Thank you, Alisha. I'd like to provide some key highlights from our strong second quarter financial results. Unless otherwise noted, each of the comparisons I make during my remarks are versus the second quarter of 2024. We delivered 7% revenue growth in the quarter on strong commercial execution, particularly from our 4 launch products, which generated $252 million in revenue in the quarter and our MS business in the U.S. This strong commercial execution, combined with our disciplined operating expense management, resulted in non-GAAP diluted EPS growth of 4% in the quarter, absent the approximately $0.26 impact from the acquired IPR&D upfront and milestone expense in the quarter, non-GAAP diluted EPS would have been $5.73, up 9%. Based on the strength of the business performance in the first half of the year, we are raising our full year 2025 financial guidance. I will provide details on guidance shortly. First, I will cover our Q2 performance. Starting with our MS franchise. In the U.S., as Alisha noted, we had a strong quarter with revenue of $657 million. This was driven in part by higher VUMERITY demand approximately $32 million of favorable inventory dynamics from [Technical Difficulty] and TYSABRI and an approximately $48 million favorable gross to net change in estimate impact across the franchise with $27 million of this gross to net dynamic favorably impacting VUMERITY. Outside the U.S., sales are primarily impacted by expected generic pressures for TECFIDERA and a biosimilar for TYSABRI in Europe. We continue to defend our IP. However, we expect accelerating competitive pressures on the ex U.S. MS business in the second half of 2025, particularly for TECFIDERA in Europe. For SPINRAZA, we continue to be encouraged by the consistency in demand globally. And as expected, ex U.S. SPINRAZA was impacted by the drawdown of the inventory build from the first quarter, which we expect to continue into Q3. We continue to expect full year global SPINRAZA revenue to be relatively similar in 2025 as compared to 2024. Due to timing of shipments, we expect revenue in the second half of the year to be lower than the first half. Our 4 launch products each saw increases in demand in the second quarter and together delivered $252 million of revenue to Biogen, which was an increase of 26% quarter-over-quarter and 91% year-over-year. Again, this quarter, the year-over-year performance of these products together offset the decline in our MS portfolio. We continued to see steady sequential demand growth for LEQEMBI globally with second quarter global end market sales booked by Eisai of approximately $160 million. This includes the favorable impact of the timing of shipments to China of approximately $35 million as the collaboration optimized global inventory positions in Q2. We expect this inventory build to work down in the second half of the year. What is encouraging is that excluding the China shipment timing impact, global sales grew 29% sequentially and 211% year-over-year. SKYCLARYS saw continued demand growth globally and the U.S. demand growth more than offset the expected Medicare discount dynamics in the quarter. Internationally, SKYCLARYS was negatively impacted by the timing of shipments in certain markets. We expect SKYCLARYS to continue to grow globally and we are working to secure reimbursement in certain European markets as well as in Brazil. We experienced strong demand growth for ZURZUVAE in the quarter. And as Alisha noted, Q2 revenue was $46 million, up 213% year-over-year and 68% quarter-over-quarter. As a reminder, Biogen shares 50% of the profit or loss on ZURZUVAE, which is recognized in the collaboration profit sharing line on our P&L. I would like to note we understand that earlier this month, IQVIA updated their methodology for reporting shipped prescriptions for ZURZUVAE and other products as part of their routine data review. This may mean the capture rate may be lower. We are encouraged by the opportunity for ZURZUVAE, including the potential in Europe with the recent positive CHMP opinion. Turning to contract manufacturing revenue. The increase in revenue was driven by the acceleration of timing for manufacturing batch releases, some of which were associated with LEQEMBI due to our Q4 planned plant maintenance activities. We continue to believe that contract manufacturing revenue will be roughly consistent when comparing full year 2025 with full year 2024 and we expect minimal revenue in Q4 2025 due to the planned maintenance activity. Now a few comments on the rest of the P&L. Non-GAAP cost of sales was impacted by higher lower-margin contract manufacturing revenue in Q2 2025, a continuation of the trend we saw in the first quarter as we accelerated batches ahead of the planned Q4 plant maintenance I just mentioned. Non-GAAP core operating expense or R&D plus SG&A expense decreased 2% year-over-year as we continued to deliver on our R&D prioritization and Fit for Growth initiatives. Non-GAAP operating income included approximately $47 million of acquired in-process R&D charges. This includes $16 million related to City Therapeutics transaction and a $30 million milestone related to initiation of the second Phase III study for felzartamab. Excluding the impact from acquired IPR&D, non-GAAP operating income would have been approximately $1 billion, up 5% year-over-year. Now I'd like to provide a brief update on our balance sheet. We generated $134 million of free cash flow in the second quarter. This reflects $745 million in cash tax payments in the quarter. Our cash tax payments for the year are heavily concentrated in Q2. Also in the second quarter, we used the proceeds of the $1.75 billion of newly issued debt to fully redeem our $1.75 billion of senior notes that were due in September. And while this financial transaction resulted in no net change to our overall debt profile, we expect roughly $15 million to $20 million of incremental interest expense in the second half of 2025, which we have factored into our updated guidance for the year. We ended the second quarter with $2.8 billion of cash and approximately $3.5 billion of net debt and we believe that our balance sheet remains strong, allowing us to continue to invest in both internal and external growth opportunities. We believe the structure of our business model positions us to be potentially more resilient to macroeconomic factors and policy uncertainty. Today, a significant portion of our U.S. product revenue is derived from products which are largely manufactured in the United States. And we recently announced a plan to continue to invest in our North Carolina manufacturing operations. This is a combination of capital and operating expense over several years that is intended to modernize and add manufacturing capabilities to fuel the continued advancement of Biogen's late-stage pipeline and support our next wave of potential products. It is also important to note that there are other aspects of our business model that we believe are important to our ability to be resilient in an uncertain environment. We generate a relatively high percentage of our revenue outside of the U.S. We also have a significant rare disease business and our payer channel mix in the U.S. is diversified and skewed more towards commercial payers. We believe these are important considerations as we navigate the current environment and we will continue to monitor the evolving landscape. Turning now to guidance, where we have raised our full year 2025 non-GAAP diluted earnings per share to be in the range of between $15.50 and $16 from $14.50 to $15.50. We are raising our guidance to reflect a stronger expected business outlook for the full year, largely reflecting the strong first half revenue performance including the resilient performance of the U.S. business and MS and the performance of our launch products, partially offset by the impact of the City Therapeutics transaction in the second quarter. Please note that the impact from the $30 million felzartamab milestone I mentioned earlier was already contemplated in our previous guidance. The following are some key considerations underlying the guidance raise. We now expect total revenue for 2025 to be approximately flat compared to full year 2024. This reflects the strong first half revenue performance, including the resilient performance of the U.S. MS business. Excluding the $75 million of favorability from inventory and the onetime gross to net adjustments in the second quarter, we expect U.S. revenue trends for the second half of 2025 to be roughly in line with the first half. We also expect increased competitive pressures on the ex U.S. MS business in the second half of 2025, particularly for TECFIDERA in Europe. And as I mentioned previously, we expect minimal contract manufacturing revenue in Q4 this year due to planned plant maintenance activities. Importantly, we remain on track to deliver the $1 billion of gross savings and $800 million of net savings under our Fit for Growth initiative. In the second half of 2025, we plan to make additional investments in R&D to enable acceleration and expansion of clinical development activities, primarily in support of rare disease. On this call, we talked about our excitement around moving salanersen to registrational studies and plans for our fourth indication for felzartamab. As we continue to expand our increasingly exciting pipeline, we believe it's important to make these investments in support of our long-term growth objectives. We now expect combined non- GAAP R&D and SG&A expense for the full year 2025 to be approximately $4 billion. Please be sure to review this slide and our press release for other important guidance assumptions. Finally, we continue to focus on capital deployment that provides long-term value for our shareholders. And with that, I will pass the call back to Tim to open the call for questions.