This is a multiregional open-label extension (OLE) to assess the safety, tolerability, and efficacy of long-term treatment with tividenofusp alfa (DNL310), an investigational central nervous system (CNS)-penetrant intravenous (IV) enzyme replacement therapy (ERT) for Hunter syndrome (MPS II). Participants who complete at least through the Week 49 visit in Study DNLI-E-0002 and do not discontinue study intervention early and participants who complete Study DNLI-E-0007 will be enrolled in this OLE. All participants will receive DNL310 for up to 5 years from the time of entry in this OLE. Participants, site staff, and the Sponsor will remain blinded to the original treatment assignment for participants entering this OLE from Study DNLI-E-0007.
Phase 2 trials begin testing efficacy in a larger patient group (100–300). This is often where biotech binary events occur — positive Phase 2 data can significantly advance a company's pipeline narrative, while failures can be terminal for a program.
Phase 3 trials are pivotal studies with large patient populations (hundreds to thousands) designed to prove efficacy and safety for FDA submission. A successful Phase 3 readout is typically the last major hurdle before a New Drug Application (NDA) or BLA filing.
Current status: ENROLLING BY INVITATION.
Denali Therapeutics (DNLI) is the sponsoring company for this trial. BiotechSign currently grades this company C (61/100) based on composite catalyst signals across its full pipeline. This trial is one data point in that overall catalyst picture.