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​​​​​​Leino: DelSiTech Long Acting Injectables


DelSiTechTMSilica Matrix is an advanced delivery technology for parenteral and local administration of injectable and implant dosage forms. The proprietary technology is based on silica (SiO2) matrix into which the molecule or therapeutic agent of interest is embedded using a process called sol-gel. The resulting Matrix is nonporous, biocompatible, and it can be designed to biodegrade by matrix dissolution at the desired rate to ensure a tightly controlled release of the active substance over periods of days up to many months or a year.

In this project, DelSiTech will develop silica-based, injectable, controlled-release formulations of the broadly neutralizing antibody PGT-121, with the eventual goal of preventing HIV infection. The initial target duration of release will be 6 months.

The following target product profile has been set for the long-acting HIV bNAb PGT-121:

- ​Injectable subcutaneous depot

- At least 6 months’ duration of drug release

- ​Daily released dose of 0.4 mg

- Minimal burst and tail

- Preferably zero order release profile

- Injectable with at least a 25G needle

- Removable in case of adverse events​

The grant is led by Dr. Lasse Leino at DelSiTech Oy in Turku, Finland.


The project comprises eight work packages:

1. Analytical method set-up and preliminary stability and compatibility evaluation of PGT-121

2. Development of PGT-121 silica microparticles with 6 months’ release time

3. Development of injectable PGT-121 silica microparticles-silica hydrogel formulations with 6 months’ release time

4. Scale-up and optimization of spray-drying manufacture of PGT-121 silica microparticles

5. Preliminary stability study

6. Manufacture of PGT-121 silica microparticles-silica hydrogel test items for preclinical PK/PD/tolerability studies

7. Manufacture of placebo silica microparticles-silica hydrogel test items for preclinical PK/PD/tolerability studies

8. Conducting a preclinical PK/tolerability study in the rat with PGT-121 silica microparticle-silica hydrogel test items for 3 months


Grant at a Glance

​​Principal Investigator

Lasse Leino, Ph.D.

Grantee Institution

DelSiTech Oy (Turku, Finland)

Project Title

DelSiTech Long Acting Injectables

​Grant Number

  • ​INV​-008575​

Grant Award

Up to $2.1 Million awarded in May, 2019

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