Plasmid manufacturer VGXI has entered a long-term supply agreement to support development of Geneos Therapeutics’ personalized cancer vaccines.
“DNA vaccines are unique from typical vaccines in that they contain no protein components,” Christy Franco, senior manager of BD at VGXI, told this publication.
“A synthetic, circular DNA encodes for portions of the patient’s tumor that have been identified as immunogenic. After delivery, the DNA vaccine expresses those protein segments which trigger your body’s immune system to identify, track down, and eliminate the cancerous cells.”
Such therapies are composed of circular pieces of DNA called plasmids, she continued. “VGXI specializes in large scale plasmid production for use in both vaccines and gene therapy applications.”
Her comments come after the contract manufacturing organization (CMO) entered a long-term master supply agreement to support Geneos’ personalized cancer therapies through the production of DNA-plasmid. Financials of the deal have not been divulged.
“In this case we will be supplying the API, or core component of Geneos Therapeutics DNA vaccine product. For Geneos, each product is unique to that patient’s specific tumor.”
DNA vaccine production
Geneos Therapeutics is developing neoantigen-targeting, personalized cancer immunotherapies based on its clinically validated Exquisitely Personalized Immunotherapies for Cancer (GT-EPIC) Platform.
The products are made using four steps:
1) The firm sequences the DNA from a patient tumor sample, identifying 1-1000+ mutations by comparing the tumor genetic sequences to the patient’s normal genome.
2) After selecting appropriate mutated sequences to target, it makes the synthetic neoantigen DNA sequences and insert the DNA sequences into a proprietary DNA plasmid.
3) The firm manufactures the patient specific neoantigen-coding DNA plasmids through a two week proprietary manufacturing process.
4) The formulation is injected into the patient using an in vivo electroporation (EP) based delivery system.
As for the plasmid step, VGXI starts with a small amount of reference plasmid provided by the client, Franco said.
“Using large scale fermentation in E. coli, this DNA is amplified to produce the required amount for our client’s product. The plasmid DNA is then extracted from the host cells and processed to produce GMP-grade, high purity DNA that can be delivered to a patient.”