Prolia (Denosumab) Biosimilars

Prolia Biosimilars

Prolia (denosumab) is a human IgG2 monoclonal antibody targeting and blocking the receptor activator of nuclear factor kappa-B ligand (RANKL) protein. RANKL inhibition by Prolia halts the activation of osteoclasts, which are cells that break down bone tissue.

Prolia is used to treat osteoporosis, a chronic condition that weakens bones making them fragile and at increased risk of breakage. The development of new Prolia biosimilars would improve patient access to Prolia by lowering costs. However, biosimilar development programs require complex technical procedures and thorough product characterization before meeting approval criteria.

Sartorius has developed a suite of ready-to-use analysis packages to simplify the development of your Prolia biosimilar. Our platform solutions and pre-qualified assays combine to provide industry-leading comparability data, giving your confidence in your product development.


Simplify Your Biosimilar Characterization

Sartorius delivers pre-qualified, integrated characterization and comparability packages to support the development and production of Prolia biosimilars.

  • Uncover valuable insights into your biosimilar 

  • Accelerate development times 

  • Meet regulatory requirements 

  • Boost confidence in your product 

  • Limit the risks associated with biosimilar development 

Consult Our Experts

Characteristics of Prolia

Dynamic bone remodeling is part of the normal maintenance of the skeleton. Osteoclasts are cells that degrade bone tissue, which is essential for normal bone metabolism and repair.  

Aberrations in the balance of bone remodeling can lead to a situation where bone resorption occurs more quickly than new bone can be produced to replace it.  As a result, the bone becomes fragile and porous, leading to osteoporosis, a chronic condition that weakens bones and makes them vulnerable to fracture.  

Prolia exerts its clinical activity by blocking the development of osteoclasts, preventing them from contributing to the degradation of bone tissue. Prolia is approved for the treatment of osteoporosis, as well as some rare bone cancers and bone metastases from solid tumors. 

Prolia binds to RANKL, neutralizing the protein and inhibiting RANKL-mediated activation of RANK. RANK is a receptor central in regulating bone tissue remodeling by controlling osteoclast differentiation and subsequent activation. Therefore, increased RANKL activity can lead to accelerated bone loss.  

Molecularly, RANKL binds to RANK receptors on the cell surface and triggers downstream signaling by recruiting adaptor molecules such as TNFR-associated factors (TRAFs). These adaptor molecules activate mitogen-activated protein kinases (MAPKs) and nuclear factor-κB (NF-κB), leading to gene expression changes that promote bone reabsorption. Prolia blocks RANKL signaling, limiting downstream signaling cascades. 

Sartorius provides an integrated package for biosimilar comparability assessments. Our robustly designed binding assays and bioassays enable you to characterize the key features of your anti-RANKL biosimilar. 

  • Physicochemical and structural assays reveal detailed insights into the composition of your biosimilar   

  • Binding assays quantify and evaluate the affinity of your biosimilar for RANKL  

  • Our potency-based bioassays measure the interaction of your Prolia biosimilar with RANKL. We are currently developing cell-based assays further to characterize the mechanism of action of your biosimilar.  

Assay Types

Physicochemical and structural characterization is a crucial step in determining the potential biological activity, stability, and safety of your biosimilar.   

Our versatile platform of physicochemical methods provides the basis for your comparability study.  With options suited for clone selection through to formal comparability, we can build detailed insights into the properties of your biosimilar.    

The combination of our off-the-shelf physicochemical and structural analyses and our binding and bioassays allows you to evaluate the structure-function relationship and ticks the regulators' box for orthogonal comparability.   

Consult Our Experts

The bioassay is the only analytical method that directly measures the biological activity of Prolia. Therefore, they represent one of the most important assessments that should be conducted as part of product characterization, lot release, and stability programs. 

Sartorius offers an off-the-shelf reporter gene bioassay to evaluate the biological activity of Prolia biosimilar and innovator materials (DiscoverX). 

In this assay design, a transgenic U2OS cell line expresses RANK and an IκB-enzyme donor fusion protein. Upon exposure to the enzyme acceptor in the substrate, the active enzyme forms and hydrolyzes the substrate, producing a chemiluminescent signal. RANKL binds to the RANK receptor on the cell surface resulting in NF-κB signaling and IκB degradation, leading to a decrease in chemiluminescent signal.  Prolia inhibits RANKL-based activation of RANK, leading to an increase in chemiluminescence. The chemiluminescence signal is directly proportional to the functional activity of Prolia. 

Consult Our Experts

Interaction and affinity methodologies are fundamental to the evaluation of monoclonal antibodies as therapeutic products.   

Sartorius utilizes a broad range of techniques to assess the association and dissociation of Prolia with RANKL. These methods have been developed using a variety of platforms, including ELISA, electrochemiluminescence (MSD), and surface plasmon resonance (SPR). Assays can be performed with different reporting mechanisms, such as affinity, on and off rates, and relative binding, providing you with complete, industry-leading comparability reports to understand all aspects of the performance of your biosimilar. 

A full range of appropriate Fc receptor binding assays by SPR are also available for Prolia biosimilars. 

Consult Our Experts

Related Assets


Physicochemical and Biological Analytical Comparability for Biosimilars

PDF | 898.8 KB

Consult Our Experts

Consult Our Experts

Related Content


Cell Line Development

Learn More

Cell Banking

Learn More


Learn More