NKTR-102 Scientific and Clinical Data Presentations

Data Presentation from 2008 EORTC-NCI-AACR Symposium - October 23, 2008

• Press Release: Significant Anti-Tumor Activity and Extended Half-Life of NKTR-102 (PEG-irinotecan) Highlighted in Phase 1 Data Presented at EORTC-NCI-AACR Symposium

• Poster #595: First Phase I Trial of NKTR-102 (PEG-irinotecan) Reveals Early Evidence of Broad Anti-Tumor Activity in Three Different Schedules - Authors: D.D. Von Hoff, G.S. Jameson, M.J. Borad, L.S. Rosen, J. Utz, M. Basche, C. Alemany, S. Dhar, L. Acosta, T. Barker, J. Walling, J.T. Hamm.

Data presentation from ASCO Annual Meeting - June 2, 2008

• Investigator Presentation to Investors: Phase 1 Data Discussed at Investor Event by Dr. Daniel Von Hoff, lead investigator for NKTR-102

• Press Release: New Positive Data Announced for NKTR-102 (PEG-irinotecan), Highlights Promise of Nektar's Innovative Small Molecule PEG-Oncolytics

Data Presentations from AACR 2008 - April 14, 2008

• Press Release: Additive Anti-Tumor Activity of NKTR-102 in Combination With Bevacizumab Highlighted in Positive Preclinical Data Presented at AACR Meeting

• Poster #766: Enhanced anti-tumor activity of NKTR-102, a novel PEGylated-irinotecan, when administered in combination with bevacizumab in a mouse model of human colorectal tumors

• Poster #5741: NKTR-102, a novel PEGylated-irinotecan, has an enhanced pharmacokinetic profile with reduced gastrointestinal and hematopoietic toxicity compared to irinotecan with repeat dosing in dogs

• Poster #5742: NKTR-102, a novel PEGylated-irinotecan, has a superior acute safety, tolerability, and pharmacokinetic profile compared to irinotecan in rats and dogs

Data Presentations from 2007 AACR-NCI-EORTC International Conference - October 25, 2007

• Press Release: NKTR-102 (PEG-Irinotecan) Demonstrates Significant Tumor Growth Inhibition in Multiple Preclinical Tumor Models

• Poster #C10: NKTR-102, a novel polyethylene glycol conjugate of irinotecan, has improved anti-tumor activity in three mouse xenograft models

• Poster #C157: NKTR-102, a novel PEGylated-irinotecan conjugate, results in sustained tumor growth inhibition in mouse models of human colorectal and lung tumors that is associated with increased and sustained tumor SN38 exposure

Data Presentations from ECCO 14 Conference - September 27, 2007

• Press Release: NKTR-102 (PEG-Irinotecan) Demonstrates Significant Anti-Tumor Activity and Improved Time-Concentration Profile in Preclinical Studies Presented at ECCO 14

• Poster #722: Anti-tumor activity and pharmacokinetics of NKTR-102, a novel PEGylated-irinotecan conjugate, in irinotecan-resistant colorectal tumors implanted in mice - Presented at ECCO 14 (14th Annual European Cancer Conference)

• Poster #727: NKTR-102, a novel PEGylated-irinotecan conjugate, demonstrates improved pharmacokinetics with sustained exposure of irinotecan and its active metabolite-Presented at ECCO 14 (14th Annual European Cancer Conference)