PS01.04: A Phase II Study of Etirinotecan Pegol (NKTR-102) in Patients with Refractory Brain Metastases and Advanced Lung Cancer

Clinical applications of nanomedicines in lung cancer treatment

Lung cancer is the leading cause of cancer mortality worldwide. Owing to a lack of early-stage diagnosis, most lung cancers are detected in advanced stages, limiting the available therapeutic options. Moreover, extensive systemic chemotherapy of lung tumors is often associated with severe off-target toxicity and drug resistance of cancer cells, thus diminishing the outcomes of chemotherapy modalities. In this light, nanomedicines have opened an alternative avenue to develop more efficacious therapeutic platforms while addressing several current challenges. Clinical findings have revealed that nanomedicines improve the pharmacokinetics and biodistribution of the therapeutic agents while decreasing their systemic toxicity. This review provides an update on nanomedicines that have been clinically approved or are undergoing clinical trials for treatment of lung cancer. By discussing the clinical findings of the current nanoformulations, this review provides prospects for the development of more efficacious nanomedicines to improve the clinical outcomes of lung cancer treatment.

Etirinotecan Pegol (NKTR-102) in Third-line Treatment of Patients With Metastatic or Recurrent Non-Small-cell Lung Cancer: Results of a Phase II Study

BACKGROUND

Third-line treatment options are limited for patients with metastatic non-small-cell lung cancer (NSCLC). Etirinotecan pegol (NKTR-102) is a long-acting topoisomerase-I inhibitor. We conducted a single-arm phase II trial to evaluate its efficacy in third-line treatment.

PATIENTS AND METHODS

Patients aged ≥ 18 years with histologically proven NSCLC who had received 2 previous systemic therapy regimens, measurable disease, Eastern Cooperative Oncology Group (ECOG) performance status ≤ 1, and adequate end-organ function were eligible. Etirinotecan pegol was administered at a dose of 145 mg/m² intravenously once every 3 weeks until progression. The response was assessed every 6 weeks using Response Evaluation Criteria In Solid Tumors, version 1.1. The primary endpoint was the overall objective response rate. The secondary endpoints included progression-free survival (PFS), overall survival (OS) and safety. A Simon 2-stage design was implemented for futility.

RESULTS

From January 2013 to January 2015, 40 patients were enrolled. Their median age was 66 years (range, 19-85 years), 45% were female, 30% had an ECOG performance status of 0, 96% were current and former smokers, and 31 had adenocarcinoma. Patients received a median of 3 cycles (range, 2-15) of protocol therapy. The best response was a partial response in 2 patients. The treatment was well tolerated; 3 patients had grade 3 gastrointestinal toxicity attributable to therapy. The median PFS was 2.3 months (95% confidence interval [CI], 1.3-4.4 months), and the median OS was 7.1 months (95% CI 4.2-11.4 months).

CONCLUSIONS

Etirinotecan pegol was well tolerated and led to 2 partial responses and disease stabilization with this third-line treatment of metastatic NSCLC. However, the study failed to meet its prespecified response rate endpoint.