AstraZeneca has made an offer of about $10 billion to acquire Rhythm Pharmaceuticals, the maker of treatments for rare metabolic disorders and severe obesity, Reuters reported on November 4th, 2026, citing three people familiar with the matter.

The reported price depends on the outlet. Reuters said AstraZeneca offered as much as $134 a share in a non-binding proposal, a figure that includes payments tied to milestone achievements. The Wall Street Journal reported earlier on Wednesday, November 4th, 2026 that AstraZeneca had put forward $124 a share last month. That leaves a reported range of $124 to $134 a share.

What happened

The Reuters story, bylined Sabrina Valle, Milana Vinn and Amy-Jo Crowley, said the acquisition would be pursued through Alexion, AstraZeneca's rare disease business. AstraZeneca bought Alexion for $39 billion in 2021 to expand beyond its core oncology and biopharmaceutical franchises.

The Wall Street Journal reported that AstraZeneca had expressed interest in Rhythm before and renewed its pursuit in recent months. An AstraZeneca spokesperson declined to comment to Reuters, and representatives for Rhythm did not respond to a request for comment. As of November 4th, 2026 there is no definitive agreement, no SEC filing and no company announcement confirming any offer.

What the share price did

Reuters reported that Rhythm Pharmaceuticals shares closed up 28% at $110.68 on the news, giving the company a market capitalization of about $7.64 billion. The account based on the Wall Street Journal report put the market value at about $7.6 billion, citing LSEG data.

On the buyer's side, Reuters noted that chief executive Pascal Soriot is trying to turn investor attention back to growth after a turbulent few months. AstraZeneca carries a $292 billion market value, has absorbed clinical trial setbacks, and has seen its shares weighed down by reports of a potentially transformative deal with Bristol Myers Squibb. CNBC reported on August 3rd, 2026 that AstraZeneca shares fell as much as 7% after reports of merger discussions with Bristol Myers Squibb that could value the combination at roughly $400 billion, and that the company is targeting $80 billion in sales by 2030, up from $58.7 billion the prior year.

More on the acquirer is at /companies/AZN.

What the record shows

Rhythm filed third quarter results on November 3rd, 2026, one day before the reports. Net product revenue from global sales of IMCIVREE (setmelanotide) was $92.1 million in the third quarter of 2026, a 29% sequential increase. The company said it had received more than 700 patient start forms for acquired hypothalamic obesity from more than 500 prescribers as of September 30th, 2026.

The same release noted that the U.S. Food and Drug Administration approved IMCIVREE for acquired hypothalamic obesity on March 19th, 2026, and that Rhythm began the commercial launch of IMCIVREE in Japan for acquired HO on October 13th, 2026.

Rhythm also moved on financing and licensing days before the reported approach. On November 2nd, 2026 it announced an amendment to its exclusive licence agreement with LG Chem for the oral MC4R agonist bivamelagon. bioXconomy reported the amendment raised the deal's potential value from $305 million to as much as $855 million, with Rhythm paying LG Chem additional fixed payments totalling $350 million over four years. Alongside it, Rhythm announced a five-year term loan facility of up to $750 million led by KKR's HealthCare Royalty in partnership with Blackstone.

What to watch

The first thing to watch is whether anything is confirmed. A non-binding proposal reported by sources is not a transaction, and neither company has said anything on the record. A definitive agreement or an SEC filing would settle the price question that the $124 and $134 figures currently leave open.

The second is structure. Reuters reported that the maximum figure includes milestone payments, so headline value and upfront value are not the same thing. The third is Alexion's role, since routing the deal through the rare disease arm says something about how AstraZeneca is framing Rhythm's franchise: rare metabolic disease first, obesity alongside it.

Reporting in this article comes from Reuters, The Wall Street Journal, CNBC, BioSpace and bioXconomy, with company figures taken from Rhythm Pharmaceuticals' SEC filings, as of November 4th, 2026.

Informational only, not investment advice.