Background Although kinase inhibitors (KIs) are generally effective, their use has a large impact on the current health care budget. Dosing strategies to reduce treatment costs are warranted.... Show moreBackground Although kinase inhibitors (KIs) are generally effective, their use has a large impact on the current health care budget. Dosing strategies to reduce treatment costs are warranted. Boosting pharmacokinetic exposure of KIs metabolized by cytochrome P450 (CYP)3A4 with ritonavir might result in lower doses needed and subsequently reduces treatment costs. This study is a proof-of-concept study to evaluate if the dose of erlotinib can be reduced by co-administration with ritonavir. Methods In this open-label, cross-over study, we compared the pharmacokinetics of monotherapy erlotinib 150 mg once daily (QD) (control arm) with erlotinib 75 mg QD plus ritonavir 200 mg QD (intervention arm). Complete pharmacokinetic profiles at steady-state were taken up to 24 h after erlotinib intake for both dosing strategies. Results Nine patients were evaluable in this study. For the control arm, the systemic exposure over 24 h, maximum plasma concentration and minimal plasma concentration of erlotinib were 29.3 mu g*h/mL (coefficient of variation (CV):58%), 1.84 mu g/mL (CV:60%) and 1.00 mu g/mL (CV:62%), respectively, compared with 28.9 mu g*h/mL (CV:116%, p = 0.545), 1.68 mu g/mL (CV:68%, p = 0.500) and 1.06 mu g/mL (CV:165%, p = 0.150) for the intervention arm. Exposure to the metabolites of erlotinib (OSI-413 and OSI-420) was statistically significant lower following erlotinib plus ritonavir dosing. Similar results regarding safety in both dosing strategies were observed, no grade 3 or higher adverse event was reported. Conclusions Pharmacokinetic exposure at a dose of 75 mg erlotinib when combined with the strong CYP3A4 inhibitor ritonavir is similar to 150 mg erlotinib. Ritonavir-boosting is a promising strategy to reduce erlotinib treatment costs and provides a rationale for other expensive therapies metabolized by CYP3A4. Show less
Steendam, C.M.J.; Peric, R.; Walree, N.C. van; Youssef, M.; Schramel, F.M.N.H.; Brocken, P.; ... ; NVALT Study Grp 2021
Background: Earlier preclinical and phase II research showed enhanced effect of docetaxel plus intercalated erlotinib. The NVALT-18 phase III study was designed to compare docetaxel with docetaxel... Show moreBackground: Earlier preclinical and phase II research showed enhanced effect of docetaxel plus intercalated erlotinib. The NVALT-18 phase III study was designed to compare docetaxel with docetaxel plus intercalated erlotinib in relapsed metastasized non-squamous (NSQ) non-small cell lung cancer (NSCLC).Methods: Patients with relapsed Epidermal Growth Factor Receptor (EGFR) wild type (WT) NSQ-NSCLC were randomized 1:1 to docetaxel 75 mg/m(2) intravenously on day 1 every 21 days (control), or docetaxel 75 mg/m(2) intravenously on day 1 plus erlotinib 150 mg/day orally on day 2-16 every 21 days (experimental arm). Progression free survival (PFS) was the primary endpoint, secondary objectives were duration of response, overall survival (OS) and toxicity.Results: Between October 2016 and April 2018 a total of 45 patients were randomized and received treatment in the control (N = 23) or experimental arm (N = 22), the study was stopped due to slow accrual. Median PFS was 4.0 months (95% CI: 1.5-7.1) versus 1.9 months (95% CI 1.4-3.5), p = 0.01 respectively; adjusted hazard ratio (HR) 2.51 (95% CI: 1.16-5.43). Corresponding median OS was 10.6 months (95% CI: 7.0-8.6) versus 4.7 months (95% CI: 3.2-8.6), p = 0.004, with an adjusted HR of 3.67 (95% CI: 1.46-9.27). Toxicity was higher with combination therapy, with toxicity >= CTCAE grade 3 in N = 6 (26%) in the control arm and N = 17 (77%) in the experimental arm (p < 0.001), mainly consisting of gastrointestinal symptoms and leukopenia.Conclusions: Our study shows detrimental effects of docetaxel plus intercalated erlotinib, and strongly discourages further exploration of this combination in clinical practice. Show less
Background: high recurrence rates of up to 75% within 2 years in pancreatic ductal adenocarcinoma (PDAC) patients resected for cure indicate a high medical need for clinical prediction tools and... Show moreBackground: high recurrence rates of up to 75% within 2 years in pancreatic ductal adenocarcinoma (PDAC) patients resected for cure indicate a high medical need for clinical prediction tools and patient specific treat-ment approaches. Addition of the EGFR inhibitor erlotinib to adjuvant chemotherapy failed to improve out-come but its efficacy in some patients warrants predictors of responsiveness.Patients and Methods: we analysed tumour samples from 293 R0-resected patients from the randomized, multicentre phase III CONKO-005 trial (gemcitabine +/- erlotinib) with targeted sequencing, copy number, and RNA expression analyses.Findings: a total of 1086 mutations and 4157 copy-number aberrations (CNAs) with a mean of 17.9 /tumour were identified. Main pathways affected by genetic aberrations were the MAPK-pathway (99%), cell cycle control (92%), TGFb signalling (77%), chromatin remodelling (71%), and the PI3K/AKT pathway (65%). Based on genetic signatures extracted with non-negative matrix factorization we could define five patient clusters, which differed in mutation patterns, gene expression profiles, and survival. In multivariable Cox regression analysis, SMAD4 aberrations were identified as a negative prognostic marker in the gemcitabine arm, an effect that was counteracted when treated with erlotinib (DFS: HR=1.59, p = 0.016, and OS: HR = 1.67, p = 0.014). Integration of differential gene expression analysis established SMAD4 alterations with low MAPK9 expression (n = 91) as a predictive biomarker for longer DFS (HR=0.49; test for interaction, p = 0.02) and OS (HR = 0.32; test for interaction, p = 0.001).Interpretation: this study identified five biologically distinct patient clusters with different actionable lesions and unravelled a previously unappreciated association of SMAD4 alteration status with erlotinib effective-ness. Confirmatory studies and mechanistic experiments are warranted to challenge the hypothesis that SMAD4 status might guide addition of erlotinib treatment in early-stage PDAC patients. (C) 2021 The Author(s). Published by Elsevier B.V. Show less
Verheijen, R.B.; Duijl, T.T. van; Heuvel, M.M. van den; Vessies, D.; Muller, M.; Beijnen, J.H.; ... ; Huitema, A.D.R. 2021
Purpose We studied EGFR mutations in circulating tumor DNA (ctDNA) and explored their role in predicting the progression-free survival (PFS) of non-small cell lung cancer (NSCLC) patients treated... Show morePurpose We studied EGFR mutations in circulating tumor DNA (ctDNA) and explored their role in predicting the progression-free survival (PFS) of non-small cell lung cancer (NSCLC) patients treated with erlotinib or gefitinib. Methods The L858R, T790M mutations and exon 19 deletions were quantified in plasma using digital droplet polymerase chain reaction (ddPCR). The dynamics of ctDNA mutations over time and relationships with PFS were explored. Results In total, 249 plasma samples (1-13 per patient) were available from 68 NSCLC patients. The T790M and L858R or exon 19 deletion were found in the ctDNA of 49 and 56% patients, respectively. The median (range) concentration in these samples were 7.3 (5.1-3688.7), 11.7 (5.1-12,393.3) and 27.9 (5.9-2896.7) copies/mL, respectively. Using local polynomial regression, the number of copies of EGFR mutations per mL increased several months prior to progression on standard response evaluation. Conclusion This change was more pronounced for the driver mutations than for the resistance mutations. In conclusion, quantification of EGFR mutations in plasma ctDNA was predictive of treatment outcomes in NSCLC patients. In particular, an increase in driver mutation copy number could predict disease progression. Show less
Background: Erlotinib is an epidermal growth factor receptor inhibitor prescribed to patients with locally advanced or metastasized non-small cell lung carcinoma after failure of at least one... Show moreBackground: Erlotinib is an epidermal growth factor receptor inhibitor prescribed to patients with locally advanced or metastasized non-small cell lung carcinoma after failure of at least one earlier chemotherapy treatment. Approximately 75% of the patients treated with erlotinib develop acneiform skin rashes.Case Report: A patient treated with erlotinib 3 months after finishing concomitant treatment with chemotherapy and radiotherapy for non-small cell lung cancer is presented. Unexpectedly, the part of the skin that had been included in his previously radiotherapy field was completely spared from the erlotinib-induced acneiform skin rash.Conclusion: The exact mechanism of erlotinib-induced rash sparing in previously irradiated skin is unclear. The underlying mechanism of this phenomenon needs to be explored further, because the number of patients being treated with a combination of both therapeutic modalities is increasing. The therapeutic effect of erlotinib in the area of the previously irradiated lesion should be assessed. Show less
