BACKGROUND: Interleukin-2 (IL2)-based immunotherapy is curative for a small subset of patients with metastatic renal-cell carcinoma (mRCC). Preclinical data suggests that bevacizumab (BEV), a humanized anti-VEGF monoclonal antibody, has potential immunomodulatory effects by permitting efficient natural killer (NK) cell-mediated killing and by reverting immune suppression.
PATIENT AND METHODS: We performed a randomized phase II study comparing IL2/IFN (interferon)/BEV with IL2/IFN in favourable/intermediate-risk mRCC patients. One hundred and eighteen patients received IFN 3 MIU subcutaneously (sc) daily and IL2 2.4 MIU/m2 sc twice daily, 5 days per week for two consecutive weeks every 28-day-cycle, for 9 months; or supplemented with BEV 10 mg/kg, every 2 weeks intravenously (iv) until progression, unacceptable toxicity, or 1 year following no evidence of disease (NED). Primary end point was progression-free survival (PFS).
RESULTS: Baseline characteristics were well-balanced between the two arms; metastasis-free interval <1 year (75 versus 76%); prior nephrectomy (85 versus 86%); MSKCC favourable/intermediate-risk group (51/49 versus 52%/48%); three or more disease sites (41 versus 44%), respectively. The median PFS was 8.0 mo (95% CI, 4.2-11.9) with IL2/IFN/BEV and 8.1 mo (95% CI, 5.1-11.0) with IL2/IFN, p = .73. There was no difference in secondary endpoints, IL2/IFN/BEV versus IL2/IFN; median time-to-treatment failure (7.4 versus 5.6 mo, p = .54), response rate (44.1 versus 28.8%, p = .13), surgery of residual disease (17.0 versus 17.0%, p = 1.0), patients achieving NED (3.4 versus 8.5%, p = .44), and median overall survival (30.3 versus 34.1 mo, p = .39), respectively. TKI post progression was well-balanced (85 versus 78%). No new/unexpected toxicity was observed. Most common Grade 3/4 adverse events for IL2/IFN/BEV and IL2/IFN were fatigue (64 versus 61%), flu-like symptoms (37 versus 41%) and thrombosis (6.8 versus 18.6%, p = .01), respectively.
CONCLUSIONS: The addition of BEV to IL-2/IFN did not add efficacy in mRCC. (ClinicalTrials.gov, NCT01274273.).