pe
pep-10778 v1 CC-BY-SA-4.0

Davunetide: brain-protecting peptide (NAPVSIPQ)

A tiny peptide snipped from a critical brain protein that shields neurons from damage; studied in clinical trials for neurodegenerative and cognitive conditions, but not yet an approved drug.

statusbioassayed targetLONGEVITY length8 aa refs6
status 3 / 5 · 1 verified on platform
prediction metrics boltz-2 2.2.1
ipTM0.000
pTM0.217
avg pLDDT97.3
ranking score0.822
STRUCTURE · PEP-10778 × LONGEVITY
ranking0.822
?
RECEPTOR UNKNOWN
peptide conformation only · no target structure
target interface 4.5Å peptide drag rotate · ctrl+scroll zoom · right-click pan
sequence8 aa
158
NAPVSIPQ
in the news 8 articles
overview readme

What this is

NAP (also called davunetide or CP201) is a tiny 8-amino-acid peptide — the sequence NAPVSIPQ — snipped out of a much larger brain protein called ADNP (Activity-Dependent Neuroprotective Protein). Despite its small size, it protects neurons at extraordinarily low concentrations, active in the femtomolar range (10⁻¹⁵ M) that are far below most drugs. The ADNP gene is essential for mammalian brain formation: complete loss of ADNP in mice is embryonic-lethal, while partial loss causes cognitive deficits. NAP carries the key neuroprotective activity of the parent protein and has been studied in human clinical trials for several neurodegenerative and cognitive conditions.

History

ADNP was discovered in the Gozes laboratory at Tel Aviv University around 1999. The initial line of inquiry began with vasoactive intestinal peptide (VIP), a neuropeptide that had long been known to protect neurons and promote synapse formation through glial activation. Searching for proteins regulated by VIP in cerebral cortical astrocytes, Gozes and colleagues identified a novel 828-amino-acid protein they named Activity-Dependent Neuroprotective Protein — ADNP. Peptide activity scanning of the ADNP sequence located a short 8-residue motif, NAPVSIPQ, that retained the parent protein's neuroprotective activity at femtomolar concentrations. This fragment was named NAP after the first three residues of its sequence (Gozes and colleagues, Annals of the New York Academy of Sciences, 1999).

Development of NAP as a drug candidate was taken up by Allon Therapeutics (Vancouver, Canada), which developed an intranasal formulation known as AL-108, and later advanced the compound under the name davunetide into Phase 1, Phase 2, and Phase 2/3 trials. After Allon Therapeutics became insolvent and was acquired by Paladin Labs in 2013, clinical development stalled. Interest was revived when ADNP mutations were identified in 2012–2014 as a cause of a rare neurodevelopmental disorder now called ADNP syndrome (Helsmoortel-Van der Aa syndrome). Exonavis Therapeutics licensed davunetide from Tel Aviv University in 2021 and has been pursuing it as a treatment for children with ADNP syndrome, with a Phase 3 trial begun in October 2024.

What it does

In cell culture and animal models, NAP protects neurons against a broad range of insults — beta-amyloid peptide toxicity, oxidative stress, stroke, closed head injury, glucose deprivation, HIV envelope protein toxicity, and zinc overload, among others. In mouse models of Alzheimer's disease, treatment reduced accumulation of hyperphosphorylated tau and improved cognitive performance (Matsuoka and colleagues, 2008). In a mouse model of alpha-synuclein overexpression relevant to Parkinson's disease, short-term NAP treatment improved motor function and reduced alpha-synuclein inclusions. NAP has also shown protection against ethanol-induced fetal developmental toxicity in mouse embryo models, with half-maximal effects at 36 fM, traced to antagonism of ethanol's disruption of L1-mediated cell adhesion (Wilkemeyer and colleagues, 2003).

The compound crosses the blood-brain barrier after both intranasal and intravenous administration, reaching the cerebrospinal fluid.

Mechanism

NAP contains an SxIP motif (the Ser-Ile-Pro region that is essential for its activity) that directly engages EB1 and EB3 — end-binding proteins that sit at the growing tips of microtubules and serve as master regulators of the microtubule cytoskeleton. By binding to EB1 and EB3, NAP promotes microtubule assembly and stabilizes the cytoskeletal network inside neurons. Silencing EB1 and EB3 (but not EB2) abolishes NAP's neuroprotective activity, confirming these proteins as the critical mediators.

The downstream consequence of this microtubule stabilization is protection against tau pathology. NAP inhibits tau hyperphosphorylation at serine 262 — a site whose phosphorylation impairs tau's ability to bind EB proteins — and produces striking increases (described as approximately 20-fold) in EB1/EB3–tau interactions, recruiting tau back to microtubules under stress conditions (Gozes group, Molecular Psychiatry, 2016). This mechanism distinguishes NAP from conventional tubulin-targeting cytotoxic drugs: it acts selectively on brain-derived tubulin without affecting proliferating cells, and no adverse effects were observed after six months of exposure in animal models.

ADNP itself functions as a chromatin remodeler and transcription factor, interacting with the SWI/SNF chromatin remodeling complex. The NAP fragment captures the microtubule-interacting dimension of ADNP biology.

Evidence

  • Human: Phase 2 trial in amnestic mild cognitive impairment (144 subjects, placebo-controlled, intranasal NAP) showed statistically significant improvement in memory performance versus placebo at 8 and 16 weeks (Gozes and colleagues, 2009). Phase 2 trial in schizophrenia (63 patients) missed the primary composite cognitive battery endpoint but showed significant improvement on a functional capacity measure (UPSA scale); MRS substudy in DLPFC found modest increases in N-acetylaspartate and choline ratios consistent with a neuroprotective signal (Neuropsychopharmacology, 2013). Phase 2/3 trial in progressive supranuclear palsy (Boxer and colleagues, Lancet Neurology, 2014): 313 participants randomized 1:1 to davunetide 30 mg intranasal twice daily or placebo for 52 weeks across 47 sites; the trial found no difference on either primary endpoint (PSP Rating Scale or Schwab–England Activities of Daily Living), establishing that davunetide is not effective for PSP. A Phase 3 trial in children with ADNP syndrome (97 participants, ExoNavis) began October 2024; results are pending.
  • Animal: Reduced tau hyperphosphorylation and improved cognition in transgenic Alzheimer's mouse models; improved motor function and reduced alpha-synuclein inclusions in synucleinopathy mouse models; neuroprotection across stroke, head injury, apolipoprotein E-deficiency, and cholinergic toxicity models.
  • In vitro: Protection at femtomolar concentrations against beta-amyloid, NMDA, oxidative stress, HIV gp120, and zinc toxicity in neuronal cultures; promotion of microtubule assembly and neurite outgrowth in cellular models (Gozes and Divinski, Current Alzheimer's Research, 2007).

Known effects

  • Neuroprotection (broad-spectrum) — Preclinical; demonstrated against multiple distinct neurotoxic insults in vitro and in vivo
  • Tau pathology reduction — Preclinical (AD mouse models); reduced hyperphosphorylated tau and cognitive improvement
  • Microtubule stabilization — Mechanistic; well-characterized via EB1/EB3 interaction and direct tubulin binding
  • Memory improvement (MCI) — Phase 2 human signal (short-term, 8–16 weeks); not replicated in larger trials
  • Functional capacity in schizophrenia — Phase 2 human signal (UPSA endpoint); composite cognition endpoint not met
  • PSP treatment — Phase 2/3 negative; not effective for progressive supranuclear palsy
  • Alpha-synuclein pathology reduction — Preclinical only (mouse model)

Safety signals

Across Phase 1 and Phase 2 human trials in adults, NAP/davunetide was generally reported as safe and well tolerated. Non-clinical toxicology studies at doses up to 300 mg/kg/day in rats, dogs, and mice showed no significant adverse events, providing the safety basis for clinical entry. In the Phase 2/3 PSP trial (Boxer and colleagues, Lancet Neurology, 2014), nasal adverse events were more frequent in the davunetide group than placebo: epistaxis (12% vs. 8%), rhinorrhoea (10% vs. 5%), and nasal discomfort (10% vs. less than 1%). Serious adverse event rates were similar between groups (54 per arm), including 11 deaths in the davunetide arm and 10 in the placebo arm, with no drug-attributed mortality signal identified. No adverse proliferative or cytotoxic effects on non-neuronal tissues have been reported in preclinical studies, consistent with the compound's selectivity for brain-derived tubulin.

Regulatory status

  • US: Investigational. No FDA approval. FDA Orphan Drug Designation and Rare Pediatric Disease Designation granted for ADNP syndrome treatment.
  • EU: EMA Orphan Drug Designation for ADNP syndrome.
  • WADA: Not listed on the WADA Prohibited List (not a performance-relevant compound).

Related peptides

NAP (NAPVSIPQ) belongs to the family of ADNP-derived neuropeptides. A companion peptide SAL (SALLRSIPA), also derived from ADNP, shares the SxIP motif and shows overlapping neuroprotective activity in vitro. More recently, researchers designed mirror-image variants (D-NAP, SKIP, D-SKIP) to probe the structural requirements for activity and extend half-life. The parent protein ADNP is itself regulated downstream of VIP/PACAP receptor signaling; see the VIP card for the upstream signaling context.

Hypotheses4 directions▾ collapse

Research directions for this peptide, selected from the current sources — hypotheses you can explore and model. None of it is proven yet; tap any one to see the full thinking.

openupdated 2026-06-11

Could giving children with ADNP syndrome extra doses of the NAP fragment help reduce cognitive and behavioral symptoms?

If it worked, children with this severe autism-intellectual disability syndrome, which has no approved treatment, might gain an option using a compound already tested for safety in adults.

The hypothesis
Davunetide has therapeutic potential in ADNP haploinsufficiency syndrome (Helsmoortel-Van der Aa syndrome), a rare autism-spectrum intellectual disability caused by de novo ADNP mutations, where exogenous NAPVSIPQ could compensate for the loss of neuroprotective signaling from the mutant allele.
Why it’s plausible
ADNP haploinsufficiency causes a defined pediatric syndrome. The NAP motif is the minimal active fragment of ADNP for neuroprotection. If the loss-of-function in ADNP syndrome is partly mediated by failure to produce or correctly fold NAP-like activity, then exogenous NAP peptide at femtomolar concentrations could act as a replacement. This is distinct from adult-onset neurodegeneration clinical trials already conducted for NAP. The pediatric genetic disease has no approved treatment and represents an unmet need that aligns directly with NAP's known mechanism.
Why it matters
Davunetide is a clinically tested compound with known safety profile. Repurposing it into a pediatric orphan indication for ADNP syndrome would require only targeted efficacy studies, offering a faster route to treatment than de novo drug discovery for a currently untreatable condition.
Plausibility.65
Novelty.50
Impact.75
Basis · grounding2 computed/notes
[1]
noteComplete ADNP loss is embryonic-lethal in mice; partial loss causes cognitive deficits; this maps directly onto the human Helsmoortel-Van der Aa syndrome caused by heterozygous ADNP mutations.
[2]
noteNAP carries the key neuroprotective activity of the parent protein ADNP and has been studied in human clinical trials for neurodegenerative conditions, establishing safety and central access data.
openupdated 2026-06-11

Could attaching a small targeting molecule to the free end of davunetide guide it into the brain from a simple injection or pill?

If the tagged peptide reaches the brain more efficiently, the same protective effect could be achieved with a lower dose or via a more convenient route, benefiting patients with Alzheimer's disease, traumatic brain injury, or stroke who currently have limited effective treatment options.

The hypothesis
Davunetide can be engineered into a bifunctional conjugate by C-terminal extension with a blood-brain barrier (BBB) shuttle peptide, improving CNS bioavailability by at least one order of magnitude without losing femtomolar activity, because the Q at position 8 provides a free C-terminus amenable to linker attachment that does not contact the putative binding interface.
Why it’s plausible
The current challenge for davunetide clinical use is CNS delivery; intranasal administration has been the primary route. If the active surface of NAP is on the N-terminal NAPVSI face (as implied by the SxIP-like motif centered on VSIP), then the C-terminal Q and the free carboxyl are peripheral to binding. Appending a known BBB-penetrating motif (e.g., angiopep-2, rabies virus glycoprotein RVG peptide, or transferrin receptor-binding sequences) at the C-terminus could create a self-delivering neuroprotective conjugate active at femtomolar concentrations.
Why it matters
Poor CNS penetration is a primary limitation of peptide-based neurological drugs. A validated BBB-shuttle conjugate of davunetide would remove the biggest barrier to systemic or oral administration, enabling clinical use outside of specialized nasal delivery protocols.
Plausibility.60
Novelty.55
Impact.60
Basis · grounding1 paper · 2 computed/notes
[1]
sequenceThe C-terminal glutamine (Q8) of NAPVSIPQ is outside the putative SxIP-like VSIP motif at positions 4-7, suggesting it is not required for the core binding interaction and is available for conjugation.
[2]
noteDavunetide has been studied in human clinical trials for neurodegeneration, indicating acceptable safety; the primary delivery challenge is CNS access, which conjugation strategies are designed to address.
[3]
paper
2025 study applying davunetide in chronic brain ischemia models highlights ongoing need for effective CNS delivery of NAP-related peptides.
doi: 10.12775/jehs.2025.83.70617
openupdated 2026-06-11

Does davunetide's brain-focused activity depend on binding a protein found mostly in neurons?

If confirmed, this would suggest fewer side effects outside the brain, which could make the peptide more attractive for diseases like Alzheimer's or frontotemporal dementia.

The hypothesis
Davunetide exhibits selective activity in neurons over non-neural cell types because its femtomolar potency depends on a neuron-enriched binding partner (such as CRMP2 or EB3) rather than a ubiquitous receptor; in non-neuronal tissues the peptide is inert at physiological concentrations.
Why it’s plausible
NAP is derived from ADNP, a protein whose expression is highest in the brain. The VIP-pathway origin of ADNP discovery implies it was found in a neuronal context. CRMP2 (collapsin response mediator protein 2) is neuron-enriched, interacts with microtubule end-binding proteins, and has been linked to ADNP biology. If NAPVSIPQ's SxIP-like VSIP motif specifically engages EB3 (the brain-dominant EB isoform over EB1), that would produce inherent neural selectivity without any receptor subtype distinction.
Why it matters
Understanding the basis of neural selectivity is critical for predicting off-target effects and for deciding whether davunetide can be used systemically or must be delivered intranasally/centrally. It also identifies whether dose-escalation could cause peripheral toxicity.
Plausibility.70
Novelty.35
Impact.55
Basis · grounding1 paper · 2 computed/notes
[1]
sequenceNAPVSIPQ contains VSIP motif; EB3 (MAPRE3) is expressed predominantly in neurons while EB1 is ubiquitous, so if VSIP preferentially engages EB3, selectivity follows from isoform distribution.
[2]
noteADNP was discovered in cerebral cortical astrocytes activated by VIP, and NAP retains the parent protein's neuroprotective activity, implying a brain-tissue-specific mechanistic context.
[3]
paper
PACAP/PAC1 analogue literature cited alongside NAP; PAC1 is expressed widely but at highest density in neurons, suggesting the VIP/PACAP receptor family context does not account for strict neural selectivity, pointing to a separate neuronal-enriched mechanism.
doi: 10.1111/j.1476-5381.2011.01676.x
openupdated 2026-06-11

Are the two proline residues (at positions 3 and 7) in davunetide important for its low-dose brain protection?

If proline-enforced shape matters, chemists could try building a stable small molecule with the same shape, potentially enabling an oral form where current peptides need nasal or injected delivery.

The hypothesis
The proline at position 6 of NAPVSIPQ (sequence: N-A-P-V-S-I-P-Q) is a structural switch that introduces a local turn preventing the peptide from adopting an extended beta-strand, and this rigid conformation is essential for its femtomolar activity; substituting Pro6 with any alpha-helix or beta-strand-favoring residue would abolish neuroprotection.
Why it’s plausible
Pro residues enforce backbone rigidity and restrict phi/psi angles, creating predictable turns. In an 8-mer, two prolines (positions 3 and 7 in standard numbering, i.e., P at aa3 and P at aa7 of NAPVSIPQ) would create a constrained cyclic-like backbone topology. The high pLDDT of 97.3 for this monomer suggests the predicted structure is well-defined despite being an 8-mer. If both prolines are load-bearing for activity, single or double Pro-to-Ala substitution should produce a sharp activity cliff, useful for SAR mapping.
Why it matters
Pinning which backbone atoms are required for activity is the first step toward peptidomimetic design: a constrained non-peptide scaffold mimicking the Pro-kinked conformation could achieve NAP-like potency with improved metabolic stability for CNS drugs.
Plausibility.45
Novelty.40
Impact.50
Basis · grounding2 computed/notes
[1]
sequenceSequence NAPVSIPQ contains prolines at positions 3 and 7 (1-indexed), both of which would impose backbone constraints at two ends of a short 8-aa peptide, defining a constrained loop or turn topology.
[2]
structurepLDDT=97.3 for the 8-mer monomer is unusually high for such a short peptide and implies a well-defined predicted structure, consistent with the proline constraints locking the backbone conformation.
details expand to inspect
full evidence table1 metrics
metricvaluetool
ranking score 0.8215410113334656 boltz-2
3-letter notation
Asn-Ala-Pro-Val-Ser-Ile-Pro-Gln
recipeboltz-2 2.2.1
parametervalue
modelboltz-2 2.2.1
weights
hardwarevast_v100_32gb
mlx version
python
random seed1
msa strategynone_monomer
runtime
predicted by
predicted at2026-05-23
citationbibtex
peptidemodel (2026). Davunetide: brain-protecting peptide (NAPVSIPQ) (pep-10778, v1). PeptideModel. https://peptidemodel.com/card/pep-10778
@peptide{pep10778,
  sequence = {NAPVSIPQ},
  target   = {longevity},
  author   = {peptidemodel},
  year     = {2026},
  status   = {bioassayed}
}
clinical trials 2 on ct.gov · checked 2026-05-22
ct.gov trials 2
with results 1
PubMed reviews 4
by phase
1phase 11phase 2
by status
2completed
references 6 papers
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