July 6, 2021 published on IHS Markit, author Joseph Harvey

Orthros Medical offers antibody opportunity to animal health collaborators

July 6, 2021.

Dutch firm Orthros Medical is aiming to extend the use of llama antibodies into the animal health sector.

The company is working on its own internal pipeline of disease-modifying osteoarthritic drugs for dogs and horses.
Orthros’ candidates are based on VHH single chain antibodies that target inflammation and pain. The drugs are applied
via intra-articular injection into the joint or area of pain and are formulated as slow-release gels.

The VHH concept is well established in the human health sector, with Ablynx – a pioneering business in this area – selling
to Sanofi for $4.8 billion in 2018. Llama antibodies are around 10 times smaller than that of humans. This gives them low
immunogenicity, effective over a longer period of time, easier to engineer and cheaper to produce compared to
conventional antibody-based medicines.

Orthros was founded in 2017 to pursue the use of VHH to tackle osteoarthritis in humans and animals. The company’s
chief executive Robert Jan Lamers said the first product candidate for osteoarthritis-related pain is set to be evaluated in
pet dogs before the end of 2021, before progressing to human trials. The company is also working on a therapy targeting
inflammation in dogs with osteoarthritis. Further down the line, Orthros will also study indications in horses.
“The VHH field is now accelerating in the human market,” Mr Lamers told IHS Markit Animal Health at the recent Animal
Health Innovation USA forum. “We feel there is also a great opportunity in animal health because of the low cost of goods,
it is easy to engineer and its high specificity. We can make VHH with two functionalities. One function is to anchor to a
specific tissue and the other is to target a disease trigger.”

He also suggested there should not be any significant hurdles when taking VHH-based therapeutics to the regulatory
authorities, with this type of product having already been scrutinized by regulators in the human health sector.

Mr Lamers pointed out: “These antibodies are small and we produce them for local applications – in the joint, for
example. If they get into circulation, they are pretty quickly cleared by the body. This gives them a good safety profile.”

As well as seeking co-development partners for its pipeline, Orthros has another string to its bow. The company can also
manufacture VHH at GMP-grade on a contract basis for any animal health businesses interested in using the antibodies for
other indications. Mr Lamers noted the first application of VHH is for localized diseases.