Systematic Catalogue of FDA-Approved Drugs with Macaque Evidence

Provenance: User-pasted report delivered via Hermes WebUI, 2026-09-12 (second report on this topic; companion to raw/articles/fda-macaque-target-evidence-report-2026.md). AI-generated (ChatGPT conversation excerpt). Content: Tier A/B/C framework + catalogue of ~35 FDA-approved drugs with macaque evidence, gold-standard cases, Animal Rule drugs, and negative controls. Verbatim text follows; key claims were web-verified during ingest — see macaque-target-validation for per-case status.

Yes. I think the more useful way to organize this is not simply “FDA-approved drugs that used macaques”, but to distinguish what the macaque actually contributed to the drug-development argument.

I would use the following hierarchy:

Tier A — Direct macaque efficacy / disease-model evidence: the drug altered a disease phenotype, pathological endpoint, or clinically meaningful physiological phenotype in macaques.
Tier B — Target-specific macaque pharmacology / PD: the macaque demonstrated target engagement and a downstream biological effect, but did not provide the main disease-efficacy experiment.
Tier C — NHP PK / safety / species relevance only: macaques were important to development, but there is little basis for claiming that macaque work validated the therapeutic target itself.

That distinction produces a much stronger argument than simply counting NHP studies.

Systematic catalogue of FDA-approved drugs with macaque evidence

Drug	FDA-approved target / mechanism	Disease / indication	Macaque species	What macaques contributed	Tier
Nemolizumab (NEMLUVIO)	IL-31RA	Atopic dermatitis; prurigo nodularis	Cynomolgus	IL-31 produced an itch phenotype; nemolizumab inhibited IL-31-driven scratching in vivo	A
Mepolizumab (NUCALA)	IL-5	Eosinophilic asthma; eosinophilic diseases	Cynomolgus	Reduced circulating eosinophils and pulmonary eosinophilia in an Ascaris-induced asthma model	A
Tocilizumab (ACTEMRA)	IL-6R	Rheumatoid arthritis and other inflammatory disease	Cynomolgus	Pharmacologically relevant primate inflammatory/arthritis studies; demonstrated consequences of IL-6R blockade	A
Denosumab (PROLIA/XGEVA)	RANKL	Osteoporosis; skeletal disease	Cynomolgus	Ovariectomized monkeys: reduced bone turnover, increased BMD and bone strength; model closely recapitulated postmenopausal bone loss	A
Romosozumab (EVENITY)	Sclerostin	Osteoporosis	Cynomolgus	Ovariectomized monkeys showed large increases in BMD, bone formation and bone strength; additional fracture/healing model	A
Ranibizumab (LUCENTIS)	VEGF-A	Neovascular AMD and retinal vascular disease	Cynomolgus	Laser-induced CNV model: reduced CNV development and vascular permeability	A
Aflibercept (EYLEA)	VEGF-A / VEGF trap	Neovascular AMD etc.	Cynomolgus	Laser-induced CNV: reduced lesion severity/leakage and demonstrated activity against established lesions	A
Faricimab (VABYSMO)	VEGF-A + Ang-2	Retinal vascular disease	Cynomolgus	Laser-induced CNV; reduced lesion severity, with evidence supporting the added Ang-2 mechanism	A/B
Raxibacumab (ABthrax)	Anthrax protective antigen (PA)	Inhalational anthrax	Cynomolgus	FDA Animal Rule pivotal efficacy studies; 40 mg/kg produced 69% 28-day survival vs 0% placebo	A
Tecovirimat (TPOXX)	Orthopoxvirus VP37/F13L	Smallpox	Cynomolgus	Four pivotal NHP/monkeypox efficacy studies; significant survival benefit and dose/duration optimization	A
Remdesivir (VEKLURY)	Viral RNA-dependent RNA polymerase	COVID-19	Rhesus	SARS-CoV-2 macaques showed reduced clinical disease, lung pathology and lung viral burden	A
Cabotegravir (VOCABRIA/CABENUVA/APRETUDE)	HIV integrase	HIV treatment/prevention	Rhesus/pigtail	Multiple macaque SHIV/SIV studies demonstrated strong protection at clinically relevant exposure and supported long-acting PrEP development	A
Benralizumab (FASENRA)	IL-5Rα	Eosinophilic asthma	Cynomolgus	Species-relevant receptor binding and profound depletion/suppression of eosinophils and precursors	B+
Erenumab (AIMOVIG)	CGRP receptor	Migraine	Cynomolgus	Inhibition of capsaicin-induced dermal vasodilation, a functional readout of CGRP-receptor blockade	B
Fremanezumab (AJOVY)	CGRP	Migraine	Cynomolgus	Demonstrated inhibition of CGRP-mediated/neurogenic vasodilation	B
Galcanezumab (EMGALITY)	CGRP	Migraine	Cynomolgus	~86% inhibition of capsaicin-induced dermal blood flow at 5 mg/kg IV	B
Eptinezumab (VYEPTI)	CGRP	Migraine	Cynomolgus	Functional NHP assays demonstrated inhibition of CGRP-mediated vasodilation	B
Inclisiran (LEQVIO)	PCSK9 mRNA	Hypercholesterolemia / ASCVD	Cynomolgus	Reduced circulating PCSK9, with correlated sustained LDL-C and total-cholesterol reductions	B+
Ocrelizumab (OCREVUS)	CD20	Multiple sclerosis	Cynomolgus	Relevant NHP species; rapid depletion of CD20+ B cells to near-undetectable levels	B
Ofatumumab (KESIMPTA/ARZERRA)	CD20	CLL / MS	Cynomolgus	Dose-dependent and prolonged B-cell depletion; clear target-mediated PD	B
Golimumab (SIMPONI)	TNF-α	RA/PsA/AS/UC	Cynomolgus	Cynomolgus TNF was pharmacologically neutralized; macaque was selected as the pharmacologically relevant species	B/C
Sutimlimab (ENJAYVO)	C1s	Cold agglutinin disease	Cynomolgus	Near-complete inhibition of classical complement pathway activity, sustained over repeated dosing	B
Pegcetacoplan (EMPAVELI/SYFOVRE)	C3	PNH; geographic atrophy etc.	Cynomolgus	Monkey was the principal pharmacologically relevant species; inhibited human and cynomolgus complement	B/C
Polatuzumab vedotin (POLIVY)	CD79b	DLBCL	Cynomolgus	Human drug did not adequately cross-react; a cynomolgus-CD79b surrogate ADC was used to demonstrate target-mediated primate pharmacology	B−
Nivolumab (OPDIVO)	PD-1	Cancer	Cynomolgus	Demonstrated species-relevant PD/immunological effects, including altered T-cell phenotypes; tumor efficacy required other models	B
Pembrolizumab (KEYTRUDA)	PD-1	Cancer	Cynomolgus	High-affinity binding and target inhibition in monkey; pharmacodynamic saturation demonstrated in repeat-dose studies	B
Tafasitamab (MONJUVI)	CD19	DLBCL	Cynomolgus/rhesus	Relevant primate binding/cross-reactivity and safety pharmacology; no direct primate tumor efficacy model	C/B−
Guselkumab (TREMFYA)	IL-23p19	Psoriasis etc.	Cynomolgus	Important species for chronic safety and pharmacology assessment, but no compelling primate efficacy demonstration	C
Brolucizumab (BEOVU)	VEGF-A	Neovascular AMD	Cynomolgus	Extensive ocular PK and repeat-dose ocular toxicity studies; the key efficacy evidence was not a macaque efficacy model	C
Adalimumab (HUMIRA)	TNF-α	RA/IBD/PsA etc.	Cynomolgus	Developmental/reproductive studies; macaques demonstrated safety rather than target efficacy	C
Certolizumab pegol (CIMZIA)	TNF-α	RA/IBD/PsA	Cynomolgus	Pharmacokinetic and repeat-dose toxicology because of limited rodent cross-reactivity; no major macaque efficacy demonstration	C
Daratumumab (DARZALEX)	CD38	Multiple myeloma	Cynomolgus + chimpanzee	Important lesson: daratumumab did not bind cynomolgus/rhesus CD38; NHP studies therefore relied on surrogate material and were not target-validation experiments for the human drug	C
Lecanemab (LEQEMBI)	Aggregated Aβ	Alzheimer’s disease	Cynomolgus	Monkey PK supported development, but the disease-modifying efficacy evidence came principally from transgenic mouse models and clinical studies	C
Donanemab (KISUNLA)	Aβ-pE3	Alzheimer’s disease	Cynomolgus	Cynomolgus PK/safety; young monkeys were not expected to express the pharmacological target, making them unsuitable for efficacy	C
Aducanumab (ADUHELM)	Aggregated Aβ	Alzheimer’s disease	Cynomolgus	Extensive monkey PK/toxicology, but not a disease-efficacy validation model	C

The strongest cases are actually stronger than the earlier list suggested

There are several cases here that I would put in a “gold standard” subgroup because the macaque provides something much harder to obtain from a conventional rodent.

1. IL-31RA → nemolizumab

This remains perhaps the cleanest example for the argument you’re developing.

FDA explicitly states that nemolizumab:

binds human and cynomolgus IL-31RA;
blocks IL-31 signaling;
and inhibits IL-31-induced itching in cynomolgus monkeys.

So the chain is unusually direct:

human target → conserved primate target → target activation → disease-relevant behavioral phenotype → pharmacological reversal

(FDA Access Data)

That is much stronger than simply saying “macaques were used in toxicology.”

2. RANKL → denosumab

This may actually be one of the best examples for your broader thesis because FDA explicitly explains why macaques were needed.

Denosumab binds human and NHP RANKL but does not bind rodent RANKL, so conventional rodent pharmacology could not substitute for the primate.

The ovariectomized cynomolgus-monkey model then produced a clinically meaningful osteoporosis phenotype. Denosumab reduced bone formation and resorption markers, increased BMD, prevented ovariectomy-associated loss of cortical and cancellous bone, and increased bone strength.

That is a remarkably complete:

target → mechanism → disease model → therapeutic phenotype

relationship. (FDA Access Data)

3. Sclerostin → romosozumab

Romosozumab is another unusually compelling example.

In ovariectomized cynomolgus monkeys, treatment increased BMD by roughly 14–26% at the lumbar spine and proximal femur, with corresponding increases in bone strength. A separate monkey study used an actual critical bone-defect/fracture-repair paradigm. FDA’s review explicitly describes these studies. (Wiley Online Library)

This is especially interesting because bone architecture and biomechanics are considerably more human-like than many small-animal osteoporosis endpoints.

4. VEGF → ranibizumab / aflibercept / faricimab

This is arguably the strongest entire therapeutic class.

For ranibizumab, FDA’s original review reports that the molecule could limit development of CNV and reduce vascular permeability in monkeys. (FDA Access Data)

For aflibercept, FDA specifically states:

“Primary pharmacology studies showed VEGF-Trap reduced choroidal neovascular (CNV) lesions in monkeys…”

(FDA Access Data)

And for faricimab, FDA reports that cynomolgus monkeys with laser-induced CNV showed dose-dependent reductions in lesion severity, with faricimab outperforming ranibizumab at an equimolar binding-site comparison. (FDA Access Data)

This is important conceptually because the macaque was not merely a convenient toxicity species: the relevant tissue, vascular anatomy and disease phenotype made the NHP model a biologically informative bridge to humans.

The CGRP story is particularly interesting

The four anti-CGRP migraine biologics provide a very nice target-class replication argument:

Target	Approved drug	NHP functional assay
CGRP receptor	Erenumab	Capsaicin-induced dermal blood-flow inhibition
CGRP	Fremanezumab	Neurogenic/CGRP-mediated vasodilation inhibition
CGRP	Galcanezumab	~86% reduction of capsaicin-induced dermal blood flow
CGRP	Eptinezumab	Functional inhibition of CGRP-mediated vasodilation

Erenumab’s FDA review specifically discusses capsaicin-induced dermal blood flow as a functional readout of CGRP-receptor inhibition. (FDA Access Data)

Fremanezumab’s pharmacology review similarly describes inhibition of neurogenic and capsaicin-induced vasodilation. (FDA Access Data)

For galcanezumab, the FDA package reports approximately 86% inhibition in cynomolgus monkeys at 5 mg/kg IV. (FDA Access Data)

I would classify these as Tier B rather than Tier A, because the macaque demonstrated pathway pharmacology rather than a macaque migraine disease phenotype. Nevertheless, the convergence of four independently developed approved drugs is powerful.

PCSK9 → inclisiran is another unusually clean molecular example

Inclisiran is not a biologic antibody, so it demonstrates that the phenomenon isn’t limited to therapeutic antibodies.

FDA reports that subcutaneous inclisiran in cynomolgus monkeys decreased plasma PCSK9 and that the reduction correlated with sustained reductions in LDL-C and total cholesterol. (FDA Access Data)

That gives you:

gene target → target knockdown → circulating protein → physiological biomarker

in an NHP.

This is exactly the sort of evidence that could support a “human-relevance validation layer” argument.

The Animal Rule provides an even more dramatic category

Two cases should probably be highlighted separately because the FDA actually relied on animal efficacy because human efficacy trials were not ethically/practically feasible.

Raxibacumab → anthrax protective antigen

FDA evaluated raxibacumab in cynomolgus macaques challenged with lethal aerosolized B. anthracis. At 40 mg/kg, survival was:

9/13 (69%) macaques vs 0/10 controls

with a highly significant difference. (FDA Access Data)

Raxibacumab was ultimately FDA-approved under the anthrax therapeutic framework. (FDA Access Data)

This is therefore not merely “NHP informed development.” NHP efficacy substituted for conventional human efficacy evidence.

Tecovirimat → orthopoxvirus VP37

This is even stronger.

FDA states explicitly that tecovirimat’s approval for smallpox was supported under the Animal Rule, with efficacy demonstrated in monkeypox-infected cynomolgus macaques and rabbitpox-infected rabbits. ([FDA Access Data][13])

Four pivotal NHP studies were conducted, examining dose, treatment duration and treatment delay. FDA reports significant survival advantages even when therapy was initiated after clinical disease had appeared. ([FDA Access Data][14])

The mechanistic aspect is also unusually clean: resistance-associated substitutions arose in VP37, the defined drug target, linking genotype → target → drug resistance in the NHP model. ([FDA Access Data][15])

Remdesivir is another important case, with a caveat

The rhesus macaque SARS-CoV-2 study demonstrated reduced clinical disease, pulmonary infiltrates, lung viral load and lung injury following remdesivir treatment. ([PubMed][16])

More importantly, the FDA’s own review quantified the effects: all six treated macaques had significantly reduced clinical signs, reduced pulmonary pathology, and approximately a 2.2-log reduction in lung viral RNA at necropsy. ([FDA Access Data][17])

The caveat is that the macaque disease model is milder and more acute than severe human COVID-19. So I would call this:

A — direct NHP efficacy evidence, but imperfect disease-model fidelity.

That nuance actually strengthens rather than weakens the general argument.

HIV offers a different kind of powerful NHP contribution

Cabotegravir is particularly valuable because macaques were used in transmission/prophylaxis models that are difficult to reproduce in conventional rodents.

Long-acting cabotegravir produced high protection against rectal and vaginal SHIV transmission in macaques at clinically achievable concentrations and was explicitly described as supporting dose selection and clinical development. ([PubMed][18])

There are also intravenous SIV challenge experiments demonstrating substantial protection. ([PubMed Central (PMC)][19])

This is different from the osteoporosis or CNV examples: here the advantage is not primarily anatomy, but the ability to model a complex viral transmission system in an intact primate immune system.

Lenacapavir gives another interesting example, although I would place it in a separate box because the strongest macaque PrEP studies were conducted after its original FDA treatment approval. Those studies nevertheless showed complete protection in the pigtail-macaque simian-tropic HIV model under the tested conditions. ([ScienceDirect][20])

A useful negative-control category

The Tier C cases are actually intellectually important.

Consider daratumumab.

Daratumumab is an anti-CD38 drug, but FDA found that it bound human and chimpanzee CD38 but not cynomolgus or rhesus CD38. Consequently, macaque studies could not directly model the pharmacology of the actual human therapeutic antibody; surrogate antibodies were required. ([FDA Access Data][21])

Similarly, donanemab provides an excellent CNS example of where macaques do not provide meaningful target validation: FDA explicitly notes that the young monkeys used in the studies were not expected to express the pharmacological target AβN3pE-x. ([FDA Access Data][22])

These are useful because they prevent the argument from becoming:

“NHPs are always better.”

A much more defensible claim is:

When the therapeutic target and disease biology are conserved in the primate, macaques can provide a level of target engagement, systems pharmacology and disease validation that cannot be obtained from standard rodent models.

What I think the systematic evidence actually says

A preliminary classification of the examples above gives roughly:

Evidence class	Approx. examples in this dataset	What it demonstrates
A — Direct NHP efficacy	~12	Target manipulation changes a clinically relevant disease/pathophysiological phenotype
B — Target-specific NHP PD	~11	Target engagement produces an integrated physiological/systemic response
C — PK/safety/species relevance only	~9	NHP was useful for development but does not establish target validity
Total identified here	~32	FDA-approved drugs with meaningful macaque involvement

This is not yet an exhaustive census of every FDA-approved drug, so I would not quote “32” as a final epidemiological statistic. It is better treated as a curated, evidence-ranked dataset.

The really striking observation

The strongest examples are not random. They cluster around situations where rodents fail to reproduce the relevant human biology, particularly:

human-specific biologics → immune targets → receptor pharmacology → vascular biology → bone biology → complex viral infection/transmission.

And several of the best examples are exactly the sorts of systems where an intact primate has substantial advantages:

IL-31 / itch, IL-5 / eosinophils, RANKL / bone, sclerostin / bone, VEGF / retinal vasculature, CGRP / neurovascular biology, PCSK9 / lipid metabolism, HIV / adaptive immunity, SARS-CoV-2 / respiratory disease.

That pattern is much more interesting than simply showing that “macaques occur somewhere in an FDA dossier.”

Sources supporting the central examples

FDA’s original and review documents provide especially strong primary evidence for nemolizumab, mepolizumab, denosumab, romosozumab, ranibizumab, aflibercept, faricimab, inclisiran, ocrelizumab, ofatumumab, sutimlimab, pembrolizumab, nivolumab, tecovirimat and raxibacumab. (FDA Access Data)

The next step I would recommend is to turn this into a proper systematic evidence matrix, with columns for FDA drug, target, approval year, indication, macaque species, study design, n, endpoint, whether the target was cross-reactive, whether macaque data affected dose selection, whether macaque efficacy was part of the approval package, Animal Rule status, and primary FDA/paper citation. That would let us calculate something much more persuasive, such as the proportion of NHP-involved approvals in which macaque data contributed target validation vs PK/PD vs safety only.

[13]: https://www.accessdata.fda.gov/drugsatfda_docs/nda/2018/208627Orig1s000PharmR.pdf?utm_source=chatgpt.com “NDA 208627

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