Etanercept (Enbrel®) Safety Review March 4, 2003 Good morning. Members of the committee, the FDA, ladies and gentlemen. It is a pleasure to be here today to provide a safety review of etanercept, which, as you are all aware, has become well established as a significant therapy for patients with rheumatoid arthritis, juvenile rheumatoid arthritis and psoriatic arthritis. The efficacy and safety of Etanercept has been discussed before this committee on several occasions including -- the review associated with initial licensure in 1998, the review associated with the label extension in 2000 and -- the comprehensive review of TNF antagonist safety in August 2001. We welcome the opportunity to engage the committee, and have been asked by the FDA to focus attention today on safety observations relevant to lymphoma and heart failure.

Presentation Outline Introduction Dan Burge, MD Etanercept Clinical Profile Pharmacovigilance General Safety Malignancy/Lymphoma Epidemiology of Lymphoma in RA Alan Silman, MD Lymphoma and Etanercept Dan Burge, MD Heart Failure Experience Ongoing Pharmacovigilance Summary We will begin by describing some of the unique characteristics of etanercept and aspects of the etanercept pharmacovigilance program. We will then share some general observations from the extensive experience accrued with etanercept. Dr. Alan Silman will provide perspective on the epidemiology of lymphoma in RA patients. We will then review our data regarding lymphoma and heart failure and conclude by reviewing our ongoing Pharmacovigilance program. The P75 receptor was cloned by Immunex in 1990. Immunex was acquired by Amgen in 2002. To avoid confusion I will refer to Immunex and Amgen collectively as Amgen for the remainder of the presentation. C2

Consultants Jeffrey Borer, MD Division of Cardiology The New York Hospital Cornell University Medical Center New York, New York Mary K. Crow, MD Dept. of Rheumatology Cornell University Hospital for Special Surgery Annette Langer-Gould, MD Dept. of Health Research and Policy Stanford University School of Medicine Palo Alto, California Alan Silman, MD Epidemiology Research Unit University of Manchester Medical School ARC Professor of Rheumatic Disease Epidemiology,University of Manchester Manchester, United Kingdom Julie Vose, MD Department of Internal Medicine Section of Oncology/Hematology University of Nebraska Medical Center Omaha, Nebraska Several consultants have kindly consented to join us today: Dr. Jeffrey Borer from the Cornell University Medical Center Dr. Mary Crowe from the Hospital for Special Surgery in New York Dr. Annette Langer-Gould from Stanford University Dr. Alan Silman from the University of Manchester, United Kingdom Dr. Julie Vose from the University of Nebraska Medical Center C3

Etanercept: Distinctive Properties Only soluble receptor TNF antagonist Fully human protein Low immunogenicity Does not bind compliment and is not associated with compliment mediated cell lysis Dosing schedule maintains stable serum concentrations No pharmacokinetic interaction with methotrexate Though etanercept is in the TNF antagonist class, it is distinct as the only soluble TNF receptor utilizing receptor binding specificity. The human protein has low immunogenicity and no neutralizing anti-etanercept antibodies have been detected. Etanercept does not activate complement nor does it initiate complement mediated cell lysis. The dosing schedule and pharmacokinetic profile of etanercept results in a relatively smooth concentration curve throughout the treatment period. As Etanercept may be administered alone or in combination with methotrexate, it is important to note that coadministration with methotrexate does not modify etanercept pharmacokinetics. We believe that these product specific differences in structure, function and pharmacokinetics are relevant to the Etanercept efficacy and safety profiles. C4

Etanercept: Sustained Benefit With Corticosteroid Reduction Long-Term Efficacy Reduction in Corticosteroids 10 30 TENDER P< 0.0001 25 JOINTS Prednisone (mg/day) SWOLLEN 20 JOINTS Median Joint Count 5 15 10 Although the focus of today’s discussion is on safety issues, in order to appropriately assess the etanercept benefit/risk profile it is important to appreciate the efficacy of etanercept. The clinical improvement is rapid, substantial, and sustained for up to 6 years in clinical trials…..and frequently permits tapering or discontinuation of concomitant corticosteroids and methotrexate, each of which can be independently associated with safety issues. 5 1 2 3 4 5 6 Baseline N=385 4 Years N=267 Time on Therapy (years) Median (Interquartile range) Moreland 2002 ACR abstract 1427 C5

Etanercept: Consistent and Substantial Efficacy Percentage of Patients Achieving ACR 20 72% 75% 59% 71% 70% ERA Trial Monotherapy 2 years DMARD Failures MTX Combo 6 months Failures Phase 3 Monotherapy 6 months Failures Phase 2 Monotherapy 3 months Phase 3/EU In multiple clinical settings including early RA, patient with more advanced disease, pts treated with monotx or in combo with MTX, pts receiving etanercept consistently achieve ACR 20 responses in the 70% range. This level of benefit is also observed in patients with JRA and psoriatic arthritis. Bathon J. N Engl J Med. 2000:343:1586-1593. Moreland LW, et al. N Engl J Med. 1997;337:141-147. Weinblatt ME, et al. N Engl J Med. 1999;340:253-259. Moreland L, et al. Ann Intern Med. 1999;130:478-486. European Etanercept Investigators Group. EULAR 2000, Nice, France. C6

Etanercept: Milestones 1990 P75-TNF receptor cloned 1993 First administration to RA patient 1998 FDA approval for RA (alone or with MTX) 1999 FDA approval for JRA 2000 FDA approval as initial therapy for RA FDA approval for inhibition of radiographic progression 2001 FDA Arthritis Advisory re: TNF Antagonists Safety 2002 FDA approval for psoriatic arthritis (alone or with MTX) 2002 FDA approval of three year efficacy and safety data in RA The p75 TNF receptor was cloned at in 1990. Etanercept was developed shortly thereafter, and was first administered to RA patients in 1993. It was initially approved for commercial application in November 1998 for the reduction of signs and symptoms of rheumatoid arthritis as either monotherapy or as combination therapy with methotrexate. In May 1999, Etanercept was additionally approved for the treatment of children with juvenile rheumatoid arthritis…. and in June of 2000, Etanercept was approved as a first-line disease modifying therapy for RA and for inhibition of radiographic progression. In August of 2001, we provided a review of Etanercept safety information to this committee. In 2002, Etanercept became the first Disease Modifying therapeutic approved for the treatment of psoriatic arthritis. C7

Etanercept Pharmacovigilance Program Ongoing clinical studies (over 3,000 patients) Long-term open label extension studies (n ~1,600) North America and Europe Safety trial of RA patients with comorbidities (n=1,000) Combination DMARD studies (n ~ 800) Observational studies (over 12,000 patients) Juvenile rheumatoid arthritis registry (n=600) RADIUS I and II: observational studies (n=10,000) European RA registries (n ~ 1,600) Germany Sweden United Kingdom We have long been committed to providing meaningful information regarding the safety of etanercept to patients and prescribers. Even prior to product approval, Amgen and Wyeth jointly made a substantial commitment to the development of a comprehensive pharmacovigilance program. During the 4 years since product approval, this program has been further expanded and includes multiple elements as outlined here. Multiple long-term open-label clinical trials remain ongoing in North America and in Europe, with over 1600 patients entered--some of whom have now been observed for over six years. Studies of patients with comorbities, patients on combination therapies have been initiated to further explore the safety profile of etanercept. Observational studies have been initiated in other special populations, such as children with JRA. The RADIUS program is now nearing its goal of enrolling 10,000 RA patients. This 5 year program will permit monitoring of the interaction between therapies, comorbidities, clinical status and safety. Several national registries have also been established in Germany, Sweden and the UK. C8

Etanercept Pharmacovigilance Program (continued) Epidemiologic studies Ingenix UnitedHealthcare (n ~ 50,000 rheumatic disease patients): establishing background incidence of adverse events in rheumatic disease populations Continued surveillance of facilitated post-marketing adverse event reports 1.2 Million phone contacts in 150,000 patients Each call is an opportunity for reporting 88% adverse event reports are patient initiated Half of health care provider reports are patient initiated As the background epidemiology for adverse events in patients with rheumatic diseases is often not well characterized, ...we have sponsored several epidemiologic studies, including a project with Ingenix UnitedHealthcare—a database with approximately 50,000 rheumatic disease patients—to establish the background rates of adverse events in the RA, psoriatic arthritis and AS patient populations. Surveillance of adverse events has also been ongoing since product approval in November 1998. Special programs have been in place, such as the ENLIVEN and ENROLLMENT programs. ENLIVEN is a patient support system and the enrollment program was in place to help facilitate drug distribution during the previous period of limited supply. Over 1.2 million phone contacts with the 150,000 patients who have received etanercept therapy have facilitated adverse event reporting. 88% of all reports have been initiated by patients. Follow up of patient reports with health care providers accounts for half of the health care provider reports. We believe that the increased interactions with patients improves safety surveillance. C9

Over 230,000 Patient-Years of Etanercept Experience Pt-Yrs Patients Committee Date FDA Advisory >116,000 >111,000 3389 2664 August 2001 >230,000 >150,000 8336 3839 March 2003 -- 491 745 May 1998 Commercial Experience Clinical Trial Clinical Trials: 1084 patients in 5th year of therapy 390 patients in 6th year of therapy At the time of initial approval, etanercept filled a significant unmet medical need for patients with RA. Recognizing that the experience at the time of approval was limited, we initiated a significant number of additional clinical programs, some of which served to satisfy post approval commitments. In August 2001, we met again with the Committee and had the opportunity to present a safety update which reflected the greatly expanded experience, including more than 111,000 patients. We are able to present here today our experience based on over 8,000 pt-years of clinical trial experience and over 230,000 pt-years of practice experience. This includes over 1,000 patients in their 5th year of treatment and over 390 patients in their 6th year of treatment. C10

SAE / patient-year in North America Serious Adverse Event Rates in Etanercept Patients Similar to Placebo and Stable Over Time SAE / patient-year in North America Control Etanercept Yr 1 Yr 2 Yr 3 Yr 4 Yr 5 Yr 6 Overall Early RA 0.11 0.09 0.08 0.19 -- Advanced RA 0.20 0.13 0.14 0.16 0.12 0.25 Controlled Trials Long-Term Etanercept Serious adverse events, as defined by ICH, are carefully reported and evaluated. In clinical trials, the rate of serious adverse events are similar in the etanercept treated patients and the control groups. [Describe slide] control v etanercept over time early disease v more advanced disease Interestingly, one can see that the rate of serious adverse events is higher, in both control and etanercept groups, in patients with more advanced disease. This supports the widely held impression of practicing rheumatologists, that patients with more advanced disease have more intercurrent illness. C11

Open-label Etanercept Serious Infection Rates in Etanercept Patients Similar to Placebo and Stable Over Time Serious Infections / patient-year in North America Control Etanercept Yr 1 Yr 2 Yr 3 Yr 4 Yr 5 Yr 6 Overall Early RA 0.031 0.024 0.022 0.030 0.028 0.034 -- Advanced RA 0.050 0.043 0.054 0.033 0.048 0.037 0.00 0.044 Controlled Trials Open-label Etanercept Serious infections, defined as those associated with hospitalization or IV antibiotics have also been carefully monitored in clinical trials. The rates of serious infection in the control groups is once again, similar to that seen in the etanercept groups. Again, the rates do not increase with prolonged therapy, with up to 6 years experience. C12

Presentation Outline Malignancy Introduction Dan Burge, MD Etanercept Clinical Profile Pharmacovigilance General Safety Malignancy Epidemiology of Lymphoma in RA Alan Silman, MD Lymphoma and Etanercept Dan Burge, MD Heart Failure Experience Ongoing Pharmacovigilance Summary I would like to refocus our attention on a general overview of malignancies before discussing lymphoma in detail. We will begin by describing some of the unique characteristics of etanercept and aspects of the etanercept pharmacovigilance program. We will then share some general observations from the extensive experience accrued with etanercept. Dr. Alan Silman will provide perspective on the epidemiology of lymphoma in RA patients. We will then review our data from clinical trials and post marketing regarding lymphoma and will conclude with observations regarding etanercept and heart failure. (DELETE??) C13

The Surveillance, Epidemiology, and End Results (SEER) Program National Cancer Institute’s cancer registry Data based on 11 population-based cancer registries and 3 supplemental registries Covers approximately 14% of US population Provides incidence, prevalence and mortality data for cancers When evaluating the incidence of malignancies in clinical experience, we have utilized the National Cancer Institutes database, called the Surveillance, Epidemiology and End Results or SEER Program. This database collects population-based information from multiple regions, representing approximately 14% of the US population and provides data regarding incidence, prevalence and mortality for the various types of malignancies. Utilizing age, gender and race-specific rates for the SEER database, one can calculate the expected number of cases in the general population relative to the trial cohort. The expected rate can then be used as the denominator in calculating the standard incidence ratio, or SIR, as shown here. Standardized Incidence Ratio = Observed/Expected C14

Total Malignancies Not Increased in Clinical Trials Controlled Trials All Trials Control Etanercept Etanercept Observed 5 11 55 Expected* 3.57 8.80 56.2 SIR 1.40 1.25 0.98 This table represents data regarding malignancies observed in etanercept clinical trials. [Describe slide] control observed v expected etanercept observed v expected SIR for control and etanercept All etanercept clinical trial experience with SIR Furthermore, when one evaluates the entire clinical trial experience, the number of malignancies observed is not above that expected from the general population with an SIR of 0.98. *Derived from NCI SEER database, adjusted for age and gender C15

Malignancies Rates are Stable Over Time All Etanercept Clinical Trials Malignancies / 100 patient-years Controlled Trial All Etanercept Experience Control Etanercept Yr 1 Yr 2 Yr 3 Yr 4 Yr 5 Yr 6 Overall 1.0 0.9 0.8 0.6 1.1 1.4 The rate of malignancies is shown on this slide as a rate, or events per 100 patient-years of observation. Once again, the rate is similar between etanercept and controls and there is no increase over time. C16

SIR with 95% Confidence Intervals for All Malignancies in Clinical Trials All Sites Breast Digestive Respiratory Female Genital Male Genital Urinary System Oropharyngeal Lymphoma Endocrine Skin1 Neurologic Leukemia Myeloma Other This slide represents the SIR with confidence intervals for malignancies by organ system. You can see that the confidence intervals for all groups include one. The distribution seen in post marketing is comparable. 1 2 3 4 5 6 7 8 9 10 Risk Ratio 1. Exclude basal cell and squamous cell. C17

Presentation Outline Epidemiology of Lymphoma in RA Alan Silman, MD Introduction Dan Burge, MD Etanercept Clinical Profile Pharmacovigilance General Safety Malignancy/Lymphoma Epidemiology of Lymphoma in RA Alan Silman, MD Lymphoma and Etanercept Dan Burge, MD Heart Failure Experience Ongoing Pharmacovigilance Summary Now we would like to have a brief discussion about the epidemiology of lymphoma in RA. We will begin by describing some of the unique characteristics of etanercept and aspects of the etanercept pharmacovigilance program. We will then share some general observations from the extensive experience accrued with etanercept. Dr. Alan Silman will provide perspective on the epidemiology of lymphoma in RA patients. We will then review our data from clinical trials and post marketing regarding lymphoma and will conclude with observations regarding etanercept and heart failure. (Delete?) C18

Background Epidemiology of Lymphoma in RA Alan Silman, MD Director, Arthritis Research Campaign’s Epidemiology Research Unit University of Manchester Medical School ARC Professor of Rheumatic Disease Epidemiology,University of Manchester Manchester, United Kingdom For this presentation, I would like to introduce Dr. Alan Silman, rheumatologist and epidemiologist from the Medical Research Council of the United Kingdom who is currently one of the lead investigators for the UK national RA registry. Dr Silman is Professor at the University of Manchester and will share some of his thoughts regarding the epidemiology of lymphoma in patients with RA Dr. Silman... C19

Components of Lymphoma Risk in Etanercept Treated Patients Background population risk Risk attributable to RA per se Increased risk attributable to severe RA Increased risk attributable to prior exposure to: Other immunosuppressives (azathioprine, methotrexate) Other biologic agents C20

Measures of Risk Standardized Incidence Ratio = Observed Expected Attributable (Absolute) Risk = Observed – Expected Attributable Risk Fraction = Observed – Expected Expected C21

Example Observed Incidence = 3/1000 pyr Expected Incidence = 2/1000 pyr SIR = 3/2 = 1.5 Absolute Risk = 3/1000 – 2/1000 = 1/1000 pyr ARF = 3/1000 – 2/1000 = 0.33 (33%) 3/1000 C22

Considerations in Determination of Risk Background incidence in comparable population Accurate exposure data Completeness of follow-up Population characterization (age, gender, race, etc.) Disease/treatment characterization Accurate and complete detection of incident cases Case ascertainment Case validation Causality, prevalence or proportions give point estimate Talk to ITT issue, discuss with Silman C23

Other Methodological Issues Lymphoma rare and risk estimates have wide confidence intervals Surveillance bias – are early lymphomas likely to be due to drug or better detection Influence of dose Ever/never, duration etc Influence of length of follow up Follow up periods may not have equivalent risk C24

Variation in Lymphoma Incidence: RA Populations

Increased Risk of Lymphoma In RA Patients* Reference SIR Lower CL Upper CL Isomaki 2.7 1.9 3.7 Gridley 1.3 2.6 Mellenkjaer 2.4 2.9 Thomas 2.1 1.7 All 2.2 2.0 2.5 Dr. Silman speaks Then Dan comes back to the podium. Thank you Dr. Silman. *Based on data generated prior to the availability of TNF antagonists C26

Available Evidence on Lymphoma Clinical Trials Post-Marketing Safety Surveillance Histology Conclusions We would now like to discuss the available data on lymphoma from etanercept clinical trials and post-marketing experience. We will review the histology of lymphoma reports and state the conclusions that can be drawn from this data. C27

95% Confidence Intervals SIR for Lymphoma in Etanercept Clinical Trials Relative to General Population Lymphoma during clinical trials 8336 Patient-years 0.85 – 5.03 2.31 2.59 6 95% Confidence Intervals SIR Expected Cases Recall that an accurate estimation of SIR is dependant on precise ascertainment of incident cases and the corresponding period of observation. Clinical studies provide the only opportunity to accurately estimate the SIR for the treated population. In the etanercept clinical trials program, 6 cases of lymphoma have been reported on study. Utilizing the SEER database, applied to a comparable cohort in the general population one would expect 2.59 cases yielding an SIR of 2.31. Note that the confidence interval includes one … and the point estimate is similar to the 2.2 represented by Dr. Silman. Note that this table will act as a reference on the next 3 slides for further analyses. C28

SIR for Lymphoma in Etanercept Clinical Trials Relative to General Population Lymphoma during clinical trials 8336 Patient-years 0.85 – 5.03 2.31 2.59 6 95% Confidence Intervals SIR Expected Cases Lymphoma SIR by disease duration Population Cases Patient-years Expected SIR 95% Confidence Intervals Early 2 1942 0.582 3.44 0.42 – 12.41 Advanced 4 6394 2.012 1.99 0.54 – 5.09 Etanercept has been evaluated in a broad range of patient populations. The vast majority of patients regardless of disease duration, had moderate to severe RA with mean tender and swollen joint counts in the high 20s. Other than the early RA study, patients had typically failed 3 or more DMARDs and had a mean disease duration of greater than 10 years. Evaluating the lymphoma SIR in early vs. more advanced disease we obtain numbers that are quite similar. Additionally, time to onset is dispersed over time with a range of 0.4 - 4.8 years. Time to onset: Median years (range): 2.6 (0.4-4.8) C29

SIR for Lymphoma in Etanercept Clinical Trials Relative to General Population Lymphoma during clinical trials 8336 Patient-years 0.85 – 5.03 2.31 2.59 6 95% Confidence Intervals SIR Expected Cases Lymphoma cases during and after clinical trials completion Three additional lymphomas have been reported after study completion in patients previously treated with etanercept in clinical trials. As the period of post-trial observation for all patients is not known, an accurate denominator cannot be calculated and we cannot derive an accurate SIR. However, if we consider only the patient time on study, and use the expected number of 2.59, this conservative SIR is 3.47. > 8336 Patient-years 1.59 – 6.59 < 3.47 > 2.59 9 95% Confidence Intervals SIR Expected Cases C30

SIR for Lymphoma in Etanercept Clinical Trials Relative to RA Population Lymphoma during clinical trials (relative to general population) 8336 Patient-years 0.85 – 5.03 2.31 2.59 6 95% Confidence Intervals SIR Expected Cases Lymphoma cases in clinical trials (relative to RA population)* The SIR calculated in the previous slides has been relative to the general population. Using the benchmark of 2.2 fold increased risk described by Dr. Silman for the RA population, we multiple the 2.59 expected cases in the general population by the 2.2 and derive an expected number of 5.7 for the RA population.The SIR for this analysis is 1.05. Recognize that patients treated with etanercept have more severe disease than the general RA population which is known to confer greater risk than lymphoma. No adjustment for severe disease has been made. 8336 Patient-years 0.39 – 2.29 1.05 5.70 6 95% Confidence Intervals SIR Expected Cases *Benchmark factor of 2.2 for RA population C31

Post-Marketing Lymphoma Reports Reported cases*: 70 / 140,000 pts Reporting rate: 0.3 / 1000 pt-yrs Demographic characteristics of patients Female 69% Mean age 61 years Past or concurrent MTX 60% Lymphomas have been described in post-marketing reports in patients who have received etanercept therapy. The reporting rate is 0.3 cases per 1000 patient-years. The background incidence in the general population is 0.3 per 1000 patient-years. Utilizing the adjustment of 2.2 would yield an incidence for the RA population of 0.66 per 1000 patient-years. As would be expected in a predominantly rheumatoid arthritis population, most of the reports are from women, the mean age is 61 and the majority previously treated with methotrexate. *Data through November 2, 2002 C32

Lymphoma Reporting Rates from Commercial Experience are Stable Over Time 200 By report date 160 By diagnosis date 120 Reports per 100,000 pt-yrs 80 We have carefully tracked these reports since commercialization. Shown here are the rate of reports by report date in yellow and by diagnosis date in blue. As one can see, the reporting rate for lymphoma, presented in 6 month intervals here, are stable over the 4 years of commercial experience. 40 11/98-4/99 5/99-10/99 11/99-4/00 5/00-10/00 11/00-4/01 5/01-10/01 11/01-4/02 5/02-10/02 Data through November 2,2002. Error bars represent the upper limit of exact 95% confidence intervals. C33

Clinical Trials and Post-marketing Reports (Pooled) Lymphoma Subtypes Clinical Trials and Post-marketing Reports (Pooled) We have evaluated the distribution of subtypes of lymphoma in the clinical trials and post marketing experience. As can be seen here, the distribution -- 14% Hodgkins and 86% Non-Hodgkins -- is nearly identical to that expected in the general population utilizing rates in the SEER database. *Proportions represented in SEER database C34

Histology of Non-Hodgkin’s Lymphomas Similar to RA Population1 Histology Etanercept Reports2 RA3 Non-RA Controls3 Diffuse large cell 43% 38% 43% Mantle cell 5% 0% 2% Peripheral T cell 8% 2% 4% Follicular 16% 33% 27% Small lymphocytic lymphoma/B-cell CLL 22% 14% 12% Waldenstrom’s Macro. 5% NA NA Marginal zone 0% 7% 0% Other NA 2% 2% We additionally obtain, whenever possible, pathology reports on cases of lymphoma and have them reviewed by an oncologist or hematopathologist for classification into histologic subtypes. Histopathology was obtained for over two thirds of the reports. The distribution of the NHL subtypes is compared here to the distribution reported in the literature for a rheumatoid arthritis population and to non-RA controls. The distribution of histologic subtypes is similar in all three groups. Immunosuppression, such as that seen following organ transplantation, is commonly associated with an increase in the proportion of diffuse large B cell lymphomas….and this pattern is not seen with etanercept therapy as shown in the first line of this slide. If Remicade and/or Humira have a profile similar to transplant patients them bring in the created backup. 1 Histopathology report available in 67% of lymphoma reports 2 Data through November 2, 2002, combined clinical trials and post-marketing reports 3 Kamel et al. J. Rheum. 1999 C35

Conclusions Lymphoma Incidence Consistent with Background RA Lymphoma reports with etanercept are rare Comprehensive pharmacovigilance program has been in place for 4-1/2 years The rate observed in clinical trials is consistent with the expected rate observed for RA (SIR=2.31) Post-marketing experience is compatible with clinical trial experience The proportion of histologic subtypes comparable with background Six years of sustained therapy has revealed no increase in incidence In conclusion, lymphoma reports with etanercept are rare. A comprehensive pharmacovigilance has been in place for 4-1/2 years. The rate of lymphomas observed in clinical trials is consistent with the expected rate for RA patients with an SIR of 2.3. Our post-marketing experience is compatible with clinical experience and the distribution of histologic subtypes is as expected. With 6 years of sustained therapy we see no evidence of an increase in lymphoma incidence. C36

Amgen Initiatives Update label to describe experience Submitted October 2002 (Adverse Reactions) Describes lymphoproliferative disorders from post-marketing and clinical studies Lymphoproliferative disorders, including lymphoma, have been reported from patients on etanercept Rates similar to RA population Presentations at scientific meetings ACR, Sabath et al, Arth.Rheum., 2002 EULAR, Sabath et al, Ann Rheum Dis., 2002 Large, long-term clinical trials Observational studies / registries in over 12,000 patients Epidemiologic studies Safety surveillance of post-marketing reports Amgen supports proactive communication to health care providers and has initiated processes to assure timely dissemination of information. We therefore, in the latter part of 2002, submitted a proposal to the FDA to represent the lymphoma experience in the Adverse Events section of the etanercept package insert. The purpose of this proposal was two-fold—1) to inform physicians that the background incidence of lymphoma in RA was increased and 2) that “The observed incidence of lymphoproliferative disorders from clinical trials and the post-marketing reporting rate are similar to those expected.” We have presented this data at scientific meetings for Rheumatologists. We believe that the programs we have in place: long-term clinical trials, observational studies, further characterization of epidemiology, and continued safety surveillance are an important part of our commitment to patients. C37

Presentation Outline Heart Failure Experience Introduction Dan Burge, MD Etanercept Clinical Profile Pharmacovigilance General Safety Malignancy/Lymphoma Epidemiology of Lymphoma in RA Alan Silman, MD Lymphoma and Etanercept Dan Burge, MD Heart Failure Experience Ongoing Pharmacovigilance Summary In 2002, the product label was updated with information from the etanercept heart failure program, which was designed to test the hypothesis that etanercept was effective in treating chronic heart failure. I would like to share some observations from the studies. C38

Etanercept CHF Trials Design RENAISSANCE (n = 925) Placebo (n = 309) Etanercept 25mg x biw (n = 308) Etanercept 25mg x tiw (n = 308) Analysis of Combined Data RECOVER (n = 1123) Placebo (n = 373) Etanercept 25mg x q wk (n = 375) Etanercept 25mg x biw (n = 375) RENEWAL (n = 2048) The etanercept CHF program consisted of over 2000 patients in 2 studies. The global trial, called RECOVER, included 3 treatment groups: placebo, etanercept 25 mg once weekly and 25 mg twice weekly. The North American Trial, called RENAISSANCE, also included 3 treatment groups: placebo, and etanercept 25 mg twice and three times weekly. The analysis of the combined studies was called RENEWAL. (Pause) The program had in place predefined interim analyses for safety and efficacy. One of these analyses, a futility analysis, specified that the studies were to be discontinued if meaningful clinical benefit was not likely to be demonstrated. In March of 2001, the futility endpoint was met and the studies were stopped. These trials were discontinued when a pre-specified interim analysis determined that etanercept was unlikely to be associated with meaningful clinical benefit. Trials discontinued after pre-specified interim analysis determined study was unlikely to demonstrate benefit. C39

Etanercept CHF Trials Primary Efficacy Endpoint: All Cause Mortality/CHF Hospitalization Unadjusted Analysis* Renaissance 25mg vs. placebo (2x/wk) 25mg vs. placebo (3x/wk) Recover 25mg vs. placebo (1x/wk) Renewal BIW + TIW vs. placebo RR = 1.21, p = 0.17 RR = 1.23, p = 0.13 RR = 1.01, p = 0.97 RR = 0.87, p = 0.45 The primary efficacy endpoint of RENEWAL, an analysis of data from the combined studies, was time to all cause mortality or CHF hospitalization. This morbidity and mortality endpoint was also evaluated in the individual studies but was not the primary endpoint. [Describe slide] confidence interval of all analyses includes one trend in Renaissance toward worse outcomes trend not replicated in Recover The relative risk from the primary analysis, was 1.1. RR = 1.10, p = 0.33 0.5 1.0 1.5 2.0 Risk Ratio *Results from Cox model. Both analyses include strata (NYHA class and use of beta-blockers) C40

Renaissance: Randomization Imbalances Favor Placebo Group Etanercept Placebo 25 mg biw 25 mg tiw (n = 309) (n = 308) (n = 308) Afib/flutter(%) 29 36 36 CABG (%) 33 42 41 SBP - mm Hg (median) 110 108 105 DBP - mm Hg (median) 68 66 64 Anti-arrhythmics (%) 15 22 21 6-min walk - meters (median) 295 293 288 A number of patient characteristics known to have significant impact on heart failure outcomes were prospectively identified as covariates relevant to the interpretation of the trial findings. In the Renaissance study, randomization of patients resulted in imbalances of some of these characteristics in favor of the placebo group. For example, the percentage of patients with a history of afib or flutter is 29% in the placebo group and 36% in each of the etanercept groups. C41

Etanercept CHF Trials Primary Efficacy Endpoint: All Cause Mortality/CHF Hospitalization Unadjusted Analysis* Analysis with Covariates* Renaissance 25mg vs. placebo (2x/wk) 25mg vs. placebo (3x/wk) Recover 25mg vs. placebo (1x/wk) Renewal BIW + TIW vs placebo RR = 1.21, p = 0.17 RR = 1.09, p = 0.55 RR = 1.23, p = 0.13 RR = 1.11, p = 0.43 RR = 1.01, p = 0.97 RR = 0.98, p = 0.92 RR = 0.87, p = 0.45 RR = 0.90, p = 0.56 The left side of this slide represents the data previously shown. On the right side of the slide,is the relative risk after adjustment, using Cox proportional hazards regression, for the predictive and imbalanced covariates. The trends seen in the RENAISSANCE study have diminished and the combined analysis results in a relative risk of 1.01. RR = 1.10, p = 0.33 RR = 1.01, p = 0.90 0.5 1.0 1.5 2.0 0.5 1.0 1.5 2.0 Risk Ratio Risk Ratio *Results from Cox model. Both analyses include strata (NYHA class and use of beta-blockers) C42

Etanercept CHF Trials: Analysis of All Cause Mortality (Secondary Efficacy Endpoint) Unadjusted Analysis* Analysis with Covariates* Renaissance 25mg vs. placebo (2x/wk) 25mg vs. placebo (3x/wk) Recover 25mg vs. placebo (1x/wk) Renewal BIW + TIW vs. placebo RR = 1.27, p = 0.24 RR = 1.13, p = 0.55 RR = 1.37, p = 0.12 RR = 1.22, p = 0.33 RR = 0.68, p = 0.16 RR = 0.66, p = 0.13 This slide represents a secondary endpoint of time to all cause mortality. The findings of this endpoint are similar to the primary endpoint shown previously. There was a trend in worse outcomes in the RENAISSANCE study that was not duplicated in RECOVER . Again, after accounting for covariates, the trends diminish and the relative risk of the combined analysis was 0.96. [go to slide for this description] RR = 0.83, p = 0.47 RR = 0.85, p = 0.55 RR = 1.13, p = 0.39 RR = 0.96, p = 0.79 0.0 0.5 1.0 1.5 2.0 2.5 0.0 0.5 1.0 1.5 2.0 2.5 Risk Ratio Risk Ratio *Results from Cox model. Both analyses include strata (NYHA class and use of beta-blockers) C43

New Onset CHF in North American Rheumatic Disease Trials Controlled Trials Control 2 Etanercept 2 All Trials Observed 7 Expected1 15.2 In conjunction with the review of the data from patients with underlying heart disease, we also analyzed heart failure occurrences in rheumatic disease clinical trials, patients who were not known to have underlying heart disease. The number of subjects developing new onset heart failure was equal in etanercept and control arms in the controlled trials. As much of our experience is from open label trials, where no comparator data is available, we have used benchmarks from the literature to calculate the expected number of cases. The number of cases of new onset CHF treated with etanercept, in rheumatic disease trials was 7 compared to an expected 15.2. The rate of CHF is not increased in the etanercept clinical trials. 1. Kannel WB, J Clin Epidemiol 53 (2000) C44

Etanercept Label Precaution: Patients with Heart Failure Two large clinical trials evaluating the use of ENBREL in the treatment of heart failure were terminated early due to lack of efficacy. Although the studies did not demonstrate harm, there was a suggestion of worse heart failure outcomes with ENBREL treatment in one of the two trials. There have been post-marketing reports of worsening of congestive heart failure (CHF), with and without identifiable precipitating factors, in patients taking ENBREL. Physicians should exercise caution when using ENBREL in patients who also have heart failure. Despite no clear evidence of deleterious effect of etanercept in heart failure, we felt it was appropriate to communicate these findings to health care providers, particularly rheumatologists. On that basis, in May of 2002, we added a precaution in the product label. Additionally, the data from the heart failure trials was presented at scientific meetings for cardiologists and rheumatologists. C45

Conclusions Two large heart failure studies were discontinued due to lack of efficacy One of two studies showed a trend toward worse heart failure outcomes that diminishes with adjustment for covariates No evidence from rheumatic disease trials that etanercept increases risk for CHF Proactive communication in product label and at scientific meetings In conclusion, Two large heart failure studies were discontinued due to lack of efficacy Although, one of the two studies showed a trend toward worse heart failure outcomes that diminishes with adjustment for covariates, the second trial did not. Overall, there is no clear treatment effect of etanercept in heart failure patients. Additionally, there is no evidence from rheumatic disease trials that etanercept increases risk for CHF However we chose to inform prescribers through labeling and presentations at scientific meetings. C46

Extensive Proactive Pharmacovigilance Large, long term clinical trials Epidemiologic studies Observational studies and registries Safety surveillance and post-marketing reports Proactive risk communication We have built a foundation of extensive long term safety experience with etanercept. This experience encompasses the clinical trials discussed in the is presentation complimented by observational and epidemiologic studies and ongoing safety surveillance. Amgen is committed to proactive communication. C47

Ongoing and Future Pharmacovigilance Programs Prospective Program Status Planned Duration (yrs.) Current or Planned Enrollment North American long term clinical trials 5 years experience 10 1100 EU long term clinical trials 4 years experience 4 549 RADIUS I (all DMARDS) Fully enrolled 5 5000 RADIUS II (etanercept) 80% enrolled JRA Registry > 50% enrolled 3 600 EU Registries Enrolling 5-8 1600 (approx.) This table summarizes the initiatives that are being conducted by Amgen and Wyeth. We anticipate that these programs going forward will provide further insights into the safety issues discussed today. The long term clinical trials, where we have already accrued 5 years of experience, will be conducted for at least 10 years. Additionally, the ongoing RADIUS program will prospectively observe 10,000 RA patients for 5 years in the clinical practice setting. Furthermore, a JRA registry has been established in the US and National RA registries have been implemented in Germany, Sweden and the United Kingdom. This comprehensive program will advance our understanding of etanercept and underscores Amgen and Wyeth’s commitment to patient safety. We believe long-term clinical trials, large observational studies, post-marketing surveillance and improved epidemiologic understanding support more-informed prescribing and better care for patients. C48

Nearing Completion of Post-Marketing Commitment for Long Term Follow-up Submitted 3 year data: currently labeled Submitted 4 year data: January 2003 Plan to submit 5 year data: August 2003 Ongoing Amgen commitment: continued follow-up for additional 5 years for a total of 10 years Three year safety and efficacy data from our long term trials have been included in our product label and we have submitted to the FDA our 4 year data. We plan to submit data regarding 5 years of etanercept experience to the FDA this Summer. These data have been included in the presentations this morning. Although we have nearly fulfilled our post-marketing commitment to the FDA, we will continue to follow these patients for an additional 5 years. C49

Etanercept Summary Unique mechanism of action Established track record Over 9 years experience treating rheumatic disease patients Over 4 years of clinical practice experience Robust pharmacovigilance program Safety profile well established Benefit / risk highly favorable In summary, the soluble receptor, Etanercept, has a unique structure, mechanism of action and pharmacokinetic profile, that we believe make etanercept a unique therapeutic. Etanercept has an established track record, with over 9 years of experience in treating rheumatic disease patients and over 4 years of clinical practice experience. This extensive experience --along with the robust pharmacovigilance program -- has allowed us to characterize the etanercept safety profile. With its highly favorable benefit/risk profile, etanercept remains a very important contribution in the therapy of patients with rheumatic diseases. C50