Development of cavitation while on bevacizumab (BV) therapy in patients (pts) with non-small cell lung cancer (NSCLC): Results from ARIES—A bevacizumab (BV) treatment observational cohort study (OCS)

Abstract

e19045 Background: BV (Avastin), an anti-VEGF monoclonal antibody, prolongs progression-free and overall survival in advanced NSCLC pts. Severe (≥grade 3) pulmonary hemorrhage (sPH) is a rare but serious event that has been associated with BV-based therapy in phase 3 trials (rate of 2–4%). Potential risk factors include squamous histology, prior history of hemoptysis, and presence of tumor cavitation. Rates of baseline (BL) cavitation in NSCLC pts and development of cavitation on BV therapy are unknown. Pts in ARIES, an OCS of approximately 2,000 pts with NSCLC, had BL scans assessed for tumor cavitation. A substudy of approximately 250 pts also had follow-up scans to analyze the likelihood of developing cavitation on BV therapy. For the entire ARIES population, any pt developing sPH is assessed for tumor cavitation. Methods: Pts at specified ARIES sites submitted on-treatment CT scans to an independent review facility (IRF), in addition to BL scans. Evaluable pts had measurable disease at BL and at least one-post-BL scan. Correlations between cavitation (pre-existing or developing on-study) and clinical, tumor and treatment characteristics are evaluated using a chi-squared test or t-test. Incidence of sPH based on cavitation status will be assessed using Fisher's exact test. Results: As of 9/15/08, 210 pts had a post-BL CT scan reviewed by the IRF. Of these pts, 171 had measurable tumors at BL. For the 171 pt cohort: median F/U is 9.2 m; 99% have ≥1 quarterly update. Key BL characteristics for the substudy and overall cohorts, respectively, include: 44% vs 51% ≥65 yrs; 67% vs 67% adenocarcinoma; 6% vs 5% therapeutic AC. BL radiographic features: 41% vs 39% presence of central tumor; 13% vs 15% presence of cavitation. In substudy pts, there is 1 sPH to date in a pt without baseline cavitation. Conclusions: sPH is a rare, potentially serious event in pts with NSCLC receiving BV. Whether cavitation (BL or developing on-treatment) is associated with an increased risk of sPH has not been defined. The final analysis of an ARIES Lung substudy assessing on-study development of cavitation and association with sPH will be presented at the meeting. [Table: see text]