A Study to Evaluate the Safety and Efficacy of NEXAGON® (Lufepirsen Ophthalmic Gel) in Subjects With PCED

Inclusion Criteria:

1. Have a PCED that is at least 2 weeks in duration and refractory to one or moreconventional non-surgical standard of care (SOC) treatments

2. Have no clinical evidence of improvement in the PCED within 2 weeks prior torandomization despite the use of non-surgical SOC treatment

3. Subject must provide written informed consent (or assent)

4. Subjects with childbearing potential must be 1-year postmenopausal, surgicallysterilized, or have a negative urine pregnancy test

Exclusion Criteria:

1. Have a known ocular infection that is deemed to be active requiring therapeuticintervention

2. Present with a corneal surface defect in either eye that is directly attributed toan infectious etiology (bacterial, viral, fungal and/or protozoal) that has notfully resolved and/or treatment has not been completed

3. Present with evidence of corneal ulceration/melting involving the posterior third ofthe stroma and/or perforation in either eye

4. Have a blepharitis or meibomian gland disease in the study eye that is deemed to beclinically relevant and/or active

5. Have a history of ocular surgery or any ocular procedure(s) not meeting thedesignated washout time

6. Have any other ocular disease requiring topical ocular medication in the affectedeye

7. Have a presence or history of any ocular or systemic disorder or condition thatcould interfere the safety or efficacy of the study treatment, or the interpretationof the study results

8. Have a known hypersensitivity to one of the components of the study or proceduralmedications (e.g., NEXAGON, fluorescein)

9. Participated in an interventional clinical drug or device trial within 28 days priorto Day 1

10. Use of the medications presented in the protocol that are prohibited in the study.