Two Tyrosine Kinase Inhibitors Research Articles

Real-word experience of pazopanib and sorafenib in patients with desmoid tumors: A CanSaRCC multi-center study

BackgroundSorafenib and pazopanib, two tyrosine kinase inhibitors (TKI), are widely used in patients with progressive symptomatic desmoid tumors (DT). Limited real-word data is available on long-term outcomes of patients who progressed on, stopped, or continued TKIs. MethodsPatients diagnosed with DTs and treated with sorafenib or pazopanib between 2011 and 2022 at 11 institutions were reviewed. Patient history, response to therapy and toxicity were recorded. Statistical analyses utilized Kaplan-Meier and log-rank tests. Results142 patients with DT treated with sorafenib (n=126, 88.7%) or pazopanib (n=16, 11.3%) were analyzed. The median treatment duration was 10.8 months (range: 0.07- 73.9). The overall response rate and the disease control rate were 26.0% and 95.1%, respectively. The median tumor shrinkage was -8.5% (range -100.0%- +72.5%). Among responders, the median time to an objective response was 15.2 months (range: 1.1 to 33.1). The 1-year and 2-year progression-free survival rates were 82% and 80%. Dose reductions were necessary in 34 (23.9%) patients. Grade 3 or higher adverse events were reported in 36 (25.4%) patients. On the last follow-up, 55 (38.7%) patients continued treatment. Treatment discontinuation (n=85, 59.9%) was mainly for toxicity (n=35, 45.9%) or radiological or clinical progression (n=30, 35.3%). For the entire cohort, 36 (25.4%) patients required subsequent treatment. In the 32 responders, only 1 (3.1%) patient required a subsequent treatment. In patients who discontinued TKI, 25 (44.6%) with stable disease received subsequent treatment compared to 0 (0.0%) of responders. ConclusionThis retrospective study represents the largest cohort of DT patients treated with sorafenib or pazopanib to date. Discontinuation of treatment in responders is safe. The optimal treatment duration in patients with stable disease remains to be defined.

Safety and Efficacy of Imatinib, Nilotinib, and Artesunate in COVID-19 Patients: A Systematic Review of Current Evidence

Introduction: There is a need for better treatment options against COVID-19. This systematic review aimed to assess the safety and efficacy of imatinib and nilotinib, two tyrosine kinase inhibitors (TKIs), as well as artesunate (an anti-malarial agent), whose multilayer activ-ities against SARS, MERS, and SARS-CoV-2 pathogenesis have been suggested in laboratory and observational studies. Methods: A comprehensive search strategy targeting relevant literature on PubMed, Scopus, and Web of Science online databases was constructed. The retrieved records were reviewed and screened by title/abstract and full text with eligibility criteria, and the most pertinent articles were included in the final qualitative synthesis. This review adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to ensure the reliability of the results. Results: This systematic review assessed the safety and applicability of imatinib, nilotinib, and artesunate in COVID-19 patients. The results showed not only possible anti-COVID-19 effects but also acceptable safety for both generic users with comorbidities with COVID-19 and off-label use in other COVID-19 patients. Promising results were also reported enhancing the sur-vival of COVID-19 patients. Conclusion: A double-blinded multicenter randomized controlled trial found survival benefits for imatinib with no significant treatment-related adverse events. However, no clinical trials or large observational studies exist for artesunate and nilotinib, and the evidence relies only on case reports and case series. Molecular mechanisms revealed in preclinical studies support the possible benefits of these medications in COVID-19 treatment. However, the scarcity of reliable evidence requires further studies on possible COVID-19 treatments, including but not limited to artesunate, nilotinib, and imatinib. Nevertheless, these drugs' lack of serious adverse events suggests their safe use for other indications during the COVID-19 pandemic.

Cancer-associated fibroblast-derived secreted phosphoprotein 1 contributes to resistance of hepatocellular carcinoma to sorafenib and lenvatinib.

Cancer-associated fibroblasts (CAFs) play an important role in the induction of chemo-resistance. This study aimed to clarify the mechanism underlying CAF-mediated resistance to two tyrosine kinase inhibitors (TKIs), sorafenib and lenvatinib, and to identify a novel therapeutic target for overcoming TKI resistance in hepatocellular carcinoma (HCC). We performed a systematic integrative analysis of publicly available gene expression datasets and whole-transcriptome sequencing data from 9 pairs of CAFs and para-cancer fibroblasts isolated from human HCC and para-tumor tissues, respectively, to identify key molecules that might induce resistance to TKIs. We then performed in vitro and in vivo experiments to validate selected targets and related mechanisms. The associations of plasma secreted phosphoprotein 1 (SPP1) expression levels before sorafenib/lenvatinib treatment with progression-free survival (PFS) and overall survival (OS) of 54 patients with advanced HCC were evaluated using Kaplan-Meier and Cox regression analysis. Bioinformatic analysis identified CAF-derived SPP1 as a candidate molecule driving TKI resistance. SPP1 inhibitors reversed CAF-induced TKI resistance in vitro and in vivo. CAF-derived SPP1 activated rapidly accelerated fibrosarcoma (RAF)/mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) through the integrin-protein kinase C-alpha (PKCα) signaling pathway and promoted epithelial-to-mesenchymal transition (EMT). A high plasma SPP1 level before TKI treatment was identified as an independent predictor of poor PFS (P = 0.026) and OS (P = 0.047) in patients with advanced HCC after TKI treatment. CAF-derived SPP1 enhances TKI resistance in HCC via bypass activation of oncogenic signals and EMT promotion. Its inhibition represents a promising therapeutic strategy against TKI resistance in HCC. Moreover, plasma SPP1 level before TKI treatment represents a potential biomarker for treatment response prediction.

Comparative Characteristics of the Effectiveness of Tyrosine Kinase Inhibitors Vs Allogeneic Hematopoietic Stem Cell Transplantation in the Chronic Phase of Chronic Myeloid Leukemia

Background: Chronic myeloid leukemia (CML) patients (pts) with the resistance at least to two tyrosine kinase inhibitors (TKIs) should be considered as candidates for allogeneic hematopoietic stem cell transplantation (allo-HSCT). At the same time, the majority of pts in real clinical practice continue conservative third-line therapy with TKIs (TKI-3L). Aim: To compare the long-term results of TKI-3L vs allo-HSCT therapy in chronic phase (CP) CML. Methods: We have included 139 pts in CP CML from six centers in Saint Petersburg and Leningrad Region (males, n=66) in the multicenter retrospective study: 73 pts on TKI-3L and 66 pts after allo-HSCT. Me age in the whole group was 45(19-88) mos. Basic characteristics of patients according to groups are presented in the Table. At the start of TKI-3L there were 51/73(71%) pts with no cytogenetic response (CyR). The best baseline CyR was minimal or minor (mmCyR), partial (PCyR) in 12/73(16%), 10/73(13%) cases, respectively. In the group with allo-HSCT there were 62/66(93%) pts with no CyR. The best baseline CyR was PCyR in 3(5%) cases. Reasons for TKI-2L discontinuation were: resistance in 56/73(76%) or intolerance in 17/73(24%) cases respectively. Reasons for performing allo-HSCT were: resistance in 65/66(98%), including 6 interferon-resistant cases, or intolerance in 1/66(2%) cases respectively. Descriptive statistics were used for analysis, significance of differences between groups were estimated using chi-square test and Fisher's exact test. The rate of complete CyR (CCyR) (equal to BCR::ABL transcript level ≤1% by IS) were assessed. Overall (OS) and progression-free survival (PFS) were analyzed by Kaplan-Meier method. Log-rank test was used to assess the significance of differences in survival between patients' groups. Results: The Me duration of TKI-3L therapy was 14(1-120) mos, the Me time of follow-up (FU) from initiation of TKI-3L was 25(3-136) mos. The Me duration time of FU from allo-HSCT was 42(1-322) mos. CCyR and MMR were achieved in 22/73(30%) and 9/73(12%) pts respectively in TKI-3L group while CCyR and PCR-negativity were achieved in 53/66(80%) and 29/66(44%) pts respectively in the group after allo-HSCT (with p≤0,05 in CCyR and MR in both groups). Progression to acceleration phase or blast crisis (AP/BC) was observed in 13/73(17%) pts with the Me time to progression 17 mos in TKI-3L group and in 7/66(10%) pts with the Me time to progression 6 mos in allo-HSCT group, p=0,24 (See Fig. 1A). Death occurred in 19/73(26%), including five deaths from non-CML-related causes with Me time to death 17,2 mos in TKI-3L group and in 26/66(39%), including 17 transplant-related deaths and 6 CML-related with Me time to death 14 mos in allo-HSCT group, p=0,25 (See Fig. 1B). Estimated 1-year, 3-year and 5-year OS was 95%, 65% and 65% respectively in TKI-3L group as well as 90%, 65% and 60% respectively in allo-HSCT group. During FU time Me PFS and OS was not reached in both groups. In pts with any CyR at baseline in TKI-3L group with FU time 25(3-136) mos no pts progressed to AP/BC and only 2 CML-unrelated deaths occurred. At the last visit, TKI-3L therapy was continued in 13/73(18%) with Me FU time 7,5(4-99) mos. Most of them(n=10) with CCyR or better responses. TKI-3L discontinuation was mainly associated with resistance in 42/60(70%) pts. In allo-HSCT group 40/66(61%) pts alive with 21/40(53%) in stable PCR-negativity. Conclusion: In our observation OS and PFS was equal under TKI-3L or after allo-HSCT. No Pts with any CyR at baseline progressed and dead due to CML in TKI-3L group. Meanwhile less than one third pts and a few of them obtained CCyR and MMR, respectively, whereas the majority of pts after allo-HSCT reach CCyR and nearly half of them obtained PCR-negativity in this heavily pretreated group. Despite there are some biases (retrospective study, undirected comparison, in allo-HSCT group were included pts with any number TKIs or even without ones, much less FU time in the TKI-3L group), it seems that allo-HSCT is preferable option for pt after two second generation TKIs failure. Also in pts with any CyR after 2TKIs failure the use of TKI-3L therapy might be justified. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

PIH8 Cost-Effectiveness Analysis Of Dasatinib Versus Imatinib In Treating Pediatric Philadelphia Chromosome-Positive Acute Lymphoblastic Leukemia Patients In China

To compare the cost-effectiveness of the two tyrosine kinase inhibitors (TKI), imatinib and dasatinib, in treating pediatric patients with philadelphia-positive acute lymphoblastic leukemia (Ph+ ALL) in China.

Profile of Cabozantinib for the Treatment of Hepatocellular Carcinoma: Patient Selection and Special Considerations.

Management of advanced hepatocellular carcinoma is challenging. With an increasing number of options for the first and second-line treatment, understanding and developing optimal systemic treatment strategies are crucial. In second line, two tyrosine kinase inhibitors (TKI) and one monoclonal antibody have been approved after sorafenib by both the European Medicines Agency and the Food and Drug Administration based on the results of phase 3 trials: cabozantinib, regorafenib and ramucirumab. Cabozantinib has demonstrated an improved overall survival and progression-free survival in the phase 3 CELESTIAL study in second and third line, in patients in good general condition (performance status 0–1) and with a normal liver function Child-Pugh class A. Analysis of subgroups has shown that even elderly patients over 65 years, or patients with high baseline alpha-fetoprotein ≥400 ng/mL benefit from cabozantinib. The choice in second-line between the three drugs should be based on factors such as previous tolerance of sorafenib, safety profile of drugs and quality of life. In this review, we will analyze clinical data available on cabozantinib, clarifying the choice between the different possible treatments. However, the upcoming of a new standard in first line with the combination atezolizumab and bevacizumab will change the game and will warrant further investigations to define the accurate subsequent sequence of TKIs. Cabozantinib is also actually tested in first-line in combination with atezolizumab, results of the phase 3 COSMIC trial are eagerly awaited.

Increased therapeutic effect on medullary thyroid cancer using a combination of radiation and tyrosine kinase inhibitors.

Since patients with medullary thyroid cancer (MTC) often have metastatic disease at the time of diagnosis, the development of efficient systemic treatment options for MTC is important. Vandetanib and cabozantinib are two tyrosine kinase inhibitors (TKIs) that were recently approved by FDA and EMA for systemic treatment of metastatic MTC. Additionally, since MTC is of a neuroendocrine tumour type, treatment with radiolabelled somatostatin analogues (e.g. 177Lu-octreotate) is a valid option for patients with MTC. The aim of this study was to investigate the potentially increased therapeutic effect of combining radiation therapy with these TKIs for treatment of MTC in a mouse model. Nude mice carrying patient-derived MTC tumours (GOT2) were treated with external beam radiotherapy (EBRT) and/or one of the two TKIs vandetanib or cabozantinib. The tumour volume was determined and compared with that of mock-treated controls. The treatment doses were chosen to give a moderate effect as monotherapy to be able to detect any increased therapeutic effect from the combination therapy. At the end of follow-up, tumours were processed for immunohistochemical (IHC) analyses. The animals in the combination therapy groups showed the largest reduction in tumour volume and the longest time to tumour progression. Two weeks after start of treatment, the tumour volume for these mice was reduced by about 70-75% compared with controls. Furthermore, also EBRT and TKI monotherapy resulted in a clear anti-tumour effect with a reduced tumour growth compared with controls. The results show that an increased therapeutic effect could be achieved when irradiation is combined with TKIs for treatment of MTC. Future studies should evaluate the potential of using 177Lu-octreotate therapy in combination with TKIs in patients.

Development of innovative artificial neural networks for simultaneous determination of lapatinib and foretinib in human urine by micellar enhanced synchronous spectrofluorimetry.

A highly selective and simple micellar synchronous spectrofluorimetric method was described for simultaneous analysis of two tyrosine kinase inhibitors (TKIs); namely lapatinib (LPB) and foretinib (FTB) in human urine. The method depended on measuring synchronous fluorescence of the two drugs in micellar media composed of cremophor RH 40 (Cr RH 40) surfactant using feed-forward and cascade-forward neural networks preceded by genetic algorithm for data manipulation. Different experimental conditions that affect fluorescence of the cited drugs are optimized including pH, diluting solvent, surfactant's type and concentration. A training set of nine mixtures containing different concentrations of both drugs was prepared for models' construction. Extra validation set composed of other nine mixtures was prepared to validate prediction performance for the constructed models. Root mean square error of prediction (RMSEP) was used as a tool to compare prediction power of each model. The method was extended for quantification of LPB and FTB in spiked human urine.

Association between clinically relevant toxicities of pazopanib and sunitinib and the use of weak CYP3A4 and P-gp inhibitors.

Sunitinib and pazopanib, two tyrosine kinase inhibitors (TKI), may be targets of potential pharmacokinetic drug-drug interactions (P-PK-DDIs). While strong cytochrome P4503A (CYP3A4) inhibitors or inducers should cause a clinically relevant modification in plasma TKI concentrations, the effect of weak inhibitors is unknown. The objective of this study was to evaluate the association between weak P-PK-DDI and clinically relevant toxicity in real life. This was a single-center retrospective study including patients treated with sunitinib or pazopanib for any malignancies, for whom a PK-DDI analysis was performed before starting TKI. The primary endpoint was the correlation between P-PK-DDIs and a dose decrease after 1month of treatment. The secondary endpoint was the correlation between PK-DDIs and drug withdrawal due to toxicity. Seventy-six patients were assessed. A P-PK-DDI with weak CYP3A4 or P-gp inhibition was found in 14 patients. In patients with P-PK-DDI or without, the dose was reduced during the first month in 57.1% and 17.7% (p = 0.003) and the drug withdrawn in 42.8% and 11.3% (p = 0.011), respectively. In multivariate analysis, a significant correlation was found between P-PK-DDI (CYP3A4 and P-gp inhibitors) and dose reduction, and between drug withdrawal and PK-DDI (CYP3A4 inhibitors). P-PK-DDI was correlated with dose reduction and drug withdrawal due to toxicity. The causality of this relationship warrants to be assessed; therefore, therapeutic drug monitoring is necessary in patients treated with TKI.

Health-related quality of life assessment for patients with advanced or metastatic renal cell carcinoma treated with a tyrosine kinase inhibitor using electronic patient-reported outcomes in daily clinical practice (QUANARIE trial): study protocol

BackgroundTwo main therapies, pazopanib and sunitinib, are used in the first-line setting for metastatic renal cell carcinoma (mRCC). These two tyrosine kinase inhibitors (TKI) are equally effective in terms of survival; however, they frequently induce adverse events. In this setting, Health-Related Quality of life (HRQoL) is a key element in the choice between these two treatments and the evaluation of treatment effectiveness. It could be of interest to evaluate HRQoL in daily clinical practice to aid adequate therapy choice and management. Currently, the development of information and communication technology may allow HRQoL monitoring in routine practice. The objective of the QUANARIE study is to evaluate the use of HRQoL assessment in daily clinical practice for patients with mRCC treated with TKI using electronic patient-reported outcomes (e-PRO). The present article describes the key elements of the study protocol.MethodsThe QUANARIE study is an interventional, prospective, multicentre trial. Patients diagnosed with mRCC initiating sunitinib or pazopanib treatment will be invited to complete the EORTC QLQ-C30 questionnaire, nine additional questions from the EORTC items library, and the EuroQoL EQ-5D, prior to each visit with the physician. Questionnaires will be completed by patients using tablets and/or computer terminals via the e-PRO software. The physician will have real-time access to a visual summary of the HRQoL evaluation. The primary objective is to assess the proportion of patients having good compliance with Routine Electronic Monitoring of HRQoL (REMOQOL) during the first 12 months. Physicians’ satisfaction with REMOQOL will be assessed as a secondary objective. We hypothesise that 80% of patients having good compliance with REMOQOL would be meaningful. A sample size of 56 patients would be needed.DiscussionThe results of this study will show whether REMOQOL is feasible on a large scale and whether patients are receptive to this new practice. This study will also determine how real-time multidimensional evaluation of patient perception can help physicians in their daily practice and how they used it in conjunction with other clinical information to manage patient care.Trial registrationClinicalTrials.gov; Identifier: NCT03062410; First Posted: February 23, 2017; Last Update Posted: August 9, 2017.

Metalloporphyrin-Catalyzed Oxidation of Sunitinib and Pazopanib, Two Anticancer Tyrosine Kinase Inhibitors: Evidence for New Potentially Toxic Metabolites.

Oxidation of two tyrosine kinase inhibitors (TKIs) sunitinib and pazopanib, using a chemical catalytic system able to mimic the cytochrome P450 type oxidation, allowed us to prepare putative reactive/toxic metabolites of these anticancer drugs. Among these metabolites, aromatic aldehyde derivatives were unambiguously characterized. Such biomimetic oxidation of TKI-type drugs was essential to facilitate the identification of low amounts of aldehydes generated from these TKIs when incubated with human liver microsomes (HLM), which are classical models of human hepatic metabolism. These TKI derivative aldehydes quickly react in vitro with amines. A similar reaction is expected to occur in vivo and may be at the origin of the potentially severe hepatotoxicity of these TKIs.

Tyrosine kinase inhibitors in Ph+ acute lymphoblastic leukaemia: facts and perspectives.

Two tyrosine kinase inhibitors (TKIs), imatinib and dasatinib, are registered for the treatment of Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukaemia (ALL) in adults. Other two TKIs (nilotinib and ponatinib) have been tested in the second-line, can offer an alternative in the patients who fail the first-line, and can acquire a role also in the first-line. Here, we provide a summary of the reports of TKIs, used alone, and in combination with chemotherapy. TKIs are very effective alone and with corticosteroids and are likely to improve substantially the outcome when they are combined with standard or dose-adapted chemotherapy. While the complete haematologic remission rate is always very high, close to 100 %, the cytogenetic and molecular remission rates are lower, so that TKIs are still considered as a complement to chemotherapy and as a bridge to allogeneic stem cell transplantation (allo-SCT). However, many patients relapse before transplant, and many patients still relapse, even if they have been submitted to allo-SCT. A proper use of TKIs, the introduction of ponatinib, and of "new generation" TKIs should improve further on the outcome of Ph+ ALL.

A combination of sorafenib and nilotinib reduces the growth of castrate-resistant prostate cancer.

Castrate-resistant prostate cancer (CRPC) remains incurable due to the lack of effective therapies. Several tyrosine kinases have been implicated in the development and growth of CRPC, as such targeting these kinases may offer an alternative therapeutic strategy. We established the combination of two tyrosine kinase inhibitors (TKIs), sorafenib and nilotinib, as the most cytotoxic. In addtion, to improve their bioavailability and reduce their metabolism, we encapsulated sorafenib and nilotinib into styrene-co-maleic acid micelles. The micelles’ charge, size, and release rate were characterized. We assessed the effect of the combination on the cytotoxicity, cell cycle, apoptosis, protein expression, tumor spheroid integrity, migration, and invasion. The micelles exhibited a mean diameter of 100 nm, a neutral charge, and appeared highly stable. The micellar TKIs promoted greater cytotoxicity, decreased cell proliferation, and increased apoptosis relative to the free TKIs. In addition, the combination reduced the expression and activity of several tyrosine kinases and reduced tumor spheroid integrity and metastatic potential of CRPC cell lines more efficiently than the single treatments. The combination increased the therapeutic potential and demonstrated the relevance of a targeted combination therapy for the treatment of CRPC. In addition, the efficacy of the encapsulated drugs provides the basis for an in vivo preclinical testing.

The Role of Everolimus in Renal Cell Carcinoma.

Everolimus (RAD001) is an orally administered agent that inhibits the mammalian target of rapamycin serine-threonine kinase. A phase III pivotal trial on everolimus, published in 2008, provided the first evidence for the efficacy of sequential therapy for patients with metastatic clear cell renal cell carcinoma (RCC). In this study, everolimus was used after failure of one or several previous lines of therapy, and it demonstrated a 3-month survival benefit relative to placebo. Currently, based on the level 1 evidence, everolimus represents the molecule of choice for third-line therapy after failure of previous two tyrosine kinase inhibitors (TKIs). However, second-line use after failure of one TKI is challenged by two new molecules (nivolumab and cabozantinib), which proved to have better efficacy with similar toxicity profile. In non-clear cell metastatic RCC, the current evidence recommends everolimus as a second-line therapy after failure of previous first-line sunitinib.

Abstract 5454: Inhibition of Bcr-Abl tyrosine kinase sensitizes cells to sapacitabine

Abstract CNDAC, the active form of sapacitabine, is a nucleoside analog which kills cells by a unique mechanism of action. Incorporation of CNDAC triphosphate into DNA results in a single-strand break, which is converted to a one-ended double-strand break (DSB) upon subsequent collapse of the DNA replication fork. CNDAC-induced DSBs are repaired predominantly through the homologous recombination pathway which consists the key recombinase Rad51 and its associated proteins. Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm; its central pathogenesis is a reciprocal chromosomal translocation between chromosomes 9 and 22. This abnormal chromosomal fusion results in the formation of a chimeric gene that encodes a constitutively active tyrosine kinase, Bcr-Abl, which promotes CML through stimulating downstream signaling cascades for cell survival and deregulated cell growth. Bcr-Abl tyrosine kinase modulates DNA repair mechanisms to protect leukemic cells from DNA damage induced cell death. In response to DSBs, it phosphorylates Rad51 at Tyr315 which enhance the damage repair process. Based on this evidence, we hypothesized that inhibition of Bcr-Abl will further sensitize cells to CNDAC. To test this postulate, we used the CML cell line K562 as well as murine Ba/F3 cells transfected with wild-type Bcr-Abl (Ba/F3p210wt) or the Bcr-Abl mutant (Ba/F3p210T315I) as model systems. Two tyrosine kinase inhibitors (TKI) were utilized to inhibit Bcr-Abl. Imatinib, the first generation TKI, is only effective inhibiting wild type Bcr-Abl. Ponatinib, a subsequent TKI, is potent in inhibiting both wild type and mutant Bcr-Abl tyrosine kinases. First, these cells were treated with CNDAC, imatinib or ponatinib alone to determine the IC50 values for each drug using PrestoBlue cell viability assay. Based on the single drug IC50s, combinations of CNDAC with imatinib or ponatinib were applied to these cell lines and their combination indexes were calculated by CalcuSyn software. We found that CNDAC and imatinib were synergistic in K562 and Ba/F3 wild type Bcr-Abl cells while they were additive in the Bcr-Abl T315I mutant cells. In contrast, ponatinib sensitized CNDAC treatment as their combination was synergistic in all these cell lines. Finally, to investigate the mechanism underlying the observed synergism, K562 cells were treated with either equitoxic concentrations of CNDAC, imatinib or ponatinib alone or in combinations for 48 hours when lysates were collected for immunoblot analysis. It was found that when Bcr-Abl was inhibited, the phosphoryation of Rad51 at Tyr315 was reduced, phospho H2AX and cleaved caspase 3 were increased in response to CNDAC. Thus further sensitization of CNDAC was a result of deficient damage repair due to Bcr-Abl inhibition. Together, our results link the Bcr-Abl tyrosine kinase to CNDAC-induced DNA damage repair process and provide rationale for CNDAC/sapacitabine combination therapy in diseases such as CML. Citation Format: Yingjun Jiang, Xiaojun Liu, Adrienne Chestang, William Plunkett. Inhibition of Bcr-Abl tyrosine kinase sensitizes cells to sapacitabine. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5454. doi:10.1158/1538-7445.AM2014-5454

Abstract 2780: Tyro3 and Axl receptors tyrosine kinase as potential therapeutic targets in leiomyosarcoma

Abstract Leiomyosarcoma (LMS) represents 15% of adult sarcomas. Once metastatic, curative options are limited and innovative strategies are needed. TYRO3 and AXL proto-oncogenes belong to TAM family (Tyro3/Axl/Mer) of tyrosine kinase receptors, with oncogenic properties that are often overexpressed or activated in various malignancies. Using kinexus phosphoprotein microarrays (KAM-1.1) and western blot analyses, we evidenced that Tyro3 and Axl are overexpressed in LMS along with Gas6, their ligand. Interestingly LMS samples harbouring high levels of Gas6 and its receptors also presented AKT phosphorylation on S473 residue keeping with previous studies that highlighted AKT- mTOR activation in leiomyosarcomas. Based on these premises, we asked whether Tyro3-Axl axis may drive LMS proliferation and could represent potential targets in these tumors. The overexpression of Tyro3 was found to be associated with a specific miRNA signature, notably with an overexpression of miR22 in LMS tumors. Furthermore Tyro3 and Axl were found overexpressed in a panel of 6 LMS cell lines (SK-LMS-1 from ATCC and IB112, IB118, IB133, IB134 and IB136 from Institut Bergonié), compared with normal human smooth muscle. Tyro3 or Axl knockdown via shRNA retroviral vector reduced cell proliferation by up to 50 and 64% respectively and decreased soft agar colony-forming ability. Crizotinib and foretinib are two tyrosine kinase inhibitors (TKI) targeting Met and Axl. Treatment of LMS cell lines with both TKIs resulted in a significant increase in cell death, with IC50 values ranging from 3.6 to 14.6µM and 0.7 to 1.8µM, respectively. Annexin V and PI staining revealed that cell death was mainly due to apoptosis. Flow cytometric cell cycle analysis demonstrates that both TKIs altered cell cycle phase distribution. A sub-G1 phase accumulation was observed for one of the cell lines; meanwhile the other cell lines presented a G2 arrest and 4n chromosomes accumulation accompanied by an increase in cell and nucleus sizes. Only foretinib induced nuclear fragmentation consistent with late apoptosis. Pharmacological inhibition also reduced migration and colony formation in soft agar. Drug combinations with an AKT inhibitor led to significant increase in growth inhibition in all tested cell lines. Crizotinib and foretinib reduced activation of Tyro3 or Axl-mediated downstream signaling including MAPK/ERK, PI3K/AKT along with an inhibition of Axl phosphorylation in a dose dependent manner. By immunoprecipitation we observed also a reduction in Tyro3 phosphorylation, following exposure to both agents, showing that Tyro3 is a new target for those drugs. IHC analysis of Tyro3, Axl and Gas6 expression in a cohort of LMS patient is ongoing. In vivo analysis wil be performed. In conclusion these results strongly suggest that Tyro3 and Axl are relevant therapeutic targets for LMS treatment and will be investigated in a proof of concept clinical trial. Citation Format: Carmela Dantas-Barbosa, François Le Loarer, Marta Mendiola, Isabelle Treilleux, Frederic Chibon, Hyba El Sayadi, Jean Michel Coindre, Laurent Alberti, Jean-Yves Blay. Tyro3 and Axl receptors tyrosine kinase as potential therapeutic targets in leiomyosarcoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2780. doi:10.1158/1538-7445.AM2014-2780

Overview and management of dermatologic events associated with targeted therapies for medullary thyroid cancer.

Treatment options for patients with advanced or metastatic medullary thyroid cancer (MTC) have, in recent years, expanded with the approval of two tyrosine kinase inhibitors (TKIs): vandetanib and cabozantinib. Other agents, including TKIs, are under clinical investigation for MTC. Although patients treated with TKIs are at risk of developing dermatologic adverse events (AE), these untoward events may be mitigated through AE-driven algorithms. AE-driven algorithms combine effective nonpharmaceutical and pharmaceutical treatment modalities implemented by a multidisciplinary effort that incorporates nursing interventions, patient education, and referrals to pain-management specialists, podiatrists, and dermatologists, as appropriate. Effective AE prevention and management reduce the need for dose interruptions and modifications, allowing patients the opportunity to derive the maximal benefit from TKI therapy, while maintaining quality of life. Optimal use of targeted therapies in the treatment of MTC depends on careful patient selection, interdisciplinary communication, and patient education and encouragement to enhance compliance and safety, optimize consistent dosing, and maximize the use of effective therapies.

Treating Ph+ Acute Lymphoblastic Leukemia (ALL) in the Elderly: The Sequence of Two Tyrosine Kinase Inhibitors (TKI) (Nilotinib and Imatinib) Does Not Prevent Mutations and Relapse.

AbstractAbstract 2601▪▪This icon denotes a clinically relevant abstract Background:Tyrosine Kinase Inhibitors (TKI) have been shown to be very effective for the treatment of Acute Lymphoblastic Leukemia (ALL), with a Complete Hematologic Remission (CHR) rate close to 100%, and a high rate of Complete Cytogenetic and Molecular responses (CCgR and CMR). However, when they are used alone, as single agents, most patients relapse, so that they are currently used in combination with chemotherapy and as a preparation to allogeneic stem cell transplantation (SCT). Since Ph+ ALL is more frequent in the elderly, many patients cannot tolerate intensive chemotherapy and are not eligible for SCT. We have explored if the administration of two TKIs, Nilotinib (NIL) and Imatinib (IM) can improve the results without increasing the toxicity. Aims:To evaluate the response and the outcome of Ph+ ALL patients treated with the sequential administration of NIL and IM, to investigate the type and number of BCR-ABL kinase domain mutations developing during and after the study. Methods:We have designed a study (ClinicalTrials.gov. NCT01025505) in which patients more than 60 years old or unfit for intensive chemotherapy and SCT where treated with two TKIs, NIL 400 mg twice daily, and IM 300 mg twice daily, alternating for 6 weeks for a minimum of 24 weeks (study core) and indefinitely in case of response. The 6-weeks rotation schedule was respected, irrespectively of temporary discontinuations. The primary end-point was the rate of Disease Free Survival (DFS) at 24 weeks (4 courses of treatment); the secondary end points included the evaluation of CHR, CCgR and CMR rates. Mutation analysis was performed by nested RT-PCR amplification of the ABL kinase domain of the BCR-ABL transcript (codons 206 through 421). Amplified products were screened by denaturing-high performance liquid chromatography (D-HPLC). Samples scored positive for the presence of sequence variations were then subjected to direct automatic sequencing to characterize the mutation. Results:39 patients have been enrolled in 15 Italian hematologic Centers (median age 66 years, range 28–84). Among these, 8 patients were unfit for standard chemotherapy or SCT (median age 50 years, range 28–59). 27 patients were p190, 5 were p210 and 7 were p190/p210. After 6 weeks of treatment, 36 patients were evaluable for response: 34 were in CHR (94%) and 2 in PHR (6%). 23 patients have already completed the study core (24 weeks), 87% were in CHR and 17 are currently continuing therapy in the protocol extension phase.Thus, the OS at 1 year is 79%, and 64% at 2 years. Overall, 1 patient was primarily resistant and 13 patients have relapsed, with a median time to relapse of 7.6 months (range 0.8–16.1 months), for a DFS of 51.3% at 12 months (Figure 1). Mutations detected were T315I in 2 cases, Y253H in 3 cases, T315I and Y253H in 1 case, E255K in 1 case, T315I and E255K in 1 case, E255V and Y253H in 1 case. Two patients were WT.A detailed kinetics of Molecular responses is shown in Table 1. Data on mutational analysis are reported in Table 2. Further details about Cytogenetic and Molecular responses, and about Adverse Events will be provided on site. Conclusions:In this small cohort of Ph+ ALL elderly/unfit patients, the rates of relapse and progression were not likely to be different from the rates observed with Imatinib alone (Vignetti et al, Blood 2007, May 1;109(9):3676-8) and Dasatinib alone (Foà, Blood 2011, Dec 15;118(25):6521-8).It's important to notice that the mutations that occurred at the time of relapse were sensitive to other TKIs (Dasatinib and Ponatinib). Acknowledgments:COFIN, Bologna University, BolognAIL, PRIN, Fondazione del Monte di Bologna e Ravenna, INPDAP.Table 1Kinetics of Molecular responsenUndetectable (<0.0001)Total DetectableBCR-ABL <0.001BCR-ABL >0.1baseline3600036week 63137813week 123029127week 18222884week 24182772Table 2Mutational analysis was performed in 11/14 patients who failedPtsMutationTime to relapse (months)006001y253h, e255v5.5006012t315i, y253h20.1006018e255k, t315i3006020y253h8.8006026e255k7.3008007t315i2.5008015y253h14.5012035wt3.8042004wt10.1043009y253h17.4043030t315i7.3 [Display omitted] Disclosures:Pizzolo:Hoffmann-La Roche: Consultancy, Honoraria. Luppi:CELGENE CORPORATION: Research Funding. Vallisa:CELGENE CORPORATION: Research Funding. Martinelli:NOVARTIS: Consultancy, Honoraria, Speakers Bureau; BMS: Consultancy, Honoraria, Speakers Bureau; PFIZER: Consultancy; ARIAD: Consultancy. Baccarani:ARIAD, Novartis, Bristol Myers-Squibb, and Pfizer: Consultancy, Honoraria, Speakers Bureau.

Comparison of Disease Outcomes for Patients with Chronic Myelogenous Leukemia in Chronic Phase Switched to Nilotinib or Dasatinib As Second-Line Therapy.

AbstractAbstract 2796 Background:Nilotinib and dasatinib are two tyrosine kinase inhibitors (TKIs) commonly used for the treatment of patients with chronic myelogenous leukemia in chronic phase (CML-CP) who are resistant or intolerant to imatinib. Both TKIs have been shown to be more potent than imatinib. However, no head-to-head clinical trials have been conducted comparing the efficacy of nilotinib to dasatinib as 2nd-line therapy for CML-CP patients resistant or intolerant to imatinib. This study compared disease outcomes of patients treated in the community who were switched from imatinib to 2nd-line nilotinib or dasatinib. Methods:Through an online chart abstraction form, participating community physicians submitted de-identified information on CML-CP patients ≥ 18 years old who switched after 10/28/2007 from imatinib to 2nd-line nilotinib or dasatinib with at least 30 days of follow-up. When multiple patients met the selection criteria, up to 8 patients in each group were selected randomly by physicians. Patients enrolled in clinical trials or with concurrent malignancies were excluded. Information was collected on demographics, clinical characteristics, cytogenetic response, progression to accelerated phase or blast crisis, and death from any cause. Documented complete cytogenetic response (CCyR) at a particular time point was defined as 0% Philadelphia chromosome positive cells on cytogenetic testing; patients with missing tests at that time point were counted as non-responders. Disease progression to accelerated phase or blast crisis, progression-free survival, and overall survival were compared using multivariate Cox proportional hazards models, adjusting for potential confounding factors, including patient demographics and clinical characteristics at the time the patient switched to a 2nd-line TKI. Results:122 hematologists and oncologists provided information on 597 patients, including 301 patients on nilotinib and 296 patients on dasatinib. The median follow-up was 11 months for nilotinib patients and 10 months for dasatinib patients. Age, sex, race, comorbidities, and other clinical characteristics were similar for both groups, except that nilotinib patients were more likely than dasatinib patients to have switched due to secondary imatinib resistance (p=0.047) and were less likely to have switched due to imatinib intolerance (p=0.024). Nilotinib patients had similar rates of documented CCyR compared to dasatinib patients at 12 months (37% vs. 35%, p=0.54), 24 months (42% vs. 40%, p=0.62), and 36 months (44% vs. 44%, p=0.95) following the switch. However, nilotinib patients had lower risk of progression (p=0.004), higher progression free survival (p=0.023) and a trend towards prolonged overall survival (p=0.067), adjusting for potential confounders. The table below summarizes these results. Conclusions:Among patients with CML-CP switched to nilotinib or dasatinib for 2nd-line therapy, nilotinib patients had significantly lower rates of progression and longer progression-free survival compared to dasatinib patients.OutcomeNilotinib EventsDasatinib EventsUnadjusted Hazard RatioP-valueAdjusted Hazard RatioP-value(n=301)(n=296)Progression5 (1.7)13 (4.4)0.39 (0.14–1.09)0.0720.15 (0.04–0.55)0.004Progression-free Survival286 (95.0)269 (90.9)1.81 (0.96–3.40)0.0672.14 (1.11–4.12)0.023Overall Survival291 (96.7)279 (94.3)1.71 (0.78–3.75)0.1772.13 (0.95–4.78)0.067 Disclosures:Griffin:Novartis: Consultancy, Research Funding. Guerin:Analysis Group, Inc.: Consultancy, Employment, I am an employee of Analysis Group, Inc, which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Chen:Novartis Oncology: Employment, Own stock in Novartis Other. Macalalad:Analysis Group, Inc.: Consultancy, Employment, I am an employee of Analysis Group, Inc, which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Luo:Analysis Group, Inc.: Consultancy, Employment, I am an employee of Analysis Group, Inc, which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding. Wu:Analysis Group, Inc.: Consultancy, Employment, I am an employee of Analysis Group, Inc, which has received consulting fees from Novartis Pharmaceuticals Other, Research Funding.

Antitumor activity of sorafenib in human cancer cell lines with acquired resistance to EGFR and VEGFR tyrosine kinase inhibitors.

Treatment of non small cell lung cancer (NSCLC) and colorectal cancer (CRC) have substantially changed in the last years with the introduction of epidermal growth factor receptor (EGFR) inhibitors in the clinical practice. The understanding of mechanisms which regulate cells sensitivity to these drugs is necessary for their optimal use.An in vitro model of acquired resistance to two tyrosine kinase inhibitors (TKI) targeting the EGFR, erlotinib and gefitinib, and to a TKI targeting EGFR and VEGFR, vandetanib, was developed by continuously treating the human NSCLC cell line CALU-3 and the human CRC cell line HCT116 with escalating doses of each drug. MTT, western blot analysis, migration, invasion and anchorage-independent colony forming assays were conducted in vitro and experiments with established xenografts in athymic nude mice were performed in vivo in sensitive, wild type (WT) and TKI-resistant CALU-3 and HCT116 cell lines.As compared to WT CALU-3 and HCT116 human cancer cells, TKI-resistant cell lines showed a significant increase in the levels of activated, phosphorylated AKT, MAPK, and of survivin. Considering the role of RAS and RAF as downstream signals of both the EGFR and VEGFR pathways, we treated resistant cells with sorafenib, an inhibitor of C-RAF, B-RAF, c-KIT, FLT-3, RET, VEGFR-2, VEGFR-3, and PDGFR-β. Sorafenib reduced the activation of MEK and MAPK and caused an inhibition of cell proliferation, invasion, migration, anchorage-independent growth in vitro and of tumor growth in vivo of all TKI-resistant CALU-3 and HCT116 cell lines.These data suggest that resistance to EGFR inhibitors is predominantly driven by the RAS/RAF/MAPK pathway and can be overcame by treatment with sorafenib.