ENTA had ~$330M of pro forma cash at 6/30/22 (#msg-169621212), so the ATM looks like a backup contingency in case ENTA decides to conduct the phase-2(/3) EDP-235 trial without a partner.
p.s. ENTA has never raised capital as a public company apart from its 2013 IPO. HCV milestones and royalties from ABBV have been sufficient to fund ENTA's operations.