Proof-of-concept study data on CAD treatment expected later this year

Annexon trial testing ANX1502's oral tablet formulation likely to start soon

Marisa Wexler, MS avatar

by Marisa Wexler, MS |

Share this article:

Share article via email
A bar graph, a pie graph and a bottle of an oral prescription medication are sandwiched between the words

Initial results from a planned proof-of-concept clinical trial testing Annexon Biosciences’ treatment candidate ANX1502 in people with cold agglutinin disease (CAD) are expected in the second half of the year.

“We anticipate clinical proof-of-concept data from our novel oral inhibitor ANX1502 later in the year,” Douglas Love, president and CEO of Annexon, said in a company press release announcing last year’s financial results and this year’s anticipated clinical milestones.

While Annexon did not provide specific details at this time about the trial’s design or where it will be conducted, the company noted that the study will assess the effects on the body and efficacy of an oral tablet formulation of ANX1502 in CAD patients.

According to the pipeline page on the company’s website, the trial is expected to start in the second quarter of this year, which would mean a launch by the end of June.

Recommended Reading
banner image for Mary Lott's

What it’s like to travel around the world for CAD treatment

Positive data seen in trial testing liquid formulation of CAD treatment

CAD is an autoimmune disease caused by self-reactive antibodies that wrongly stick to red blood cells at low temperatures. When these antibodies bind to red blood cells, they activate a group of immune proteins called the classical complement cascade.

Activating these immune proteins is normally one of the main ways that antibodies help fend off infections in the body. However, in autoimmune diseases like CAD, activation of the classical complement cascade leads to the destruction of antibody-bound cells.

ANX1502 is an orally available small molecule that works by specifically targeting the active form of C1s, the complement protein that together with the C1q complement protein propagates classical pathway activation.

As such, the experimental CAD treatment is expected to suppress the classical complement pathway, prevent red blood cell destruction, and ease disease symptoms.

A two-part Phase 1 clinical trial (NCT05521269), previously conducted at a single site in the Netherlands, evaluated the safety and pharmacological properties of ANX1502’s liquid suspension formulation in healthy adult volunteers.

In the first part, participants received single doses of either ANX1502, at dose levels ranging from 25 mg to 1,050 mg, or a placebo. Then in the second part of the study, participants were given the therapy, at doses ranging from 200 mg to 525 mg, or a placebo, twice daily for 14 days.

Trial results showed ANX1502 was generally well-tolerated across all doses evaluated — no severe nor serious side effects were reported, and there weren’t any noteworthy clinical or laboratory abnormalities. The most frequently reported side effects in the study were gastrointestinal problems, which included nausea, vomiting, and diarrhea.

Pharmacological data showed that the doses tested led to target levels of the therapy in participants’ blood.

In addition, ANX1502 appeared to block complement activation as designed. In healthy volunteers with higher than median levels of a marker of complement activation called C4d when they entered the study, a single dose of ANX1502 at different doses effectively suppressed blood C4d levels.

If data from the upcoming proof-of-concept study are positive, the company plans to start testing ANX1502 in other complement-mediated autoimmune disorders, according to Annexon.