Ambrose expands rare disease pipeline with €161M AM-Pharma acquisition
British rare disease specialist Ambrose Healthcare has acquired Dutch biotech AM-Pharma for up to €161 million, adding an enzyme replacement therapy to its pipeline and a development base in Utrecht.
The acquisition gives AM-Pharma’s ilofotase alfa another chance after setbacks in kidney disease. It also illustrates Ambrose’s strategy: acquire stalled compounds with existing human data and develop them for rare diseases, aiming to reduce the time and cost of bringing treatments to market.
According to the deal’s announcement, Ambrose acquired all of AM-Pharma’s shares. Shareholders are entitled to an undisclosed upfront payment and commercialization milestones totaling up to €161 million, plus royalties on future sales. The acquisition also brings regulatory, quality and scientific infrastructure that Ambrose intends to use across its pipeline.
Backstory: AM-Pharma was once a coveted biotech. Pfizer paid $87.5 million in 2015 for a minority stake and an option to acquire AM-Pharma. That agreement included up to $512.5 million in additional payments tied to exercising the option and a potential product launch.
Pfizer subsequently walked away after reviewing Phase 2 data in sepsis-associated acute kidney injury. AM-Pharma raised €163 million to pursue a Phase 3 trial, but that study also failed, prompting staff cuts and a shift toward other indications.
The new focus: Ilofotase alfa is now ready for Phase 2 development in hypophosphatasia, an inherited disease caused by low activity of alkaline phosphatase, an enzyme needed for bone mineralization. Symptoms include fractures, tooth loss, muscle weakness, fatigue and pain.
The treatment replaces the deficient enzyme. According to Ambrose, it showed dose-dependent effects on disease biomarkers in a Phase 1b study in adults and has a safety database spanning nearly 700 patients.
“Ilofotase alfa already has an extensive human safety database, has shown a dose-dependent effect on disease biomarkers of HPP, and has orphan drug status in two major markets,” said Toby Wilson Waterworth, CEO of Ambrose Healthcare.
The treatment gap: An enzyme replacement therapy, Strensiq (asfotase alfa), is already approved in Europe for hypophosphatasia that began in childhood. This includes adults whose symptoms started in childhood, but patients whose disease first appears in adulthood fall outside that approved indication. Ambrose says there is currently no approved treatment for this adult-onset group, leaving an opening for ilofotase alfa if further trials establish its benefit.
Ambrose’s strategy: Ambrose targets compounds whose development has stalled despite potentially useful clinical evidence. It combines repurposing with rare disease regulatory pathways, aiming to complete development faster and at lower cost.
Ilofotase alfa becomes its third asset after two previous acquisitions:
- Renzapride: Acquired in 2024 and being developed for gastrointestinal symptoms of cystic fibrosis, drawing on earlier studies in other gastrointestinal conditions.
- VAL401: Licensed in 2025, the reformulated antipsychotic risperidone is being developed for pancreatic cancer following earlier testing in lung cancer.
What’s next: Ambrose says ilofotase alfa has orphan drug designations in the U.S. and Europe and an agreed development plan centered on a single pivotal study. It has not disclosed a trial start date.
“With Ambrose Healthcare’s sole focus on rare diseases, we believe ilofotase alfa is in the right hands to continue its development and ultimately reach the patients who need it most,“ said Dr. Juliane Bernholz, CEO of AM-Pharma.
