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Clinical Trial Summary

Retinitis pigmentosa (RP) is the most common hereditary retinal disorder (accounts for 20% of children attending blind schools in Pakistan) which causes degeneration of rod and cone photoreceptors. Rods and cones largely depend on the retinal pigment epithelium for their proper functioning. Various growth factors and their receptors are present in retinal epithelium and a number of genes are responsible for the production of these growth factors. Genetic mutation in any of these genes causes retinal degeneration by progressive loss of retinal pigment epithelium and photoreceptors. The disease initially starts with night blindness and leads to the loss of central vision and eventually total blindness. To date, there is no definitive cure for patients suffering from RP. Recently, stem cell based therapies have shown great promise for the management of RP. It is well documented that umbilical cord derived mesenchymal stem cells (UMSCs) have the ability to release various paracrine and immunomodulatory factors that are similar to those synthesized by retinal pigment epithelium. Multiple routes including systemic (intravenous) and localized (subretinal, intravitreal, suprachoroidal and sub-tenon) have been employed to administer UMSCs for the management of RP. It is important to note that deep sub-tenon region (space between the sclera and the conjunctiva) acts as both natural culture medium for cells and as immune privileged site because of avascularity of the region. It has been reported that the injection of UMSCs in sub-tenon space of human subjects have improved the visual acuity even after 1 year post-injection. In addition, the injection of UMSCs in suprachoroidal space enhances the entry of growth factors released by the cells into choroidal flow and maintain the constant growth factors secretion to the choroidal and retinal tissues. Limoli and colleagues were the first to report the suprachoroidal administration of cells being the safe mode of cell delivery with no complications. The present study is aimed to investigate the safety and therapeutic efficacy of UMSC injection employing two different routes (sub-tenon injection versus suprachoroidal injection) for the treatment of RP in human subjects.


Clinical Trial Description

Isolation and characterization of human umbilical cord derived mesenchymal stem cells (UMSCs): The culturing and characterization of UMSCs will be performed as documented by Ali and colleagues. Briefly, human umbilical cord tissues along with informed consent forms will be collected from COVID-19- and hepatitis B, C virus-negative women with healthy pregnancies during the Cesarean Section surgery after completion of gestation period. The umbilical cord tissue will be transported in sterile 1x phosphate-buffered saline (PBS) containing penicillin and streptomycin on ice. In the biosafety cabinet, the cord will be washed with 4-5 changes of sterile 1x PBS and placed in a Petri plate with 15ml PBS. The cord will then gently scrap with a surgical blade to remove any dead cells. A 9 cm umbilical cord will be cut into three equal pieces and wash thoroughly to remove blood clots, umbilical cord arteries, and veins. Segments will be washed three times with PBS and minced. The minced pieces will be incubated in 17.5ml of collagenase solution (201 U/ml collagenase type I in serum-free DMEM-HG) in a 50ml conical tube for ~3 hrs in an incubator at 5% CO2, 95% humidity at 37oC. After ~3 hrs, the digested lysate will be passed through strainer and will be diluted three times with 1x PBS. Following centrifugation, the cells will be seeded into two T-25cm2 flasks and will be placed in an incubator at 5% CO2, 95% humidity at 37o C. The flasks will be fed with fresh media (DMEM-HG supplemented with 20% FBS and 1% antibiotic solution) every third day. At around day 18, cells will reach up to 85% confluency and will be transferred in two T-75cm2 flasks with media replaced at alternate days. UMSCs at P3 will be characterized using different specific antibodies. Cells at P3 will be employed for injection in RP patients. ;


Study Design


Related Conditions & MeSH terms


NCT number NCT04763369
Study type Interventional
Source Jinnah Burn and Reconstructive Surgery Centre, Lahore
Contact Sheikh Riazuddin, PhD
Phone +9242935164422
Email riazuddin@aimrc.org
Status Recruiting
Phase Phase 2
Start date February 2021
Completion date June 2022

See also
  Status Clinical Trial Phase
Active, not recruiting NCT03975543 - Retrospective Natural History Study of Retinitis Pigmentosa
Completed NCT02320812 - Safety of a Single, Intravitreal Injection of Human Retinal Progenitor Cells (jCell) in Retinitis Pigmentosa Phase 1/Phase 2
Completed NCT01543906 - Oral QLT091001 in Retinitis Pigmentosa (RP) Subjects With an Autosomal Dominant Mutation in Retinal Pigment Epithelial 65 Protein (RPE65) Phase 1
Completed NCT02575430 - Natural History Study in Inherited Retinal Disease Subjects Caused by Mutations in RPE65 or LRAT N/A