Spherox
spheroids of autologous matrix-associated chondrocytes
Sources:EMA assessment report ↗
Species
MousePigOther
Longest study
39 wk
Genotox
Not conducted Not conducted
Carcinogenicity
Not conducted Not conducted
Repro
Not conducted Not conducted
First dose
Not conducted Not stated publicly
Speciesopen answer page →
Species
Immunodeficient (SCID/NSG) mice, Goettingen minipig, Merino sheep; no conventional tox
“Comparative analyses of chondrocytes from different species showed that only a limited number of animals including Göttinger mini-pig and Merino sheep were capable of producing stable spheroids.”
Why that species
Only minipig and Merino sheep chondrocytes form stable spheroids; large orthotopic joint models
“These species were then selected for proof-of-concept studies.”
Surrogate molecule
Yes: autologous porcine and ovine spheroids produced analogously to Spherox; human spheroids in immunodeficient mice
“In these studies, either human Spheroxs or autologous spheroids produced analogously to human Spheroxs were used.”
Species: general tox
None (no conventional toxicity studies; autologous product, not considered necessary)
“No conventionally designed toxicity studies on Spherox have been performed; given that the product is autologous and that manufacturing takes place without any growth factors or other external stimuli that requires safety testing, such studies are not considered necessary.”
Species: DART
Not conducted; autologous cells with local mechanism of action and limited biodistribution
“Reproductive and developmental toxicity studies were not conducted. 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.”
Species: carcinogenicity
No conventional carcinogenicity; 6-month GLP tumourigenicity study in immunodeficient mice
“including the 6 months GLP study in immunodeficient mice which support the absence of the tumourigenic potential.”
Surrogate used in
Yes: autologous porcine and ovine spheroids produced analogously to Spherox (minipig, Merino sheep); human spheroids in immunodeficient mice
“In these studies, either human Spheroxs or autologous spheroids produced analogously to human Spheroxs were used.”
Study lengthopen answer page →
Longest pivotal study
39 weeks
“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.”
Pivotal GLP studies
GLP Merino sheep 6/9-month implantation (failed, implant lost); GLP NSG mouse 6-month biodistribution/tumourigenicity; minipig 2-month
“study Merino sheep was designed to evaluate local and systemic toxicity during 6 months of implantation of autologous spheroids in a femoral condyle defect.”
Route in tox
Subcutaneous (mice); knee joint implantation/injection (minipig, sheep)
“In the in vivo studies, a single dose of spheroids was either injected or implanted into a knee joint or administered subcutaneously in the back of the animal.”
Skipped studiesopen answer page →
Genotoxicity
Not conducted (per cell-based product guideline)
“No genotoxicity, conventional carcinogenicity and reproductive- and developmental toxicity studies were performed”
Carcinogenicity
Not conducted (conventional); 6-month GLP mouse tumourigenicity part and in vitro senescence studies
“No genotoxicity, conventional carcinogenicity and reproductive- and developmental toxicity studies were performed”
Reproductive & developmental
Not conducted; autologous cells with local action and limited biodistribution
“Reproductive and developmental toxicity studies were not conducted.”
Safety pharmacology
Not evaluated; autologous cells implanted locally, no secreted substances affecting vital organs
“Safety pharmacology was not evaluated with Spherox.”
Genotox: Ames
Not conducted (in line with cell-based product guideline)
“No genotoxicity, conventional carcinogenicity and reproductive- and developmental toxicity studies were performed”
Genotox: in vitro mammalian
No standard assay; extended monolayer culture studies indicate genetic instability risk increasing with passage number
“Data also indicate a risk for genetic instability which increases with higher number of passages.”
Genotox: in vivo
Not conducted (in line with cell-based product guideline)
“No genotoxicity, conventional carcinogenicity and reproductive- and developmental toxicity studies were performed”
Carcinogenicity model
GLP NSG mouse study, human spheroids implanted subcutaneously: no tumour or ectopic tissue formation after 6 months
“In a GLP compliant study using immunodeficient NSG mice, biodistribution of cells out from human Spheroxs implanted subcutaneously into the back was investigated after 4 weeks. There were no indications of significant systemic distribution of the cells, or were there any indications of tumour or ectopic tissue formation after 6 months in the tumourigenicity part of this study.”
Carcinogenicity timing
Not required: conventional carcinogenicity omitted per cell-based product guideline
“No genotoxicity, conventional carcinogenicity and reproductive- and developmental toxicity studies were performed which is in line with the guideline on cell-based medicinal products (EMEA/CHMP/410869/2006).”
hERG / QT
Not conducted (safety pharmacology not evaluated)
“Safety pharmacology was not evaluated with Spherox.”
First doseopen answer page →
First-in-human starting dose
Not stated in public reviews
Why it's blank
The public FDA and EMA reviews of Spherox don't say how the first human dose was chosen. That rationale is in the IND, which is confidential, so it is missing for most approved products.
How it's usually set for cell therapies
FDA expects preclinical proof-of-concept and toxicology studies to identify active dose levels and support the choice of starting dose and escalation. The 2013 guidance gives no numeric formula or scaling rule for the starting dose.
“Selection of potential starting dose level, dose-escalation schedule, and dosing regimen for clinical trials.”
✓ VerifiedFDA 2013: Preclinical Assessment of Investigational Cellular and Gene Therapy…, p. 7Source ↗
This product's starting point
NOAEL / key findings: No NOAEL; no treatment-related adverse effects or signs of general/local toxicity in any study (EMA assessment report, p. 32)
NOAEL / key findings
No NOAEL; no treatment-related adverse effects or signs of general/local toxicity in any study
“There were no indications of treatment related adverse effects and the implant was well tolerated.”
Risksopen answer page →
Immune & cytokine safety
No immunogenicity studies; enlarged popliteal lymph nodes in 2 sheep with allogeneic cells, possible immune response
“It should be noted that poplietal lymph nodes (lymph nodes draining the knee joint) of two of the animals were enlarged.”
Biodistribution & persistence
GLP NSG mouse study: no significant systemic distribution or tumour/ectopic tissue; sheep: spheroids retained in joint
“There were no indications of significant systemic distribution of the cells, or were there any indications of tumour or ectopic tissue formation after 6 months in the tumourigenicity part of this study.”
Modality-specific risk
Migration/infiltration into subchondral bone, genetic instability with passaging, tumourigenicity
“migration might also be a potential safety issue if the cells should have a capacity to infiltrate e.g. subchondral bone when implanted in full thickness cartilage defects”
Anti-drug antibodies: animals
Enlarged popliteal lymph nodes in 2 sheep given allogeneic spheroids; immune response to allogeneic cells not excluded
“It should be noted that poplietal lymph nodes (lymph nodes draining the knee joint) of two of the animals were enlarged. This could be due to the surgical procedure, but it cannot be excluded that an immune response towards the allogeneic cells was induced.”
Anti-drug antibodies: patients
Not stated in public reviews
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Tox packageopen answer page →
Before first-in-human
First-in-human: where
Not stated in public reviews
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
Repeat-dose tox before first-in-human
Not stated in public reviews
Not reported in the public reviews. Reviewers summarise selectively, so this usually means it wasn't discussed publicly, not that it wasn't studied.
First-in-human starting dose
Not stated in public reviews
Why it's blank
The public FDA and EMA reviews of Spherox don't say how the first human dose was chosen. That rationale is in the IND, which is confidential, so it is missing for most approved products.
How it's usually set for cell therapies
FDA expects preclinical proof-of-concept and toxicology studies to identify active dose levels and support the choice of starting dose and escalation. The 2013 guidance gives no numeric formula or scaling rule for the starting dose.
“Selection of potential starting dose level, dose-escalation schedule, and dosing regimen for clinical trials.”
✓ VerifiedFDA 2013: Preclinical Assessment of Investigational Cellular and Gene Therapy…, p. 7Source ↗
This product's starting point
NOAEL / key findings: No NOAEL; no treatment-related adverse effects or signs of general/local toxicity in any study (EMA assessment report, p. 32)
Longest repeat-dose systemic studies
Longest repeat-dose study and recovery
No repeat-dose study (single administration of spheroids in all in vivo studies)
“In the in vivo studies, a single dose of spheroids was either injected or implanted into a knee joint or administered subcutaneously in the back of the animal.”
Pivotal GLP studies
GLP Merino sheep 6/9-month implantation (failed, implant lost); GLP NSG mouse 6-month biodistribution/tumourigenicity; minipig 2-month
“study Merino sheep was designed to evaluate local and systemic toxicity during 6 months of implantation of autologous spheroids in a femoral condyle defect.”
DART package
Species: DART
Not conducted; autologous cells with local mechanism of action and limited biodistribution
“Reproductive and developmental toxicity studies were not conducted. 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.”
Reproductive & developmental
Not conducted; autologous cells with local action and limited biodistribution
“Reproductive and developmental toxicity studies were not conducted.”
PPND / ePPND: when
Not conducted: autologous cells with local action and limited biodistribution
“Reproductive and developmental toxicity studies were not conducted. In line with guidelines on cell-based medicinal products (EMEA/CHMP/410869/2006), the applicant has provided an acceptable justification for omitting these studies”
Carcinogenicity
Species: carcinogenicity
No conventional carcinogenicity; 6-month GLP tumourigenicity study in immunodeficient mice
“including the 6 months GLP study in immunodeficient mice which support the absence of the tumourigenic potential.”
Carcinogenicity model
GLP NSG mouse study, human spheroids implanted subcutaneously: no tumour or ectopic tissue formation after 6 months
“In a GLP compliant study using immunodeficient NSG mice, biodistribution of cells out from human Spheroxs implanted subcutaneously into the back was investigated after 4 weeks. There were no indications of significant systemic distribution of the cells, or were there any indications of tumour or ectopic tissue formation after 6 months in the tumourigenicity part of this study.”
Carcinogenicity timing
Not required: conventional carcinogenicity omitted per cell-based product guideline
“No genotoxicity, conventional carcinogenicity and reproductive- and developmental toxicity studies were performed which is in line with the guideline on cell-based medicinal products (EMEA/CHMP/410869/2006).”
Safety marginopen answer page →
Safety margin at NOAEL
Minipig study up to 3.2-fold the maximum clinical dose; other studies at doses similar to the clinical dose
“Except for one study in the minipig, in which up to 3.2 fold the maximum clinical dose was applied, all studies used doses similar to the intended clinical dose.”
NOAEL / key findings
No NOAEL; no treatment-related adverse effects or signs of general/local toxicity in any study
“There were no indications of treatment related adverse effects and the implant was well tolerated.”
Efficacy evidenceopen answer page →
Efficacy evidence
Immunodeficient mice (human spheroids) plus minipig pilot and 6-month Merino sheep studies with analogously produced autologous spheroids
“of-concept studies were conducted in immunodeficient mice and in two large animal models: a pilot study in minipig and a pivotal 6-month study in Merino sheep. In these studies human Spheroxs or autologous spheroids produced in an analogous way were used.”
Why that model
Only a few species (Göttinger minipig, Merino sheep) produce stable chondrocyte spheroids, so these were selected
“Comparative analyses of chondrocytes from different species showed that only a limited number of animals including Göttinger mini-pig and Merino sheep were capable of producing stable spheroids. These species were then selected for proof-of-concept studies.”
Reviewer's view of the efficacy data
Mode of action convincingly demonstrated in cartilage explants in vitro and subcutaneously implanted explants in vivo
“The mode of action was convincingly demonstrated in in vitro cartilage explants and in vivo in subcutaneously implanted cartilage explants.”
Flexibilityopen answer page →
Flexibility accepted
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.”
“The lack of non-clinical data on local and general toxicity after long-term exposure to autologous spheroids is considered acceptable.”
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.”
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.”
“CAT/CHMP that the risk for migration/infiltration is low and that additional non-clinical biodistribution studies are not called for.”
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.”
Similar precedents
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