It has been about a month since the last earnings report for Biogen Inc. (BIIB Quick QuoteBIIB - Free Report) . Shares have added about 3.8% in that time frame, underperforming the S&P 500.

Will the recent positive trend continue leading up to its next earnings release, or is Biogen due for a pullback? Before we dive into how investors and analysts have reacted as of late, let's take a quick look at the latest earnings report in order to get a better handle on the important catalysts.

Q1 Earnings & Sales Beat

Biogen reported first-quarter 2026 adjusted earnings per share (EPS) of $3.57, which significantly beat the Zacks Consensus Estimate of $2.95. Earnings rose 18% year over year. The adjusted EPS reflected approximately 20 cents per share impact of IPR&D charges, related primarily to Alteogen and Alloy transactions.

Total revenues during the quarter came in at $2.48 billion, up 2% year over year on a reported basis. However, revenues declined 2% on a constant-currency basis. Revenues beat the Zacks Consensus Estimate of $2.25 billion.

Lower sales of key Tecfidera and Spinraza were partially offset by higher revenues from new drugs, 
Skyclarys, Qalsody and Zurzuvae. Improved inventory dynamics also benefited sales of MS drugs like Tysabri and Vumerity in the quarter. 

Biogen’s growth products (Skyclarys, Qalsody, Zurzuvae, Vumerity and Spinraza Alzheimer’s revenues form Leqembi collaboration) generated sales of $851 million in the first quarter, rising 12% year over year.

Product sales in the quarter were $1.75 billion, down 3% year over year on a constant currency basis. 

Revenues from anti-CD20 therapeutic programs rose 11% to $419 million.

Contract manufacturing and royalty revenues declined 20% year over year to $247.0 million. Alzheimer’s collaboration revenues were $60 million, up 80% year over year. 

Alzheimer’s collaboration revenues include Biogen’s 50% share of net product revenues and cost of sales (including royalties) from Leqembi. Eisai recorded nearly $168 million in global revenues from Leqembi sales in the first quarter, up 74% year over year and 25% sequentially, driven by demand growth globally. The drug’s U.S. sales rose 10.3% quarter over quarter to $86 million.

Multiple Sclerosis Revenues

MS revenues totaled $958 million, down 3% on a constant-currency basis, due to generic competition for Tecfidera globally and Tysabri in Europe and rising competitive pressure in the MS market.

Tecfidera sales declined 47% to around $109.5 million due to generic erosion globally, particularly in Europe. The drug’s sales also missed the Zacks Consensus Estimate of $111 million.

Vumerity recorded $179 million in sales, up around 29% year over year, driven by strong demand and improved inventory dynamics in the United States. This metric beat the Zacks Consensus Estimate of $164 million.

Tysabri sales rose 15.7% year over year to $441.5 million as the impact of biosimilar competition in Europe and a decrease in U.S. demand were offset by favorable adjustments to discounts and allowances and the favorable impact of inventory timing. The drug’s sales beat the Zacks Consensus Estimate of $359 million.

Combined interferon revenues (Avonex and Plegridy) were almost flat year over year at about $227.5 million.

In 2026, Biogen expects revenues for MS products, excluding Vumerity, to decline by a mid-teen percentage versus 2025.

Rare Disease Drugs

Sales of Spinraza declined around 12% to $374 million. The figure missed the Zacks Consensus Estimate of $379 million

Spinraza’s U.S. sales declined 8% year over year to $142.2 million due to lower demand and unfavorable inventory dynamics. In the rest of the world, Spinraza sales declined 14% to $231.8 million due to unfavorable timing of shipments.

Skyclarys generated sales of $150.7 million, up 21.6% year over year, driven by continued demand growth. In the United States, revenues of $71.8 million rose 4% year over year. However, on a sequential basis, Skyclarys’ U.S. sales declined 19.2% due to unfavorable inventory dynamics, which offset the positive impact of moderate demand growth. In ex-U.S. markets, sales rose 44% to $78.9 million, driven by strong adoption trends. 

Qalsody added sales of $32.5 million, up more than 100% year over year, driven by demand growth.

In 2026, Biogen expects Rare Disease revenues to grow due to the continued launch of Skyclarys in the EU and other ex-U.S. markets and the continued launch of Qalsody in Europe. Biogen expects global Spinraza revenues to be relatively flat in 2026.

Other Products

New drug Zurzuvae (for postpartum depression) recorded sales of nearly $55.4 million in the quarter, down 16% on a sequential basis as demand growth was partially offset by inventory dynamics. 

Biosimilar revenues declined 7% year over year to $182 million during the quarter.

Costs Decline

Adjusted research and development (R&D) expenses rose 13% year over year to $480 million due to increased costs behind the company’s late-stage candidates like litifilimab and felzartamab.

Adjusted selling, general and administrative (SG&A) expenses rose 5% to $600 million due to higher costs to support the new product launches.

In the quarter, the collaboration profit-sharing was a net expense of around $74 million, which included nearly $57 million of net profit-sharing expenses related to Biogen’s biosimilar collaboration with Samsung Bioepis and around $17 million of net profit-sharing expenses linked to Biogen’s collaboration with Supernus Pharmaceuticals for marketing Zurzuvae in the United States.

Maintains 2026 Guidance

Biogen maintained its revenue guidance for the year while lowering its earnings guidance to include IPR&D charges related to M&A activities.

Total revenues are expected to decline by a mid-single-digit percentage in constant currency terms in 2026 from the 2025 level. A decline in MS revenues (excluding Vumerity) is expected to be partially offset by higher revenues from growth products. 

Adjusted EPS guidance was lowered from a range of $15.25 to $16.25 to $14.25 to $15.25 to include an IPR&D charge of $1.00 per share. The charge comprised approximately 20 cents recorded in the first quarter and approximately 80 cents expected to be recorded in the second quarter (mainly for the TJ Bio transaction for felzartamab rights in China) but does not include any costs related to the Apellis transaction.

Biogen expects Apellis to be accretive to earnings in 2027 and the acquisition to boost Biogen’s adjusted EPS growth rate over the remainder of the decade. 

The gross margin in 2026 is expected to be similar to the 2025 levels. Combined adjusted R&D and SG&A costs are also expected to be similar to 2025 levels.

In the second quarter, Biogen expects core operating expenses to be roughly consistent with the first quarter. 

How Have Estimates Been Moving Since Then?

Since the earnings release, investors have witnessed a downward trend in estimates revision.

The consensus estimate has shifted -20.37% due to these changes.

VGM Scores

At this time, Biogen has a nice Growth Score of B, though it is lagging a lot on the Momentum Score front with an F. However, the stock has a grade of B on the value side, putting it in the second quintile for this investment strategy.

Overall, the stock has an aggregate VGM Score of B. If you aren't focused on one strategy, this score is the one you should be interested in.

Outlook

Estimates have been broadly trending downward for the stock, and the magnitude of these revisions indicates a downward shift. Interestingly, Biogen has a Zacks Rank #3 (Hold). We expect an in-line return from the stock in the next few months.