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Preclinical data underscores the potential to deliver a strong protective effect using Polymeric Nanoparticles (PNPs), an alternative to Lipid Nanoparticles (LNPs) to deliver the payload

Leiden, The Netherlands, APRIL 15, 2024 – 20Med Therapeutics, an innovator in the delivery of mRNA payloads for vaccines, today announced the publication of novel, preclinical data from its lead infectious disease development program in influenza in the peer-reviewed scientific journal ‘Molecular Therapy: Nucleic Acids’. The data demonstrates preclinical, in vivo proof-of-concept for an mRNA-based prophylactic vaccine candidate delivered via the company’s proprietary polymeric nanoparticles (PNP) platform. In an established influenza challenge model, 20Med’s vaccine candidate showed no local or systemic reactogenicity, elicited strong humoral and cellular immune responses, and reduced clinical symptoms following virus exposure. The project was supported by the UK Health Security Agency, and 20Med will continue to advance the program toward clinical evaluation. For the full publication, please click here.

“Seasonal influenza and pandemic periods are estimated to lead to several hundred thousand deaths each year, and hence massive investments are being made by academia and the industry to address the issue. mRNA-based vaccines can have a transformative impact in influenza, but still need ultra-cold chain transport and storage, and the efficacy can be improved with reduced associated side effects,” commented Jaap Rip Ph.D., Chief Scientific Officer of 20Med Therapeutics. “The preclinical data sets evaluating our lead PNP-based mRNA vaccine candidate underscore the potential to develop a clearly differentiated vaccine candidate by switching the delivery vehicle to a polymer-based nanoparticle.”

“In the infectious disease community, alternative delivery vehicles to LNPs continue to gain traction as a more heterogeneous environment in mRNA-based vaccine development can unlock complimentary and potentially improved approaches, which is ultimately in the best interests of patients’, in addition to healthcare providers and supply chains,” commented Hugo Fry, Chief Business Officer of 20Med Therapeutics. “In parallel to generating this and additional data sets on our lead influenza vaccine candidate, the company’s alliance with CEPI aimed at validating the improved thermostable properties of our vaccine platform continuous to mature.”

The data set now published in Molecular Therapy: Nucleic Acids evaluated the immunological and protective properties of 20Med’s influenza vaccine candidate in an established ferret virus challenge model. No local reactogenicity, such as swelling at the injection site, nor systemic side effects measured by body weight loss or temperature changes were observed following primary or booster vaccination. Clinical symptoms, such as sneezing, nasal discharge, and inactivity, were monitored up to 14 days after viral challenge and were significantly milder in vaccinated animals. Vaccinated animals also showed no cases of labored breathing, considered a much more severe clinical symptom, which only occurred in the non-vaccinated control arm. Virus titers measured once daily via a nasal wash were overall significantly less in the vaccinated animals than in the non-vaccinated group. Six days after the virus challenge, the vaccinated animals no longer showed detectable virus particles in the nasal wash, while cases of virus shedding via the nose persisted in the non-vaccinated group beyond day 6.

+++ Meet the 20Med Therapeutics team at BIO International Conference, June 3-6, 2024 to discuss partnering opportunities around our PNP-based mRNA vaccine delivery platform +++

About 20Med Therapeutics

At 20Med Therapeutics, we develop RNA-based vaccines based on proprietary bioresponsive polymer nanoparticles. Our non-LNP delivery platform offers distinct advantages in terms of development speed, ease of manufacture, stability, cost of goods, and freedom to operate. We have partnered with CEPI to develop thermostable vaccines for influenza, tackling the barriers to wider application and distribution of mRNA-based vaccines using LNPs as the delivery vehicle. 20Med Therapeutics applies pioneering biomaterial and medical science and is located in Enschede and Leiden in the Netherlands. For further information, please visit: or contact


20Med Therapeutics

Charlotte Voorhoeve

Director Strategy & Operations

Phone +31 61 205 86 43

For media

Mario Brkulj

Valency Communications

Phone: +49 160 9352 9951


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