Study to Assess LX201 for Prevention of Corneal Allograft Rejection or Graft Failure in Subjects Who Have Experienced One or More Rejection Episodes Following Penetrating Keratoplasty

Inclusion Criteria: * Subjects who, within 6 months prior to study randomization, have experienced 1 or more corneal allograft rejection episodes following penetrating keratoplasty * Must be on a stable medical regimen for at least 14 days at the time of randomization into the study * Conjunctiva must be suitable for implantation with the study device Exclusion Criteria: * Any condition that would greatly increase the risk of non-rejection graft failure such as Stevens-Johnson syndrome, xerophthalmia or severe exposure keratitis. * Schirmer's test ≤ 5 mm in 1 minute. * Clinical evidence of limbal stem cell deficiency. * History of or active herpes simplex virus keratitis or other acute corneal infection * Subjects who have had \> 3 failed grafts in the ipsilateral eye * Uncontrolled glaucoma as evidenced by an intraocular pressure of \> 21 mmHg while on maximal medical therapy * Clinically suspected or confirmed ocular lymphoma * Treatment with a systemic immunosuppressive regimen within the previous 30 days; systemic prednisone (or its equivalent) of ≤ 10 mg daily is, however, permitted. * Any implantable corticosteroid-eluting device (e.g., Retisert™, Posurdex®, Medidur™, I-vation™ triamcinolone acetonide \[TA\] intravitreal implant) * Subjects who periodically require high-dose systemic steroid treatment (e.g., for exacerbation of chronic obstructive pulmonary disease). * Subjects who have received treatment with a monoclonal antibody or any other biologic therapy withi…