Germany’s Mologen has started a Phase IIa clinical trial to assess the combination of lefitolimod with new virus-neutralising antibodies to treat human immunodeficiency virus (HIV) patients.

The trial is being performed in collaboration with Aarhus University Hospital in Denmark. The first participants have received dosing as part of the study.

Lefitolimod is a synthetic DNA-based TLR9 agonist designed to induce the immune system. The drug will be tested in combination with virus-neutralising antibodies developed by Rockefeller University in the US to delay viral rebound.

Named TITAN, the randomised, double-blind, placebo-controlled Phase IIa trial will investigate the safety and efficacy of the combination in 48 patients on antiretroviral therapy (ART) to mitigate the HIV reservoir.

US-based pharmaceutical company Gilead Sciences is funding the study, which is expected to be completed in 2021.

Mologen chief medical officer Dr Matthias Baumann said: “The TITAN study builds on the learnings from our TEACH trial and is an important step in our new strategy to investigate lefitolimod in combination approaches also in HIV.”

TEACH is a Phase Ib/IIa study conducted to evaluate lefitolimod as a monotherapy on top of standard ART to treat HIV infection.

During the Phase Ib/IIa study, lefitolimod demonstrated favourable effects for reactivation of the immune system. Results also showed an encouraging safety profile.

The TITAN trial aims to analyse if the combination of the drug with broadly neutralising monoclonal antibodies could enhance immunological control of the HIV infection.

The combination treatment is also expected to delay time-to-viral rebound after patients interrupt their regular HIV therapy.

Mologen is further studying lefitolimod as a potential treatment for different cancer types, including metastatic colorectal cancer and small-cell lung cancer.