ABSTRACT Aficamten is a next‐in‐class small molecule cardiac myosin inhibitor that was recently approved by the United States Food and Drug Administration (FDA) for the treatment of symptomatic obstructive hypertrophic cardiomyopathy (oHCM). A comprehensive drug–drug interaction (DDI) evaluation of aficamten was achieved through two phase 1 studies in healthy participants. Aficamten as a victim of DDIs was studied using a moderate‐to‐strong P450 inducer (carbamazepine) and CYP inhibitors—itraconazole (strong CYP3A), paroxetine (strong CYP2D6), fluconazole (strong CYP2C19 and moderate 2C9 and 3A), and fluoxetine (strong CYP2D6 and 2C19). Aficamten's potential for P‐glycoprotein (P‐gp) inhibition was assessed using dabigatran etexilate (sensitive P‐gp substrate). Minor increases in aficamten exposure (area under the curve) were observed following treatment with itraconazole (26%), paroxetine (27%), and fluoxetine (32%) compared with aficamten alone. Treatment with carbamazepine decreased aficamten exposure by 50%. Concomitant administration of aficamten with fluconazole, a multi‐P450 inhibitor, resulted in a 278% increase in aficamten exposure. Taken together, results from these studies indicate that aficamten is primarily eliminated via CYP2C9‐mediated metabolism (fraction metabolized [fm] = 54%) with contributions from CYP2D6 (fm = 21%), CYP3A (fm = 21%), and minimal metabolism via CYP2C19 (fm = 3%). A small increase (26%–27%) in dabigatran exposure was observed in the presence of aficamten; indicative of weak inhibition of P‐gp. Aficamten was well tolerated, and adverse events were generally mild. In conclusion, aficamten is metabolized by multiple P450 enzymes, limiting its DDI liability. Only weak DDIs (< 2‐fold) are likely from strong inhibition of any one pathway, and only moderate (< 5‐fold) impact on aficamten exposure is expected with strong multi‐pathway inhibitors or inducers.