GLPCriticised but acceptedBeyond the letter
Pivotal 13-week monkey toxicology study failed GLP inspection; a new GLP-compliant 13-week study was run during the procedure
Why: New GLP study confirmed the 30 mg/kg NOAEL; target well known; primate studies poorly predict checkpoint-inhibitor toxicity · Weight of evidence · Class precedent
“Importantly, despite the Applicant declared the pivotal toxicology study as GLP-compliant, the outcome of the triggered GLP inspection was negative.”
✓ VerifiedEMA assessment report, p. 30Source ↗ “Considering the new study results confirming the NOAEL at 30mg/kg, the results of additional tests confirming the specific binding of tislelizumab to PD-1, the well-known target and that “nonclinical toxicity studies in nonhuman primates have been poor in predicting clinical toxicities for antibodies mediating immune checkpoint blockade (Wang et al 2014)” the GLP and the specificity findings have been resolved.”
✓ VerifiedEMA assessment report, p. 30Source ↗ GLPAcceptedBeyond the letter
Tissue cross-reactivity studies not GLP-compliant; replaced by a Retrogenix cell-microarray binding assay
Why: Retrogenix results cleared doubts about insufficient binding · Other reason
“The GLP TCR studies submitted in the original application were not considered GLP compliant therefore the study results were replaced with Retrogenix assay”
✓ VerifiedEMA assessment report, p. 29Source ↗ “These results, together with the data provided for answer 45 contribute to clear up the doubts about tislelizumab possible insufficient binding. The major objection is therefore considered solved.”
✓ VerifiedEMA assessment report, p. 30Source ↗ DARTAccepted
No reproductive and developmental toxicity studies; pregnancy risk assessed by weight of evidence
Why: In line with ICH S9; weight-of-evidence approach per ICH S6(R1) for pregnancy risk · Within the guideline · Weight of evidence
“Reproductive and developmental toxicity studies have not been conducted with tislelizumab. In line with ICH S9, omission of fertility/early embryonic development studies and of pre-/post-natal development studies is accepted.”
✓ VerifiedEMA assessment report, p. 30Source ↗ “A weight of evidence approach, as outlined in ICH S6(R1) was applied to describe the potential risk of tislelizumab to human pregnancy, which is acceptable.”
✓ VerifiedEMA assessment report, p. 30Source ↗ Efficacy modelVerdict not stated
No in vivo comparison with nivolumab or pembrolizumab to confirm lack of Fc effector function
“Therefore, a comparative study with Nivolumab and Pembrolizumab in an animal model to determine the lack of antibody effector function in vivo would have been supportive of the non-clinical proof of concept of tislelizumab.”
✓ VerifiedEMA assessment report, p. 29Source ↗