patients. Multiple effective ALK tyrosine kinase inhibitors (TKIs), with the amelioration of the activity at central nervous system level, are now available, leading to substantial prognosis improvement. The exposure to TKIs triggers resistance mechanisms and the sequential administration of other TKIs and chemotherapy is, for the most part, not targeted. In this context, extending the benefit deriving from precision medicine is paramount, above all, when disease progression occurs in a limited number of sites. Retrospective data indicate that, in oligoprogressive disease, targeted therapy beyond progression combined with definitive local treatment of the progressing site(s) is an effective alternative. In these cases, a multidisciplinary approach becomes essential for an integrated treatment strategy, depending on the site of disease progression, in order to improve not only survival, but also quality of life. In this review we provide an updated and comprehensive overview of the main treatment strategies in cases of ALK rearranged oligoprogression, including systemic treatment as well as local therapy, and report a real-world clinical story, with the final aim of identifying the most promising management for this subset of patients.

Intracellular Reduction-Responsive Molecular Targeted Nanomedicine for Hepatocellular Carcinoma Therapy.

The stimuli-responsive polymer-based platform for controlled drug delivery has gained increasing attention in treating hepatocellular carcinoma (HCC) owing to the fascinating biocompatibility and biodegradability, improved antitumor efficacy, and negligible side effects recently. Herein, a disulfide bond-contained polypeptide nanogel, methoxy poly(ethylene glycol)−poly(l-phenylalanine-co-l-cystine) [mPEG−P(LP-co-LC)] nanogel, which could be responsive to the intracellular reduction microenvironments, was developed to deliver lenvatinib (LEN), an inhibitor of multiple receptor tyrosine kinases, for HCC therapy. The lenvatinib-loaded nanogel (NG/LEN) displayed concise drug delivery under the stimulus of glutathione in the cancer cells. Furthermore, the intracellular reduction-responsive nanomedicine NG/LEN showed excellent antitumor effect and almost no side effects toward both subcutaneous and orthotopic HCC tumor-allografted mice in comparison to free drug. The excellent tumor-inhibition efficacy with negligible side effects demonstrated the potential of NG/LEN for clinical molecular targeted therapy of gastrointestinal carcinoma in the future.

Managing Central Nervous System Spread of Lung Cancer: The State of the Art

Brain metastases (BrM) are common in both non–small-cell lung cancer and small-cell lung cancer. Substantial progress in BrM management has occurred in the past decade related to advances in both radiation and medical oncology. Recent and ongoing radiation trials have focused on increasing the candidacy for focal therapy of BrM with stereotactic radiosurgery; reducing the toxicity and improving patient selection for whole brain radiotherapy; and, in small-cell lung cancer, evaluating brain magnetic resonance imaging surveillance without prophylactic cranial irradiation, hippocampal avoidance in prophylactic cranial irradiation and whole brain radiotherapy, and the role of upfront stereotactic radiosurgery for BrM. In medical oncology, the development of multiple tyrosine kinase inhibitors with encouraging CNS activity and emerging data on the CNS activity of immune checkpoint inhibitors in some patients have opened the door to novel systemic and multidisciplinary treatment strategies for the management of BrM. Future research will focus on more robust characterizations of the CNS activity of targeted therapy and immunotherapies, as well as optimal integration and patient selection for multidisciplinary strategies involving CNS-active drugs, radiation therapy, and CNS surveillance.

Treatment of hepatocellular carcinoma with autologous platelets encapsulating sorafenib or lenvatinib: A novel therapy exploiting tumor-platelet interactions.

Hepatocellular carcinoma (HCC) activates platelets through the action of adjacent sinusoidal cells. Activated platelets bind to tumor-associated endothelial cells and release growth factors that promote tumor progression. We hypothesized that platelets encapsulated with tumor inhibitors would function as drug carriers for tumor therapy. We propose a therapeutic strategy for HCC using autologous platelets encapsulating multiple tyrosine kinase inhibitors in a rat chemically induced HCC model. Sorafenib or lenvatinib was encapsulated in platelets isolated from tumor-bearing rats in vitro. The rats were divided into groups that received repeated intravenous injections (twice a week for 10 weeks) of the following materials: placebo, sorafenib (SOR), lenvatinib (LEN), autologous platelets, autologous platelets encapsulating sorafenib (SOR-PLT) and autologous platelets encapsulating lenvatinib (LEN-PLT). The therapeutic effect was then analyzed by ultrasonography (US) and histopathological analysis. Histopathological and US analysis demonstrated extensive tumor necrosis in the tumor tissue of SOR-PLT or LEN-PLT, but not in other experimental groups. By liquid chromatography-mass spectrometry, more abundant sorafenib was detected in tumor tissues after SOR-PLT administration than in surrounding normal tissues, but no such difference in sorafenib level was observed with SOR administration. Therefore, the use of autologous platelets encapsulating drugs might be a novel therapeutic strategy for HCC.

Synergistic Combination Activity of the Novel GSPT1 Degrader CC-90009 in Acute Myeloid Leukemia Models

Introduction: CC-90009 is a novel cereblon E3 ligase modulator (CELMoD ®) agent that is a first-in-class degrader of translation termination factor G1 to S phase transition 1 (GSPT1). CC-90009 has demonstrated antileukemic activity as a single agent and is currently under investigation in patients with acute myeloid leukemia (AML; NCT02848001). Treatment with CC-90009 led to rapid reductions in peripheral and bone marrow blasts, and demonstrated preliminary promising efficacy, including several complete remissions, in patients with relapsed or refractory AML. Here, we describe the identification and preclinical activity of select anti-AML agents as potential combination partners of CC-90009 to further improve its efficacy and therapeutic index. Based on these results, the combination activity of CC-90009 with venetoclax (VEN)/azacitidine (AZA) is being evaluated in a phase 1/2 trial in patients with AML (NCT04336982).Methods: A high-throughput cell viability screen was performed to identify synergistic partners of CC-90009. AML cell lines (HL-60, HNT-34, KG-1, ML-2, NOMO-1, MOLM-13, MV4-11, F-36P, OCI-AML2, OCI-AML3) were treated with CC-90009 in combination with > 70 compounds, including standard anti-AML agents, tyrosine kinase inhibitors (TKIs), unfolded protein response inducers, transcription inhibitors, and epigenetic agents. MOLM-13 and MV4-11 are fms-like tyrosine kinase 3 internal tandem duplication (FLT3-ITD) cell lines. Hits were validated in a colony formation (CF) assay using primary AML cells and bone marrow mononuclear cells (BMMC) from healthy donors. Synergy of the combination partners with CC-90009 was further assessed in AML patient-derived xenograft (PDX) models. Synergy between the isocitrate dehydrogenase 2 (IDH2) inhibitor enasidenib and CC-90009 was evaluated in a TF-1 erythroleukemia cell line overexpressing IDH2 R140Q mutant, and an IDH2 R140Q PDX model, AM7577.Results: Our high-throughput combination screen revealed multiple TKIs, epigenetic agents, and pro-apoptotic agents as potential combination partners of CC-90009 in AML cell lines. FLT3 inhibitors, including sunitinib, pexidartinib, midostaurin, lestaurtinib, crenolanib, and gilteritinib, synergized with CC-90009 to reduce viability in FLT3-ITD AML cell lines MV4-11 and MOLM-13. Similarly, the B-cell lymphoma 2 (BCL2) inhibitor VEN potentiated CC-90009-induced apoptosis and accelerated cell-autonomous killing. Reduction in levels of MCL-1, an anti-apoptotic factor, by CC-90009 most likely contributed to the synergy with VEN.We prioritized the evaluation of FLT3, BCL2, and IDH2 inhibitors as partners of CC-90009. In CF assays, midostaurin enhanced the inhibitory effect of CC-90009 in primary AML cells, without augmenting the effect of CC-90009 in CD34+ BMMC from healthy donors. Similarly, VEN enhanced the reduction in CF by CC-90009 in AML patient-derived BMMC without exacerbating the decrease in CF by CC-90009 in BMMC from healthy donors.We characterized FLT3 inhibitor/CC-90009 and BCL2 inhibitor/AZA/CC-90009 combinations in a FLT3-ITD PDX murine model, PDX1. The FLT3 inhibitor quizartinib significantly prolonged survival when combined with CC-90009 compared with either agent alone (P < 0.001). Similarly, VEN/AZA/CC-90009 combination markedly extended survival compared with single agents or VEN/AZA doublets (P < 0.001).The synergy between CC-90009 and epigenetic modulators was validated and further characterized in customized cell differentiation assays. Addition of CC-90009 to enasidenib, a mutant IDH2 inhibitor, enhanced differentiation and killing of CD34+ stem and progenitor cells, and increased differentiated CD235a+ erythroblasts, compared with enasidenib alone in a TF-1 cell line overexpressing IDH2 R140Q. Enasidenib/CC-90009 combination treatment reduced CD45+ malignant populations and increased differentiated CD14+ cells, leading to significantly prolonged animal survival in an IDH2 R140Q PDX model, AM7577, compared with either agent alone (P < 0.0001).Conclusion: Using a high-throughput combination screen, we identified rational combination partners that synergize with CC-90009 in in vitro and in vivo AML models. Collectively, these results support the clinical evaluation of CC-90009 in combination with FLT3, BCL2, and IDH2 inhibitors to further improve treatment outcomes for patients with AML. DisclosuresPierce: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Yao: Bristol Myers Squibb: Consultancy, Current equity holder in publicly-traded company, Ended employment in the past 24 months, Research Funding. Pace: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties. Wang: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Flandin-Blety: Bristol Myers Squibb: Current Employment. Benitez: Bristol Myers Squibb: Current Employment. Guarinos: Bristol Myers Squibb: Current Employment. Hoffmann: Bristol Myers Squibb: Current Employment. Carrancio: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company. Pourdehnad: Bristol Myers Squibb: Current Employment, Current equity holder in publicly-traded company, Patents & Royalties.

Real-World Analysis of the Clinical and Economic Burden of Later Line in Chronic Myeloid Leukemia Patients in Italy

BackgroundThe use of real-world data in oncology is gaining increasing interest, as it can provide valuable insights into treatments and related outcomes in routine daily oncology practice, thus integrating the evidence coming from clinical trials. The study aims to describe the characteristics of patients (pts) with chronic myeloid leukemia (CML) in 2 nd or ≥3 rd tyrosine kinase inhibitors (TKI) lines of therapy, analyze their drug utilization and evaluate healthcare direct costs for the Italian National Health Service in order to estimate the impact of disease burden.MethodsThis retrospective observational analysis was based on administrative databases covering around 15.3 million subjects in Italy. All adult pts with prescription of the TKIs bosutinib (BOS), dasatinib (DAS), imatinib (IMA), nilotinib (NIL), ponatinib (PON) in 2 nd or ≥3 rd line of therapy during 01/2015-12/2018 were included. Specifically, those with IMA, DAS or PON prescription were enrolled if they also presented ≥1 CML hospitalization or previous prescription for NIL or BOS or ≥1 BCR-ABL1 RQ-PCR test without hospitalization for acute lymphoid leukemia. Pts enrolled in clinical trials were not captured. Index date was 1 st prescription date for a TKI in 2 nd or ≥3 rd line. Comorbidities were assessed by hospitalization diagnosis codes and/or presence of specific drugs as proxy of diagnosis. Mean annual healthcare resource costs were evaluated during follow-up (from index date to end of study) in terms of drugs other than TKI (excluded), visits, tests, hospitalizations (overall and comorbidity-related during treatment).ResultsOverall, 491 pts in 2 nd and 144 in ≥3 rd line were included. In each calendar year from 2015 to 2018, the incidence of pts who entered a 2 nd line changed from 22.6% to 28.7%, whereas the ≥3 rd line fluctuated from 37% to 46.7%. An increment of 97.6% was observed in the number of pts treated in ≥3 rd line from 2015 to 2018 (figure 1). As 2 nd line, 40.9% was represented by DAS, 28.9% NIL, 12.2% BOS, 10.2% PON and 7.8% IMA. Mean age ranged from 56.1 (PON) to 68.2 (BOS) years. At baseline, hypertension was the most reported comorbidity (from 64.1% for NIL to 91.7% for BOS), followed by metabolic (from 27.9% in DAS pts to 63.2% for IMA) and blood count (from 28.4% for DAS to 58.0% for PON) alterations. Among pts in ≥3 rd line, 26.3% received imatinib, 22.2% PON, 18.8% NIL, 16.7% BOS, 16% DAS. Mean age was 57 years for NIL, 64.8 PON and 69.5 BOS pts. Same trend of comorbidities was reported in the ≥3 rd line cohort, with hypertension detected in all pts starting BOS to a minimum of 65.2% pts in DAS group, followed by blood count alteration (34.8% for DAS to 59.4% for PON) and metabolic alterations (37.0% for NIL to 50.0% for BOS). Baseline cardiovascular comorbidities were present in 22.8% of pts starting a 2 nd line and in 35.4% of pts starting ≥3 rd line. After a median follow up of 3.0 and 2.6 years, 13% and 19% of pts died in 2 nd and ≥3 rd lines, respectively, around 40% in both lines discontinued their treatment. Median time to discontinuation was 5.5 (95%CI: 4.7-6.2) (2 nd line) and 4.3 (95%CI: 3.2-5.2) (≥3 rd line) years. Mean number of annual hospitalizations was 0.6 (from 0.4 for NIL to 1.1 for PON) in 2 nd line, and 0.5 (from 0.4 for IMA and NIL to 0.7 for PON) in ≥3 rd line. Total mean annual costs/pts (TKI excluded) were of €10,168 (PON), €6,106 (BOS), €5,086 (DAS), €4,779 (NIL) and €3,905 (IMA), with hospitalizations comorbidity-related accounting for €3,245 among PON, €2,820 BOS, €1,739 NIL, €1,573 DAS and €1,448 IMA pts. Mean annual costs per lines are shown in figure 2.ConclusionsThis real-world study provided a demographic and clinical profile of CML pts in 2 nd and ≥3 rd TKI lines and described drug utilization and resource consumption in the Italian clinical practice setting. An increase of pts treated with TKIs in ≥3 rd line was reported, reflecting the availability of multiple TKIs over the years; moreover, a highly comorbid population suggests an increasingly complex CML management. Our results underlined a heavy clinical and economic burden for pts in 2 nd or ≥3 rd lines, especially in terms of comorbidities, treatment discontinuation and hospitalizations suggesting the need of novel therapeutic options for management of later lines CML. [Display omitted] DisclosuresBreccia: Novartis: Consultancy; Pfizer: Consultancy; BMS: Consultancy; INCYTE: Consultancy; Abbvie: Consultancy. Chiodi: Novartis: Current Employment. Valsecchi: Novartis Farma SpA: Current Employment. Rendace: Novartis Farma S.p.A.: Current Employment. Coco: Novartis Farma S.p.A.: Current Employment. Premoli: Novartis Farma SpA: Current Employment.

A phase I study of the tyrosine kinase inhibitor anlotinib combined with platinum/pemetrexed-based chemotherapy in untreated nonsquamous non-small-cell lung cancer

SummaryBackground. Anlotinib hydrochloride is an oral small molecule inhibitor of multiple tyrosine kinases, and it has been approved as a third-line therapy for patients with advanced non-small-cell lung cancer (NSCLC) in China. This dose-exploration study was designed to investigate the feasibility of anlotinib in combination with other chemotherapy regimens in patients with nonsquamous NSCLC. Methods. This phase I study followed a 3 + 3 dose reduction design with three doses of anlotinib (12 mg, 10 mg, and 8 mg). Anlotinib was given at an initial dose of 12 mg with pemetrexed (500 mg/m2) plus cisplatin (75 mg/m2) or carboplatin (AUC = 5) on 21-day cycles for 4 cycles. The primary goal of the study was to identify the maximum tolerated dose (MTD), and secondary endpoints included progression-free survival (PFS) and overall survival (OS). Results. A total of eight participants were enrolled. Dose-limiting toxicities (DLTs) were observed in two patients (pts) at anlotinib 12 mg (grade 3 hand-foot syndrome and grade 3 appetite loss). No DLTs occurred with 10 mg anlotinib, and the MTD was 10 mg. Among seven evaluable pts, four achieved a confirmed partial response (PR), and three had stable disease (SD). With a median follow-up of 10.05 months, the median PFS was 7.00 months (95% CI: 2.76 to NE). Grade 3 treatment-related adverse events (TRAEs) included appetite loss (n = 2), hypertension (n = 2), thrombocytopenia (n = 1), diarrhea (n = 1) and hand-foot syndrome (n = 1). No grade 4 or grade 5 TRAEs were observed during the treatment. Conclusion. The feasible dose of anlotinib in combination with platinum/pemetrexed-based chemotherapy as a first-line regimen was 10 mg, which was well tolerated and showed promising antitumor activity in advanced nonsquamous NSCLC.

Lung Cancer Driven by BRAFG469V Mutation Is Targetable by EGFR Kinase Inhibitors

IntroductionMutations in BRAF occur in 2% to 4% of patients with lung adenocarcinoma. Combination dabrafenib and trametinib, or single-agent vemurafenib is approved only for patients with cancers driven by the V600E BRAF mutation. Targeted therapy is not currently available for patients harboring non-V600 BRAF mutations. MethodsA lung adenocarcinoma patient-derived xenograft model (PHLC12) with wild-type and nonamplified EGFR was tested for response to EGFR tyrosine kinase inhibitors (TKIs). A cell line derived from this model (X12CL) was also used to evaluate drug sensitivity and to identify potential drivers by small interfering RNA knockdown. Kinase assays were used to test direct targeting of the candidate driver by the EGFR TKIs. Structural modeling including, molecular dynamics simulations, and binding assays were conducted to explore the mechanism of off-target inhibition by EGFR TKIs on the model 12 driver. ResultsBoth patient-derived xenograft PHLC12 and the X12CL cell line were sensitive to multiple EGFR TKIs. The BRAFG469V mutation was found to be the only known oncogenic mutation in this model. Small interfering RNA knockdown of BRAF, but not the EGFR, killed X12CL, confirming BRAFG469V as the oncogenic driver. Kinase activity of the BRAF protein isolated from X12CL was inhibited by treatment with the EGFR TKIs gefitinib and osimertinib, and expression of BRAFG469V in non–EGFR–expressing NR6 cells promoted growth in low serum condition, which was also sensitive to EGFR TKIs. Structural modeling, molecular dynamic simulations, and in vitro binding assays support BRAFG469V being a direct target of the TKIs. ConclusionsClinically approved EGFR TKIs can be repurposed to treat patients with non-small cell lung cancer harboring the BRAFG469V mutation.

The immunomodulatory activity of lenvatinib prompts the survival of patients with advanced hepatocellular carcinoma.

BackgroundLenvatinib is a novel multiple receptor tyrosine kinase inhibitor used for hepatocellular carcinoma (HCC) treatment. Although its main function is to suppress VEGFR and FGFR pathway, its immunomodulatory activity in HCC is not elucidated. Thus, this study aimed to investigate the immunomodulatory capability of lenvatinib in HCC.Material and methodsTotally 47 patients with HCC were enrolled in this study, and the immune cells and serum cytokine profiles before initiation of treatment and after 1 and 3 months were measured. The immune checkpoint receptors on the immune cells were also evaluated. Kaplan–Meier survival estimate and log rank tests were used to assess the prognostic value.ResultThe frequency of T helper (Th) cells and T regulatory (Treg) cells reduced after lenvatinib treatment, while cytotoxic T lymphocyte (CTL) cells increased significantly. The cytokine profiles showed IL‐2, IL‐5, IFN‐γ increased; other cytokines including IL‐6, IL‐10, TNF‐ α and TNF‐ β decreased with lenvatinib therapy. Furthermore, the PD‐1 and TIM‐3 expressed on CTL had greatly decreased; the expression of TIM‐3 and CTLA‐4 was reduced on Treg cells as well. Besides, the new index CTL/Treg ratio was created, and low ratio was associated with the unfavorable outcome of HCC patients.ConclusionOur results confirmed that lenvatinib is capable of improving patients’ immune status, saving the effector cells from exhaustion status and inhibiting the number and function of immunosuppressive cells. The novel index CTL/Treg ratio qualifies as a predictor for the outcome of patients with lenvatinib therapy.

P51.02 Stacking on the Targets: Secondary Resistant, Potential Targetable Genetic Alterations in Patients With Epidermal Growth Factor Receptor NSCLC

With multiple tyrosine kinase inhibitors (TKI) approved for EGFR mutated NSCLC over the last decade, patients with this disease have superior outcomes compared to other NSCLC subsets. However, resistance to these agents is inevitable. With first and second generation TKI, the most common resistant mechanism is development of EGFR T790M mutation. However, now that osimertinib has emerged as the most favorable first-line EGFR TKI, we are now seeing a plethora of new resistance pathways. Retesting for actionable mutations at progression is important since secondary genetic alterations may sometimes be discovered which may be exploited for therapeutic benefit.

FP09.03 Phase II Randomized Trial to Evaluate Prednisone Taper With or Without Nintedanib for the Treatment of Radiation Pneumonitis

Radiation pneumonitis (RP) is the most common limiting toxicity for definitive thoracic radiation therapy. Currently, the only standard management consists of an empiric prolonged steroid taper. Nevertheless, many patients with RP experience subsequent pulmonary exacerbations and worsening lung function leading to significant decline in quality of life. Nintedanib, a multiple tyrosine kinase inhibitor, has been shown to be effective in the treatment of idiopathic pulmonary fibrosis that shares many pathophysiological pathways with the chronic inflammation of the subacute phase of RP.

MA11.01 Development of Novel EGFR Mutant NSCLC Mouse Models and Murine Cell Lines: New Tools for NSCLC Research

EGFR mutant lung cancer accounts for approximately 15-30% of all non-small cell lung cancer (NSCLC) cases, with the prevalence varying in different populations. A point mutation L858R and in-frame deletions in exon 19 of the EGFR gene account for the majority of all EGFR activating mutations. EGFR tyrosine kinase inhibitors (TKIs) have led to significant advances in the treatment of EGFR mutant NSCLC; however, many patients show a partial response and all eventually develop resistance. Better preclinical models are required to design rational combination therapies. Our group has used syngeneic orthotopic mouse models of NSCLC to study interactions between cancer cells and the tumor microenvironment in the lung. These approaches are limited by the availability of murine lung cancer cell lines. To our knowledge, there are currently no EGFR mutant murine lung cancer cell lines. Therefore, we developed a novel transgenic mouse strain that conditionally expresses mutant EGFR mediated by Cre-recombinase. Administration of adeno-Cre virus into the lungs resulted in the development of EGFR-driven lung tumors. In collaboration with the Mouse Genetics Core at National Jewish Health, we developed two novel EGFR mutant mouse models (Rosa-loxP-STOP-LoxP- EGFR L860R/del19-mC3-WPRE): one with a deletion 19 and one with an L860R mutation (equivalent to the human L858R mutation) in the mouse EGFR gene. Tumors are initiated through intratracheal injections of the adeno-Cre virus. These mice were bred with p53flox mice from Jackson Laboratories to increase the diversity of tumors. Tumors were harvested and submitted to histological characterization by H&E staining or processed to create cell lines. These cell lines were characterized by in vitro growth assays, western blot analyses, and sequencing to confirm their genotype and responsiveness to EGFR TKIs. Cell lines were implanted into both the flanks and lungs of mice to determine their responsiveness to EGFR TKIs. Tumor-bearing mice were imaged by CT and treated by oral gavage with the EGFR TKIs. Intratracheal administration of adeno-Cre led to the development of multiple tumors throughout all lobes of the lung in both del19 and L860R mice. Time to tumor formation occurred within 4-12 weeks. Importantly, treatment of the mice with osimertinib resulted in tumor shrinkage and improvement in the health of mice. Moreover, we were able to successfully isolate 3 distinct cell lines (del19.1, del19.2, L860R.1) from these tumors. In vitro, these cell lines are responsive to multiple EGFR TKIs, as evidenced by a decrease in proliferation and inhibition of phospho-ERK. These cells form tumors when implanted into the flanks of nu/nu mice, del19.1-derived tumors undergo shrinkage in response to osimertinib. Orthotopically injected del19.1 cells form tumors in the left lungs of WT C57Bl/6 mice. We have developed novel mouse models as well as murine cell lines that reflect mutant EGFR-driven NSCLC which will be useful tools for studying NSCLC both in vitro and in vivo. By increasing the number of murine NSCLC cell lines, we can better recapitulate human disease to increase our understanding of NSCLC and develop novel therapeutic strategies that can be used to treat patients.

Nintedanib Regulates GRK2 and CXCR2 to Reduce Neutrophil Recruitment in Endotoxin-Induced Lung Injury.

The role of nintedanib, a multiple tyrosine kinase inhibitor, in the treatment of sepsis-induced acute lung injury (ALI) remains unclear. Lipopolysaccharide (LPS), also known as endotoxin, has been used to induce ALI. The goal of this study was to assess the effect of nintedanib in attenuating the histopathological changes of LPS-induced ALI. Nintedanib was administered via oral gavage to male C57BL/6 mice 24 h and 10 min before intratracheal endotoxin instillation. Lung histopathological characteristics, adhesion molecule expression, and the regulatory signaling pathways of neutrophil chemotaxis were analyzed after 24 h. We found that nintedanib significantly reduced histopathological changes and neutrophil recruitment in LPS-induced ALI. The number of neutrophils in bronchoalveolar lavage fluid (BALF) was reduced in nintedanib-treated relative to untreated mice with ALI. Nintedanib mediated the downregulation of the chemotactic response to LPS by reducing the expression of adhesion molecules and the phosphorylated p38:total p38 mitogen-activated protein kinase (MAPK) ratio in the lungs of mice with ALI. Nintedanib also reduced the expression of lymphocyte antigen 6 complex locus G6D (Ly6G) and very late antigen 4 (VLA-4) in BALF neutrophils and mediated the downregulation of chemokine (C-X-C motif) receptor 2 (CXCR2) and upregulation of G protein-coupled receptor kinase 2 (GRK2) activity in peripheral blood neutrophils in mice with LPS-induced ALI. Nintedanib improved the histopathological changes of LPS-induced ALI by reducing neutrophil chemotaxis. These effects were mediated by the inhibition of adhesion molecules via the activation of GRK2 and the inhibition of p38 MAPK and CXCR2.

Nrf2 signaling promotes cancer stemness, migration, and expression of ABC transporter genes in sorafenib-resistant hepatocellular carcinoma cells.

As a multiple tyrosine kinase inhibitor, sorafenib is widely used to treat hepatocellular carcinoma (HCC), but patients frequently face resistance problems. Because the mechanism controlling sorafenib-resistance is not well understood, this study focused on the connection between tumor characteristics and the Nrf2 signaling pathway in a sorafenib-resistant HCC cell line. A sorafenib-resistant HCC cell line (Huh7) was developed by increasing the dose of sorafenib in the culture medium until the target concentration was reached. Cell morphology, migration/invasion rates, and expression of stemness-related and ATP-binding cassette (ABC) transporter genes were compared between sorafenib-resistant Huh7 cells and parental Huh7 cells. Next, a small interfering RNA was used to knock down Nrf2 expression in sorafenib-resistant Huh7 cells, after which cell viability, stemness, migration, and ABC transporter gene expression were examined again. Proliferation, migration, and invasion rates of sorafenib-resistant Huh7 cells were significantly increased relative to the parental cells with or without sorafenib added to the medium. The expression levels of stemness markers and ABC transporter genes were up-regulated in sorafenib-resistant cells. After Nrf2 was knocked down in sorafenib-resistant cells, cell migration and invasion rates were reduced, and expression levels of stemness markers and ABC transporter genes were reduced. Nrf2 signaling promotes cancer stemness, migration, and expression of ABC transporter genes in sorafenib-resistant HCC cells.

8P The characterization of tumors associated with the antitumor activity of lenvatinib plus anti-PD-1 antibody combination therapy in a mouse syngeneic model panel

Lenvatinib is a multiple receptor tyrosine kinase inhibitor targeting mainly vascular endothelial growth factor and fibroblast growth factor receptors. We also reported that lenvatinib has immunomodulatory activity that contributes to the antitumor activity of lenvatinib and enhances the antitumor activity in combination treatment with anti-PD-1 antibody (anti-PD-1). In this study, we investigated the characters of tumors associated with the antitumor activity of the lenvatinib plus anti-PD-1 combination treatment.

Ponatinib dose-ranging study in chronic-phase chronic myeloid leukemia: a randomized, open-label phase 2 clinical trial

AbstractIn PACE (Ponatinib Ph+ ALL and CML Evaluation), a phase 2 trial of ponatinib that included patients with chronic-phase chronic myeloid leukemia (CP-CML) resistant to multiple prior tyrosine kinase inhibitors (TKIs), ponatinib showed deep and durable responses, but arterial occlusive events (AOEs) emerged as notable adverse events. Post hoc analyses indicated that AOEs are dose dependent. We assessed the benefit/risk ratio across 3 ponatinib starting doses in the first prospective study to evaluate a novel, response-based, dose-reduction strategy for TKI treatment. Adults with CP-CML resistant to or intolerant of at least 2 prior BCR-ABL1 TKIs or with a BCR-ABL1 T315I mutation were randomly assigned 1:1:1 to 3 cohorts receiving ponatinib 45, 30, or 15 mg once daily. In patients who received 45 or 30 mg daily the dose was reduced to 15 mg upon response (BCR-ABL1IS transcript levels ≤1%). The primary end point was response at 12 months. From August 2015 through May 2019, 283 patients were randomly assigned to the cohorts: 282 (94 per dose group) received treatment (data cutoff, 31 May 2020). The primary end point (98.3% confidence interval) was achieved in 44.1% (31.7-57.0) in the 45-mg cohort, 29.0% (18.4-41.6) in the 30-mg cohort, and 23.1% (13.4-35.3) in the 15-mg cohort. Independently confirmed grade 3 or above treatment-emergent AOEs occurred in 5, 5, and 3 patients in the 45-, 30-, and 15-mg cohorts, respectively. All cohorts showed benefit in this highly resistant CP-CML population. Optimal benefit/risk outcomes occurred with the 45-mg starting dose, which was decreased to 15 mg upon achievement of a response. This trial is registered on www.clinicaltrials.gov as NCT02467270.

Expression of Cancer Stem Cell Markers EpCAM and CD90 Is Correlated with Anti- and Pro-Oncogenic EphA2 Signaling in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. Additionally, the efficacy of targeted molecular therapies with multiple tyrosine kinase inhibitors is limited. In this study, we focused on the cellular signaling pathways common to diverse HCC cells and used quantitative reverse phase protein array (RPPA) and statistical analyses to elucidate the molecular mechanisms determining its malignancy. We examined the heterogeneity of 17 liver cancer cell lines by performing cluster analysis of their expression of CD90 and EpCAM cancer stem cell markers. Gaussian mixture model clustering identified three dominant clusters: CD90-positive and EpCAM-negative (CD90+), EpCAM-positive and CD90-negative (EpCAM+) and EpCAM-negative and CD90-negative (Neutral). A multivariate analysis by partial least squares revealed that the former two cell populations showed distinct patterns of protein expression and phosphorylation in the EGFR and EphA2 signaling pathways. The CD90+ cells exhibited higher abundance of AKT, EphA2 and its phosphorylated form at Ser897, whereas the EpCAM+ cells exhibited higher abundance of ERK, RSK and its phosphorylated form. This demonstrates that pro-oncogenic, ligand-independent EphA2 signaling plays a dominant role in CD90+ cells with higher motility and metastatic activity than EpCAM+ cells. We also showed that an AKT inhibitor reduced the proliferation and survival of CD90+ cells but did not affect those of EpCAM+ cells. Taken together, our results suggest that AKT activation may be a key pro-oncogenic regulator in HCC.

EGFR activation limits the response of liver cancer to lenvatinib.

Hepatocellular carcinoma (HCC)-the most common form of liver cancer-is an aggressive malignancy with few effective treatment options1. Lenvatinib is a small-molecule inhibitor of multiple receptor tyrosine kinases that is used for the treatment of patients with advanced HCC, but this drug has only limited clinical benefit2. Here, using a kinome-centred CRISPR-Cas9 genetic screen, we show that inhibition of epidermal growth factor receptor (EGFR) is synthetic lethal with lenvatinib in liver cancer. The combination of the EGFR inhibitor gefitinib and lenvatinib displays potent anti-proliferative effects in vitro in liver cancercell lines that express EGFR and in vivo in xenografted liver cancercell lines, immunocompetent mouse models and patient-derived HCC tumours in mice. Mechanistically, inhibitionof fibroblast growth factor receptor (FGFR) by lenvatinib treatment leads to feedback activation of the EGFR-PAK2-ERK5 signalling axis, which is blocked by EGFR inhibition. Treatment of 12 patients with advanced HCC who were unresponsive to lenvatinibtreatment with the combination of lenvatinib plus gefitinib (trial identifier NCT04642547) resulted in meaningful clinical responses. The combination therapy identified here may represent a promising strategy for the approximately 50% of patients with advanced HCC who have high levels of EGFR.