Shire and Takeda come to terms with a $64B deal, the biggest pharma M&A in years

We have a deal—a preliminary one, at least.

Late Tuesday, after a fifth buyout offer from Takeda, Shire said the Japanese drugmaker had finally landed on a proposal worth recommending to shareholders. It's a cash-and-stock bid now worth $64 billion or so, about $4 billion more than its first offer.

The deal still has to be approved by both boards and is subject to due diligence. The U.K.'s takeover board, which has strict rules for the timing and disclosure of bids, extended a deadline to give Takeda and Shire until May 8 to wrap it up.

In per-share terms, Takeda would fork over 0.839 new Takeda shares and $30.33 in cash for each Shire share. Based on Takeda's share price at Monday's close, that's £49 per share, Shire said in a statement—and £5 per share more than its first bid.

That share price is a moving target, though; Takeda's stock plummeted by 7% on the news Wednesday morning.

Structured this way, the deal “seems to be much more of a merger,” Bernstein analyst Ronny Gal pointed out in a note to clients. Shire shareholders will receive 50% of the value of the combined company, and the companies will do reciprocal due diligence before any deal closes.

RELATED: Fifth and final bid? A determined Takeda said to be nearing $60B-plus Shire deal

At least one analyst isn’t so sure Shire shareholders will be interested.

“Are SHPG shareholders willing to accept an offer that is in effect 44% cash and 56% equity?” Jefferies' David Steinberg wrote in a note to clients. While the latest bid is much more heavily weighted toward cash than Takeda's third bid—just 38% cash—“we still wonder if it is enough to satisfy SHPG shareholders, who would still bear some not insignificant risk going forward as ~50% owners of NewCo,” he wrote.

Gal, on the other hand, figures the deal will go through. 

“The risk to the deal is unlikely in our view to come from Shire shareholders or anti-trust authorities,” he wrote, noting that its Takeda’s shareholders, not Shire’s., that have sent the stock downward throughout the bidding process. Still, he pegged the probability of the deal going through at between 80% and 90%.

“Short of Takeda stock price imploding a deal is likely,” he added.

RELATED: What would a Shire buy look like for Pfizer, Amgen or AbbVie? Analysts lay out pros and cons

Both analysts agree on one thing, though: Another bidder, which some industry watchers previously expected, probably won’t come out of the woodwork at this point.

“We expect Shire bankers to have left no stone unturned looking for other bidders,” Gal wrote, with Steinberg adding that “we continue to think any potential group of buyers to be very limited … it’s arguably less than a 50% chance that another suitor emerges.”