Background: Acquired resistance to approved tyrosine kinase inhibitors limits their clinical use in patients with gastrointestinal stromal tumor (GIST). This study investigated the safety,... Show moreBackground: Acquired resistance to approved tyrosine kinase inhibitors limits their clinical use in patients with gastrointestinal stromal tumor (GIST). This study investigated the safety, tolerability and efficacy of alpelisib, a phosphatidylinositol 3-kinase inhibitor, used in combination with imatinib in patients with advanced GIST who had failed prior therapy with both imatinib and sunitinib. Methods: This phase 1b, multicenter, open-label study consisted of 2 phases: dose escalation and dose expansion. Dose escalation involved 200 mg once daily (QD) alpelisib, initially, followed by 250 and 350 mg. These were combined with 400 mg QD imatinib until maximum tolerated dose (MTD) and/or a recommended phase 2 dose (RP2D) of alpelisib in combination with imatinib was determined. This MTD/RP2D dose was tested to evaluate the clinical activity of this combination in dose expansion. Results: Fifty-six patients were enrolled, 21 and 35 in the dose escalation and expansion phases, respectively. The MTD of alpelisib given with imatinib was determined as 350 mg QD. Combination treatment showed partial response in 1 (2.9%) and stable disease in 15 (42.9%) patients. Median progression-free survival was 2 months (95% CI 1.8-4.6). Overall, 92.9% patients had adverse events (AEs) while 46.4% had grade 3/4 AEs, hyperglycemia being the most common (23.2%). Conclusions: The MTD of alpelisib was estimated as 350 mg QD when used in combination with imatinib 400 mg QD after oral administration in patients with advanced GIST. The safety and tolerability profile of this combination was acceptable; however, the combination did not demonstrate sufficient clinical activity to justify additional clinical testing. Show less
Background: Gastrointestinal stromal tumour (GIST) is commonly treated with tyrosine kinase inhibitors (TKIs), but most patients ultimately develop secondary resistance. Cabozantinib, a multi... Show moreBackground: Gastrointestinal stromal tumour (GIST) is commonly treated with tyrosine kinase inhibitors (TKIs), but most patients ultimately develop secondary resistance. Cabozantinib, a multi-targeted TKI inhibitor, has activity in patient-derived GIST mouse xenograft models and can overcome compensatory MET signalling occurring on TKI treatment. European Organisation for Treatment of Cancer (EORTC) 1317 'CaboGIST' assessed the safety and activity of cabozantinib in patients with GIST who had progressed on imatinib and sunitinib.Methods: In this multi-center, open label, single arm phase II study, eligible GIST patients received oral cabozantinib (60 mg) once daily. Primary end-point was the progression-free survival rate at 12 weeks assessed by the local investigator per Response Evaluation Criteria in Solid Tumours 1.1. If at least 21 of the first 41 eligible and evaluable patients were progression-free at week 12, the activity of cabozantinib was sufficient to warrant further exploration according to the A'Hern one-stage study design.Findings: A total of 50 eligible patients started treatment between 02/2017 and 08/2018, including four (8%) still continuing cabozantinib at clinical cut-off (09/2019). The number of 3-weekly treatment cycles ranged from 1 to 30. Among the first 41 eligible and evaluable patients, 24 were progression-free at week 12 (58.5%, 95% confidence interval [CI] 42.0 -74.0%). Among all 50 patients, 30 were progression-free at week 12 (60%, 95% CI 45 -74%). Seven patients achieved a partial response (14%, 95% CI 6-27%), and 34 had stable disease (68%, 95% CI 53-80%) as best response. Progression was seen in eight patients (16%, 95% CI 7-29%), and one was not evaluable. Disease control was achieved in 41 patients (82%, 95% CI 69-91%). Median progression-free survival was 5.5 months (95% CI 3.6-6.9). The most common adverse events were diarrhoea (76%), palmar-plantar erythrodysesthesia syndrome (60%), fatigue (50%), hypertension (42%), weight loss (40%) and oral mucositis (30%), with 32 (64%) patients requiring dose reductions, 27 (54%) having treatment interruptions and no cabozantinib-related deaths observed.Interpretation: EORTC 1317 met its primary end-point, with 24/41 patients being progression free at week 12 of treatment. The objective response was 14% with an encouraging disease control rate of 82%. Results of this trial confirm preclinical findings and warrant further exploration of cabozantinib in GIST. (C) 2020 Elsevier Ltd. All rights reserved. Show less
This thesis on systemic treatment options in soft tissue sarcomas consists of two parts. In part I, the pharmacogenetics of systemic gastro-intestinal stromal tumors (GIST) treatment is... Show moreThis thesis on systemic treatment options in soft tissue sarcomas consists of two parts. In part I, the pharmacogenetics of systemic gastro-intestinal stromal tumors (GIST) treatment is investigated. SNPs related to the pharmacokinetics and pharmacodynamics of imatinib and sunitinib have been associated to survival and to toxicity. SNPs in VEGFA and SLCO1B3 have been associated to worse progression free survival during imatinib treatment of advanced GIST. SNPs in ABCG2 and CYP1A2 have been associated with the need for dose reduction in patients receiving imatinib for GIST. A SNP in POR was associated with better progression free survival during sunitinib treatment of advanced GIST . In part II the usage of trabectedin is soft tissue sarcomas (STS) in the Netherlands is studied. Trabectedin as second line treatment of soft tissue sarcoma was compared to ifosfamide monotherapy. The Incremental Cost-Effectiveness Ratio for leiomyosarcomas and liposarcomas was at the top end of what is considered acceptable in the Netherlands. For other soft tissue sarcomas subtypes, ifosfamide dominated trabectedin. The venous access related adverse events of trabectedin have been described. The research in this thesis contributes towards personalised treatment for advanced soft tissue sarcomas. Show less
Sunitinib has been approved by FDA in 2006 and became the first-line treatment for patients with clear cell metastatic renal cell carcinoma (cc-mRCC) due to its dramatic improvement in... Show moreSunitinib has been approved by FDA in 2006 and became the first-line treatment for patients with clear cell metastatic renal cell carcinoma (cc-mRCC) due to its dramatic improvement in progression-free survival (PFS) and overall survival (OS) and affordable toxicity. However, the inter-individual variability of sunitinib outcomes is large. Some clinical factors, such as blood pressure, can partly predict sunitinib efficacy, but they are not enough. More insight into the genetic factors underlying sunitinib outcome could also be helpful to improve optimization of treatment. In this thesis, the relevance of single nucleotide polymorphisms (SNPs) to sunitinib treatment in (cc)-mRCC patients was investigated with regard to efficacy and toxicity.We identified SNPs in IL8,IL13, VEGFR, CYP3A5 and CTLA-4 were associated with efficacy, toxicity and clearance.Further validation in independent cohorts is need before the implementation of these genetic biomarkers into clinical practice. Show less
Sunitinib treatment requires a personalized approach, since patients can respond very differently to this drug. Pharmacogenetics may improve our ability to provide a tailored therapy by studying... Show moreSunitinib treatment requires a personalized approach, since patients can respond very differently to this drug. Pharmacogenetics may improve our ability to provide a tailored therapy by studying how genetic variations could influence drug response. The objective of this thesis was to find genetic markers that can predict toxicity and efficacy of sunitinib in patients with metastatic renal cell carcinoma. This research builds upon previous findings from candidate gene studies by testing a selection of SNPs based on plausible involvement in pharmacokinetics or pharmacodynamics of the drug of interest. We observed that SNPs located in genes involved in metabolism and drug absorption (CYP3A4, CYP3A5, and ABCB1) are potentially associated with the clearance of sunitinib and its active metabolite. In analogy to this, we confirmed SNP associations from previous studies for SNPs in CYP3A5 and ABCB1 that predict the need for dose reductions and improvement of PFS on sunitinib. Sunitinib-induced toxicity is possibly related to SNPs in CYP3A4 and CYP3A5, and in interleukin genes IL8 and IL13. VEGFR-2 (KDR) rs34231037 G-allele variant carriers were potentially associated with a favorable response to sunitinib. A GWAS learned us that SNPs in chromosome 21 are involved in sunitinib efficacy, probably by influencing drug resistance mechanisms. Show less
Both tyrosine kinase inhibitors (tki) and mammalian target of rapamycin (mTOR) inhibitors are oral targeted therapies that are used for the treatment of a variety of malignancies. Due to the... Show moreBoth tyrosine kinase inhibitors (tki) and mammalian target of rapamycin (mTOR) inhibitors are oral targeted therapies that are used for the treatment of a variety of malignancies. Due to the growing evidence for drug exposure-response relationships, in combination with their high interpatient variability in pharmacokinetics (pk) and a fixed dosing regimen, it is hypothesized that dose individualization of oral targeted therapies may lead to better treatment outcomes both in terms of efficacy as well as toxicity. This thesis describes the results of different studies that investigated dose optimization strategies of oral targeted therapies used in oncology, with a focus on the TKIs pazopanib and sunitinib and the mTOR inhibitor everolimus. Show less
Wit, D. de; Erp, N.P. van; Khosravan, R.; Wiltshire, R.; Allred, R.; Demetri, G.D.; ... ; Gelderblom, H. 2014
Het doel van het in dit proefschrift beschreven onderzoek was meer kennis te vergaren over de farmacokinetiek van imatinib en sunitinib in pati_nten met kanker. Ook zijn verschillende mogelijkheden... Show moreHet doel van het in dit proefschrift beschreven onderzoek was meer kennis te vergaren over de farmacokinetiek van imatinib en sunitinib in pati_nten met kanker. Ook zijn verschillende mogelijkheden onderzocht om de therapie beter op de individuele pati_nt af te stemmen en daarmee over- en onderdoseringen te voorkomen. Show less
