P2.12-13 Lurbinectedin (L) Combined with Paclitaxel (P) or Irinotecan (I) in Relapsed SCLC. Results from Two Phase Lb Trials

Lurbinectedin in small cell lung cancer

Few treatment options are available for patients with small cell lung cancer (SCLC) in progression after a first-line therapy. A novel therapeutic approach is represented by lurbinectedin, a synthetic derivative of trabectedin that works by inhibiting oncogenic transcription and promoting apoptosis in tumor cells. A phase II basket trial demonstrated the activity of lurbinectedin at the dose of 3.2 mg/m² in patients with SCLC who had failed a previous chemotherapy, with a response rate of 35.2%, a median progression-free survival (mPFS) of 3.5 months, and a median overall survival (mOS) of 9.3 months. Common severe adverse events (grades 3–4) were hematological disorders, including anemia (9%), leukopenia (29%), neutropenia (46%), and thrombocytopenia (7%). On the basis of the positive results of this phase II study, on June 2020, lurbinectedin was approved by the Food and Drug Administration as second line for SCLC patients in progression on or after platinum-based therapy. The subsequent phase III trial comparing the combination of lurbinectedin plus doxorubicin vs. CAV (cyclophosphamide, Adriamycin, and vincristine) or topotecan did not demonstrate an improvement in overall survival, although the experimental arm showed a superior safety profile. Combinations of lurbinectedin with other drugs, cytotoxic agents and immune checkpoint inhibitors, are currently under investigation. The results of these studies should better define the optimal clinical application of lurbinectedin.

Therapeutic Modalities in Small Cell Lung Cancer: a paradigm shift after decades of quiescence

INTRODUCTION

Small cell lung cancer (SCLC) is known to be the most aggressive of all thoracic malignancies, notoriously known for its very poor prognosis. Platinum based chemotherapy has been the standard of care for decades. Despite years of research, no treatment novelties with significant impact on survival have been achieved until recently. The last few years have witnessed light at the end of the tunnel with immunotherapy proving to improve survival. Nevertheless, responses were not homogeneous in all subgroups, and finding who would best benefit from treatment remains unanswered. Multiple limitations exist, and the quest for optimal biomarkers seemed unfruitful until the discovery of different SCLC phenotypes.

AREAS COVERED

In this review, the authors briefly discuss SCLC phenotypes and biomarker assays. Then, the authors continue with the main trials of SCLC treatment using chemotherapy, immunotherapy and targeted treatment in the front-line or subsequent line settings.

EXPERT OPINION

Research has been extensively implemented to better understand the biology of SCLC, and test for the optimal use of immunotherapy in patients with SCLC, as well as to enhance responses via possible combinations. Targeted mechanisms of action have also been attempted; yet no solid proof of efficacy has been established.

Lurbinectedin in the treatment of relapsed small cell lung cancer

Lurbinectedin is a marine-derived drug that inhibits transcription, a process that is frequently dysregulated in small cell lung cancer. The activity of lurbinectedin has been studied in many solid tumors, showing not only promising results but also a favorable safety profile. In relapsed small cell lung cancer, the drug has shown encouraging activity both as a single agent and in combination with doxorubicin, paclitaxel or irinotecan. The USA FDA has recently granted accelerated approval to lurbinectedin monotherapy in this setting. This article provides an update on available data and ongoing studies of lurbinectedin in small cell lung cancer, including Phase I combination trials, the basket Phase II trial and the ATLANTIS Phase III trial.