Novo Nordisk to buy Akero Therapeutics for up to $5.2 billion, adding MASH drug efruxifermin

Novo Nordisk has agreed to acquire Akero Therapeutics for $54 a share in cash, about $4.7 billion, plus a contingent value right of up to $6 a share that could lift the total to $5.2 billion ^[1][4]. The deal, announced October 9, brings Novo a late-stage experimental drug for MASH, a liver disease closely tied to obesity and type 2 diabetes ^[1][3].

The drug, efruxifermin, is an analog of fibroblast growth factor 21 (FGF21), a liver-secreted hormone involved in how the body uses and stores fat ^[2]. It is given as a once-weekly subcutaneous injection and is being tested in three phase 3 trials together called SYNCHRONY, with about 3,500 participants, in two groups: people with moderate to advanced scarring (fibrosis stages F2-F3) and people with compensated cirrhosis (F4) caused by MASH ^[1][3]. Native FGF21 lasts less than two hours in the body; Akero engineered efruxifermin so it lasts days, which allows weekly dosing ^[2].

Novo pointed to two 96-week phase 2b trials as the basis for the purchase. In the HARMONY trial of F2-F3 patients, 49% of efruxifermin-treated patients had a reduction in fibrosis without worsening of MASH, compared with 19% on placebo. In the SYMMETRY trial of F4 patients, the figures were 29% and 11% ^[1][3]. Novo says efruxifermin is the only treatment to have shown significant fibrosis regression in F4 patients in a phase 2 trial ^[1][3].

"MASH destroys lives silently — and efruxifermin has the potential to change that by reversing liver damage," Novo president and CEO Mike Doustdar said in the announcement. He added that, if approved, it "could become a cornerstone therapy, alone or together with Wegovy (semaglutide)" ^[1][3].

MedCity News reported that the Akero deal is the largest research and development acquisition in Novo's history and the first since Doustdar became chief executive in August ^[2]. On price, the outlets described the premium differently depending on the measure used: MedCity News said $54 a share was a 16% premium to Akero's closing price the day before and a 42% premium to its May 19 close, before takeover speculation ^[2], while Fierce Biotech described it as a 19% premium to Akero's 30-day average stock price ^[4].

MASH is a progressive disease in which fat builds up in the liver, causing inflammation and scarring that can lead to cirrhosis, liver failure and liver cancer ^[1]. Novo estimates more than 250 million people worldwide have MASH, and the FDA has said about 14.9 million Americans have it ^[1][2]. More than 40% of MASH patients also have type 2 diabetes, and over 80% are overweight or living with obesity, according to Novo ^[1]. About 20% of MASH patients progress to cirrhosis ^[1].

Akero is not alone in this field. Madrigal Pharmaceuticals' Rezdiffra, approved in 2024 for moderate-to-advanced MASH, generated $350 million in the first half of this year ^[4]. Novo's own Wegovy (semaglutide) was approved for MASH in August, but that label covers only F2 and F3 patients ^[2][4]. Roche agreed to buy 89bio and its FGF21 drug for up to $3.5 billion, and GSK acquired efimosfermin in a $1.2 billion deal ^[2][4]. A Leerink Partners analyst noted the Akero purchase is the third MASH-related acquisition this year, all for FGF21-targeted drugs, and said federal trade regulators may review it given the overlap between the companies' pipelines ^[2]. Novo discontinued its own FGF21 candidate after a failed phase 2 trial, MedCity News reported ^[2].

Why it matters for patients

Efruxifermin is not approved, so it is not an option today. For people with MASH, currently cleared treatments are limited to Rezdiffra and, for F2-F3 disease, Wegovy ^[2][4]. Novo says a need remains for patients with F4 cirrhosis and for patients who may not respond to a GLP-1 drug ^[2].

Novo has said it plans to explore combining efruxifermin with its GLP-1 medicines ^[2]. Whether such combinations will be studied in people already taking a GLP-1, and how efruxifermin would be priced or covered by insurance, has not been disclosed.

What happens next

Akero's board approved the deal, but it still needs Akero shareholder and regulatory approvals ^[1][2]. Novo said it expects the transaction to close around the turn of the year ^[1]; MedCity News reported the companies expect completion by the end of this year ^[2].

The $6-a-share contingent payment requires US approval of efruxifermin for compensated cirrhosis due to MASH by June 30, 2031 ^[2]. Novo's announcement did not give a date for that decision ^[1]. The first phase 3 readout, from the real-world SYNCHRONY trial, is expected as early as next year, with the other trials reporting later ^[2]; Fierce Biotech reported the phase 3 program is scheduled to start delivering data in the first half of next year ^[4].

Novo also said the purchase is expected to reduce its 2025 free cash flow by about $4 billion and to add roughly 3 percentage points of drag on 2026 operating profit growth, with the deal mainly financed by debt ^[1].