Zalmoxis
allogeneic T cells modified with HSV-TK / dLNGFR (nalotimagene carmaleucel)
Sources:EMA assessment report ↗
Species
Mouse
Longest study
3 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 NOD/SCID mice (GvHD xenograft models); no conventional tox species
“Two studies in two different GvHD animal models both based on the NOD/SCID system were performed to evaluate the PK and primary PD of MM-TK.”
Why that species
Product is species specific; NOD/SCID mice permit human T cell engraftment and GvHD readout
“The MM-TK DP is a species specific product and therefore standard carcinogenicity studies using rodents or non-human primates as described in the ICH guidelines are not appropriate.”
Surrogate molecule
No surrogate; human MM-TK cells in NOD/SCID mice (one model with grafted human skin)
“NOD/SCID mice subcutaneously transplanted with human skin were also used so that the direct evaluation of allogeneic GvHD response against the grafted human skin could be observed.”
Species: general tox
No repeat-dose studies; toxicity assessed within two NOD/SCID mouse GvHD models (integrated PD/PK/tox)
“To evaluate safety and functional properties of MM-TK, the Applicant developed an integrated approach which included both in vivo pharmacodynamic, toxicology and kinetic data concurrently obtained taking advantage of two different immunodeficient mouse models for Graft versus Host Disease (GvHD) based on the Non-Obese Diabetes/Severe Compromised Immunodeficient (NOD/SCID) mouse system”
Species: DART
Not conducted; absence considered justified
“The lack of studies on reproductive and development toxicity is justified.”
Species: carcinogenicity
Not conducted (species-specific product; rodent/NHP carcinogenicity studies not appropriate)
“The MM-TK DP is a species specific product and therefore standard carcinogenicity studies using rodents or non-human primates as described in the ICH guidelines are not appropriate.”
Surrogate used in
No surrogate used; the human MM-TK product (original and optimized vector) was tested in immunodeficient mice
“Preclinical in vitro and in vivo studies in immune deficient mice were performed using for cell preparation both the SFCMM-3 #35 retroviral vector and an optimized version of the vector”
Study lengthopen answer page →
Longest pivotal study
3 weeks
“Xenogenic GvHD incidence was monitored in all treated mice at week 1, 2, and 3 post-infusion”
Pivotal GLP studies
No GLP tox; two integrated PD/PK/tox NOD/SCID GvHD mouse studies (20x10^6 cells/mouse), up to ~3 weeks
“Single dose toxicity has been assessed in the immunodeficient animal models in the pharmacodynamic studies.”
Route in tox
Intravenous (mice)
“The available data indicate that the cells can end up in any tissue which is not an unexpected finding following iv administration.”
Skipped studiesopen answer page →
Genotoxicity
Not conducted; in vitro retroviral integration site analysis instead
“Genotoxicity studies have not been submitted.”
Carcinogenicity
Not conducted in vivo (species-specific product); in vitro clonality, integration, IL-2 dependence, RCR
“Therefore, no specific in vivo carcinogenicity studies were performed for the MM-TK to date.”
Instead of genotoxicity
In vitro clonality, insertional pattern, growth-factor independent growth and RCR studies
“The in vitro studies pertain 1) evaluation of clonality of the transduced cell population, 2) characterisation of the insertional pattern, 3) evaluation of growth-factor independent growth, and 4) assessment of break out of replication competent retroviruses (RCR).”
Reproductive & developmental
Not conducted; justified
“The lack of studies on reproductive and development toxicity is justified.”
Safety pharmacology
Not submitted; agreed given product type
“There are no specific studies on secondary pharmacodynamics and safety pharmacology, which is agreed considering the type of product.”
Genotox: Ames
Not conducted (cell therapy)
“Genotoxicity studies have not been submitted.”
Genotox: in vitro mammalian
Not conducted (cell therapy)
“Genotoxicity studies have not been submitted.”
Genotox: in vivo
Not conducted (cell therapy)
“Genotoxicity studies have not been submitted.”
Carcinogenicity model
No in vivo study; in vitro clonality, insertion-site profile, growth-factor-independent growth and RCR assessments
“The in vitro studies pertain 1) evaluation of clonality of the transduced cell population, 2) characterisation of the insertional pattern, 3) evaluation of growth-factor independent growth, and 4) assessment of break out of replication competent retroviruses (RCR).”
Carcinogenicity timing
Not required: species-specific product, standard rodent/NHP carcinogenicity studies not appropriate; in vitro oncogenic-risk studies instead
“The MM-TK DP is a species specific product and therefore standard carcinogenicity studies using rodents or non-human primates as described in the ICH guidelines are not appropriate.”
hERG / QT
Not conducted; no safety pharmacology studies, agreed for product type
“There are no specific studies on secondary pharmacodynamics and safety pharmacology, which is agreed considering the type of product.”
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 Zalmoxis 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; GvHD occurred in mice but with lower incidence/severity than unmanipulated PBL; limited safety assessment (EMA assessment report, p. 26)
NOAEL / key findings
No NOAEL; GvHD occurred in mice but with lower incidence/severity than unmanipulated PBL; limited safety assessment
“Non clinical safety data obtained in two different immunedeficient animal models for Graft Versus Host disease did not indicate special hazards for humans, but allowed only a very limited safety assessment.”
Risksopen answer page →
Immune & cytokine safety
GvHD is the key immune risk; no antigenicity/immunotoxicity studies; GCV suicide gene as mitigation
“Studies on antigenicity or immunotoxicity, dependence, metabolites, impurities were not submitted”
Biodistribution & persistence
No formal biodistribution; human CD3+ cells in lymphohaematopoietic organs, GvHD target organs and skin at 3 weeks
“No formal biodistribution studies have been performed for MM-TK.”
Modality-specific risk
GvHD and oncogenic transformation (retroviral insertional mutagenesis); RCR
“it is agreed that the occurrence of GvHD and oncogenic transformation are the two main concerns associated with this product.”
Anti-drug antibodies: animals
Not conducted (no antigenicity or immunotoxicity studies)
“Studies on antigenicity or immunotoxicity, dependence, metabolites, impurities were not submitted”
Anti-drug antibodies: patients
No ADA incidence reported; immunological events (antibody formation) to be followed post-authorisation
“In addition, the MAH will follow-up on the risks of Graft versus Host Disease (GvHD), Severe systemic infection CMV and EBV reactivation, Febrile neutropenia, Hepatic failure, Carcinogenicity, Genotoxicity, Late complications (malignancies, autoimmunity), Immunological events (antibody formation)”
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 Zalmoxis 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; GvHD occurred in mice but with lower incidence/severity than unmanipulated PBL; limited safety assessment (EMA assessment report, p. 26)
Longest repeat-dose systemic studies
Longest repeat-dose study and recovery
No repeat-dose study; single-dose toxicity assessed within immunodeficient-mouse GvHD pharmacodynamic studies
“Single dose toxicity has been assessed in the immunodeficient animal models in the pharmacodynamic studies. Repeat dose toxicity Repeat-dose toxicity studies were not submitted (See discussion on non-clinical aspects).”
Pivotal GLP studies
No GLP tox; two integrated PD/PK/tox NOD/SCID GvHD mouse studies (20x10^6 cells/mouse), up to ~3 weeks
“Single dose toxicity has been assessed in the immunodeficient animal models in the pharmacodynamic studies.”
DART package
Species: DART
Not conducted; absence considered justified
“The lack of studies on reproductive and development toxicity is justified.”
Reproductive & developmental
Not conducted; justified
“The lack of studies on reproductive and development toxicity is justified.”
PPND / ePPND: when
No reproductive toxicology studies; omission considered acceptable
“Conventional toxicology, carcinogenicity, mutagenicity and reproductive toxicology studies have not been performed, which is considered acceptable.”
Carcinogenicity
Species: carcinogenicity
Not conducted (species-specific product; rodent/NHP carcinogenicity studies not appropriate)
“The MM-TK DP is a species specific product and therefore standard carcinogenicity studies using rodents or non-human primates as described in the ICH guidelines are not appropriate.”
Carcinogenicity model
No in vivo study; in vitro clonality, insertion-site profile, growth-factor-independent growth and RCR assessments
“The in vitro studies pertain 1) evaluation of clonality of the transduced cell population, 2) characterisation of the insertional pattern, 3) evaluation of growth-factor independent growth, and 4) assessment of break out of replication competent retroviruses (RCR).”
Carcinogenicity timing
Not required: species-specific product, standard rodent/NHP carcinogenicity studies not appropriate; in vitro oncogenic-risk studies instead
“The MM-TK DP is a species specific product and therefore standard carcinogenicity studies using rodents or non-human primates as described in the ICH guidelines are not appropriate.”
Safety marginopen answer page →
Safety margin at NOAEL
Mouse target dose ~two log above proposed clinical dose; this dose caused 100% GvHD mortality (no NOAEL)
“In preliminary studies a dose dependent GvHD-induced mortality was observed with a 100% incidence at the dose of 20x106 cells/mouse, which was chosen as the target dose. Of note, the chosen target dose is around two log higher than the proposed clinical dose, thus providing large safety margins.”
NOAEL / key findings
No NOAEL; GvHD occurred in mice but with lower incidence/severity than unmanipulated PBL; limited safety assessment
“Non clinical safety data obtained in two different immunedeficient animal models for Graft Versus Host disease did not indicate special hazards for humans, but allowed only a very limited safety assessment.”
Efficacy evidenceopen answer page →
Efficacy evidence
Xenogeneic GvHD models in NOD/SCID mice comparing MM-TK with unmanipulated PBL
“Two studies in two different GvHD animal models both based on the NOD/SCID system were performed to evaluate the PK and primary PD of MM-TK.”
Why that model
Human T-cell product; mouse models lack human cytokines (IL7, IL15, IL2) and HLA-expressing APCs, limiting extrapolation
“The DLI engraftment is dependent on the availability of human cytokines IL7, IL15 and IL2, and promoted by the TCR of HLA-expressing antigen presenting cells, which are not present in the animal model.”
Reviewer's view of the efficacy data
Limited: GCV efficacy tested only in first model and few animals developed GvHD
“Only in the first model the efficacy of GCV treatment was evaluated. However, as only a limited number of animals developed GvHD/Xeno-reaction only limited information on the effectiveness of GVC treatment could be obtained in this study.”
Test articleopen answer page →
Test article vs clinical lot
MM-TK made with the original SFCMM-3 #35 vector and the optimized Mut2 #48 vector and process
“Preclinical in vitro and in vivo studies in immune deficient mice were performed using for cell preparation both the SFCMM-3 #35 retroviral vector and an optimized version of the vector, encoding a mutated form of the HSV-TK gene (HSV-TK Mut2 #48), as well as and an optimized process manufacture developed before launching the phase III clinical study.”
Genetically modified?
Donor T lymphocytes genetically modified with SFCMM-3 Mut2 #48 retroviral vector (HSV-TK, ΔLNGFR)
“The finished medicinal product of Zalmoxis is defined as frozen donor T lymphocytes genetically modified with the SFCMM-3 Mut2 #48 retroviral vector and encoding for the HSV-TK and the ΔLNGFR genes”
First approval
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.
Flexibilityopen answer page →
Flexibility accepted
OtherCriticised but acceptedBeyond the letter
No conventional toxicology studies; safety read from two immunodeficient-mouse GvHD pharmacology models
Why: GvHD mouse models indicated no special hazards but allowed only a very limited safety assessment
“Conventional toxicology, carcinogenicity, mutagenicity and reproductive toxicology studies have not been performed, which is considered acceptable.”
“Non clinical safety data obtained in two different immunedeficient animal models for Graft Versus Host disease did not indicate special hazards for humans, but allowed only a very limited safety assessment.”
CarcinogenicityAccepted
No in vivo carcinogenicity studies; in vitro clonality, insertion-site, growth-factor independence and RCR studies instead
Why: Species-specific product; in vitro evaluation indicates low risk of malignant transformation · No relevant species · Within the guideline · Weight of evidence
“The MM-TK DP is a species specific product and therefore standard carcinogenicity studies using rodents or non-human primates as described in the ICH guidelines are not appropriate.”
“In vitro evaluation of oncological potential indicate that the risk of malignant transformation is low.”
BiodistributionCriticised but acceptedBeyond the letter
No formal biodistribution study; cell tracking in the GvHD mouse models only
Why: Cells can reach any tissue, an expected finding after IV administration · Pharmacology or kinetics
“No formal biodistribution studies have been performed for MM-TK.”
“The available data indicate that the cells can end up in any tissue which is not an unexpected finding following iv administration.”
DARTAcceptedBeyond the letter
No reproductive and developmental toxicity studies
“The lack of studies on reproductive and development toxicity is justified.”
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