# Development of novel small molecule analgesics modulating the nNOS-NOS1AP protein-protein interaction

> **NIH NIH R44** · ANAGIN · 2020 · $286,072

## Abstract

Abstract
This application, “Development of novel small molecule analgesics modulating the nNOS-NOS1AP protein-
protein interaction,” addresses the critical need for more effective medications to treat chronic neuropathic pain
affecting ~116 million people in the United States. Current pain medications such as NSAIDS, steroids, opiates
and gabapentin analogs have documented and often severe side effects, are poorly effective in neuropathic
pain and provide adequate relief only in limited subsets of patients. Because of its high prevalence and poor
treatment options, chronic pain results in socioeconomic costs estimated at $560-635 billion annually in the
US. Activation of NMDA receptors (NMDARs) mediates central nervous system sensitization, which is
implicated in the development and maintenance of neuropathic pain. NMDA-mediated central sensitization
depends on formation of a multi-protein cascade complex at the receptor that includes post-synaptic density 95
protein (PSD95), neuronal nitric oxide synthase (nNOS) and NOS1 adaptor protein (NOS1AP). A peptide
disruptor of the NMDAR multi-protein complex is efficacious in preclinical stroke and pain models and is
currently in clinical trials for ischemic stroke. Small molecule inhibitors targeting this complex have the potential
to be effective analgesics without the side effects associated with broad inhibition of NMDARs. A direct
downstream effector of the NMDAR complex is nNOS-NOS1AP. A compound inhibiting this complex will likely
be efficacious against neuropathic pain, stroke and chronic neurological diseases precipitated or exacerbated
by excessive NMDAR activity. In the funded Phase I SBIR program, our team ran an extensive small molecule
high-throughput screen to identify inhibitors of the nNOS-NOS1AP protein-protein interaction. After
confirmation of activity, selectivity and initial administration-distribution-metabolism-excretion/toxicity (ADME/T)
studies on the top leads, we chose two drug-like, selective nNOS-NOS1AP inhibitors with distinct scaffolds for
in vivo studies. Both inhibitors are efficacious in pain models. We initiated a small chemistry effort on one
chemical series, identifying regions for selectivity and potency. In the current proposal, a traditional drug
medicinal chemistry approach will be used to design and develop novel analogs with improved
pharmacokinetic properties and potency compared to the parent compounds. Anagin and its research partners
at AMRI and Indiana University will advance at least one series through early lead optimization studies. In
addition to improving potency and ADME/T properties, we will demonstrate that the best analogs are acting on
the intended target in cells, validate their activity in two preclinical pain models and assess their safety profile in
key behavioral in vivo models. Compounds that do not meet our set criteria will not be advanced. We anticipate
that our lead compound would have a better therapeutic index than current pain medic...

## Key facts

- **NIH application ID:** 10016857
- **Project number:** 5R44NS098885-04
- **Recipient organization:** ANAGIN
- **Principal Investigator:** STEPHANIE K FLORIO
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $286,072
- **Award type:** 5
- **Project period:** 2016-08-15 → 2022-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10016857

## Citation

> US National Institutes of Health, RePORTER application 10016857, Development of novel small molecule analgesics modulating the nNOS-NOS1AP protein-protein interaction (5R44NS098885-04). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10016857. Licensed CC0.

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