Clinical evaluation of allogeneic eye drops from cord blood platelet lysate

Abstract

Background: Current treatments for several corneal lesions show limited efficacy. Here we report the clinical evaluation of the efficacy of a novel eye drop preparation produced in a public cord blood (CB) bank.

Materials and methods: In a multicentre, retrospective, consecutive case study we evaluated 33 patients (46 eyes) unresponsive to conventional treatments who required urgent intervention. The patients were given allogeneic eye drops obtained from cord blood platelet lysate (CBED) to treat severe ocular surface lesions under a compassionate use protocol. The CBED were prepared from CB units donated for haematopoietic stem cell transplantation that did not contain the minimum stem cell dose required for this use. Patients were grouped by acute conditions (neurotrophic ulcers: group I; other corneal ulcers: group II; corneal burns: group III), and chronic conditions (ocular graft-versus-host disease: group IV; severe dry eye syndrome: group V). The patients received one or two drops of the product to the affected eye four to six times per day for 19 days. A further 19-day cycle of treatment could be repeated according to the initial clinical response.

Results: Patients received a median of 19 CBED vials (interquartile range 19-57, range 19-442) to complete the therapy. Group I-II-III patients showed full and partial ulcer recovery in 25 (78%) and six (19%) eyes respectively. One eye (3%) did not respond to treatment. For groups IV-V improvement was reported for 12 (85%) eyes and lesions worsened on treatment in both eyes (15%) of one patient. No severe adverse events were directly attributed to CBED.

Discussion: Promptly available CBED resulted in a well-tolerated allogeneic treatment that showed evidence of efficacy in this cohort of patients. These positive results support further studies on CBED from platelet lysate as a novel product of CB banks. A prospective clinical trial in neurotrophic keratitis (NCT03084861) is ongoing to confirm these preliminary data.

Conflict of interest statement

CONFLICT OF INTEREST

PR is a co-inventor of a patent on platelet fractions from cord blood and holds shares of Episkey, a start-up company aimed at developing novel reagents and therapeutics from human blood.

Figures

Figure 1. Algorithm of the decision to administer or stop treatment with cord blood-derived eye drops

CBED: cord blood-derived eye drops.

Figure 2. Clinical outcomes

CCU4, a 75-year old patient with exposure-induced corneal ulcers in both eyes before (a and c) and after (b and d) treatment with cord blood-derived eye drops (CBED). CCU27, a 1-month old patient with corneal ulcer caused by trauma before (e) and after (f) application of CBED. CCU23, a 3-year old patient who presented with acute bilateral corneal burns before (g and i) and after (h and j) CBED treatment to the right eye (RE) and left eye (LE). CCU33, a 44-year old presenting with acute bilateral corneal burns before (k and m) and after (l and n) CBED treatment to the RE and LE. CCU: unique patient’s number.

Figure 3. Clinical outcomes

CCU14, a patient with severe dry eye syndrome, hypovitaminosis A and hepatitis C virus infection, 3 weeks after discontinuing treatment (A) and 2 days after resuming treatment with cord blood-derived eye drops (B). CCU: unique patient’s number.