Akero, bruised from earlier failure, soars as liver scarring improves in longer MASH trial

Akero Therapeutics’ roller coaster ride has lurched once again. After a whiplash rise and fall, the biotech has bounced back with 96-week data linking its FGF21 analog efruxifermin to significant improvements in liver scarring in metabolic dysfunction-associated steatohepatitis (MASH).

California-based Akero published 24-week data from the phase 2b HARMONY trial in 2022. On the low and high doses, respectively 39% and 41% of patients experienced a one stage or more improvement in fibrosis without worsening of MASH. The response rate on placebo was 20%. The data sent Akero’s stock soaring, only for the failure of another efruxifermin trial to wipe out the gains last year.

Now, Akero has shared 96-week data from the HARMONY study. In the high-dose cohort, 75% of patients had a one-stage or more improvement in fibrosis without worsening of MASH, compared to 24% of their peers on placebo. The low dose split the difference, recording a response rate of 46%.

The difference between efruxifermin and placebo is more pronounced in the analysis of patients who had a two-stage or more improvement in fibrosis without worsening of MASH. Akero reported that 31% and 36% of patients on the low and high dose met that endpoint, respectively. Only 3% of patients in the placebo group experienced such an improvement. 

In Akero’s statement Stephen Harrison, M.D., medical director of Pinnacle Clinical Research and principal investigator for the HARMONY study, noted the “inherent limitations in making cross-trial comparisons” but still went on to call the response rates the largest “reported publicly to date for these endpoints in any MASH population.” 

The deepening responses seen between Week 24 and Week 96 bode well for the Akero study that failed last year. At the time, Akero argued showing a statistically significant improvement in fibrosis by Week 36 was a “high bar.” The biotech is tracking participants in the failed trial through Week 96, suggesting it may reverse the failure at a later readout if responses improve over time. Results are due next year.

In terms of safety and tolerability, Akero reported 15 serious adverse events, “which were generally balanced across dose groups.” Three patients stopped taking efruxifermin because of adverse events between Week 24 and Week 96. 

Investors responded to the latest data by sending Akero’s stock up 62% to $45 in premarket trading. The rise returned the stock to the price range it bounced around in between the earlier phase 2b readouts.