Which animal species did regulators accept for approved oligonucleotides?

“The pivotal (GLP) general toxicity studies were conducted in adult male C57BL/6NCrl mouse and cynomolgus monkey.”

“The pharmacological activity of casimersen was tested in vitro using human rhabdomyosarcoma cells and normal primary myoblasts, as there are no relevant animal models due to the species- and mutation-specific nature of PMO ASOs.”

“The general toxicity of vutrisiran was tested in GLP-compliant subcutaneous (SC) toxicity studies in Sprague Dawley (SD) rat (13-week, 6-month) and cynomolgus monkey (13-week, 9-month).”

“There is complete homology between human and cynomolgus monkey, but not rodent (mouse, rat) or rabbit, TTR mRNA binding regions. Therefore, vutrisiran is pharmacologically active only in monkey.”

“Mice and cynomolgus monkeys were considered suitable species for the pharmacology assessment because PKK is expressed in both species.”

“Donidalorsen is not pharmacologically active in the mouse due to its lack of complementarity to the mouse PKK gene transcript.”

“The pivotal toxicity studies were conducted in mdx or C57BL mice (12-week, 3-month, and 26-week), cynomolgus monkey (12- and 39-week), and juvenile Sprague-Dawley rat (10-week).”

“For mdx mouse, the pharmacological activity of the human product cannot be tested because of differences in the dystrophin gene mutation, requiring use of a mouse-specific PMO, exon 23 skipping AON and, therefore, resulting in a different truncated dystrophin.”

“In addition to being pharmacologically active in humans, based on the nonclinical data described below, givosiran is also pharmacologically active in both rats and monkeys but is not pharmacologically active in rabbits.”

“This parent duplex, with complete sequence homology to human and monkey ALAS1, and is therefore expected to be pharmacologically active in each of the indicated species.”

“The monkey is the only species identified that could be considered relevant showing 1/10th of the ARC1905 in an in vitro activity assay against human C5.”

“The ocular studies were conducted in rabbit and dogs, which, as the Applicant indicated, are species in which ARC1905 is expected to have very low activity.”

“Mipomersen toxicity has been assessed primarily in the mouse, rat and monkey, with studies of up to 2-years duration (carcinogenicity studies) available for evaluation in the rodents and up to 1-year for the monkey.”

“Species-specific differences in the nucleotide sequence of apoB mRNA caused a reduction (monkey) or complete loss (mouse, rat, dog and rabbit) of the intended pharmacological activity of mipomersen in these species.”

“The drug was pharmacologically active in both rats and NHPs, and therefore these assessments represent characterization of both on-target and off-target effects.”

“The applicant states that the nucleotide sequence of inclisiran exhibits complete homology to the analogous sequences in the human and Cynomolgus monkey PCSK9 genes and partial homology to the rat and mouse PCSK9 gene sequences.”

“From the total of studies performed, the 6-month rabbit and 9-month dog studies are considered pivotal.”

“VEGF seems highly conserved between species and has an identical binding sequence in the pivotal toxicity species (rabbit and dog) as in humans.”

“As a consequence, general toxicology studies have been performed in cynomolgus monkeys (pharmacologically active) and rats (off-target).”

“Patisiran is a siRNA directed against human TTR mRNA and has cross-reactivity in the cynomolgus monkeys, but not in rat mouse or rabbit.”

“The target site of lumasiran in the HAO1 mRNA is conserved across mammalian species and both rodent and monkey are pharmacologically relevant species.”

“Lumasiran is pharmacologically active in both rodents, lagomorphs and nonhuman primates.”

“From the PK point of view, the monkey was the most relevant species for non-clinical efficacy and safety studies.”

“Furthermore, a single base-pair mismatch to the Cynomolgus monkey gene suggests it may be active in NHPs, thereby enabling assessment of possible on-target effects, while wild-type animals of all other species appear not to be suitable due to at least four or more mismatches in the target sequence.”

“Repeat-dose toxicology studies were conducted in healthy rats for up to 26 weeks, healthy monkeys for up to 39 weeks, and in hemophilia mice for up to 26 weeks.”

“Fitusiran is pharmacologically active in mice, rats, monkeys, and dogs because the antithrombin mRNA sequences are highly conserved across species.”

“Monkeys were deemed the most pharmacologically relevant species to evaluate on-target safety profile of plozasiran.”

“The antisense strand of plozasiran is fully complementary to monkey and human ApoC-III mRNAs, whereas plozasiran has seven sequence mismatches to the rodent ApoC-III mRNA transcript.”

“Nedosiran is inactive in the mouse because the LDHA mRNA sequence is different from humans, and hence, the toxicology of nedosiran was studied in the mouse to assess off-target hybridization effects.”

“The monkey is considered a pharmacologically relevant model because the LDHA mRNA target sequence has 100% homology with humans.”

“The mouse and monkey were used for the single- and repeat-dose toxicity studies, and mouse and rabbit were used for the EFD toxicity studies.”

“These species were selected based on sequence homology to the template region of the RNA component of human telomerase and expected relevant pharmacologic action of imetelstat across species, from human to monkey to rabbit to rodent, as well as species-specific sensitivities to known ODN class effects.”

“Based on the intended patient population (neonates to adolescents), 14- and 53-week repeat dose toxicology studies were conducted in juvenile cynomolgus monkeys using IT dose administration.”

“Since humans are the only species known to have the SMN2 gene, in vivo pharmacology was examined in mouse models of SMA in which the endogenous mouse gene has been removed and the human SMN2 gene is expressed.”

“Inotersen is pharmacologically active in cynomolgus monkey but not rodent or rabbit.”

“The target sequence of inotersen is conserved between monkeys and humans, but contains 8 mismatches in rodents and 4 mismatches in rabbits.”

“The general toxicity of olezarsen has been characterized in repeat-dose toxicity studies in CD-1 mice and cynomolgus monkeys in studies of up to 26- and 39-weeks duration, respectively, with once-weekly SC injections.”

“Olezarsen exhibits full complementarity to the apoC-III mRNA transcript of humans and cynomolgus monkeys.”

“Repeat-dose studies in adult male CD1 mice, and single and repeat-dose studies in adult male cynomolgus monkeys were conducted to evaluate the general toxicology of vitolarsen.”

“In vivo assessment of exon 53 skipping was included in the 12- and 39-week toxicity studies in monkey; viltolarsen is not pharmacologically active in rodents.”

“The toxicity of golodirsen was assessed in adult male C57BL/6NCrl mouse and cynomolgus monkey and in male juvenile Sprague Dawley rat.”

“No in vivo nonclinical studies were conducted to assess the extent of exon 53 skipping by golodirsen.”

“Eplontersen is pharmacologically active in monkey but not mouse.”

“The target sequence of eplontersen and inotersen is 100 % complementary to human and Cynomolgus monkey TTR mRNA, whereas 8 mismatches in mice and rats preclude effective hybridisation and, hence, pharmacological activity in these animals.”

“Monkey is considered the most relevant species to humans based on the general pharmacokinetic behavior of 2’-MOE ASOs (plasma AUC, Cmax, and clearance).”

“While monkeys share the same sequence at this site, due to a lack of sequence homology in other species, different 2′-MOE ASOs”

“The nonclinical package submitted to the NDA included general toxicology studies of up to 26 and 39 weeks' duration in mouse (subcutaneous [SC]) and monkey (intrathecal lumbar [ITL]), respectively, as well as a 13-week ICV toxicity study in mouse;”

“No meaningful changes in GFAP mRNA levels were observed in brain or spinal cord tissues, likely due to the single mismatch between zilganersen and monkey GFAP mRNA.”