# DEVELOPMENT OF A LIPOSOMAL PNEUMOCOCCAL VACCINE FOR CLINICAL READINESS

> **NIH NIH R44** · ABCOMBI BIOSCIENCES, INC. · 2020 · $715,951

## Abstract

PROJECT SUMMARY
 The illnesses caused by Streptococcus pneumoniae’s transition from carriage to disease result in a
mortality rate between approximately 3-10% in adults and 12-25% in elderly patients in the United States.
Furthermore, pneumococcal disease devastates resource-poor countries, causing an estimated 476,000
people to succumb to pneumococcal infection annually (~32% of vaccine-preventable deaths in children below
age five). The most effective vaccines, polysaccharide protein conjugates, require a complicated process of
collecting polysaccharide antigens from pneumococci serotypes and conjugating them to a protein adjuvant.
Abcombi Biosciences has developed a pneumococcal vaccine using liposomal encapsulation of
polysaccharides (LEPS), which has demonstrated conjugate-like efficacy against 70+ serotypes of S.
pneumoniae via animal challenge models and opsonophagocytosis activity (OPA). Since receiving our prior
Phase I SBIR award, Abcombi Biosciences has completed all proposed milestones to address concerns
regarding the risk for potential negative side effects associated with the LEPS vaccine’s formulation.
Completion of this work has led to the development of a second generation LEPS vaccine. The enclosed
Direct Phase II SBIR proposal outlines the remaining preclinical studies necessary to reach our next major
milestone, a pre-IND meeting with the FDA. The completion of these studies will serve to address
important considerations of the FDA regarding vaccine manufacturing and characterization (i.e., chemistry
manufacturing and controls, CMC) and efficacy (i.e., the animal rule). Briefly, these studies will involve the
completion the following key developmental steps: 1) optimization of our encapsulation process for all
pneumococcal capsular polysaccharides (CPSs), 2) finalization of polysaccharide dosage, 3) evaluation of
vaccine stability, and 4) a repeated-dose toxicology study in mice and rabbits. Optimization of our
polysaccharide encapsulation process will be achieved by systematically varying our process conditions
across all 24 polysaccharides to ensure efficient and consistent encapsulation for each antigen. Upon
optimizing this process, we will then identify the optimal dosage of polysaccharide by measuring antibody
titers and OPA assay performance to determine the dosage of each polysaccharide required for sufficient
immunogenicity. We will then characterize the LEPS vaccine stability by evaluating protein pH and thermal
stability as well as the integrity of the liposomes when stored over 12 months. Lastly, we will evaluate
the vaccine for toxicity in a repeated dose study in mice and rabbits. Throughout the duration of this
study, serum will be collected to evaluate organ toxicity and quantify antibody titers. In addition, post-mortem
tissue samples will be extracted to visualize histopathology. Successful completion of this work will
prepare our vaccine candidate for a pre-IND meeting with the FDA and ensure a smooth trans...

## Key facts

- **NIH application ID:** 10010219
- **Project number:** 1R44AI152908-01
- **Recipient organization:** ABCOMBI BIOSCIENCES, INC.
- **Principal Investigator:** Charles Houston Jones
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $715,951
- **Award type:** 1
- **Project period:** 2020-04-24 → 2023-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10010219

## Citation

> US National Institutes of Health, RePORTER application 10010219, DEVELOPMENT OF A LIPOSOMAL PNEUMOCOCCAL VACCINE FOR CLINICAL READINESS (1R44AI152908-01). Retrieved via AI Analytics 2026-06-11 from https://api.ai-analytics.org/grant/nih/10010219. Licensed CC0.

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