Pharma M&A Shifts to Bolt-Ons After 24 Small Deals in 2026

Big Pharma is abandoning mega-mergers for a steady stream of smaller bets — and investors are rewarding the discipline.

Big Pharma has pivoted from mega-mergers to bolt-on deals, with 24 acquisitions under $3 billion across the 16 largest drugmakers so far in 2026, after investors punished AstraZeneca for exploring a Bristol Myers tie-up.

"The only advantage for AstraZeneca in this rumoured combination with BMS seems to be to accelerate its US footprint and sales," said Lucy Coutts, investment director at JM Finn. "On balance, BMS shareholders would be the winners."

AstraZeneca shares fell as much as 7 percent Monday after the Financial Times reported merger talks, while Bristol Myers gained roughly 6 percent in premarket trading. The combined companies carried a market capitalization of nearly $400 billion. Jefferies analysts said they were "a bit perplexed" given AstraZeneca's "best-in-class pipeline," while Citi called the talks a surprise.

The episode crystallized a shift already underway: investors soured on large acquisitions after Bristol-Myers Squibb's $74 billion Celgene deal in 2019 failed to deliver positive shareholder returns. Merck, facing Keytruda patent expiry in 2028, has instead filled its cart with targeted assets — and its shares are up about 80 percent in the past 12 months.

Bolt-on deals have become the industry's staple. Across the 16 largest drugmakers, acquisitions under $3 billion have run at roughly two dozen a year over the past decade, according to Norstella M&A data provided by Evaluate. The pace has accelerated in recent years, and 2026 is running hot with 24 such deals already.

Eli Lilly, whose executives have used the supermarket analogy, was behind many of this year's deals. Its Mounjaro and Zepbound franchise generates massive cash flow, with patent protection stretching into the middle of the next decade, giving Lilly time to shop for the next decade rather than the next year. It has placed targeted bets across sleep, gene editing, cancer and psychedelics to diversify before the obesity-drug boom eventually slows.

Novartis offers a look at a buyer that has grown more disciplined over time. Its best moves came from getting in early: long before radiopharmaceutical therapy became oncology's hot trend, Novartis paid about $2 billion in 2018 for the platform that yielded Pluvicto, a prostate-cancer drug now on track for roughly $4 billion in annual sales by the end of the decade. Not every bet pays off — it took a partial write-down on its $2.9 billion MorphoSys deal after the lead drug hit clinical delays. But under Chief Executive Vas Narasimhan, the Swiss drugmaker has narrowed its ambitions toward smaller, targeted bets, with the occasional larger swing on conviction, such as its recent $12 billion deal for neuromuscular-drug developer Avidity Biosciences.

Merck's Calculated Cart

Merck is the harder test. By all rights, Chief Executive Robert Davis should be the hungriest shopper in the aisle. Keytruda generated $31.7 billion last year — more than half of Merck's pharmaceutical revenue — and begins losing patent protection in 2028. A hole that size could make any executive grab the most expensive thing on the shelf. Merck has indeed repeatedly looked at deals over $30 billion.

But rather than bet the firm on one overwhelming acquisition, Merck has filled its cart with a string of targeted assets, including the 2021 $11.5 billion acquisition of Acceleron, which gave it the fast-growing pulmonary-hypertension drug Winrevair, and the $11 billion buyout of Prometheus in 2023, a bet on an autoimmune treatment. Partnerships can be an even lower-risk way in. Merck teamed up with Moderna in 2016 to develop personalized mRNA cancer vaccines, and expanded the deal over time. The bet is paying off: on Wednesday, Merck's stock surged 13 percent to $153.12 after the vaccine delivered positive results in high-risk melanoma patients, adding roughly $44.4 billion to its market value.

The Phase 3 trial enrolled 1,137 patients with high-risk melanoma after surgery. Intismeran autogene plus Keytruda met goals for delaying recurrence and distant spread versus Keytruda alone, with no new safety signal. Barclays forecasts about $3 billion of annual melanoma sales by 2035, but the market priced more than a melanoma launch — the platform could extend Keytruda's commercial life and soften its coming patent exposure. Keytruda generated $8.37 billion in second-quarter sales, 50.4 percent of Merck's $16.61 billion total.

Risk is inherent in buying biotech companies. The best drugmakers, like the best shoppers, don't stop buying. They just make sure they're never so hungry that everything on the shelf looks good.

This article is for informational purposes only and does not constitute investment advice.