Novartis Caught Between Breakthrough Data and a Safety Scare — Investors Choose Their Side

Novartis shares rise as Remibrutinib MS trials succeed, while CAR-T study pause and deaths raise safety concerns.

The arithmetic of risk and reward rarely gets starker than it did for Novartis shareholders this week. A single trading session delivered both a clinical triumph and a safety alarm, and the market's verdict was unambiguous: the stock climbed as much as 5.6 percent in early Zurich trading, with traders betting that the promise of a new multiple sclerosis drug outweighs the perils of a stalled cell-therapy program.

The catalyst for the optimism came from the REMODEL-1 and REMODEL-2 Phase III trials, which tested the oral BTK inhibitor Remibrutinib — to be marketed as Rhapsido — against the established MS therapy Teriflunomid in roughly 2,000 patients. Novartis reported that the drug hit its primary endpoint of reducing the annualized relapse rate, while also demonstrating superiority across key secondary measures including the reduction of inflammatory brain lesions. A positive trend on delaying disability progression emerged at three months, with a nominally significant effect at six months in a pooled analysis. Notably, the company said no liver toxicity signal was observed.

What the company has not yet disclosed are the actual effect sizes. Those details are being held back for a late-breaking presentation at the MSToronto2026 congress, scheduled for October 21–23, which will be followed by an investor call. Regulatory filings for global approval are already in the pipeline.

The Other News: A Clinical Hold With Real Consequences

That same day, Novartis confirmed it had paused enrollment and ongoing treatments across eight clinical studies of its experimental CAR-T therapy Rapcabtagene autoleucel — known as rap-cel or YTB323 — in autoimmune indications including lupus, rheumatoid arthritis, and MS. The trigger: three patient deaths linked to a severe immune reaction the company refers to as IEC-HS. Bristol Myers Squibb took the precautionary step of suspending trials of a similar therapy, a coincidence that points to a potential platform-wide issue rather than an isolated problem.

The oncology studies involving rap-cel are explicitly unaffected by the pause, a distinction that matters for a company positioning cell therapy as a strategic pillar beyond its traditional small-molecule franchise. Still, the safety question is not trivial. If the root cause proves difficult to pin down or spreads to additional indications, the autoimmune program could face extended delays.

A Pipeline Story That Extends Beyond One Drug

The week's news flow did not stop at clinical readouts. Novartis also announced a licensing agreement with South Korean biotech Alteogen, securing rights to subcutaneous formulations built on the ALT-B4 platform in a deal worth up to $3.223 billion plus royalties. It marks the fourth such transaction the company has completed this year, underscoring a strategy of supplementing internal R&D with external partnerships.

That deal, combined with the MS data, paints a picture of a company actively broadening its pipeline — a hedge against the possibility that any single program stumbles. The CAR-T pause, in this framing, becomes a contained issue rather than a systemic threat.

Where the Stock Stands

The share price reaction tells its own story about investor conviction. At the time of the primary report, the stock was trading at €138.58, roughly 2.5 percent above its 50-day moving average of €135.15 — a sign the short-term trend remains intact. The Tuesday closing price of €139.02 sits about 3.7 percent below the 52-week high of €144.30 reached in late February. Year-to-date, the shares have gained 18 percent, with a 28 percent advance over the past twelve months.

The gap to the high is telling: the market has absorbed the MS victory but is not yet willing to push the stock into new territory. That hesitancy likely reflects the unresolved safety questions around rap-cel and the fact that Remibrutinib's full data set remains under wraps. Should the Toronto presentation reveal weaker-than-expected effect sizes, the current premium could quickly evaporate.

Fundamentals Provide a Floor

The operational backdrop offers some reassurance. Second-quarter results showed net sales rising 3 percent in dollar terms to $14.4 billion, driven by Kisqali, Kesimpta, Scemblix, Pluvicto, and Leqvio. Core operating income held steady at $5.9 billion, though the margin contracted 70 basis points to 41.2 percent of net sales. The company reaffirmed its July guidance for low single-digit sales growth with slightly declining core operating income at constant currencies.

Capital returns remain a supporting feature. Novartis repurchased 18.2 million shares for $2.8 billion on the SIX Swiss Exchange in the first half, leaving up to $5.6 billion outstanding under the $10 billion buyback program launched in July 2025.

The Road Ahead: Toronto and the Safety Probe

For the near term, two narratives will compete for investor attention. The bullish case rests on Remibrutinib delivering convincing efficacy data in Toronto and advancing smoothly toward regulatory submission. The drug already holds approval in the US and EU for chronic spontaneous urticaria, and a positive MS readout would give Novartis a second commercial foothold in neurology — a market long dominated by a handful of established players.

The bearish case centers on the IEC-HS deaths. Two major companies suspending similar cell therapies on the same day suggests a risk that may be tied to the rapid manufacturing processes used in these programs. Until the cause is identified and resolved, the autoimmune ambitions for rap-cel remain in limbo.

The next concrete catalyst arrives in October, when Remibrutinib's full data are unveiled in Toronto. In the meantime, investors will watch for any developments in the IEC-HS investigation, as that timeline will determine when the paused studies can resume. An upcoming fireside chat at the Jefferies "Back to School" healthcare conference on September 3 offers an early opportunity for management to address both questions. As long as the stock holds above its 50-day average and no new safety signals emerge, the MS story is likely to keep the shares within striking distance of their high — but a disappointing data reveal or an expansion of the CAR-T concerns could quickly shift the balance.