Elizabeth Woo - VP, IR James C. Mullen - President and CEO Bill Sibold - Sr. VP, US Neurology Business Unit Cecil Pickett - President, Research and Development Paul J. Clancy - EVP and CFO Bear, Stearns & Co. Joel Sendek - Lazard Capital Markets Michael Aberman - Credit Suisse Geoff Meacham - JP Morgan Eric Schmidt - Cowen and Company William Ho - Banc of America Securities Jim Birchenough - Lehman Brothers May-Kin Ho - Goldman Sachs Bill Tanner - Leerink Swann & Company Mike King - Rodman & Renshaw Maged Shenouda - UBS Adam Walsh - Jefferies & Company Jason Zhang - BMO Capital George Farmer - Wachovia Securities

Mark Schoenebaum

Good morning. My name is Janice and I will be your conference operator today. At this time, I would like to welcome everyone to the Biogen Idec First Quarter conference call. All lines have been placed on mute to prevent any background noise. After the speakers' remarks, there will be a question-and-answer session. [Operator Instructions]. Thank you. Ms. Woo, you may begin your conference. Elizabeth Woo - Vice President, Investor Relations: Thank you. Welcome to Biogen Idec's first quarter earnings conference call. Before we begin, I'd ask everyone to go to the Investor Relations section of our website, biogenidec.com and print out the press release and related financial table. These will be particularly useful when our CFO, Paul Clancy reviews the financial results and reconciliation to non-GAAP financial measures discussed today. We have also posted a slide on our website… slides on our website that outline the topics discussed on today's call. I'll start with the Safe Harbor statement. Comments made in this conference call include forward-looking statements about the company's expectations regarding future financial results, including our 2008 financial guidance, our longer-term operational and financial goals, sales potential of TYSABRI and plans for external growth and pipeline advancements. Such statements are subject to risks and uncertainties, which could cause actual results to differ materially from expectations. In particular, careful consideration should be given to the risks and uncertainties that are described in our earnings release and in item 1A of the company's reports of the Form 10-K and 10-Q and in other periodic and current reports, Biogen Idec files with the SEC. The company does not undertake any obligation to publicly update any forward-looking statements. In addition, because we have received a Board of Director's nomination and bylaw amendment proposal from one of our shareholders we are obliged to inform you this and to be sure that our stockholders have access to all the information they might need around this process. On today's call, I'm joined by Jim Mullen, CEO of Biogen Idec; Bill Sibold, Senior Vice President, US Neurology Business Unit; Dr. Cecil Pickett, President of R&D; and Paul Clancy, Chief Financial Officer and EVP of Finance. I'll now turn the call over to Jim. James C. Mullen – President and Chief Executive Officer: Thank you Elizabeth. Good morning everyone and thanks for joining us. Q1 2008 was another great quarter. We delivered record revenues and outstanding financial results in the first quarter as we more than tripled TYSABRI sales compared to the same period last year and our core products AVONEX and RITUXAN continue to generate strong sales. We made an outstanding start to 2008 and we're well on our way towards achieving our goals to 2010. We delivered record revenue and strong profits in Q1 and year-over-year revenues grew 32% and non-GAAP earnings grew 41%. We saw an acceleration of TYSABRI patient adds, as physicians grow more comfortable with the safety profile. We added 5,000 new patients in Q1 with more than half of them internationally and importantly no new cases of PML have been reported since the relaunch. AVONEX sales were very strong and outperformed expectations. AVONEX continues to maintain its worldwide leadership position in the competitive MS marketplace and provides a strong and growing cash flow contribution to the business. And we advanced our pipeline. Clinical trial activities ramping up significantly in 2008 and we are eagerly awaiting a series of new clinical data reports this year for products not yet considered in our long-term forecast. So 2008 is shaping up to be another strong year from both the financial and clinical standpoint and we're raising full year 2008 guidance. So let me just expand on a few points before I turn it over to others on the call. RITUXAN US net sales for Q1 were $605 million, which was up 13% year-over-year. This translates into revenues from the related joint business were $247 million which is up 19% year-over-year. AVONEX worldwide sales were $536 million in Q1 2008 representing a 19% growth year-over-year. With TYSABRI, we exited the first quarter at a run rate of over $600 million of end-market revenues globally. Between AVONEX and TYSABRI, our MS franchise share continue to expand. Bill Sibold, SVP, US Neurology will take you through the good news for TYSABRI. And as we start 2008, we see a continued acceleration towards our goal of 100,000 patients on TYSABRI by year-end 2010. As a result, we're raising full year non-GAAP 2008 earnings guidance, our CFO, Paul Clancy will take you through the financial and guidance details. A couple of comments on the pipeline. Pipeline advanced to 2007 and we now have 15 products in Phase II and beyond and 2008 will be a year of significant number of clinical readouts. We built this impressive pipeline with a balanced approach of organic development and execution of highly perfected business development programs. Significant R&D investment has yielded a robust pipeline with four novel compounds and registration trials and another to start later this year. While we're disappointed with the RITUXAN OLYMPUS trial and it was unable to meet the primary endpoints in the difficult to treat primary progressive MS setting, we have a number of meaningful data readouts as the year goes on and Cecil Pickett will review the pipeline accomplishments and upcoming milestones in his comments. I'll conclude the introduction by saying the future of Biogen Idec is extremely bright as evidenced by our recent operating results. In my nearly two decades with the company, I don't believe the prospects for growth today and growth in the future have been any better for the company. I'll now turn the call over to Bill Sibold, the Head of the US Neurology Business. Bill Sibold - Senior Vice President, US Neurology Business Unit: Thanks, Jim. I'm pleased to report that in Q1, we continued the momentum established in 2007. Biogen Idec's global MS franchise continues to grow everyday with more new patients entering the franchise. No one is doing more for MS than Biogen Idec. We have the number one prescribed MS therapy today, AVONEX. We have the product that has established a new level of efficacy, TYSABRI, which has been shown to delay the progression of the disease and reduce relapses by two thirds, and we have the best and broadest pipeline of MS products for the future. This reality distinguishes us from other companies in the market and positions us, unlike any other for the future. More and more physicians that I talk to understand and appreciate this commitment, which I believe positively impacts both the short and long-term prospects for the business. Our presence in MS was highlighted at AAN in Chicago last week where there were nine platform presentations and 27 poster presentations related to Biogen Idec products. This is double the next closest competitor for total presentations, once again demonstrating the breadth of our portfolio. We also had a corporate therapeutic update titled Multiple Sclerosis, Biogen Idec and the Future of Personalized Medicine, which was oversubscribed with more than 500 attendees. Turning to Q1 results, global neurology revenues were $650 million... $651 million, an increase of 10% versus the prior quarter and 36% versus the prior year. Our combined global franchise market share continues to grow. In the US, it is now at its highest level since 2005 and it is at its highest level since 2000 outside the US. We expect this trend to continue in step with TYSABRI's growth. AVONEX remains the product to start with and TYSABRI for those patients needing more efficacy. With their clear positioning and strong product profile the bulk of relapsing remitting MS patients are candidates for either AVONEX or TYSABRI. As our pipeline matures we will have new options for additional patients in need. Looking specifically at the products, AVONEX's $536 million in global revenue in Q1 was up 19% year-over-year and 7% quarter-over-quarter. AVONEX's revenue was up 14% year-over-year in the US and 27% year-over-year internationally. With over 135,000 patients on therapy worldwide and over 1 million patient years of experience, AVONEX remains the foundation of our global MS business. After 11 years on the market, AVONEX remains the only once weekly product and is the only product indicated to both slow the accumulation of physical disability and be effective for patients who have experienced a first clinical episode and have MRI features consistent with MS. Perhaps, this is why it is the treatment most associated with patients in the early stages of the disease and with those patients, who lead an active daily lifestyle and why it is the number one MS therapy in the world. AVONEX disrupts disease, not patient’ lives. Now to TYSABRI, TYSABRI continues to build momentum with in-market revenue of $160 million in the quarter, which is 23% growth over the prior quarter and an over three-fold increase over the prior year. At the AAN meeting in Chicago last week, we announced the latest patient numbers for TYSABRI. As of late March, there were approximately 26,000 patients on TYSABRI worldwide in the commercial and clinical trial setting. There were approximately 15,300 TYSABRI patients in the US with about 2,750 prescribing physicians, which is a doubling in the number of prescribers since last year. Internationally, there were about 10,200 patients on therapy. Finally, we announced that there were over 9,900 patients on therapy for over one year and over 3,600 on therapy for more than 18 months. The update was very well received by physicians who are growing more and more comfortable with the benefit risk profile of TYSABRI. Also at AAN, a poster was presented that showed that TYSABRI treatment significantly increases the proportion of patients with MS considered to be disease free. According to post talk analysis of the AFFIRM and SENTINEL clinical trials about one-third of patients were shown to have no relapses, no disability progression and no new MRI markers. Additionally, at AMCP and AAN last week, a poster was presented with results from a recent study of 451 patients on TYSABRI. The study showed that over 95% of patients reported doing as well or improving in their quality of life, functional status and disease step levels as early as three months after starting TYSABRI. Additionally, over half of the patients reported improvements in their ability to do physically demanding tasks and feeling well in the same period. These data suggest the real-world efficacy of TYSABRI. Also since the last call, our partner, Elan has launched TYSABRI for Crohn's Disease and TOUCH online has been rolled out and has been extremely well received. TOUCH online offers substantial service benefits to our prescribers and infusion sites. Additionally, we continue to see encouraging trends in the market. Worldwide TYSABRI is considered to be the most effective MS therapy by neurologists. In the US, the number is over 94% of neurologists responded this way. Positive switching trends continue with TYSABRI being the most switched to therapy. And on the subject of switching, in the US, Copaxone with its everyday injection remains the largest single source of TYSABRI patients. Finally, about 80% of TYSABRI patients in the US and nearly 90% of TYSABRI patients internationally are new to the Biogen Idec franchise. We believe TYSABRI will continue to build momentum throughout the remainder of 2008. We had a strong Q1. There continues to be positive new data about TYSABRI as evidenced by... at AAN last week and in July TYSABRI celebrates two years on the market, which is a significant milestone. All of these things make us more confident than ever that TYSABRI will achieve the previously stated goal of 100,000 patients on therapy and eventually become the leading MS therapy in the world. In conclusion, with the number one prescribed MS therapy today, AVONEX, a product that has established a new level of efficacy, TYSABRI, and the best and broadest pipeline of the MS products for the future, Biogen Idec is the leader in multiple sclerosis. Our goal is to provide products and services for MS patients from diagnosis to disease resolution. We are extremely pleased with the results of the first quarter and optimistic about the rest of the year and the future. I will now hand the call to Dr. Cecil Pickett, President, R&D. Cecil B. Pickett – President, Research and Development Thank you Bill. And good morning everyone. Today I'll report, as usual on accomplishments in the quarter and upcoming data readouts. First I'll review the recent progress and data readouts. As you know, our sBLA on TYSABRI to treat Crohn's disease was approved by the FDA on January 14th. Our partner, Elan has since launched the drug and TYSABRI for Crohn's has been available in the US since the end of February with final stages of education and training completed during the second week of March. Crohn's patients have started to receive TYSABRI therapy in the US and we are pleased to offer them this important option. We had a recent data readout and were disappointed that our RITUXAN OLYMPUS trial in primary progressive MS failed to meet the primary endpoint. The unmet medical need remains high and it is difficult to treat disease. Next I'll mention some data on TYSABRI. Starting with PML mitigation, Dr. Fox presented at AAN a sub study from the PLEX trial on leukocyte transmigration that suggested plasma exchange could be an effective means of removing TYSABRI and allowing the immune system to reestablish more rapidly. In theory, this may allow a patient to better fight off a reactivated JC virus. Staying with PML mitigation, we have initiated a program to test the anti-malarial Mefloquine in HIV patients with PML. Mefloquine has shown some antiviral activity in an in vitro screening of JC virus replication. Moving to safety, at the recent AAN meeting, our Global Head of Drug Safety, Dr. Carmen Bozic presented an update of TYSABRI safety. And, as you know, we've seen no new PML cases. As Bill mentioned, physicians are growing more and more comfortable with the benefit/risk profile of TYSABRI. To provide additional perspective, PML is associated with a growing list of immunosuppressive drugs. So it may be time to start considering PML as a potential side effect of any powerful therapy that modulates the immune system and not as something specific to TYSABRI. Next, we had a number of R&D accomplishments this quarter. We continue to make good progress on advancing and developing our late-stage clinical pipeline. We currently are accruing patients to our four ongoing pivotal registration programs with novel molecules; lumiliximab in CLL, galiximab in non-Hodgkin's lymphoma, BG-12 in relapsing remitting MS, and lixivaptan in hyponatremia. In addition, we expect to initiate another pivotal program during 2008, ADENTRI in acute decompensated congestive heart failure. We have completed enrollment for the RITUXAN Phase III LUNAR trial in lupus nephritis and the baminercept alpha Phase IIb respond trial in rheumatoid arthritis. We have achieved first patient enrolled for the daclizumab Phase II SECLECT monotherpay trail in relapsing remitting MS, the volociximab Phase II combination trial with Doxo in ovarian cancer, our lead HSP90 inhibtor Phase II trial in gastrointestinal stromal tumors and the Anti IGF-1R Phase I trial in solid tumors. Finally, we have active INDs for TYSABRI in multiple myeloma and Anti-Cripto-DM4 for solid tumors. We also published an in vitro study of Neublastin in Nature Neuroscience. Neublastin promoted regeneration of damaged sensory nerve cells and restored sensory and motor function. And also keep on the lookout for a number of abstracts from us at the upcoming ASCO and UR [ph] meetings. I'll end by reminding you about the number of data readouts expected by the end of 2008. Soon, we anticipate results from Explore, the Phase III RITUXAN study in SLE. The bayley scale will be used to assess SLE disease activity in this study and is a comprehensive, reliable, sensitive to change and effective in capturing the waxing and waning nature of lupus. Major or partial clinical response will be assessed in 52 weeks. The unmet medical need remains high in this sizable indication. We also expect to see clinical readouts in 2008 from a number of novel programs including Phase IIb data on baminercept alpha in RA, BIIB14 for Parkinson's disease, and long-acting Factor IX in hemophilia B, also our heat shock protein 90 inhibitor in volociximab in solid tumors. So in conclusion, I remain very impressed with the caliber of both the pipeline and our R&D team. 2008 is a very active year on the R&D front and on average four times as many patients in clinical trials compared to 2007. We are as eager as you to see the data from the ongoing trials. With that, I'll hand the call over to Paul Clancy, our CFO. Paul J. Clancy - Executive Vice President and Chief Financial Officer: Thanks Cecil. We delivered another strong quarter of financial results. Our impressive top line and bottom line growth is a solid testament to Biogen Idec's economic growth engine and our focus on delivering tangible results in building shareholder value. We achieved 32% top line growth with strong performance across all products in all geographies and over 40% earnings growth on a year-over-year basis. We delivered these excellent financial results while simultaneously investing heavily in our pipeline, the key imperative for sustainable long-term growth. Now I'll walk through the P&L in more detail. The GAAP financials are provided in Tables 1 and 2 of the earnings release. Table 3 is a reconciliation of the GAAP to non-GAAP financial results. So let's begin with our GAAP to non-GAAP reconciliation in accordance with Reg G, we've provided Table 3, which breaks out the items by major driver. The main items excluded from the non-GAAP P&L in Q1 were first, we adjusted $75 million for the amortization of intangibles. Second, we adjusted $25 million related to the contingent consideration payment associated with the Conforma acquisition. Third, we adjusted $6 million in employee stock option expenses. Approximately half of this is in SG&A and the remainder in R&D. And fourth, we had $80 million of tax impact to the items I just mentioned. Now I'll move on to the non-GAAP P&L operating performance. We believe it's important to share this non-GAAP perspective with shareholders because it better represents the ongoing economics of our business and it reflects how we manage the business internally and set operational goals. In Q1, we delivered $0.54 diluted EPS on the GAAP P&L and after the adjustments shown in Table 3, our non-GAAP diluted EPS was $0.83. Both of these numbers increased by over 40% versus Q1 2007. Now let's move through the first quarter detail in a bit more. Q1's total revenue was $942 million. This represents an impressive 32% growth over the same period last year. Key drivers again across all products, all geographies, the continued revenue growth of the AVONEX business, the increasing penetration of TYSABRI and the continued growth of RITUXAN franchise. Now go to the product revenues. I'll begin with AVONEX. Q1 AVONEX worldwide product revenue was $536 million representing a 19% increase of the same period last year. Q1 US AVONEX product revenue was $308 million representing a 14% increase over the same period last year. This revenue growth was supported by the strength of the AVONEX brand and its ability to support price increases in 2007. Q1 International AVONEX product revenue was $228 million representing an increase of 27% on a year-over-year basis. Approximately, 10% of that increase was driven by favorable foreign exchange rates and the balance driven by volume and mixed increases. Q1 TYSABRI worldwide Biogen Idec product revenue increased to $115 million. As Bill highlighted, TYSABRI continues to make strong progress. TYSABRI financial highlights include end-patient total sales of $160 million worldwide. US end-user TYSABRI sales totaled $86 million representing a 13% quarter-over-quarter increase. Biogen Idec booked $41 million of this amount. International end-user TYSABRI sales totaled $73 million, which is a 39% increase from the prior quarter. Moving to other product revenue. Q1 FUMADERM revenue was $12 million. In Q1, ZEVALIN product sales, which really represents our supply agreement with CTI were $2 million. Now, moving on to the RITUXAN collaboration revenues, which is referred to as revenue from unconsolidated joint business. We recorded $247 million in revenue for the quarter representing a 19% year-over-year increase. This number has three elements. First, we received our share of the US RITUXAN profits. As reported by Genentech, our partner, US RITUXAN sales were $605 million in the first quarter up 13% versus prior year. And our Q1 profit share from that business was $158 million, up 16% versus prior year. Second, we received royalty revenue on sales of rituximab outside the US and in Q1 this was $77 million, up 35% versus prior year. Third, we reimbursed $13 million for selling and development cost incurred related to RITUXAN. Q1 royalties were $24 million for the quarter. Our Q1 royalty revenue reflects the step down from Q4 driven by ANGIOMAX, which I described in our last call. Now, turning to the expense lines on the P&L, which includes the non-GAAP adjustments that I described earlier. Q1 COGS were $101 million representing 11% of revenues. Q1 R&D expense was $255 million, which is approximately 27% of revenues. Increases in our R&D spend was driven by our continued advancement of our robust pipeline. As Cecil mentioned, we have several programs in registrational trials including BG-12, lixivaptan, galiximab and lumiliximab, and we expect ADENTRI to join this group by the end of the year. We expect these late-stage programs coupled with our advancing early-stage pipeline to drive significant increase in the number of patients on clinical trials when comparing 2008 to 2007. Q1 SG&A expenses were $213 million, which represents 23% of revenues and a 17% year-over-year increase. Drivers of the year-over-year increase in absolute dollars included investments to support TYSABRI growth, specifically, several international markets including Germany and France as well as the Crohn's launch in the US in the first quarter of 2008. Continuing down the P&L, our collaboration profit-sharing line totaled $21 million of expense for the quarter. As a reminder, this line represents Biogen Idec's payment of 50% of the profits outside the US to Elan and the reimbursement of third-party royalties incurred by Elan outside the US. We expect this number to continue to grow in the coming quarters reflecting the growing profitability and uptake of our international TYSABRI business. Now moving to other income and expense. This represented $500,000 loss for the quarter, a significant change to our OIE line since the same period last year is the impact of our $3 billion share repurchase in June of 2007, which equated to 16% of our shares outstanding. Specifically, this line has been impacted by the loss of interest income from a reduction in cash and the addition of the interest expense from taking on debt. I'll also note that during the quarter, we converted our $1.5 billion temporary bridge loan to $1 billion in permanent debt. The $500 million difference was paid down with cash. The permanent debt offering included $450 million in principal at 6.0% due 2013 and 515… $550 million in principal at 6.875% due 2018. Additionally, in Q1 2008 we repurchased 4 million shares under the 20 million share repurchase program authorized by our Board of Directors in October of 2006. The purpose of this program is for share stabilization. Since the close of the quarter, an additional 5 million shares have been purchased as well. Even after our impressive share buybacks, our cash position remains strong and growing. Q1 tax rate on a non-GAAP basis is 29%, which brings us to our Q1 non-GAAP diluted EPS of $0.83, again representing a 41% increase over the same period last year. Now I'd like to conclude by discussing our updated 2008 guidance. Given our strong Q1 performance, we're raising our 2008 financial guidance. We expect annual revenue growth of 20% over 2007 driven in large part by strengthening TYSABRI uptake. This is now at the high-end of our previous revenue guidance. We expect operating margin leverage to be similar to previous guidance and the combination of non-GAAP R&D and SG&A expenses for the year to be approximately $2 billion. This number may be impacted by potential business development activity and the pace of patient accruals in our important four and moving to five late-stage development programs. I've excluded from… I've excluded our collaboration profit line from the $2 billion expense guidance for 2008. I should note that we do expect this line to grow each quarter, again reflecting the uptake in increasing profitability of the international TYSABRI business. Our non-GAAP tax rate is expected to be between 28 and 30% and this assumes the renewal of the R&D tax credit legislation. Non-GAAP diluted EPS is expected to be in the range of $3.25 to $3.45. This represents a 19 to 26% year-over-year growth rate. In addition to increasing our guidance, we've slightly widened the range to reflect the potential impact of business development activities and the pace and success of clinical trials notably again the four to five programs in late stage. GAAP EPS is expected to be in the range of $2.28 to $2.48. Overall this full-year guidance provides strong top line and bottom line growth and is an important stepping stone in achieving our longer-term operating and financial goals. So in conclusion, extremely strong performance for the quarter with is a solid testament to our strategy and our focus on creating shareholder value. We delivered 32% in the top line and grew non-GAAP EPS by 41%, all while aggressively investing in our pipeline. Now, I will hand it over to Jim for his closing comments. James C. Mullen – President and Chief Executive Officer: Thanks, Paul. In summary, we're very pleased with the Q1 2008 financial results and the strength across all products. Given the strong momentum underway and the key data readouts expected later this year, the prospects for the company have never been better. We continue to grow our MS franchise share. By year-end, several thousand patients will have been on TYSABRI therapy for two years, which will provide the MS community with a better understanding of the impact of duration on TYSABRI's safety profile. We're moving our pipeline programs forward and a number of data readouts on late-stage programs will come over the next month. The next readout will be the top line results for RITUXAN in lupus, which will be available soon, certainly in this quarter. The future of Biogen Idec is bright, we continue to work to bring more meaningful therapies to patients in need, which in turn we believe will generate strong growth that will create significant value for our shareholders. Just as we did successfully over the prior four-year period we're confident we can... we will achieve our 2010 goals. And just to reiterate those 2010 financial goals, it's 15% revenue compounded annual growth rate, 25% GAAP EPS compounded annual growth rate, and 20% non-GAAP EPS compounded annual growth rate. With that, I'll turn it back over to Elizabeth and open it up for Q&A. Elizabeth Woo - Vice President of Investor Relations: Thanks, Jim. Operator, we're now ready to open up the call for Q&A and we'd ask participants on the call to please limit themselves to one question and then re-enter the queue for any follow-up questions. Please state your name and company/affiliation. Operator, we may have the first question. Question and Answer

Thank you, Ma’am. [Operator Instructions]. Your first question comes from the line of Mark Schoenebaum with Bear Stearns. Mark Schoenebaum - Bear, Stearns & Co.: Okay. Thanks for taking my question. I really appreciate it. Can I ask you about RITUXAN for lupus and obviously I know you don't know the data yet. So I'm not going to ask… to put you in that uncomfortable position trying to handicap those data, maybe you can just help us the Street perhaps to understand this market a little bit better. There have been all kinds of sell-side reports coming out and Genentech has given out, I think 200,000 eligible patients, I see on your slide, it looks like a... it’s closer to 300,000 eligible patients. In reality, kind of a peak if the trial works and works well, how many patients do you think are actually could be on RITUXAN, I mean kind of a peak normalized year? James C. Mullen - President and Chief Executive Officer: Hey, Mark. I'll take that because the answer is while we have I think you well pointed out, it’s fairly rough estimates of what the total patient numbers are available out there, which you know by our experience is pretty difficult in these marketplaces particularly in something like lupus, where the line is exactly how they are classified tends to move around a bit. But the real answer comes with the data and how strong is the data, how compelling is the data and then, all the other factors that surround that. But... and so, we've really seen the data anything would just be finger in the wind at this point. So we're anxious to see that data, be able to really analyze the data to understand subgroup analysis, understand safety. So remember, all we are going to get on the first day is sort of top line stuff. And then, you have got a ability to start taking it back out and talking to our real practitioners to understand what the real world of relevance of the results are. Mark Schoenebaum - Bear, Stearns & Co.: And what kind of subgroups you are talking about? James C. Mullen - President and Chief Executive Officer: Well, you know it is a very heterogeneous disease by definition. So you're going to be looking at you know everything from gender to age, to prior treatments, to organs involved, etcetera. So, I think there will be a huge treasure throughout the data to go through which will help guide us where to go in the future. Mark Schoenebaum - Bear, Stearns & Co.: Okay. Thanks. Good luck.

Your next question comes from the line of Yaron Werber with Citi.

Hi, this is [inaudible] dialing for Yaron. Thanks for taking my question. My question is in terms of the strong AVONEX growth you have been seeing, can you perhaps give a little more detail as it's just a volume increase or just price increases? And how much room do you have for more price increases both in AVONEX and TYSABRI? Thank you. Paul J. Clancy - Executive Vice President and Chief Financial Officer: Yes. This is Paul. I'll try to take that. We certainly benefited from foreign exchange outside the United States sales and then from the benefit of the price actions inside the US, the price actions that we've taken in full-year 2007. Nevertheless, I would characterize Q1 as very solid with respect to our unit trends and in fact in both geographies, we saw some of the best unit trends that we have seen in a number of quarters, which is testimony to in the United States. Some of the new marketing programs, that we put in place are really taking hold as well as outside the United States kind of continuing a superiority strong momentum. With respect to forwarded looking price, we really don't as a policy talk about that and so I kind of, probably just leave it there at that for now.

Okay. Great. Thank you very much. Paul J. Clancy - Executive Vice President and Chief Financial Officer: Thank you.

Your next question comes from the line of Joel Sendek with Lazard Capital Markets. Joel Sendek - Lazard Capital Markets: Thanks a lot. Actually, I wanted to follow up on that last question. And with regard to what you said about unit trends, can you help us to understand if the instance of patients with MS is increasing? And may be are you getting more patients of the sidelines in the TYSABRI... into the TYSABRI fold and maybe that could be increasing the potential patients on AVONEX as well even though it's kind of counterintuitive given the potential cannibalization? Paul J. Clancy - Executive Vice President and Chief Financial Officer: Joe, I think that what we're seeing in terms of unit trends outside the United States is actually quite good. Inside the United States, I'd say that it's probably characterized by slowing growth in 2008 as we saw in 2007 but the penetration in other geographies and just kind of expansion across the world was actually beginning to help us. We now with respect to disease-modifying therapies there are actually now more patients on... across all disease-modifying therapies, on therapy outside the United States and inside the United States. So, I think it's one of the things that we've tried to talk about over the last year or two is the importance of the business outside the United States and I think our strategy is really starting to pay off as it relates to that. Joel Sendek - Lazard Capital Markets: Thanks.

Your next question comes from the line of Michael Aberman with Credit Suisse. James C. Mullen - President and Chief Executive Officer: Michael, are you there? Elizabeth Woo - Vice President, Investor Relations: Probably go to the next question.

Your next question comes from the line of Geoff Meacham with JP Morgan. Elizabeth Woo - Vice President, Investor Relations: Are we having technical difficulties, operator? Bill Sibold - Senior Vice President, US Neurology Business Unit: Yes we're. James C. Mullen - President and Chief Executive Officer: Yes. We have lost a queue or something.

One moment Sir. James C. Mullen - President and Chief Executive Officer: Bill, if we can reload those and start with Michael of we can find him again here and then go to Geoff.

One moment please. Mr. Aberman could you please press star one again. Okay Mr. Aberman, your line is open. Michael Aberman - Credit Suisse: Right, are you guys there? Bill Sibold - Senior Vice President, US Neurology Business Unit: Yes. Michael Aberman - Credit Suisse: Fantastic, you had me in panic. Looking at the trends for TYSABRI, in the US the actual number of patients added was flat compared to fourth quarter whereas in the ex-US you had a significant increase. Going forward was there something unique about Europe in terms of this quarter, in terms of the roll-out in new countries where we think this... this might temper a little bit going forward or should we think this of as run rate and in the US based on this new updated safety. Would you expect an inflection in the outer quarters or the next few quarters given the recent safety assays? Bill Sibold - Senior Vice President, US Neurology Business Unit: So this is Bill. So internationally, we do see the benefit of additional countries coming on-board and we expect that affect will continue through the year and into the future. In the US, Q1 was that what we had expected and we expect that there will be steady growth in the number of new patient adds which puts us on track overall for 2010 of our goal of 100,000 patients. Paul J. Clancy - Executive Vice President and Chief Financial Officer: Hi, Michael, this is Paul, I’ll just add and try to echo the fact that as we've articulated our longer term goals, we've always thought about the contribution of TYSABRI in terms of patients to be kind of in the 60% outside the US, 40% inside US and that's just based on kind of market projections in planning. In the early read based on Q4 and Q1 now is that assumption may really start to become to fruition. Michael Aberman - Credit Suisse: Thank you, very much. James C. Mullen - President and Chief Executive Officer: Can we find Geoff Meacham again?

Geoff Meacham with JP Morgan, your line is open. Geoff Meacham – JP Morgan: Hi guys can you hear me. James C. Mullen - President and Chief Executive Officer: We can Geoff. Geoff Meacham – JP Morgan: Okay. So to ask Michael's question in a different way, I guess now that you have few quarters in EU launch of TYSABRI, is there any data you can give us on the source of patients so basically the EU version of slide ten in your debt James C. Mullen - President and Chief Executive Officer: The EU version slide 10, probably what I’d say is it looks better outside the US than inside the US in terms of the number of patients they are kind of new to the franchise. So few are coming from AVONEX, more coming from the competitors and probably the returns to the market is about similar to what we have seen here. So where we say four out of five TYSABRI patients in the US are new to the Biogen Idec franchise is probably closer to 9 out of 10 outside the US and interesting there is a couple of markets where TYSABRI is pretty quickly moving to the number two position. Geoff Meacham – JP Morgan: And just as the follow-up. Do you see in Europe any bias towards use of TYSABRI in first-line patients, in Europe? James C. Mullen - President and Chief Executive Officer: Any.... no, I don't know that we've seen a lot of change for physicians yet to initiate patient, newly diagnosed patient on TYSABRI, I mean it happens in some circumstances but that's still a minority. Geoff Meacham – JP Morgan: Okay. Thanks. James C. Mullen - President and Chief Executive Officer: All right.

Your next question comes from the line of Eric Schmidt with Cowen and Company. Eric Schmidt - Cowen and Company: Congrats on the strong first quarter. My question has to do with the AAN meeting, maybe either for Bill or Cecil, there are couple of poster presentations at AAN that talked about monitoring patients for JC virus reactivation. I am just kind of wondering what Biogen's take would be on some of that data? Cecil B. Pickett – President, Research and Development Yes, I guess specifically talking about the poster from Dr. Sidqque [ph] study. Eric Schmidt - Cowen and Company: That's right Cecil B. Pickett – President, Research and Development Yes, well just to backup, just for a second, just want to remind everyone as of the end of March of 2008, there were approximately 26,000 patients on TYSABRI with no new cases of PML. That's very important. Dr. Sidqque study identified two patients with JC virus, one in the blood and one in the cerebrospinal fluid. I want to point out that these patients did not have PML and there is actually no data that exists to suggest that they are at increased risk of developing PML. So, we believe the best approach to monitor for PML is through examination and clinical vigilance. Eric Schmidt - Cowen and Company: Thank you. Cecil B. Pickett – President, Research and Development Sure.

Your next question comes from the line of William Ho with Banc of America. William Ho - Banc of America Securities: Hi guys. Congratulations on the quarter. I guess my question comes... I guess with respect to your current views of PML and the mechanism given the FDA's recent advisories due to PML from known viruses Myfortic and Roche’s CellCept and what are your future or your going forward thoughts on the risk of PML, is it a TYSABRI related event or is it just due to immunosuppression and do you see clinicians becoming more comfortable with the use TYSABRI? Cecil B. Pickett – President, Research and Development Well, I think with mycophenolic acid, which is CellCept, it's the ester of mycophenolic acid is basically CellCept. It inhibits a sort of a key enzyme and purine metabolism. And because of that it actually blocks proliferations both the T-cells and B-cells. So it is a pretty powerful immune suppressant. So, my take on that it although the data is limited today, but my take on that is that any potent immunosuppressive agents may [inaudible] this at increased rate to PML. And I think you've heard from Bill that physicians are becoming much more comfortable with the benefit risk profile of TYSABRI. William Ho - Banc of America Securities: Great. Thank you.

Your next question comes from the line of Jim Birchenough with Lehman Brothers. Jim Birchenough - Lehman Brothers: Yes. Hi, guys. Let me add my congratulations on the quarter. Just a question on the PLEX study results and implications for the market, maybe you could just comment on the number of infusion centers that have apheresis capabilities and whether you think the data will give some comfort not only around PML but for patients that might have to transition from TYSABRI to an immunosuppressive quicker than the three month lag time. Cecil B. Pickett – President, Research and Development Well, again, I mean the PLEX, the data basically suggested that three plasma exchanges actually reduces TYSABRI levels quite significantly in the plasma. And the in vitro transmigration assay that was done also suggest that with PLEX, with the plasma exchange you can basically reconstitute the immune system. So I guess we've also have done some modeling which suggest that if you go out to the five cycles, that you really significantly reduce TYSABRI levels to the extent I guess to rates of 95%. Jim Birchenough - Lehman Brothers: I guess the question is in terms of practically are infusion centers in a position to plasmapheresis? Bill Sibold - Senior Vice President, US Neurology Business Unit: Yes. We don't see that as being a barrier. Jim Birchenough - Lehman Brothers: Okay. Thanks.

Your next question comes from the line of May-Kin Ho with Goldman Sachs. May-Kin Ho - Goldman Sachs: I have a question on the lupus study. If this study is negative, what kind of least we can... sorry, what kind of conclusion should we draw with respect to the upcoming trial for nephritis… lupus nephritis? Bill Sibold - Senior Vice President, US Neurology Business Unit: Very difficult to say. I mean, I think many of us in this field for several years have thought that there was a significant B-cell, yes, there is a significant B-cell involvement in lupus. And so, we'll get the data and see what the data tells us about lupus study and sort of go from there. So I don't think actually we completed enrolment in the lupus nephritis study also. So we’ll get data from both of those studies and we don't have to sort of guess. We can base are decisions on actual data. May-Kin Ho - Goldman Sachs: I was just really trying to refer to with SLE may be... that's organ specific and with nephritis your are more selective there, so trying to figure out in terms of the trial design or the biology, can one really extrapolate anything? Bill Sibold - Senior Vice President, US Neurology Business Unit: I don't think so. I don't think so. May-Kin Ho - Goldman Sachs: Thank you.

Your next question comes from the line of Bill Tanner with Leerink Swann. Bill Tanner - Leerink Swann & Company: Thanks for taking the question. Question for Bill Sibold, may be. Just as we thinking about TYSABRI and looking all the numbers that we have obviously the ones you guys provide but if you look at the numbers of patients per physician in the US, I guess the glass-half empty way of looking at it is the growth really has come from new physician adds, glass-half full. I guess would be that you got perhaps physicians still dipping a toe in the water and you've actually established broader physician adoption. So as you do the market research, I mean in understanding the two years is really epidemiologically or pathologically not a meaningful milestone. I mean do you get the sense that there with physicians are going to begin to do more than just dip the tone rather going forward? Bill Sibold - Senior Vice President, US Neurology Business Unit: Yes, we believe that it's not just the two years but it is the release of utilization updates like at the AAN and now there are positive data as well as just the physician experience, which is taking place. One other things that we are hearing from physicians is some very compelling results with the MS patients that they treat. So, we really believe that with time, with the continued use of the product we're hearing stories of what other colleagues are doing etcetera that there will be a continue increase in the use of products from both a depth perspective. So the physicians that are currently writing and also from a breadth perspective that we expect additional neurologists will start to utilize TYSABRI. Bill Tanner - Leerink Swann & Company: Okay. Thanks.

Your next question comes from the line of Mike King with Rodman & Renshaw. Michael King - Rodman & Renshaw: Thanks for taking my question and let me add my congratulations. To start, I believe questions on lupus but I was wondering, I think one thing we could benefit from would be to understand how the actual BILAG results are going to be presented to the Street and perhaps so you again without trying to get the results from you the, just how are they going to be represented? Will they be broken down into the major and minor, will we see one large number? Can you just give us some context as how those results are going to be conveyed to investors? James C. Mullen - President, Chief Executive Officer, Director: Well, I think what you're going to give. So, first Genentech has been running the trial and you know our experience working with Genentech is they are very prompt at doing analysis and giving the top line results out, but that’s really all you are going to give at the beginning because they will do a very through but fairly quick review which means there is a lot of other thinking and analysis to be done after that. I think you are going to get the top line review, you're going to get the top line results that it meet the primary didn't meet the primary and I don't know that it will be much more than that, when we have it. I think the details will follow as is the tradition for any other company but especially Genentech and Biogen Idec at an appropriate scientific forum where they will drill into the data and a fair bit of detail with investigators. Michael King - Rodman & Renshaw: Okay but just understand correctly the primary is major and minor. Elizabeth Woo - Vice President, Investor Relations: Correct. James C. Mullen - President and Chief Executive Officer: Correct. Elizabeth Woo - Vice President, Investor Relations: Mike, that's correct. Michael King - Rodman & Renshaw: Thank you.

Your next question comes from the line of Geoffrey Porges with Sanford Bernstein.

Hi guys. It's actually Isaac was calling in for Geoff. Congratulations on the quarter again, I was hoping you guys can provide a little bit more color on TYSABRI and Crohn's disease both had a status of a potential approval here in the EU, as well as some color on your conversations with physicians ahead of the US launch or following the US launch how you think roughly 10,000 patients on TYSABRI and MS is going to aid that and any safety concerns and then finally any assumptions you guys have made for TYSABRI uptake in Crohn's for the 100,000 patients on TYSABRI by 2010? James C. Mullen - President, Chief Executive Officer, Director: Okay, as so it's probably premature to raise the 100,000 number seeing as I've spent the last nine months or so getting people warmed up to the 100,000 number. But I will be pleased to be [inaudible] by the end of the year on the 100,000 number. With respect to Crohn’s in the EU just to take everybody back to what the issue there was and I think you properly put your finger on it, it was the question of risk benefit profile and certainly as we get more patients exposures in the EU US in MS but especially in Crohn’s there is just more real data to bring to that discussion. So the plan right now is we are reengaging the EU regulatory authorities in that conversation. I think it's premature to say where that's going to go exactly and what they're going to look for. Hopefully within the next call or two here we'll be able to give you more specific guidance on that. With respect to the US launch, what you're witnessing now is just what we witnessed at the launch with MS. There is a big educational phase and qualifying physicians. There has been a number of scripts written but I don't think there is any to conclude from the very early going. So I think we just have to watch this evolve over the next couple of quarters. And Elan is leading the commercial efforts there. So they will be the company with a little bit more specific finger on the pulse there as we go forward.

Right, thanks. James C. Mullen - President and Chief Executive Officer: Yes.

Your next question comes from the line of Maged Shenouda with UBS. Maged Shenouda - UBS: Hi. So my question has to do with RITUXAN in SLE. Genentech has been cautious with regard to the ability to file for SLE with RITUXAN only with positive explorer results. I'm just wondering if you share that caution and then also realistically what labeled indication do you ultimately anticipate for the product? James C. Mullen - President and Chief Executive Officer: Well, I'll take that one. I mean what do we ultimately and with positive results in SLE positive results in nephritis are fairly broad label. You know that’s assuming lots or I guess we have to see the data. We know the first trial is... it will be analyzed relatively soon. Second trial is fully accrued, I believe. So we'll have those results in early 2009. It's of course safe to say that the agency has become quite conservative. That is not unique to this particular product or Genentech or Biogen Idec. So as it’s has been tougher to get things, moves to the FDA. I'd say my perception is the answer to that is, yes. Having said that you've got RITUXAN. Here is a product that's been out there for 10 years. It’s been in the [inaudible] thing for a couple of years now with our RA. So it does have a broad safety experience. So I think some of the concerns that the FDA would typically bring to review like this are answered given the huge database we now have of real world experience. So with a positive outcome on the data I think you can be optimistic that you can move that through, will it require both trials, I think you assume yes until you know otherwise. Maged Shenouda - UBS: Okay. Thank you. Elizabeth Woo - Vice President, Investor Relations: Operator, we'll take a couple of more questions.

Thank you ma'am. At this time, your next question comes from the line of Adam Walsh with Jefferies & Company. Adam Walsh - Jefferies & Company: Hi good morning. Jim, can you hear me, first of all. James C. Mullen - President and Chief Executive Officer: Yes. Adam Walsh - Jefferies & Company: Terrific. Jim, you've said in the past that we might expect to see additional PML cases with TYSABRI and I'm curious to know what your market research with neurologists had suggested that new cases of PML how they might impact prescribing behavior near-term and long-term and whether or not... remind us whether or not your 100,000 patients on TYSABRI by year-end 2010 would include an assumption of new cases? Thanks. James C. Mullen - President and Chief Executive Officer: Yes, good question. So, I almost always get beat up by somebody whether it's on a message quarter, simply shortly after I make a statement that we should expect PML. But realistically what we have is a black box warning. We have an educational program around this specifically. And it would be just irresponsible for me to say that otherwise and it would open up this company to an enormous amount of litigation. So, until as the data continues to play out, we'll see the statistics. But once you have that kind of association label, it's going to be there. But what changes over time of course is perception of risk benefit and it’s not adjust the risk side of the equation, which the data plays out, but it’s the benefit, it's what physicians actually sees in front of them in the clinical experience over a number of patients over a significant sweep of time. Now, we've assumed in everything that we've done that we would see cases of PML. I think all of it's going to be fact and circumstances specific if it’s one here, one there what you learn it from the cases, if it's a cluster, what do you learn from those cases that you can then use to educate physicians about the risk or how to monitor. So, we've assumed that we would continue to see some... we have assumed now that the safety profile will continue to unfold and if you will somewhat more favorable than what's in the label, I think that's already probably statistically true today, but you know, the label-to-label until it gets changed. Adam Walsh - Jefferies & Company: Thank you. Elizabeth Woo - Vice President, Investor Relations: Operator, we'll take one or two more.

Your next question comes from the line of Jason Zhang with BMO Capital. Jason Zhang - BMO Capital: Yes. Thanks for taking my question. I actually wanted to go back to slide number 10. You gave a picture of TYSABRI users on three different sources. I assume that's a recent picture. If you compare that to the very beginning, what would be the difference, do you see the shape shifting one way or another? Do you expect to see more of the patients switch from the other interferon and [inaudible] continually going into the future? Bill Sibold - Senior Vice President, US Neurology Business Unit: Yes. We've seen the… this is Bill. The shift that we have seen in time is perhaps more patients coming from the ABCRs which we would expect that as patients are in need of more efficacy that are in current therapies that they will be switching to TYSABRI and just that data, this is looking at the end of March timeframe. Jason Zhang - BMO Capital: And if you compare this slides, the pi-chart about a year ago, what would be the break down? James C. Mullen - President and Chief Executive Officer: Not a huge change. Jason Zhang - BMO Capital: Not huge difference. James C. Mullen - President and Chief Executive Officer: No. Jason Zhang - BMO Capital: Okay. That's very helpful. Thank you. Elizabeth Woo - Vice President, Investor Relations: Okay. We'll take our last question.

Your last question comes from the line of George Farmer with Wachovia Securities. George Farmer - Wachovia Securities: Hello, hi, thanks for squeezing me in. Given I guess some of the concern about the presence of JC and BK virus in CS through the spinal fluid and perhaps CRM, is there, in MS patients to with TYSABRI, is there any data out there that as looked at the normal levels of vital presence in healthy individuals. Do you know if we have, how that could be compared to the MS situation TYSABRI? James C. Mullen - President and Chief Executive Officer: I'm not aware of any data. Well, we haven't looked at that for a few years. We extensively reviewed all of that information that was available back at the time of the withdrawal and through that summer. I just don't remember off of top of my head exactly what that data said. We also did a fairly extensive look across some MS patients from data of [inaudible] against to and there is nothing there to find. So, it's a grave answer, we will dig that out for you and try to give you some more specific references to that, may be a follow-up. George Farmer - Wachovia Securities: Yes, I haven't seen anything, I was just wondering if you had… if you guys had any data on that? Elizabeth Woo - Vice President, Investor Relations: As Jim, referred to there is that study of the MS patients that we were not retreated and they didn't see anything in the cerebrospinal fluid. And as now we JC virus can be found in normal healthy in the plasma, but it is not meaningful in terms of any predictive or diagnostic value. George Farmer - Wachovia Securities: Great. Thank you very much. Elizabeth Woo - Vice President, Investor Relations: Thanks everyone for joining us on the call today.

Ladies and gentlemen, this concludes today's conference call. You may now disconnect.