# Glycoengineering eCD4-Ig

> **NIH NIH R44** · EMMUNE, INC · 2021 · $300,000

## Abstract

ABSTRACT
 We are developing eCD4-Ig, an antibody-like molecule constructed from CD4, a coreceptor-mimetic
peptide, and an antibody Fc, as a long-acting injectable therapeutic for HIV. Our progress to-date
includes having extended the plasma half-life of eCD4-Ig to the point that it now rivals or surpasses that
of the leading broadly neutralizing antibodies (bNAbs) being developed as long-acting injectables. In a
head-to-head comparison of pharmacokinetics (PK) in the human FcRn-transgenic mouse model,
eCD4-Ig had significantly better PK than a VRC01 protein that had a half-life of 71 days in humans
(Gaudinski et al., PLoS Med, 2018). With support from NIAID, we have developed a CHO cell line for
manufacturing eCD4-Ig under cGMP conditions. However, in-depth analysis of the composition of the
N-linked glycans (NLGs) at N297 of the Fc of the protein made by the cell line has highlighted a
problem shared by the entire field: The large majority of the NLGs are forms detrimental to PK. This
problem is particularly pronounced among the afucosylated forms that are active for antibody-
dependent cell-mediated cytotoxicity (ADCC). Indeed, only a few percent of the NLGs are afucosylated
forms that allow both ADCC and a long half-life. Therefore, we propose glycoengineering our cell line
for manufacturing eCD4-Ig. To do so, we will develop a glycoengineering gene cassette, introduce it
into the cell line, and derive a glycoengineered clone for manufacturing eCD4-Ig under cGMP
conditions. Although our primary goal is to manufacture eCD4-Ig protein consisting almost entirely of a
single long-lived glycoform that is active for ADCC, the same glycoengineering gene cassette can be
used to manufacture other antibody therapeutics, including bNAbs, to similarly extend effector function
and plasma half-life. This work will reduce the therapeutic concentration and increase the interval at
which long-acting protein therapeutics for treating and preventing HIV infection can be dosed.

## Key facts

- **NIH application ID:** 10326424
- **Project number:** 1R44AI165255-01
- **Recipient organization:** EMMUNE, INC
- **Principal Investigator:** MICHAEL DAVID ALPERT
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $300,000
- **Award type:** 1
- **Project period:** 2021-07-14 → 2022-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10326424

## Citation

> US National Institutes of Health, RePORTER application 10326424, Glycoengineering eCD4-Ig (1R44AI165255-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10326424. Licensed CC0.

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