GeNeuro has reported positive data from a Phase 1 clinical trial (NCT03574428) evaluating the safety and tolerability of high doses of GNbAC1, developed for the treatment of neurological and autoimmune disorders, including multiple sclerosis (MS).

The company also announced that the World Health Organization has assigned the international nonproprietary name “temelimab” to GNbAC1.

The development of temelimab is the result of a quarter century of research into human endogenous retroviruses, which are stretches of foreign, viral DNA inserted into the human genome. Some human endogenous retroviruses are known to be associated with auto-immune diseases. For example, one of these viruses, the MS-associated retrovirus (MSRV), encodes a protein (MSRV-envelope protein, or MSRV-Env) that is found in MS patients, particularly in active lesions.

Temelimab, a monoclonal antibody, works by neutralizing the MSRV-Env protein associated with MS, and subsequently blocks inflammation. Also, the therapy was shown to restore myelin, which is the insulating sheath around nerve fibers that is compromised in MS patients.

This new trial follows a previous GeNeuro clinical trial testing temelimab in the treatment of MS, the CHANGE-MS study (NCT02782858). In October 2018, GeNeuro announced the final results of this Phase 2b study, showing that temelimab could reduce the levels of key markers related to MS progression, lessen brain atrophy and lesion load, and protect the nervous system.

In the CHANGE-MS study, three temelimab doses were tested: 6, 12, and 18 mg/kg. Only the highest dose (18 mg/kg) was effective in blocking MS disease progression; the lower doses had no noticeable effects. This suggested that further clinical studies were needed to evaluate the safety of higher doses.

Now, in the Phase 1 trial, GeNeuro tested the safety of temelimab at a higher dose range. Four doses were tested: 36, 60, 85, and 110 mg/kg. The trial was a randomized, double-blind, placebo-controlled study with 24 healthy volunteers.

Results showed that no adverse events (side effects) related to safety occurred when taking temelimab at all the higher doses tested, suggesting that the therapy had a robust safety profile even at higher doses.

“The results from this high-dose study support and expand the large amount of positive clinical data we already have regarding temelimab’s safety, tolerability and efficacy,” Jesús Martin-Garcia, chairman and CEO of GeNeuro, said in a press release.

“Temelimab is the first treatment targeting an MS mechanism to have shown robust and consistent effects on key neuroprotection markers in clinical trials. The success of this Phase 1 study allows us to explore whether higher doses of temelimab provides additional benefit in MS patients as well as broadening the therapeutic areas for which this drug candidate could be used,” Martin-Garcia said.