Agenda

Table of Contents

Agenda

Efficacy Overview

Randomized Placebo-Controlled Studies

Phase 2 Dose-Ranging, Randomized,Placebo-Controlled Study

Phase 2 Summary

Phase 3 Studies

Phase 3: Psoriasis Disease Status at Baseline

PASI: Psoriasis Area and Severity Index

Phase 3 Endpoints

Determination of Response Rate:2 Weeks After Last Dose vs. Overall

PASI 50

PASI 75

Phase 3 IM Study

Phase 3 IM study design

Phase 3 IM Primary Endpoint: PASI 75, 2 Weeks After Last Dose

Phase 3 IMPGA “Almost Clear/Clear”, 2 Weeks After Last Dose

Phase 3 IMPASI 50, 2 Weeks After Last Dose

Phase 3 IM PASI 75, 2 Weeks vs. Overall Response Rate

Phase 3 IV Study

Phase 3 IV Study Design

Phase 3 IV StudyEfficacy, 2 weeks after last dose

Phase 3 IV StudyEfficacy, Overall Response Rates

Phase 3 IV Duration of Efficacy

PPT Slide

Quality of Life

PPT Slide

PPT Slide

PPT Slide

Efficacy in Sub-populations

PPT Slide

PPT Slide

Efficacy Conclusions

Pharmacodynamics

Overview of Pharmacodynamics

Lymphocyte Populations

Mean Memory and Naïve T Cells, Course 1 of Phase 3 IV Study

Mean CD4+ T Cell CountCourse 1 of Phase 3 IV Study

Mean Total Lymphocyte Count from Course 1 of Phase 3 IV study

Mean CD4+ T Cell CountCourses 1 and 2 of Phase 3 IV Study

PPT Slide

Return of CD4+ T Cell Counts to Normal RangePhase 3 IV Study, Cohort 2

Monitoring Alefacept Therapy

Lymphocyte PD: Implications

Infections and CD4+ T Cell Counts in Placebo-Controlled Studies

Immune Function Tests in Alefacept-treated Patients

Primary and Secondary AntibodyResponses to Neoantigen (?X174)

Relationship Between CD4+ Memory T Cell Effects and PASI 75, Overall Response Rate

Relationship Between T-Cell Counts in Skin Lesions and Disease Activity*

Lymphocyte PD: Conclusions