Continued high activity of figitumumab (CP-751,871) combination therapy in squamous lung cancer

Abstract

8072 Background: Figitumumab (CP-751,871) is a fully human, IgG2monoclonal antibody against the insulin-like growth factor type I receptor (IGF-IR). We reported in a randomized phase II study (ASCO 2008), preliminary evidence of high activity of the combination of paclitaxel (T), carboplatin (C) and figitumumab (F) in advanced treatment-naïve NSCLC of squamous cell histology (n=11 pts). A single arm trial extension cohort was conducted to confirm those findings. Methods: Fifty-six pts with non-adenocarcinoma NSCLC were enrolled. Pts received T (200 mg/m2), C (AUC of 6) and F (20 mg/kg) q3weeks for up to 6 cycles; pts with response (PR) or stable disease were eligible to continue F as single agent until disease progression. Statistical hypotheses were 30% (null) versus 50% (response of interest). Protein expression of the IGF-IR in core tumor biopsies was quantified using automated quantitative analysis (AQUA) technology. Results: Pts were 72% male, 28% >70 years old and 91% stage IV. Median number of treatment cycles was 4, with 46% of pts receiving single agent F beyond cycle 4. TCF was well tolerated. The most common all-causality grade 3, 4 CTCAE adverse events were neutropenia (21%), hyperglycemia (14%) and fatigue (14%). Hyperglycemia adverse events almost always occurred within the first treatment cycle and were manageable with standard measures. Responses in squamous pts are currently 25 out of 40 pts according to RECIST, with final response assessment still pending for 7 additional pts (≥53%, p<0.001). One complete response and 7 striking PRs (50–80% tumor size reduction at cycle 2) were observed. Tumor size reductions with F maintenance treatment were also seen in 2 pts. Median progression free survival has not been yet reached at 4 months follow up. A trend (p=0.1) for higher IGF-IR expression in patients responding to TCF was observed in a small data set (n=12). Median tumor IGF-IR expression in pts responding to TCF therapy and non-responders were respectively 6287 and 4131 AQUA scores. Analysis of IGF-IR and other members of the IGF-IR pathway continues. Conclusions: These data further support the activity of figitumumab combination therapy in pts with squamous NSCLC. [Table: see text]