BioSenic Puts Fracture Cell Therapy Program on Hold After Mid-Stage Failure

Pictured: Healthcare worker examining a hand X-ray/iStock

Pictured: Healthcare worker examining a hand X-ray/iStock

Belgium-based BioSenic is suspending the development of ALLOB, an investigational allogeneic cell therapy derived from mesenchymal stem cells, which was being assessed as a treatment for tibial fractures, the company announced Monday.

The decision to pause ALLOB’s development comes after disappointing results in a Phase IIb trial, which had been designed to evaluate the candidate’s safety and timing efficacy, according to BioSenic’s news release. Data from the study showed that early ALLOB administration failed to speed up the fracture healing process significantly.

While the cell therapy candidate missed its primary endpoint in the mid-stage trial, data still show “the excellent safety profile of ALLOB injections, with no reported serious adverse events related to experimental treatment,” Lieven Huysse, BioSenic’s chief medical officer, said in a statement.

Results from a previous Phase IIa study also showed that, when administered three-and-a-half to seven months after a fracture, ALLOB could significantly accelerate healing.

Together with its promising pre-clinical performance, these safety and efficacy data suggest that ALLOB “remains of potential benefit as an add-on to the standard of care,” according to BioSenic’s press release. This is particularly true for difficult fractures, especially of the tibia, which fails to heal in 5% to 10% of patients.

BioSenic was formed in October 2022 from the reverse merger between Bone Therapeutics, struggling with several late-stage failures and headcount reductions, and French company Medsenic. ALLOB is the former lead candidate of Bone Therapeutics.

The suspension of ALLOB’s development will allow BioSenic to focus on its most mature candidate, the investigational oral arsenic trioxide (OATO), which is in Phase III development for chronic graft versus host disease (cGVHD). Medsenic was initially developing OATO.

“The decision to halt the clinical development on difficult tibial fractures enables BioSenic to add additional resources for the development of the OATO platform and its current indications,” CEO François Rieger said in a statement.

OATO works through a primary two-pronged effect on the immune system. First, the drug induces oxidative stress on activated B and T cells, as well as other immune system cells, to promote apoptosis. OATO can also exert an immunomodulatory effect on inflammatory pathways.

Through this mechanism of action, an injectable formulation of arsenic trioxide achieved a 75% efficacy rate. BioSenic is preparing to launch its Phase III study testing an oral formulation of this drug.

Tristan Manalac is an independent science writer based in metro Manila, Philippines. He can be reached at or

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