Nektar Therapeutics (Nasdaq: NKTR) announced today that data presented at the European Society for Medical Oncology (ESMO) 12th World Congress on Gastrointestinal Cancer demonstrates that NKTR-102, the company's lead oncology compound, exhibits superior activity compared to irinotecan as part of either a monotherapy or combination regimen in tumor models of gastrointestinal cancers.
NKTR-102 is a novel topoisomerase I inhibitor-polymer conjugate with a sustained exposure profile and a unique macromolecular structure that targets tumor tissue through the enhanced permeation and retention (EPR) effect.
"Data presented today show that NKTR-102 achieves greater and more sustained concentration of active drug in the tumor, leading to superior activity of NKTR-102 in models of gastrointestinal cancers," said Lorianne Masuoka, MD, SVP and Chief Medical Officer of Nektar. "These preclinical results demonstrate the potential for NKTR-102 to be developed as both a single agent and in combination with 5-FU to treat patients with metastatic colorectal cancer, and also support our comprehensive development program for NKTR-102 that includes colorectal, breast and ovarian cancers."
In the studies presented, researchers evaluated the activity of NKTR-102 versus irinotecan alone or administered in combination with 5-FU in nonclinical models of gastrointestinal cancers. Anti-tumor activity was evaluated based on tumor growth delay (TGD) and regression responses. In the first study, NKTR-102 was administered as a single-agent at doses of 60, 100, and 150 mg/kg resulted in maximum TGDs of 362 percent. Regression response rates were dose-related and increased from 30-100 percent, with several animals remaining tumor free at the end-of-study at the 150 mg/kg dose level. In contrast, the irinotecan monotherapy arm of this study was minimally active, yielding slight TGDs of 64 percent, with no regressions and no end-of-study survivors at a maximum-tolerated dose of 60 mg/kg. In the second study, the combination of 100 mg/kg NKTR-102 with 50 mg/kg 5-FU was the most active regimen, yielding the maximum TGD of 232 percent, a 100-percent regression response rate and demonstrating superiority when compared to standard irinotecan in combination with 5-FU. NKTR-102 was well tolerated as a monotherapy and when administered in combination with 5-FU in all of the studies.
These data were presented in a poster titled "Activity of NKTR-102 in nonclinical models of gastrointestinal cancers" (Abstract P-0025) at the ESMO Conference: 12th World Congress on Gastrointestinal Cancer in Barcelona, Spain on July 3-5, 2010. The poster can be found on Nektar's website at http://www.nektar.com/product_pipeline/oncology_nktr-102.html.
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