Exploration of germline variants responsible for adverse events of crizotinib in anaplastic lymphoma kinase-positive non-small cell lung cancer by target-gene panel sequencing

Crizotinib induces pulmonary toxicity by blocking autophagy flux in alveolar epithelial cells

Crizotinib is the first-line drug for advanced non-small cell lung cancer with the abnormal expression of anaplastic lymphoma kinase gene. Severe, life-threatening, or fatal interstitial lung disease/pneumonia has been reported in patients treated with crizotinib. The clinical benefit of crizotinib is limited by its pulmonary toxicity, but the underlying mechanisms have not been adequately studied, and protective strategies are relatively scarce. Here, we established an in vivo mouse model in which crizotinib was continuously administered to C57BL/6 at 100 mg/kg/day for 6 weeks and verified that crizotinib induced interstitial lung disease in vivo, which was consistent with the clinical observations. We further treated BEAS-2B and TC-1 cells, the alveolar epithelial cell lines, with crizotinib and found the increased apoptosis rate. We proved that crizotinib-blocked autophagic flux caused apoptosis of the alveolar epithelial cells and then promoted the recruitment of immune cells, suggesting that limited autophagy activity was the key reason for pulmonary injury and inflammation caused by crizotinib. Subsequently, we found that metformin could reduce the macrophage recruitment and pulmonary fibrosis by recovering the autophagy flux, thereby ameliorating impaired lung function caused by crizotinib. In conclusion, our study revealed the mechanism of crizotinib-induced apoptosis of alveolar epithelial cells and activation of inflammation during the onset of pulmonary toxicity and provided a promising therapeutic strategy for the treatment of crizotinib-induced pulmonary toxicity.

Comprehensive biomarker analysis from phase II study of nivolumab in patients with thymic carcinoma

In a phase II trial of nivolumab in advanced thymic carcinoma (UMIN000022007), long SD (SD for more than 24 weeks) was seen in three patients and irAE (Gr2 or higher) was seen in four patients among 15 patients. Here, we report preplanned comprehensive biomarker analyses. We obtained tumor samples for immunohistochemistry, peripheral blood mononuclear cells (PBMCs), plasma and serum for pharmacokinetic analysis of nivolumab and cytokine evaluations, and whole blood for immuno pharmacogenomic (PGx) analysis. PD-L1 expression on tumor cells were not associated with therapeutic efficacy, but FOXP3 expression in tumor area and stroma, CD204 expression in stroma, and MHC class I in tumor area were all low among long SD patients. PBMC of long SD patients presented with larger number of naïve/memory cells prior to treatment, suggesting priming after nivolumab administration. Immuno-PGx analysis showed non-synonymous SNVs in ITGAX and PDCD1 had some correlation with PFS. Concentration of nivolumab in blood during the treatment was not related to PFS, with their overall trend towards decreased nivolumab concentration in patients with irAEs. Low immunogenicity of thymic carcinoma demonstrated in our study may require the activation of immune systems via a combination of immune checkpoint blockades.

Pharmacokinetic and pharmacogenomic analysis of low-dose afatinib treatment in elderly patients with EGFR mutation-positive non-small cell lung cancer

PURPOSE

An increasing number of advanced non-small cell lung cancer (NSCLC) cases are being reported in the ageing population. However, studies on the use of afatinib in elderly patients are scarce. We conducted a prospective multicentre, single-arm, and open-label phase II trial for low-dose afatinib (30 mg/day) use in elderly patients with NSCLC with EGFR mutation to assess quality-of-life (QOL) and pharmacokinetic (PK)/pharmacogenomic (PGx) parameters.

PATIENTS AND METHODS

The primary end-point was the objective response rate (ORR), and the planned number of registered cases was 35, with a threshold ORR of 50%, an expected ORR of 75%, α of 0.05, and β of 0.1. Secondary end-points were progression-free survival (PFS), overall survival (OS), the incidence rate of adverse events (AEs), QOL survey (FACT-L), and trough plasma concentration of afatinib at steady state (Css) and at the occurrence of clinically significant AEs.

RESULTS

The median age of the patients was 79 years. The ORR was 80.0% and the disease control rate was 91.4%. The median PFS and OS were 15.6 and 29.5 months, respectively. Four patients discontinued because of AEs. Treatment-related death was not observed. No significant change in QOL was observed at baseline and after 4, 8, and 12 weeks. Css was comparable with those in previous reports and was significantly higher in patients with grade 3 AEs. Direct correlations between afatinib treatment and PGx profiles were not observed.

CONCLUSIONS

An afatinib starting dose of 30 mg/day could be an effective and safe treatment option for elderly patients.