Successful retreatment with osimertinib after osimertinib-induced acute pulmonary embolism in a patient with lung adenocarcinoma: A case report

Three non-small cell lung cancer patients who developed pulmonary thromboses during osimertinib treatment and could safely resume concomitant anticoagulation treatment: a report of three cases

Background

Previous phase III study has demonstrated that osimertinib, a third-generation epidermal growth factor receptor (EGFR)-tyrosine-kinase inhibitor (TKI), exhibits superior antitumor effects compared to first-generation EGFR-TKIs and successfully prolonged overall survival (OS) in patients with EGFR-mutated non-small cell lung cancer (NSCLC). Although first- and second-generation EGFR-TKIs are risk factors for venous thromboembolism (VTE), whether osimertinib increases the VTE risk remains unclear. In addition, no treatment strategy exists for patients with VTE during osimertinib. Here we present the clinical course of three patients with suspected osimertinib-induced VTE who were successfully treated with direct oral anticoagulation without recurrence VTE during osimertinib therapy.

Case Description

Three male patients, aged 66-74 years, with NSCLC harboring EGFR mutations had been treated with osimertinib as the first- and second-line treatments, and developed VTE. All patients responded to osimertinib, and none showed disease progression at VTE onset. All patients were treated with direct oral anticoagulation and could resume osimertinib treatment. The progression-free survival (PFS) from VTE onset in each of the three cases was 11.4+, 7.7, and 6.1 months, respectively. The OS from VTE onset was 11.4+, 26.0, and 25.9+ months, respectively.

Conclusions

We report the cases of three NSCLC patients who developed VTE during osimertinib. Osimertinib may cause VTE and should be used cautiously. In such cases, osimertinib treatment may be continued with direct oral anticoagulation therapy.

Potential Mechanisms of Cancer-Related Hypercoagulability

The association between cancer and thrombosis has been known for over a century and a half. However, the mechanisms that underlie this correlation are not fully characterized. Hypercoagulability in cancer patients can be classified into two main categories: Type I and Type II. Type I occurs when the balance of endogenous heparin production and degradation is disturbed, with increased degradation of endogenous heparin by tumor-secreted heparanase. Type II hypercoagulability includes all the other etiologies, with factors related to the patient, the tumor, and/or the treatment. Patients with poor performance status are at higher risk of venous thromboembolism (VTE). Tumors can result in VTE through direct pressure on blood vessels, resulting in stasis. Several medications for cancer are correlated with a high risk of thrombosis. These include hormonal therapy (e.g., tamoxifen), chemotherapy (e.g., cisplatin, thalidomide and asparaginase), molecular targeted therapy (e.g., lenvatinib, osimertinib), and anti-angiogenesis monoclonal antibodies (e.g., bevacizumab and ramucirumab).

Successful osimertinib rechallenge after osimertinib-induced pneumonitis in a patient with lung adenocarcinoma

Pneumonitis is a serious adverse event of EGFR-TKI treatment. Although several cases of EGFR-TKI rechallenge after EGFR-TKI-induced pneumonitis have been reported, little is known about post-pneumonitis osimertinib rechallenge. We describe a 69-year-old never-smoking Japanese woman with postoperative recurrent lung adenocarcinoma retreated with osimertinib after osimertinib-induced pneumonitis. Although osimertinib rechallenge must be carefully chosen based on risk/benefit analysis, osimertinib rechallenge after osimertinib-induced pneumonitis may be an option, with limited alternative therapeutic options.