Study lengthCriticised but acceptedBeyond the letter
No long-term toxicity data: pivotal 9-month GLP sheep study failed through loss of the implants
“The long term effects of the Spherox product cannot be fully evaluated from the in vivo data as the GLP compliant sheep study of 9 months duration failed due to loss of Spherox implants.”
✓ VerifiedEMA assessment report, p. 35Source ↗ “The lack of non-clinical data on local and general toxicity after long-term exposure to autologous spheroids is considered acceptable.”
✓ VerifiedEMA assessment report, p. 35Source ↗ GLPCriticised but acceptedBeyond the letter
Supporting mouse and minipig safety studies non-GLP, with low animal numbers and limited duration
Why: Collectively the studies supported good tolerability of implanted spheroids · Weight of evidence
“There were some deficiencies in the experimental design which hamper the evaluation of safety of the individual studies, e.g. low numbers of treated animals, lack of GLP-compliance and limited study duration to allow long term safety assessment, but collectively they provided good support that implanted chondrocyte spheroids are well tolerated.”
✓ VerifiedEMA assessment report, p. 33Source ↗ BiodistributionCriticised but acceptedBeyond the letter
Deficient biodistribution data; no pivotal data from the failed sheep study
Why: Rapid adherence to the defect surface; no tendency for ectopic cartilage formation; low migration risk · Weight of evidence
“Despite the deficiencies of the biodistribution studies the in vitro and in vivo studies have shown that spheroid show rapid adherence to the defect surface and do not shown tendency for ectopic cartilage formation.”
✓ VerifiedEMA assessment report, p. 34Source ↗ “CAT/CHMP that the risk for migration/infiltration is low and that additional non-clinical biodistribution studies are not called for.”
✓ VerifiedEMA assessment report, p. 35Source ↗ DARTAccepted
No reproductive and developmental toxicity studies
Why: Autologous cells with local mechanism of action and limited biodistribution, per cell-based product guideline · Within the guideline · Low-risk modality
“In line with guidelines on cell-based medicinal products (EMEA/CHMP/410869/2006), the applicant has provided an acceptable justification for omitting these studies: Spherox contains autologous cells with a local mechanism of action, and the risk for biodistribution of cells is limited.”
✓ VerifiedEMA assessment report, p. 34Source ↗