Which risks did regulators probe for approved monoclonal antibodies?

“The observed anti-tocilizumab response showed a clear inverse dose relationship, an effect which is frequently observed with molecules of this type.”

“In a segment II-embryo-foetal development study in cynomolgus monkeys foetal plasma concentrations of tocilizumab were 39% and 60% of the maternal plasma concentration after application of 10 and 50 mg/kg/day, resp.”

“Primate anti-human antibodies (ADAs) were detected in toxicological studies in Cynomolgus monkeys, accompanied by hypersensitivity reactions in some animals. Anti-human antibodies against SelG1 were detected in 40% of all treated animals at least once throughout the observation period in a 26-week repeat-dose toxicity study.”

“Crizanlizumab binding was seen in platelets in the blood and spleen, and in blood vessels in the majority of tissues examined of both human and cynomolgus monkey.”

“In addition, the 26-week study included an immunophenotyping assessment which indicated that tralokinumab did not significantly modulate any of the immune cell populations investigated which including CD4 and CD8 T cells, NK cells and mature B cells.”

“There was clear evidence of placental transfer in both studies with neonate serum levels measured comparable or even in excess of maternal levels.”

“There were no ADA-positive samples.”

“All other staining was cytoplasmic, and, therefore, clinically irrelevant based on the inability of aducanumab to enter cells.”

“ADA was also observed in 3 LD animals, which resulted in reduced drug exposures (Cmax and AUC0-7d).”

“Volume of distribution typical of a monoclonal antibody suggesting limited extravascular distribution.”

“The inflammation was accompanied by increased monocytes and deposition of immune complexes (C3 complement, IgG and/or IgM). These findings were not reproduced in the 6 month study.”

“Vd was low in all species (0.07-0.14 L/kg). Tissue distribution and metabolism studies were not requested or conducted.”

“Concizumab induced ADA in all repeat dose toxicity studies. ADA led to loss in exposure although this did not affect the overall interpretation of the studies.”

“In a tissue cross reactivity study, concizumab showed anticipated binding to tissue in which TFPI is expressed. Off target binding was observed for cytoplasm but it is very unlikely that concizumab will be able to reach the cytoplasm in vivo.”

“The deaths and/or premature euthanasia of the remaining animals, primarily in the LD IV group, were attributed to immunogenicity based upon observed adverse clinical signs, although there were no histopathological findings.”

“The SC bioavailability of garadacimab (6 mg/kg) was ~66% in monkeys. Mean estimated t1/2 values for garadacimab in the single-dose PK study with monkeys ranged from 147 to 581 h (IV) and 206 to 424 h (SC).”

“Anti-product antibodies were detected in samples from 2 monkeys on Day 13 and an additional 6 monkeys on Day 26, for a total of 8 out of 12 monkeys, or 75%.”

“Staining was reported to be cytoplasmic and was specifically localized to cytoplasmic granules and/or filaments, often associated with cell borders, suggestive of intracellular cytoskeletal elements, and therefore not relevant.”

“These results suggest that administration of ofatumumab may be associated with cytokine release syndrome. However, the severity of this syndrome in the monkeys was limited and clinical manifestations were not observed.”

“Ofatumumab was present in maternal plasma up to Gestation Day 100 and was also detectable in 17 of 20 umbilical cord blood samples from the foetuses, confirming exposure to ofatumumab during late pregnancy (GD100).”

“Antibodies developed between 8 and 11 days after the initiation of dosing.”

“In most cases, foetal serum concentrations were greater than maternal serum concentrations with a median ratio of foetal serum:maternal serum concentrations of 1.87.”

“The results were limited to a 5-7 fold increase in TNFα following 24 hours of exposure to avelumab at concentrations ≥ 14.4 ng/mL.”

“Overall, except for these differences, avelumab staining of normal human and cynomolgus tissues was generally comparable.”

“In summary, across all studies, detectable, treatment emergent anti-belimumab antibodies have been identified in 12 out of 124 monkeys. Of these, 6 monkeys had reduced belimumab serum concentrations.”

“No specific staining of the human tissues by the belimumab antibody was identified at any concentration.”

“ADA response was assessed in the in vivo studies. Although antibodies were detected in all the studied groups, no effects were detected in brolucizumab exposure.”

“Following IVT administration, systemic (serum) exposure of free brolucizumab in rabbits and cynomolgus monkeys was found to be >20000-fold and >7000-fold lower than in vitreous humor.”

“None of the animals in the control or treated groups tested positive for ADA at any time point during the treatment phase. ADAs to nirsevimab was only observed in the recovery period and in a limited number of animals (four (22.2%) of the recovery animals).”

“Results revealed no staining with nirsevimab, and therefore, no tissue cross-reactivity was identified against a panel of normal human juvenile, neonatal and foetal tissues.”

“The main finding in single and repeat dose studies was the increased risk of infection due to reduced muco-epidermal immunity.”

“No cross-reactive binding of bimekizumab conjugated to fluorescein isothiocyanate was observed in any human or monkey tissue at any concentration tested”

“Levels of four inflammatory cytokines (IL-6, IL-8, IFN-γ, and TNF-α) were evaluated after repeated dosing of ublituximab and no significant changes were observed.”

“In addition, tissue cross reactivity studies in human and cynomolgus monkey tissue showed specific binding in lymphoid tissues and areas known to be positive for CD20+ cells, and no off-target or unexpected binding was observed.”

“Anti-drug antibodies were observed but did not affect drug exposure, with the exception of one animal in the 26-week Cynomolgus monkey study, which consequently was excluded from the study interpretation.”

“data from the biodistribution study in mice using 125I-radiolabeled caplacizumab suggest that free caplacizumab is eliminated via the kidneys, while vWF-complexed caplacizumab appears to target and possibly be catabolized in the liver.”

“The levels of the cytokines IL-6, IL-10, MCP-1 and TNF-α were significantly elevated especially at 2-4 hours post-dosing.”

“Alemtuzumab was detected in foetuses of dams treated with alemtuzumab during gestation which confirmed transfer across the placental barrier.”

“The antibody incidence in the main monkey toxicity studies were 10-20%.”

“The highest level of PEG was detected in the liver (7% of the dose administered). There was no indication of tissue uptake of PEG, associated with binding to membrane bound TNF alpha.”

“Immunogenicity noted in 3 animals in the pivotal toxicity study (1 at 5 mg/kg, 2 at 25 mg/kg); 1 of the 25 mg/kg animals had repeated infusion reactions c/w hypersensitivity”

“In human tissue, binding was observed in spinal cord, brain and optic nerve. No binding was seen to peripheral nerves, or any other human tissue examined.”

“Immunotoxicity was observed in one high-dose female (#451) that developed skin lesions (treated with antibiotics), splenic lymphocytic atrophy, decreased NK cell activity, and decreased T-cell dependent antigen response (TDAR; see below).”

“Serum analysis revealed that that secukinumab is transferred across the placenta during the pregnancy in cynomolgus monkeys and in marmosets, and that the fetuses are exposed to secukinumab at the level corresponding approximately 2% of the mean maternal serum concentration.”

“In all monkeys with ADA, serum concentrations of burosumab were diminished and increases in serum inorganic phosphate and 1,25-dihydroxy vitamin D were also attenuated.”

“Burosumab was detected in serum from fetuses at all dose levels, indicating transport across the placenta.”

“In immunogenicity testing, 5 of 7 animals in the 5 mg/kg group tested positive for anti-ramucirumab antibodies, 3 of 9 animals in the 16 mg/kg group tested positive for anti-ramucirumab antibodies, and none tested positive”

“Tissue cross-reactivity was observed in vascular endothelium in both human and Cynomolgus monkey tissues, consistently with the distribution of the molecular target of ramucirumab, VEGFR-2.”

“Naxitamab induced approximately 22% ADCC in human LAN-1/rat splenocyte co-cultures whereas there was 55% ADCC against the same cell line in the presence of human NK cells, indicating that the rat/rat and rat/human systems underpredicted the activity of the human/human system.”

“FDA agrees that tissue cross reactivity studies showed binding to peripheral nerve, cerebellum, spinal cord, frontal lobe, and pons.”

“There was one mortality at 5 mg/kg immediately following dosing (1.5 hours) in a female chimpanzee due to cytokine release response with overinflation, edema of the lungs following dosing with detectable levels of cytokines TNF-α, IL-6 and IFN-γ in the serum prior to necropsy.”

“Daratumumab was slowly eliminated in the blood following intravenous dosing with half-lives of approximately 15.5 to 18.8 days in chimpanzees, and 9 to 63 hours for HuMab-CD38 in the monkey.”

“REGN646 treatment did not affect the development of an antibody response to immunization with KLH.”

“In accordance with ICH S6 (R1), studies on distribution, metabolism and excretion were not conducted.”

“No clear changes in drug exposure or ex vivo EBOV GP binding activity were observed in this study, suggesting that no meaningful anti-drug antibody formation occurred in this study.”

“No off-target binding was observed with ansuvimab-zykl in any tissue under the conditions of this study.”

“Several animals had low levels of anti-drug antibodies (ADA) with no appreciable impact on exposure.”

“No specific lebrikizumab staining was observed in any human or cynomolgus monkey tissues.”

“The sponsor attributed the decreases in plasma drug levels following repeat dosing to ADA formation (no individual animal ADA data were provided).”

“A tissue cross-reactivity study assessing galcanezumab binding positively stained select human, monkey, and rat tissues that were consistent with the association of CGRP with neurons and innervated tissues; however, specific binding was also observed in tissues not expected to express CGRP (i.e., tubular epithelium of the kidney).”

“An in vitro cytokine release experiment identified elevated levels of 10 cytokines in response to elotuzumab treatment.”

“In the human tissues examined, elotuzumab stained the membrane and/or cytoplasm of plasma cells and/or immunoblasts in the bone marrow, breast, cervix, esophagus, Fallopian tube, gastrointestinal tract, liver, lymph node, pancreas, salivary gland, small intestine, spleen, stomach, thymus, thyroid, tonsil, ureter, and uterus.”

“The Agency placed the application on full clinical hold on January 6, 2017, due to the potential risk of cytokine release syndrome (based on demonstration of release of interleukins induced in human white blood cells in an in vitro cytokine release assay).”

“No off-target binding was observed with MK-1654 in any tissue observed under the conditions of this study.”

“in 2/10 animals at 60 mg/kg/week and 1/10 animal at 180 mg/kg/week. However, while sutimlimab clearance was increased in these animals, no adverse impacts on the health of animals (e.g., immune complex deposition) were observed.”

“Sutimlimab showed an expected staining pattern in human tissue line with other complement proteins. There was no obvious cross-reactivity staining to un-intended target(s).”

“Based on a human in vitro blood cytokine assay, the potential of satralizumab to induce a cytokine release syndrome (CRS) is considered to be low in terms of incidence and increase in cytokines.”

“The staining pattern produced was consistent with what is known regarding IL-6R expression in e.g. adrenal cells, liver, macrophages, and lymphocytes, and the staining pattern was similar in human and Cynomolgus monkey tissue.”

“MLN0002 did not induce T lymphocyte activation or cytokine release in whole human blood.”

“Vedolizumab staining pattern observed in Cynomolgus monkey tissues appeared to be similar to that observed in the human tissues and results were stated to be consistent with the pattern of expression of α4β7 integrin. No unanticipated tissue cross-reactivity or off-target staining was observed in TCR studies.”

“Antibody responses were observed in 3/22 (13.6%) Cynomolgus monkeys. An effect on cetuximab serum concentrations was observed for one of these animals only.”

“Clearance decreased and terminal half-life increased with increasing dose, indicating a saturated clearance at higher doses. Distribution volume indicated that cetuximab is mainly located in the plasma volume.”

“There were no adverse consequences of ADAs in rats and monkeys. In the rabbit, adverse consequences of the immune response to romosozumab (immune complex disease) occurred in a few animals.”

“A tissue cross-reactivity immunohistochemistry study showed binding of AMG785 to osteocytes in human, cynomolgus monkey, and rabbit, but not rat bone. Binding was also observed in aorta or pulmonary artery in a monkey.”

“Anti-drug antibody (ADA) responses were generally low in rats and monkeys, but evinacumab was highly immunogenic in rabbits.”

“Evinacumab crossed the placenta in rats, with mean fetal to maternal concentration ratios ranging from 0.42 to 0.65”

“While ADAs were detected in 6 animals in the 26-week repeat dose toxicity study, there was only one male at 10 mg/kg with a high ADA titre in which the depemokimab exposure was reduced.”

“The applicant concluded that no specific positive staining was observed in any human tissues examined.”

“Testing for development of anti-benralizumab antibodies was also completed and this was seen in 2 of 24 (8.3%), 9 of 36 (25%) and 2 of 36 (5.5%) of monkeys given benralizumab in the 9-, 15- and 39-week studies, respectively.”

“In pregnant monkeys, there was evidence of placental and/or milk transfer as infants showed detectable benralizumab concentrations despite not being dosed directly.”

“Emapalumab transiently impaired monkey’s capacity to mount a primary anti-Keyhole Limpet Hemocyanin (KLH) IgG response 14 days after the first KLH challenge; however, a robust IgG response was observed in all monkeys 21 days after the second KLH challenge.”

“Emapalumab did not induce in vitro antibody-dependent cell cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC) activity and it did not cross-react with a variety of human tissues tested.”

“In vitro analysis of obinutuzumab using whole blood from healthy human donors indicated that obinutuzumab can cause first-infusion cytokine release in patients.”

“Unexpected tissue cross-reactivity staining using obinutuzumab was observed localized in the membrane of human and monkey liver epithelium, salivary glands and lung endothelium (refer to Section 11).”

“This represents an incidence of 1/84 animals in repeated-dose studies in which antibodies to trastuzumab were detected.”

“Tissue cross reactivity studies with trastuzumab in monkey and human tissue did not reveal localisation to heart tissue.”

“However, both MAHA and PAHA developed after single doses, and affected the elimination. Moreover, analyses of biological activity of serum samples showed that PAHA were neutralising.”

“Available data showed that fetuses were exposed to adalimimab, corresponding to 5-10% of the maternal serum levels.”

“Analysis of plasma samples for antidrug antibody (ADA) detected ADA in a minority of rats (~28%) in the 3-month study found no evidence of marstacimab neutralization (Table 52). There was no evidence of ADA in the 3-month monkey or 6-month rat studies.”

“Therefore, as expected marstacimab binding was noted in endothelial cells one would expect release of TFPI (endothelial cell, placental spongiotrophoblasts, placental trophoblast, islet cells, endocrine epithelium, mesothelium).”

“Regarding toxicokinetics, exposure to canakinumab or 01BSUR was demonstrated in each study. With the analysis method used, no anti-drug antibodies were detected.”

“Of note, with 4-7 days the elimination half-life of canakinumab in marmosets was shorter than in rhesus monkeys (17.4 days), mice (14.5 days) and humans (26 days).”

“The results of these analyses did not reveal any tildrakizumab-related changes in lymphocyte numbers or TDAR responses.”

“The Applicant has argued that since these staining were all cytoplasmic in nature it is unlikely that such tissue cross reactivity would be able to occur in vivo.”

“In the 8- and 26-week studies, nipocalimab inhibited the T-cell dependent antibody response to keyhole limpet hemocyanin, which is expected based on nipocalimab’s mechanism of action, but did not inhibit antibody response to tetanus toxoid challenge administered during the recovery periods.”

“Nipocalimab also effectively inhibited placental transfer of itself and there was very little drug exposures to fetuses and neonates observed in the enhanced pre- and postnatal development (ePPND) study.”

“In a human whole blood assay, durvalumab did not induce the release of any cytokine”

“the volume of distribution is in the range of 40.5 to 73.0 mL/kg, which is expected for large protein molecules as these primarily resides in the plasma volume”

“In an in vitro cytokine release assay, treatment of unstimulated human PBMCs or whole blood cultures with soluble tremelimumab for up to 48 hours did not result in release of TNF‐α, IL‐6, or IL‐1β compared to untreated controls”

“In vitro tissue cross‐reactivity studies were conducted in both monkey (IM645; Module 4.2.3.7.7 ) and human (IM676; Module 4.2.3.7.7). Tremelimumab bound only to cells in tissues expected to contain CTLA‐4 expressing cells and were considered similar between species.”

“Furthermore, in an in vitro cytokine release assay, dostarlimab did not induce cytokine release at concentrations up to 400 µg/well.”

“Specific binding of dostarlimab was observed on plasma membrane elements of lymphocytes (including intravascular, perivascular, interstitial, and migrating lymphocytes) in a large number of tissues and to monocytes in peripheral blood.”

“From the TDAR assessment, there were small decreases in both the primary and secondary IgG responses to KLH challenge in males and females that received doses ≥5 mg/kg/week; this change was attributed to the immunosuppressive properties of sarilumab.”

“The positive tissue staining for biotinylated sarilumab between human and monkey tissues appeared similar with some exceptions. In human tissues, positive staining for biotinylated sarilumab was detected in the cytoplasm and/or cytoplasmic granules of various sites but not at any membrane sites.”

“Pembrolizumab was evaluated in a cytokine release assay there was no evidence of cytokine release, as assessed by IL-2 production following culture of hPBMCs in pembrolizumab-immobilized (air-dried) plates.”

“the Vss mean value (30.9, 36.8, 54.8 ml/kg) was similar to the plasma volume of monkeys suggesting that pembrolizumab has a limited distribution out of the plasma compartment”

“Anti-drug antibodies (ADA) were present in samples from 1/12 control, 1/6 LD, 1/6 MD, and 4/12 HD animals; donanemab concentrations in serum were only affected by ADA in the 2 HD recovery animals with the highest titers”

“Tissue cross-reactivity studies conducted in a panel of normal human and cynomolgus monkey tissues demonstrated specific binding of donanemab that was exclusively cytoplasmic and/or nuclear, and, therefore, toxicologically irrelevant”

“though anti-drug antibody (ADA) responses seen in at least 22% of monkeys resulted in variable exposure in all toxicology studies.”

“Anti-PDGFR-α staining was generally similar between human and cynomolgus monkey tissues.”

“No ADAs to lecanemab were detected in the serum samples from i.v. repeat-dose toxicity and s.c. local irritation studies in cynomolgus monkeys.”

“CSF-to-plasma ratios were 0.53, 0.44 and 0.30% at 1, 5 and 15 mg/kg based on AUC0-168h, respectively.”

“ADAs were detected in 19/36 (53%) monkeys dosed with REGN2810 including 11/12 (92%), 4/12 (33%), and 4/12 (33%) monkeys dosed with 2, 10, and 50 mg/kg REGN2810, respectively.”

“Traditional distribution, metabolism, and excretion studies were not conducted with cemiplimab because it is a monoclonal antibody; however, consistent with ICH S6(R1), the Applicant did include a tissue cross reactivity assay to assess distribution of the target”

“In an in vitro assay using human blood, the cytokine release profile for immobilized and soluble toripalimab was similar to that of the negative control, indicating that toripalimab is unlikely to induce cytokine release.”

“This staining was expected based on PD-1 expression in mononuclear cell types, including T cells, B cells, and other myeloid cells. No unexpected tissue cross-reactivity was observed.”

“It is therefore not surprising that it is highly immunogenic in rabbits as shown in the single-dose ocular toxicity studies. A significant antigenicity was observed also in monkeys, even within the eye.”

“In rabbits and monkeys, serum levels were >1000-fold lower than vitreous concentrations. The levels in aqueous humour and retina were 2.5 – 4-fold lower than the vitreous levels.”

“No target organs for margetuximab were identified, nor were there margetuximab-related increased release of IFN-γ, IL-2, IL-5, IL-6, IL-10, or TNF-α in serum. Margetuximab treatment resulted in partially reversible decreases in blood CD3-/CD159a+ and CD16+/CD159a+ NK cells when compared to vehicle controls.”

“These studies revealed margetuximab staining patterns consistent with reported sites of HER2 expression on human and cynomolgus monkey tissues. Direct comparison of margetuximab and trastuzumab revealed similar tissue staining.”

“The findings correlated with reduced IgG concentration in serum and a reduction in primary and secondary antibody response to keyhole limpet haemocyanin (KLH) and tetanus toxoid (TT) respectively, in an assessment of the T-cell dependent antibody response (TDAR).”

“There was no off-target binding of tafasitamab detected in tissue panels from the human and cynomolgus monkey.”

“An increase in TNF or IL-6 concentration was observed in 2 samples after nemolizumab exposure (1 sample for each of the cytokines), but the levels were considerably lower than the levels reached with the positive controls”

“Concentrations of nemolizumab in offspring plasma on postnatal day (PND) 7 were comparable to those in dams, suggesting that nemolizumab crossed the placenta.”

“In the 13-week toxicology study, the incidence of ADA induction was inversely related to the dose: 6/12 animals at 10 mg/kg, 3/12 animals at 30 mg/kg, and 1/12 animals at 100 mg/kg.”

“In a GLP tissue cross-reactivity study, the observed antibody binding was well conserved between humans and cynomolgus monkey and concordant with the expected expression of CSF-1R in tissues, including liver Kupffer cells and microglia.”

“Following immunization with Tripedia®, there were no treatment-related effects on development of specific titers to the vaccine components. Anti-mepolizumab antibodies were detected in one mother and its infant from the 10 mg/kg group.”

“Concentrations of mepolizumab were approximately 2.4 times higher in infants than in mothers for several months post-partum. Mepolizumab was quantifiable in infant plasma samples continuing through day 178 postpartum.”

“Results of TK analyses confirmed the immunogenicity of ocrelizumab at all doses levels, but ADAs were most evident at doses of 10 mg/kg or lower.”

“These data demonstrate trans-placental exposure to ocrelizumab in monkey fetuses.”

“In both six-month studies immunophenotyping, T-dependent antibody responses and NK cell cytotoxicity was assessed without any significant effect of mirikizumab on the parameters measured.”

“Furthermore, a tissue cross-reactivity study performed with human and cynomolgus monkey tissues (see toxicology section) did not identify any specific mirikizumab staining suggesting a low potential for off-target binding and pharmacological effects.”

“Nivolumab did not mediate complement dependent cytotoxicity, antibody dependent cellular cytotoxicity, or to directly elicit cytokine release from cells in the absence of TCR activation.”

“The low volume of distribution ranging between 0.046-0.071 L/kg at steady state suggests that most of the monoclonal antibody remains in the bloodstream.”

“As a monoclonal antibody, systemic hypersensitivity reactions and immunogenicity were considered additional potential risks of garetosmab treatment.”

“These findings suggest that garetosmab is an embryo-fetal/developmental toxicant due to placental transfer during organogenesis, which is consistent with neutralizing activin A.”

“The incidence of anti-drug antibody formation was 63.33% in the 6-week study and 93.33% in the 13-week study, which may explain the limited findings noted in the 13-week study.”

“PD-1 is expressed on the surface of activated T cells, B cells, and macrophages, and as the results of penpulimab tissue cross-reactivity (TCR) studies showed no unexpected binding of penpulimab to human or cynomolgus monkey tissues was found.”

“No antibodies to pertuzumab were detected in the 7- and 26-week toxicity studies. Despite possible interference in the ELISA assays, it appears that pertuzumab was not immunogenic in Cynomolgus monkeys.”

“In vitro tissue cross-reactivity studies showed similar patterns of pertuzumab binding to human and cynomolgus monkey tissues, with haired skin, mammary gland, prostate, urinary bladder and stomach identified as the major target organs, consistent with the known distribution of HER2.”

“ADA were detected in 21 out of 30 animals in the SC groups (D36) and in 8 out of 10 animals in the IV group (D15).”

“Vss exceeded the plasma volume (69.5-71.8 mL/kg), indicating some distribution into tissues. Crovalimab was transferred via the placenta in pregnant monkeys.”

“The immunogenicity of necitumumab could not be accurately assessed in animal models. High levels of circulating necitumumab may have saturated the anti-drug antibody leaving an insufficient quantity of free binding sites for the assay to detect a response.”

“In most tissues, binding was consistent in both human and monkey tissue, sometimes with minor differences in localization within the organ. There was no unexpected tissue cross-reactivity based on literature and the biology of EGFR”

“Results of the cytokine release assays varied by the experimental conditions; mogamulizumab generally caused greater cytokine release (IL-6, TNF-α, and IFN-γ) in solid phase assays with isolated PBMCs.”

“At the end of the study plasma exposure of mogamulizumab in the fetuses was ~60% that observed in the dams; this finding is consistent with the expected transfer of mogamulizumab across the placental barrier.”

“Incidences of neutralizing antibodies were low in rats and negligible in monkeys.”

“Measurable alirocumab serum concentrations were observed in the infant monkeys at birth at comparable levels to maternal serum, indicating that alirocumab, like other IgG antibodies, crosses the placental barrier.”

“However, there was no evidence for the development of anti-dabigatran antibodies. Circulating immune complexes were within normal limits in all animals and there was no evidence for immune complex deposition in the kidneys as evaluated by immunohistochemistry.”

“The plasma concentration-time profile was biphasic with a rapid initial decline phase and a slow terminal phase, with a half-life of approx. 6 hrs in rats and 4-5 hrs in rhesus monkeys. The clearance of idarucizumab was low and the volume of distribution was small.”

“Studies on immunomodulatory effects were incorporated in some pharmacology and toxicology studies in cynomolgus monkeys. These studies did not reveal any major differences compared to controls.”

“There were indications that denosumab has limited potential to cross the blood/brain barrier, the blood/testis barrier as well as the placental barrier, although this data is confounded by the presence of radiolabel in blood vessels and an unknown contribution of free radiolabel.”

“Data from the literature have shown that anti-TNFα monoclonal antibodies reduce host defence in various clinically relevant intracellular infection models”

“Consistent with the known distribution of TNFα, reactivity was observed with mononuclear and stromal cells in most tissues as well as in smooth musculature associated with vascular walls or selected muscle bundles in a number of tissues.”

“Since the interpretation of the TDAR relies on comparisons between groups of KLH-naïve animals, these animals were excluded from the TDAR analysis; the results were no longer statistically significant.”

“Measurable evolocumab serum concentrations were observed in the infant monkeys at birth at comparable levels to maternal serum, indicating that evolocumab, like other IgG antibodies, crosses the placental barrier.”

“T–cells or other cells of the non-CD20+ lymphocyte lineage were not affected in any of the experiments.”

“Single dose pharmacokinetics was performed in rats and cynomolgous monkeys. In both species t½ was 3-7 days.”

“All assays, conducted using appropriate positive and negative controls, did not indicate the potential for stimulation of UCB7665-induced cytokine release.”

“The staining patterns were generally similar between species; however, the study report did not specify whether specific binding was membranous or cytoplasmic.”

“The arteritis could be due to the deposit of ADA-mediated immunocomplexes based on positive staining of anifrolumab, monkey IgM, and complement component 3b (C3b) but not monkey IgG from kidney samples of 2 HD-IV monkeys with arteritis.”

“In the infants, mean serum concentrations of anifrolumab‑fnia on Day 30 after birth increased with dose and were approximately 4.2% to 9.7% of the respective maternal concentrations.”

“In contrast, no significant release of cytokines was observed after isatuximab incubation under any of the various assays and conditions used and for any of the donors tested.”

“The TCR test indicated that isatuximab-specific binding was mainly in the lymphoid tissues (spleen, thymus, lymph node and tonsil) and in the bone marrow; binding was also detected in the pituitary gland (endothelial cells) and prostate gland (glandular epithelial cells).”

“Immunotoxicity was investigated in cynomolgus monkeys by means of standard endpoints in repeated dose toxicity studies as well as immunophenotyping and T-cell dependent antibody response assays (KLH test) in adult and in juvenile monkeys. No significant effects were observed.”

“Brodalumab binding was largely comparable in human, monkey and rabbit tissues. The binding pattern largely corresponds to reported expression of IL-17RA”

“The incidence of antibodies to golimumab was greater at lower dose levels (3 and 10 mg/kg), than at higher dose levels (25 and 50 mg/kg).”

“When golimumab was administered to pregnant monkeys, it was shown to cross the placenta and substantial golimumab exposure was observed in the foetal circulation. Golimumab was also found in monkey breast milk.”

“Increased clearance occurred in the low dose group corresponding to the occurrence of anti-idiotypic antibodies in 75% of the animals of this group after four weeks of administration.”

“Binding studies of Simulect with standard tissues of human origin indicate specificity for cells expressing CD25 which mostly exist within lymphoid organs.”

“The immune function tests in the monkey toxicity studies showed that risankizumab did not cause immunosuppression [(as assessed by T-dependent antibody response (TDAR)] or deplete T-cells.”

“The mean infant serum exposures were 25% and 17% of the mean maternal serum exposures on Birth Day (BD) 14 in the 5 and 50 mg/kg/week treatment groups, identifying the ability of risankizumab to cross the placenta.”

“There were no remarkable macroscopic observations or histomorphological findings in mandibular or mesenteric lymph nodes related to treatment with the surrogate antibody, BB5.1 mAb, in the twenty six week mouse study.”

“Eculizumab binds to C5 on smooth muscle (intrinsic/vascular) and skeletal muscle, myoepithelium, myofibroblasts, renal tubular epithelium, and reticulum cells.”

“No specific IL-2, IL-6, TNF-α, or IFN-γ release was observed.”

“Spesolimab stained lymphocytes in tonsil epithelial cells in a variety of tissues, which was considered expected based on previous data and literature on IL-36R expression.”

“Immunotoxicity evaluations revealed no adverse effects of ustekinumab on functional immune responses, circulating lymphocyte subpopulations or distribution of T- and B-lymphocytes in lymphoid tissue.”

“The volume of distribution of ustekinumab in monkeys was 86 to 98 mL/kg following a single IV dose of 4.5 mg/kg, suggesting that the distribution of ustekinumab was mainly confined to the intravascular space”

“These effects suggest the potential for infection secondary to immune modulation. Although not common, first-dose infusion reaction occurred in a monkey (in 1 out of 52) and included moderate facial swelling.”

“Expected specific cross-reactivity staining using biotinylated siltuximab was observed in human tissues from the brain white matter and cerebellum, squamous epithelium of the cornea, axons in the gray and white matter of the spinal cord, and axons of peripheral nerves.”

“Palivizumab was immunogenic in Cynomolgus monkeys and led to the generation of anti”

“No binding was observed in any of the tested human tissues.”

“DX-2930 was highly immunogenic in rats as evidenced by the development of neutralizing anti-drug antibodies (ADA) in nearly all treated animals in a 4-week SC toxicity study.”

“In the ePPND study, DX-2930 crossed the blood-placenta barrier and was also detected in the milk of lactating monkeys.”

“There were no treatment-related changes in the anti-KLH IgG or IgM responses either during the dosing or recovery phases. At the end of the recovery period, one high dose female was positive for anti-drug neutralizing antibody.”

“No specific ixekizumab staining was observed in any human or Cynomolgus monkey tissues examined at either concentration.”

“Atezolizumab showed minimal binding to human Fcγ receptors and did not stimulate cytokine release from human PBMCs at concentrations up to 250 µg/mL or ADCC activity at concentrations up to 10 µg/mL.”

“staining was detected in the placenta, lymph node, tonsil, and thymus. Frequent, moderate, apical cytoplasmic and membranous staining was observed in syncytiotrophoblasts of the placenta.”

“In these studies, thymic lymphoid depletion did not result in depletion of T cells and was not associated with an increase in infections.”

“Teprotumumab staining was detected in all human tissues examined, except for bone marrow.”

“Beside the potential of tislelizumab to induce neutralising ADA and to possibly induce an enhanced recall response to the re-challenge antigen, no other toxicities were detected.”

“No specific tissue-cross reactivity with tislelizumab was noted in cynomolgus monkey or human tissues.”

“Mean anti-KLH IgG titers were mildly to moderately decreased at 300 mg/kg.”

“The volume of distribution (Vss) estimated in the PK study (108662) in cynomolgus monkey was approximately 50 mL/kg which is similar to the plasma volume and demonstrated limited extravascular distribution.”

“Guselkumab treatment had no effect on hematology, immunophenotyping, TDAR to KLH, histopathology of immune tissues, or T- and B-cell distribution in monkeys or their offspring.”

“Guselkumab exposure in infants was likely a result of transplacental distribution, as milk samples were below the lowest quantifiable concentration for guselkumab.”

“However, throughout the study, antibodies against ibalizumab were observed in 83% (10/12) and 58% (7/12) of the animals at the low and high dose (25 and 50 mg/kg), respectively.”

“distribution (47-52 ml/kg), approximately the plasma volume of the monkeys, suggesting that the drug was largely restricted to the vasculature.”

“In some toxicity studies shock-like reactions with complement activation and the formation of immune complexes due to high levels of anti-natalizumab antibodies were described in some cynomolgus monkeys.”

“In cynomolgus monkeys treated with natalizumab until parturition, low levels of natalizumab were detected in the breast milk of some animals”

“At both doses evaluated, slight increases (<3.5-fold) in IL-6 and IL-12 levels were evident, consistent with the release of cytokines seen following treatment of chimps with teplizumab.”

“Staining of lymphoid cells in B regions or non-T regions of lymphoid tissues was not observed.”

“Repeated SC injection of ALXN1210 caused a severe immunological reaction in rabbits, indicative of a systemic, type III hypersensitivity response with an immune complex etiology.”

“However, with the exception of the staining of proteinaceous material, all staining observed in this study was cytoplasmic in nature, and it is unlikely that the cytoplasm and cytoplasmic structures would be accessible to the test article in vivo.”

“Increases in lymphocytes, neutrophils, and NK cells were also noted in rats. The rats did appear to develop an anti-drug antibody response which affected the pharmacokinetics of dinutuximab, particularly at the lowest dose level.”

“Conclusion: Membrane/membrane granules of kidney, GI, spleen, GALT, ovary, neurons, cerebrum, and brain were identified as ch14.18-target tissues in humans.”

“In monkeys that received cosibelimab, 10% to 50% of animals were confirmed positive for the presence of ADAs during the dosing or recovery phase, with the incidence tending to decrease with increasing dose.”

“The mean half-life value was 439 hours following administration of the 100 mg/kg/dose on Day 92.”

“It appeared like ADA were primarily formed in the lowest dose groups (at 0.675 mg/kg and 0.5 mg/kg in the 1- and 3-months study respectively).”

“These results demonstrate that inebilizumab-cdon crosses the placenta and depletes B cells in the fetus.”

“Nine of ten monkeys in the low dose group were MAHA positive (Monkey anti-human antibody defined as anti-panitumumab antibody); frequency for MAHA positive was 2/10 and 1/10 in the mid and high dose groups.”

“Further, no binding of panitumumab was noted in human or monkey cardiac tissue in a formal tissue cross-reactivity studies which utilised optimised immunohistochemical techniques to assess specific panitumumab binding.”

“Nine of 36 treated animals were positive for ADA post-dose (7/12 LD animals, 2/12 HD animals). Positive ADA response did not notably affect drug exposure.”

“No plasma membrane staining with pozelimab was observed. Given the low likelihood that pozelimab will enter the cytoplasm of cells and in the absence of adverse effects in the 13- and 26-week toxicity studies, the risk of off-target binding by pozelimab resulting in clinically relevant toxicity is minimal.”

“ADAs were observed in 20% of male and female monkeys in the 25 and 50 mg/kg/dose groups, but not in the highest dose groups. No effect on exposure was observed.”

“Sibeprenlimab demonstrated placental crossing capability, with infant drug concentrations measuring 3.7-fold higher than maternal levels at postpartum Day 28.”

“This anaphylactoid reaction was associated with the presence of high levels of ADA. As immunogenicity to a human protein in animals is not predictive for clinical immunogenicity, the finding is not considered indicative of a clinical risk.”

“In a tissue cross-reactivity study, eptinezumab staining was generally in blood vessels including endothelium, smooth muscle, and adventitia.”

“In this study, ADAs were detected in 13/18 animals but not in the 4-week toxicity study.”

“Zolbetuximab crossed the placental barrier resulting in higher fetal serum concentrations on Day 18 of gestation than maternal serum concentrations on Day 16 of gestation.”

“Despite the presence of omalizumab:IgE complexes in the monkey studies, there were no indications of immune complex-mediated disease.”

“Measurable levels of omalizumab were observed in amniotic fluid (~3.3% of maternal serum levels), milk (~0.154%), and fetal (~33%) and neonatal (~33%) serum.”

“Antidrug antibodies were observed in only 2 of 40 OMS721 treated monkeys. There was no effect of ADA status on serum OMS721 concentration.”

“Narsoplimab was present in serum of F1 offspring, presumably via transfer during the lactation period. Levels of narsoplimab in maternal milk were not measured.”

“Ipilimumab generally was not immunogenic in monkeys. When including the animals with a weak antibody response, a value of 12% was calculated for the frequency of anti-ipilimumab-Ab positive animals.”

“In tissue cross-reactivity studies, ipilimumab specifically bound to activated lymphocytes expressing CTLA-4 in several normal human and/or cynomolgus monkey tissues. In addition, ipilimumab bound specifically to connective tissue in human and cynomolgus monkey placenta and to connective tissue in cynomolgus monkey ovary; no specific binding was observed in human ovary.”

“While ADAs were detected, and associated with decreases in plasma exposure in some animals, the adequacy of the studies was not adversely affected.”

“Studies in pregnant and lactating monkeys demonstrated placental transfer (umbilical cord blood:maternal blood ratios of 0.1-0.8) and excretion in milk”

“No anti-bezlotoxumab or anti-actoxumab antibodies were detected in any animals in the test article-treated groups.”

“In vivo tissue distribution studies in hamsters demonstrated that actoxumab and bezlotoxumab reached the site of infection in the lumen of the gut, and were detected at significantly higher levels in hamsters with CDI compared with healthy hamsters.”

“Upon exposure of PBMCs to retifanlimab concentrations of 10 µg/mL and 100 µg/mL (ie, 10-200 times higher than the positive control antibody OKT3), no cytokine production was observed with all three conditions of retifanlimab presentation.”

“Staining was observed in expected tissues and was limited to lymphocytes.”

“Studies with raxibacumab in rabbit, cynomolgus macaque, and human donor tissues showed no cross reactivity with brain.”