Treatment of unresectable stage III NSCLC: Real world cohort study and literature review.

INTRODUCTION: Until recently, the treatment for patients with locally advanced unresectable stage III non-small cell lung cancer (NSCLC) was combined chemoradiotherapy (CRT), delivered either concurrently (cCRT) or sequentially (sCRT). There is limited data on the outcomes and safety of CRT in a real-world setting. We conducted a real-world cohort analysis of our Leuven Lung Cancer Group (LLCG) experience with CRT for unresectable stage III NSCLC, prior to the era of consolidation treatment with immunotherapy. PATIENTS AND METHODS: In this observational, real-world monocentric cohort study, a total of 163 consecutive patients were included. They were diagnosed with unresectable stage III primary NSCLC and treated with CRT between January 1st, 2011, and December 31st, 2018. Patient and tumor characteristics, treatment patterns, toxicity, and primary outcome parameters such as PFS, OS and pattern of relapse were captured. RESULTS: CRT was concurrent in 108 patients, sequential in 55. Overall tolerability was good, with two thirds of patients without severe adverse events such as severe febrile neutropenia, ≥ grade 2 pneumonitis, or ≥ grade 3 esophagitis. All registered adverse events were more frequent in the cCRT group compared to the sCRT group. Median PFS was 13.2 months (95% CI 10.3-16.2), median OS was 23.3 months (95% CI 18.3-28.0), with a 47.5% survival rate at 2 years, and 29.4% at five years. CONCLUSIONS: This study provides a clinically relevant benchmark on the outcomes and toxicity of concurrent and sequential chemoradiotherapy in unresectable stage III NSCLC in a real-world setting in the pre-PACIFIC era.

Interaction between posaconazole and flucloxacillin in a lung transplant patient: decrease in plasma exposure of posaconazole and possible undertreatment of invasive aspergillosis: case report.

BACKGROUND: Variability in triazole plasma concentrations by drug interactions is well known. An interaction between voriconazole and flucloxacillin has already been described. In our case we observed a similar interaction between posaconazole and flucloxacillin, which in our knowledge has not ever been reported in literature. CASE PRESENTATION: A 60-year-old male who had a double lung transplantation for end-stage chronic obstructive pulmonary disease was being treated with voriconazole for invasive pulmonary aspergillosis (IPA). During this treatment he presented at the emergency room and was diagnosed with endocarditis for which a combination of amoxicillin, flucloxacillin and gentamicin was initiated. A known interaction between voriconazole and flucloxacillin was observed, with a drop of the voriconazole levels, and treatment for IPA was switched to posaconazole. After ending the treatment for endocarditis, the patient had a catheter infection for which flucloxacillin was reinitiated. Unexpectedly we saw a similar immediate drop in posaconazole levels, recovering after ending treatment with flucloxacillin. CONCLUSIONS: We describe a new interaction between posaconazole and flucloxacillin. Presumably the underlying mechanism is activation of the pregnane X receptor by flucloxacillin, which can induce cytochrome P450, uridine glucuronosyl transferase (UGT1A4) and P-glycoprotein. We advise caution when combining flucloxacillin and triazoles, because interactions may lead to undertreatment of invasive aspergillosis.