Renal Cell Carcinoma · Medical · Metastatic · First-Line Systemic Therapy · 2026-09-18

AVOREN

Does adding bevacizumab to interferon-α improve outcomes compared with interferon-α alone in previously untreated metastatic RCC?

Population

649 patients with previously untreated metastatic RCC.

Intervention

Bevacizumab 10 mg/kg IV every 2 weeks plus IFN-α2a 9 MIU three times weekly.

Comparator

Placebo plus IFN-α2a.

Sample size / primary endpoint

649 randomized patients; Overall survival primary; PFS secondary and used for regulatory submission

Absolute Effect

Primary efficacy result

Median PFS: 10.2 vs 5.4 months (+4.8 months); HR 0.63 (95% CI 0.52–0.75)

Final OS analysis reported after substantial post-protocol therapy.

Median OS was 23.3 vs 21.3 months; HR 0.91 (95% CI 0.76–1.10; P=.336). More than half of patients received subsequent therapy, confounding OS.

PFS nearly doubled with bevacizumab plus IFN; the benefit was consistent across major risk groups.

NNT / NNH

NNT: not quantifiable from median PFS alone; no reliable fixed-time absolute PFS rate was established in the primary report.

NNH: 17, based on grade ≥3 adverse events (63% vs 47%) as reported in the regulatory summary; this is a broad toxicity endpoint rather than a single-organ toxicity.

Treatment burden and toxicity

Grade ≥3 toxicity and serious adverse events were more frequent with bevacizumab. Hypertension, proteinuria, bleeding and thromboembolic events were characteristic toxicities.

Quality of life: Treatment burden included IFN-related constitutional toxicity plus VEGF-inhibition toxicities.

Subgroups / clinically important modifiers

PFS benefit was observed across MSKCC risk groups; subsequent TKI therapy complicates interpretation of OS.

Limitations and maturity

OS was confounded by post-protocol therapy and crossover/sequential treatment. The regimen is now historically important rather than contemporary standard first-line therapy.

Clinical interpretation

AVOREN established VEGF inhibition as an active systemic strategy in metastatic RCC by substantially prolonging PFS, but did not demonstrate a statistically significant OS benefit.

The trial illustrates why the primary clinical contribution of an oncology treatment may be a progression-control gain without a clean OS signal when effective subsequent therapies dilute the survival difference.

Primary / authoritative sources

AVOREN final OS analysis (PubMed)

AVOREN primary phase III report (PubMed)

FDA AVOREN approval summary (PubMed)