Biogen (BIIB) Q3 2026 Earnings: Apellis Dilution Cut to About $0.55

Biogen (BIIB) Q3 2026 earnings showed total revenue of $2,804.1 million, up 10.6% year over year, in results released on October 28, 2026 through an 8-K earnings release and the 10-Q for the quarter ended September 30. The company raised the low end of its full-year non-GAAP diluted EPS guidance from $12.00 to $12.20 [1]. Of the four questions that framed this quarter, two moved materially: the expected dilution from the Apellis acquisition fell sharply, and conversion to high-dose SPINRAZA ran faster than the company expected. Erosion of the legacy multiple sclerosis (MS) drugs did not accelerate, and LEQEMBI kept growing after the launch of the at-home IQLIK injection but did not speed up. Overall, Biogen has returned to growth, but most of the increase came from the acquisition and one-time items. Excluding Apellis, revenue grew only about 1% [1].

Biogen is a neuroscience and rare-disease drugmaker that sells mainly to wholesalers, specialty distributors and specialty pharmacies in the US [2]. Its revenue comes from MS drugs, rare-disease drugs such as SPINRAZA, the eye and kidney drugs SYFOVRE and EMPAVELI added through the May 2026 Apellis acquisition, and royalties on Roche's OCREVUS. It shares LEQEMBI economics 50/50 with Eisai [3].

Apellis dilution guidance cut from about $0.85 to about $0.55

In its earnings release, Biogen lowered the expected 2026 non-GAAP EPS dilution from the Apellis acquisition from about $0.85, the July estimate, to about $0.55 [1]. Management said synergies are arriving faster than planned and the deal is now roughly neutral on an operating basis, with the remaining dilution coming mostly from financing costs. Management also kept its view that the deal turns accretive in 2027 [4]. This improvement is the main source of the higher low end of guidance.

SYFOVRE, an eye injection for geographic atrophy (a blinding retinal disease), generated $191.3 million of third-quarter revenue, above the $162 million full-quarter figure for the second quarter [1][5]. Commercial injection volume rose 18% year over year and 7% quarter over quarter, faster than the 13% growth in the second quarter. Management attributed the growth to better physician sentiment and also acknowledged a reduction in free goods; it did not split the two effects [4]. Revenue rose about 18% sequentially, well ahead of injection volume. The gap mainly reflects an inventory build of about $11 million and a one-time price benefit whose size was not disclosed [4]. The company guided fourth-quarter SYFOVRE revenue up about a mid-single-digit percentage from the $155 million reported in the fourth quarter of 2025, which implies a sequential decline of about 15% [4].

Financing costs remain high. Non-GAAP other expense was about $91 million in the third quarter [1]. Biogen repaid $400 million of term loans during the quarter and plans to repay the remaining $1.4 billion by the end of 2027 [4].

SPINRAZA high-dose conversion beat plan, but the gain is largely one-time

Global SPINRAZA revenue was $460.6 million in the third quarter, up 23.2% year over year, ahead of the annual report's outlook for roughly flat full-year sales [1][2]. US revenue was $246.4 million, up 60.8%. The 10-Q attributed the US increase to high-dose demand, stocking and a favorable price change without splitting the three. Revenue outside the US fell 3.0%, so the growth did not come from bunched international shipments [3]. Nine-month SPINRAZA revenue rose 3.9%, reversing a first-half decline of about 5% [1].

Patient conversion drove most of the increase. Patients moving from the 12 mg dose to the high-dose regimen receive a one-time transition dose, and that revenue was concentrated in the third quarter [3]. Management said that by the end of the quarter, 70% of 12 mg patients had a high-dose start form submitted and 50% had been dosed. Some patients who had moved to competing drugs are switching back, but the company did not give a number [4]. Biogen guided fourth-quarter global SPINRAZA revenue up only about a mid-single-digit percentage from a year earlier, and fewer patients will receive the transition dose in 2027 [4].

Conclusion

The quarter shows Biogen's revenue has shifted toward its growth products, but the durable growth rate needs to be confirmed in the fourth quarter after one-time items fade; the company has already removed them from its guidance [4]. The legacy MS portfolio fell about 14% year over year, TYSABRI held flat on a US price increase, and VUMERITY fell 10.5% because Medicare Part D plans tightened formularies [1][3]. US in-market sales of LEQEMBI were $107 million and grew steadily, but Biogen's collaboration revenue still trails its share of LEQEMBI sales and marketing expense [1]. On cash, third-quarter free cash flow was about $600 million, half the prior-year level, for reasons not disclosed; net debt was about $6.4 billion [1]. The next tests are whether SYFOVRE injection growth stays above 15%, whether SPINRAZA holds above its 2025 level as transition doses decline, and whether cash flow supports debt repayment.

Sources

[1] BIIB 8-K filed 2026-10-28 · Exhibit 99.1 Q3 2026 earnings release, October 28, 2026, Biogen, 8-K Exhibit 99.1 third-quarter earnings release, https://www.sec.gov/Archives/edgar/data/875045/000087504526000094/exhibit991-q32026pressrele.htm [2] BIIB FY2025 10-K filed 2026-02-06, February 6, 2026, Biogen fiscal 2025 Form 10-K annual report [3] BIIB 10-Q filed 2026-10-28 · Item 2 MD&A (Q3 2026), October 28, 2026, Biogen, Form 10-Q Item 2 management's discussion and analysis, https://www.sec.gov/Archives/edgar/data/875045/000087504526000096/biib-20260930.htm [4] BIIB Q3 2026 earnings call 2026-10-28, October 28, 2026, Biogen third-quarter earnings call [5] BIIB Q2 2026 earnings call 2026-07-29, July 29, 2026, Biogen second-quarter earnings call