Addition of ABT-751 to pemetrexed does not improve outcome in unselected patients with recurrent NSCLC

http://www.ncbi.nlm.nih.gov/pubmed/21300929

J Clin Oncol. 2011 Feb 7. [Epub ahead of print]
Phase I/II Study of Pemetrexed With or Without ABT-751 in Advanced or Metastatic Non-Small-Cell Lung Cancer.
Rudin CM, Mauer A, Smakal M, Juergens R, Spelda S, Wertheim M, Coates A, McKeegan E, Ansell P, Zhou X, Qian J, Pradhan R, Dowell B, Krivoshik A, Gordon G.

Johns Hopkins University, Baltimore, MD; Creticos Cancer Center; Abbott Laboratories, Chicago, IL; Oblastni Nemocnice Pribam, Pribam; Masaryk Memorial Cancer Institute, Brno, Czech Republic; and the Hematology Oncology Associates of the Treasure Coast, Port St Lucie, FL.
Abstract
PURPOSE ABT-751 is an antimitotic and vascular disrupting agent with potent preclinical anticancer activity. We conducted a phase I and randomized double-blind phase II study of pemetrexed with ABT-751 or placebo in patients with recurrent advanced or metastatic non-small-cell lung cancer (NSCLC). METHODS One hundred seventy-one patients received intravenous pemetrexed 500 mg/m(2) day 1 and oral ABT-751 or placebo days 1 to 14 of 21-day cycles. The primary end point was progression-free survival (PFS). Secondary end point included overall survival (OS); pharmacokinetic and pharmacodynamic parameters were also analyzed. Results The recommended phase II dose of ABT-751 with pemetrexed is 200 mg. Fatigue, constipation, anemia, nausea, and diarrhea were the most common toxicities in both study arms. No pharmacokinetic interactions were observed. Median PFS in the ABT-751 arm was 2.3 months versus 1.9 for placebo (P = .819, log-rank) for the intention-to-treat population. However, differences in PFS (P = .112, log-rank) and OS (P = .034, log-rank; median 3.3 v 8.1 months) favoring ABT-751 were seen in the squamous NSCLC subgroup. Baseline circulating tumor cell concentrations were predictive of improved OS (P = .013). Changes from baseline of greater than 20% in plasma levels of placenta growth factor (P = .056), squamous cell carcinoma antigen (P = .03), and cytokeratin 19 fragment antigen 21-1 (P = .01) were markers best associated with improved OS. CONCLUSION Addition of ABT-751 to pemetrexed is well-tolerated, but does not improve outcome in unselected patients with recurrent NSCLC. ABT-751 may have therapeutic potential in squamous NSCLC. Exploratory cellular and molecular analyses in this study identified biomarkers that may correlate with survival.