Final Analysis Of A Multi-center, Double-blind, Placebo-controlled, Randomized Phase II Trial Of Gemcitabine/cisplatin (GC) Plus Bevacizumab (B) Or Placebo (P) In Patients (pts) With Malignant Mesothelioma (MM)
Background: In phase II trials in MM, GC on a 21-day (D) schedule has response rates of 16%–26% and median overall survival (OS) of 9.6–13 months (mo). Since VEGF has a key role in MM biology, we added anti-VEGF antibody B to GC in a multi-center, double- blind, placebo-controlled randomized phase II trial. Methods: Eligible pts had unresectable MM; no prior chemotherapy; PS 0–1; no thrombosis, bleeding, or major vessel invasion. Primary endpoint: progression-free survival (PFS). Statistics: 90% power to detect HR 0.57. Stratification: PS (0/1), histology (epithelial/other). G 1,250 mg/m2 D 1, 8 Q21D, C 75 mg/m2 D1 Q21D, and B 15 mg/kg or P D1 Q21D was given × 6 cycles, then B or P Q21D until progression. Baseline plasma VEGF was measured. 115 pts enrolled 12/01- 07/05 at 11 sites, 108 (GCB/GCP) 53/55 were evaluable. Male 74%/84%; median age 62/65 (range 44–78/20–84); PS 1 55%/47%; epithelial 74%/67%; pleural 93%/91%; thrombocytosis 40%/40%. Results: Cycles: total 458/424, median 7/6, range 1–42/2–39. Statistically significantly different (SSD) toxicity (p <0.05), any grade: alopecia 60%/38%; epistaxis 62%/24%; hypertension 45%/22%; non-neutropenic infection 15%/4%; proteinuria 62%/47%; stomatitis 23%/7%. There were no SSD toxicities = grade 3. Median PFS 6.9/6.0 mo (HR 0.93, p=0.88). Median OS 15.6/14.7 mo (p=0.91). 1-year survival 59%/57%. Partial response 25%/22%; stable disease 51%/60%. Median VEGF (N=56) 131/154 pg/ml (range 31–1760/5–1786). Higher VEGF was associated with shorter PFS (p=0.02) and OS (p=0.0066). In pts with VEGF = the median, PFS (p=0.043) and OS (p=0.028) were significantly greater for GCB than GCP; in high VEGF strata this was not SSD. Conclusion: Adding B to GC in MM pts does not yield statistically significant differences in PFS, OS, response, or grade ¾ toxicity. GCB-treated pts with low VEGF levels had longer PFS and OS. Supported by NCI grant N01-CM-17102.
No significant financial relationships to disclose.