Phase I study of lurbinectedin in combination with weekly paclitaxel with or without bevacizumab in patients with advanced solid tumors

Abstract

Lurbinectedin and paclitaxel showed synergism in preclinical studies and have non-completely overlapping toxicity profiles. This phase I trial evaluated a combination of paclitaxel and lurbinectedin with/without bevacizumab in advanced tumors. This trial was divided into Group A, which evaluated weekly paclitaxel (60 or 80 mg) plus lurbinectedin (3.0–5.0 mg flat dose [FD] or 2.2 mg/m2) every 3 weeks in advanced solid tumors; and Group B, which evaluated bevacizumab (BEV, 15 mg/kg) added to the recommended dose (RD) defined in Group A in advanced epithelial ovarian or non-small cell lung cancer (NSCLC). 67 patients (A, n = 55; B, n = 12) were treated. The RD was paclitaxel 80 mg/m2 on Day (D)1,D8 plus lurbinectedin 2.2 mg/m2 on D1. At this RD, myelotoxicity was reversible and manageable, and most non-hematological toxicities were mild/moderate. Adding BEV did not notably change tolerability. Twenty-five confirmed responses were observed: 20/51 evaluable patients in Group A (overall response rate [ORR] = 39% at all dose levels and at the RD), and 5/10 evaluable patients in Group B (ORR = 50%). Most responders had breast (n = 7/12 patients), small cell lung (SCLC) (n = 5/7), epithelial ovarian (n = 3/9) and endometrial cancer (n = 3/11) in Group A, and epithelial ovarian (n = 3/4) and NSCLC (n = 2/6) in Group B. Clinical benefit rate was 61% in Group A (58% at the RD), and 90% in Group B. No major pharmacokinetic drug-drug interactions were observed. Paclitaxel/lurbinectedin and paclitaxel/lurbinectedin/BEV are feasible combinations. Further development is warranted of paclitaxel/lurbinectedin in SCLC, breast, and endometrial cancer, and of paclitaxel/lurbinectedin/BEV in epithelial ovarian cancer.