SNY Stock Down on Double Trouble With Multiple Sclerosis Drug

Shares of Sanofi SNY fell nearly 2% on Monday after the company reported two setbacks in connection with its investigational multiple sclerosis (MS) drug, tolebrutinib.

FDA Delays Decision on SNY’s MS Drug Again

Sanofi announced that the FDA has extended the regulatory review of its filing seeking approval to treat non-relapsing secondary progressive MS (nrSPMS) and slow disability accumulation independent of relapse activity in adults.

This is the second time that the agency has extended its review period. The FDA was initially expected to give its decision by Sept. 28, 2025. However, this date was extended by an additional three months to Dec. 28 after Sanofi’s submission of additional analyses during the review process, which the agency deemed a major amendment to the original filing. The agency once again revised this date after the company submitted an expanded access protocol for the drug in nrSPMS, at the FDA’s request.

A final decision is now expected in the first quarter of 2026. A similar filing is also currently under review in the European Union.

SNY’s Tolebrutinib Also Faces Clinical Setback

In a separate press release, Sanofi announced that it did not meet the primary endpoint in the phase III PERCEUS study, which evaluated tolebrutinib in patients with primary progressive MS (PPMS). While the company did not share any numbers, it noted that the safety profile was consistent with previously conducted studies on the drug.

Based on this setback, Sanofi has decided not to pursue further development in PPMS — an area that represents 10% of the overall MS patient population. Still, the company plans to report full safety and efficacy results from this study at a future medical meeting.

MS is a chronic neurodegenerative disease that causes disability accumulation over time, which is not properly addressed by the currently available therapies that are designed to primarily address peripheral inflammation.

SNY’s Stock Performance

Post the two back-to-back announcements on tolebrutinib, investors began raising concerns about the company’s future. Many investors have been viewing the drug as one of the company’s first attempts to diversify its top line, which is currently dependent on Dupixent for growth prospects.

Though Sanofi still upheld the risk-benefit profile of tolebrutinib for nrSPMS, investors did not seem to reciprocate the same feeling. This difference of opinion was likely the reason for the sell-off in the company’s share price on Monday.

Year to date, the stock has declined 1% against the industry’s 16% growth.

More on SNY's Tolebrutinib

This is not the first time that Sanofi has faced a setback with tolebrutinib. In 2022, the FDA placed a partial clinical hold on Sanofi’s phase III studies on tolebrutinib in MS and myasthenia gravis (MG) indications after the regulatory agency identified cases of drug-induced liver injury in some study participants who were treated with the drug.

The MG studies on tolebrutinib were eventually discontinued in 2022 after careful evaluation of the emerging competitive treatment landscape.

Tolebrutinib was added to Sanofi’s portfolio with the acquisition of Principia in 2020.

SNY’s Zacks Rank

Sanofi currently carries a Zacks Rank #3 (Hold).

Sanofi Price

 

Sanofi price | Sanofi Quote

Key Picks Among Biotech Stocks

Some better-ranked stocks from the sector are ANI Pharmaceuticals ANIP and CorMedix CRMD, each sporting a Zacks Rank #1 (Strong Buy) at present. You can see the complete list of today’s Zacks #1 Rank stocks here.

In the past 60 days, estimates for ANI Pharmaceuticals’ 2025 earnings per share (EPS) have risen from $7.29 to $7.56. EPS estimates for 2026 have increased from $7.81 to $8.08 during the same period. Year to date, shares of ANIP have surged over 47%.

ANIP’s earnings beat estimates in each of the trailing four quarters, delivering an average surprise of 21.24%.

Estimates for CorMedix’s 2025 EPS have increased from $1.85 to $2.87 over the past 60 days, while the same for 2026 has increased from $2.49 to $2.88. CRMD shares have risen 42% year to date.

CorMedix’s earnings beat estimates in each of the trailing four quarters, delivering an average surprise of 27.04%.

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This article originally published on Zacks Investment Research (zacks.com).

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