Merck (MRK) buys Cidara for $9.2bn as biopharma M&A tops $93bn

Merck will acquire Cidara Therapeutics for $9.2 billion in cash, paying $221.50 a share for the antiviral biotech whose late-phase flu drug CD388 drew the drugmaker’s interest at a time when the sector is spending at a pace not seen in years. Biopharma deal values reached $92.98 billion through the first four months of 2026, and Merck’s transaction slots into a run of acquisitions by large drugmakers racing to refill pipelines before a cluster of blockbuster patents begins expiring later this decade.

BioWorld tallied biopharma deal and M&A values at $92.98 billion over the January-through-April stretch. Separately, a Reuters report on sector dealmaking put biotech M&A at $84 billion in the first quarter alone and said bankers and advisers see a path to roughly $250 billion for the full year if the current tempo holds.

The gap between the $84 billion first-quarter number and $92.98 billion through April tells its own story: dealmaking did not cool after the year’s first burst. Acquirers stayed active into the second quarter.

CD388, the late-phase antiviral candidate in Cidara’s portfolio, is the asset Merck wanted. The company said in its announcement that the deal would diversify its product base and add a programme it believes can contribute through the next decade. Robert M. Davis, Merck’s chief executive, told investors the company was “confident that CD388 has the potential to be another important driver of growth through the next decade.”

At $221.50 a share, the bid values a company built around one late-stage programme at more than $9 billion. Merck described the price as a faster route to growth than waiting for its own internal research to reach the same point, a calculation that reflects how steeply buyers are still pricing clinical-stage assets when the strategic case is straightforward. The same dynamic has played out across multiple deals this year.

Reuters reported that large drugmakers are approaching acquisitions with more urgency as a stretch of patent expiries threatens older blockbuster revenue streams. The deals that tend to close involve assets close to approval — drugs that can move into commercialisation without a long gap between research and sales. Merck’s pursuit of Cidara tracks that pattern.

Why the deal stands out

Cidara is not the only biotech target to command a premium this year, but the structure of the transaction makes it a clean marker for 2026: a straightforward cash offer for a late-stage asset, bought by an acquirer big enough to absorb the purchase without altering its wider strategy. That formula — targeted, expensive, tied to a specific revenue gap — has defined much of the recent healthcare dealmaking revival.

Reuters’ report on the Cidara transaction captured the split view. Courtney Breen described the deal as complementary but not perfectly “plug and play” with the rest of Merck’s portfolio. James Harlow told Reuters the agreement pointed to a sense of urgency at Merck to add growth through acquisitions. The two readings frame the central tension: Merck is paying a steep premium for an asset that may not fit neatly into the existing commercial base.

A deal can close an immediate growth gap and still leave questions about integration. Merck now has to show that the premium it paid buys more than a scarce late-stage asset in a seller’s market.

If the $92.98 billion tally that BioWorld tracked through April keeps climbing, the Cidara purchase will be read as part of a broader shift in biopharma capital allocation. Boards have stopped waiting for cheaper entry points or friendlier financing. They are moving on assets they think can reshape the revenue line within a reasonable window, even when the price looks high.