Effect of Hepatic Impairment or Renal Impairment on the Pharmacokinetics of Aficamten.

Background and objective: Aficamten, a small-molecule, selective cardiac myosin inhibitor, is under development for the treatment of symptomatic obstructive hypertrophic cardiomyopathy (oHCM). Aficamten is primarily eliminated by hepatic metabolism with renal excretion playing a minor role. The objective of this investigation was to evaluate the pharmacokinetics (PK) of aficamten in moderate hepatic impairment or mild to moderate renal impairment to inform dosing recommendations in HCM patients with mild or moderate hepatic impairment or mild to moderate renal impairment.

Methods: The impact of hepatic impairment on the PK of single-dose aficamten 20 mg was evaluated in a phase 1 single-dose, open-label, parallel-group study, in healthy participants with moderate (n = 8) hepatic impairment (Child-Pugh B classification) versus participants with normal hepatic function (n = 8). Safety was monitored throughout. The effect of renal impairment on aficamten PK was assessed using population PK (PopPK) modelling of phase 2/3 clinical data in patients with oHCM.

Results: Aficamten PK was similar in participants with moderate hepatic impairment and those with normal hepatic function. No serious or severe treatment-emergent adverse events or clinically significant laboratory abnormalities were reported. There were no clinical meaningful differences in aficamten exposure in patients with oHCM with mild or moderate renal impairment and those with normal renal function.

Conclusions: No clinically relevant changes in aficamten PK were observed in participants with moderate hepatic impairment. Population PK analysis indicated mild or moderate renal impairment and had no statistically or clinically significant impact on aficamten PK in patients with oHCM. Aficamten dose adjustment may not be necessary in patients with mild or moderate hepatic or renal impairment.