A phase IIa, open label, non controlled clinical trial to assess the feasibility and safety of allogeneic adipose-derived mesenchymal stem cells (ASC) in the treatment of cicatricial conjunctivitis associated with Lyell's syndrome, Stevens-Johnson's syndrome and mucous membrane pemphigoid with ocular involvement

A multicentre, nationwide clinical trial will be performed. 20 patients fulfilling eligibility criteria will be included in two different dose level cohorts: the first 10 patients included will receive a single cell application and the remainder 10 will be administered 2 cell applications separated by 15 days.

The investigational drug consists of locally administered, expanded, allogeneic adipose-derived adult mesenchymal stem cells (ASCs), at a dose of 5 million cells per ml (0,5 ml to be infused per quadrant)

Study cronogram: recruitment is estimated to take 8 months, and follow-up period will be 12 months.

Inclusion Criteria:

1. Men and women over 18 years of age.
2. Diagnosis of ocular pemphigoid in Foster stages I-IIcIIIb (2) or diagnosis of recurrent chronic or episodic inflammation accompanied by cicatricial conjunctivitis of the mucous membranes with ocular involvement after the acute phase of Stevens-Johnson Syndrome or Lyell Syndrome with insufficient disease control or inaceptable toxicity or impossibility to administer usual care treatments (according to physician or patient criteria)
3. In the case of women of childbearing age, who are willing to use an effective contraceptive method during the period of participation in the study
4. Consent to participate and signature of the informed consent

Exclusion Criteria:

1. Signs of active infection on the ocular surface.
2. History of neoplasms in the last 5 years. except for epithelial basal or squamous cell carcinoma
3. Allergy to local anesthetics
4. Patients who have participated in another clinical trial with medication during the 90 days prior to signing the IC
5. Medical or psychiatric illness of any kind that, in the opinion of the investigator, may be a reason for exclusion from the study.
6. Congenital or acquired immunodeficiencies.
7. Major surgery or serious trauma of the subject in the semester prior to signing the IC.
8. Pregnant or lactating women.
9. Impossibility or refusal to carry out the follow-up required in the study by the patient