Denosumab (trade names Prolia and Xgeva) is a human

monoclonal antibody A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a cell Lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell. Monoclonal antibodies ...

for the treatment of

osteoporosis Osteoporosis is a systemic skeletal disorder characterized by low bone mass, micro-architectural deterioration of bone tissue leading to bone fragility, and consequent increase in fracture risk. It is the most common reason for a broken bone a ...

, treatment-induced bone loss,

metastases Metastasis is a pathogenic agent's spread from an initial or primary site to a different or secondary site within the host's body; the term is typically used when referring to metastasis by a cancerous tumor. The newly pathological sites, the ...

to bone, and

giant cell tumor of bone Giant-cell tumor of the bone (GCTOB), is a relatively uncommon tumor of the bone. It is characterized by the presence of multinucleated giant cells (osteoclast-like cells). Malignancy in giant-cell tumor is uncommon and occurs in about 2% of all ...

. Denosumab is contraindicated in people with low blood calcium levels. The most common side effects are

joint A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...

and muscle pain in the arms or legs. Denosumab is a inhibitor of RANKL (receptor activator of nuclear factor kappa-Β ligand), which works by preventing the development of osteoclasts, which are cells that break down bone. It was developed by the biotechnology company

Amgen Amgen Inc. (formerly Applied Molecular Genetics Inc.) is an American multinational biopharmaceutical company headquartered in Thousand Oaks, California. One of the world's largest independent biotechnology companies, Amgen was established in T ...

Medical uses

Denosumab is used for those with

at high risk for

fracture Fracture is the separation of an object or material into two or more pieces under the action of stress. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. If a displ ...

s, bone loss due to certain medications, and in those with

bone metastases Bone metastasis, or osseous metastatic disease, is a category of cancer metastases that results from primary tumor invasion to bone. Bone-originating primary tumors such as osteosarcoma, chondrosarcoma, and Ewing's sarcoma are rare; the most co ...

Cancer

A 2012 meta-analysis found that denosumab was better than placebo,

zoledronic acid Zoledronic acid, also known as zoledronate and sold under the brand name Zometa by Novartis among others, is a medication used to treat a number of bone diseases. These include osteoporosis, high blood calcium due to cancer, bone breakdown due ...

and pamidronate, in reducing the risk of fractures in those with cancer.

Osteoporosis

In those with postmenopausal osteoporosis denosumab decreases the risk of fractures but increases the risk of infection. A 2013 review concluded that it is a reasonable treatment for postmenopausal osteoporosis. A 2017 review did not find benefit in males.

Adverse effects

The most common side effects are

and muscle pain in the arms or legs. There is an increased risk of

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable di ...

s such as

cellulitis Cellulitis is usually a bacterial infection involving the inner layers of the skin. It specifically affects the dermis and subcutaneous fat. Signs and symptoms include an area of redness which increases in size over a few days. The borders of ...

, hypocalcemia (low blood calcium), hypersensitivity allergy reactions, osteonecrosis of the jaw, and atypical

femur fracture A femoral fracture is a bone fracture that involves the femur. They are typically sustained in high-impact trauma, such as car crashes, due to the large amount of force needed to break the bone. Fractures of the diaphysis, or middle of the fem ...

s. Another trial showed significantly increased rates of

eczema Dermatitis is inflammation of the skin, typically characterized by itchiness, redness and a rash. In cases of short duration, there may be small blisters, while in long-term cases the skin may become thickened. The area of skin involved c ...

and hospitalization due to infections of the skin. It has been proposed that the increase in infections under denosumab treatment might be connected to the role of RANKL in the

immune system The immune system is a network of biological processes that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to parasitic worms, as well as cancer cells and objects such as wood splinte ...

. RANKL is expressed by T helper cells, and is thought to be involved in

dendritic cell Dendritic cells (DCs) are antigen-presenting cells (also known as ''accessory cells'') of the mammalian immune system. Their main function is to process antigen material and present it on the cell surface to the T cells of the immune system. Th ...

maturation. Discontinuation of denosumab is associated with a rebound increase in bone turnover. In rare cases this has led to severe hypercalcemia, especially in children. Vertebral compression fractures have also occurred in some people after discontinuing treatment.

Contraindications and interactions

It is contraindicated in people with hypocalcemia; sufficient calcium and

vitamin D Vitamin D is a group of Lipophilicity, fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group ar ...

levels must be reached before starting on denosumab therapy. Data regarding interactions with other drugs are missing. It is unlikely that denosumab exhibits any clinically relevant interactions. Denosumab works by lowering the hormonal message that leads to excessive osteoclast-driven bone removal and is active in the body for only six months. Similarly to

bisphosphonate Bisphosphonates are a class of drugs that prevent the loss of bone density, used to treat osteoporosis and similar diseases. They are the most commonly prescribed drugs used to treat osteoporosis. They are called bisphosphonates because they ...

s, denosumab appears to be implicated in increasing the risk of osteonecrosis of the jaw (ONJ) following extraction of teeth or oral surgical procedures but, unlike bisphosphonate, the risk declines to zero approximately 6 months after injection. Invasive dental procedures should be avoided during this time.

Mechanism of action

Bone remodeling is the process by which the body continuously removes old bone tissue and replaces it with new bone. It is driven by various types of cells, most notably

osteoblast Osteoblasts (from the Greek language, Greek combining forms for "bone", ὀστέο-, ''osteo-'' and βλαστάνω, ''blastanō'' "germinate") are cell (biology), cells with a single Cell nucleus, nucleus that synthesize bone. However, in the p ...

s (which secrete new bone) and osteoclasts (which break down bone);

osteocyte An osteocyte, an oblate shaped type of bone cell with dendritic processes, is the most commonly found cell in mature bone. It can live as long as the organism itself. The adult human body has about 42 billion of them. Osteocytes do not divide an ...

s are also present in bone. Precursors to osteoclasts, called pre-osteoclasts, express surface receptors called

RANK Rank is the relative position, value, worth, complexity, power, importance, authority, level, etc. of a person or object within a ranking, such as: Level or position in a hierarchical organization * Academic rank * Diplomatic rank * Hierarchy * ...

(receptor activator of nuclear factor-kappa B). RANK is a member of the

tumor necrosis factor receptor The tumor necrosis factor receptor superfamily (TNFRSF) is a protein superfamily of cytokine receptors characterized by the ability to bind tumor necrosis factors (TNFs) via an extracellular cysteine-rich domain. With the exception of nerve grow ...

(TNFR) superfamily. RANK is activated by RANKL (the RANK-Ligand), which exists as cell surface molecules on osteoblasts. Activation of RANK by RANKL promotes the maturation of pre-osteoclasts into osteoclasts. Denosumab inhibits this maturation of osteoclasts by binding to and inhibiting RANKL. Denosumab mimics the natural action of osteoprotegerin, an endogenous RANKL inhibitor, that presents with decreasing concentrations (and perhaps decreased

effectiveness Effectiveness is the capability of producing a desired result or the ability to produce desired output. When something is deemed effective, it means it has an intended or expected outcome, or produces a deep, vivid impression. Etymology The ori ...

) in patients with osteoporosis. This protects bone from degradation, and helps to counter the progression of the disease.

Regulatory approval

United States

On 13 August 2009, a meeting was held between Amgen and the Advisory Committee for Reproductive Health Drugs (ACRHD) of the U.S.

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

(FDA) to review the potential uses of denosumab. In October 2009, the FDA delayed approval of denosumab, stating that they needed more information. On 2 June 2010, denosumab was approved by the FDA for use in postmenopausal women with risk of osteoporosis under the trade name ''Prolia'', and in November 2010 as ''Xgeva'' for the prevention of skeleton-related events in patients with

from solid

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

s. Denosumab is the first

RANKL inhibitor Receptor activator of nuclear factor kappa- ligand (RANKL), also known as tumor necrosis factor ligand superfamily member 11 (TNFSF11), TNF-related activation-induced cytokine (TRANCE), osteoprotegerin ligand (OPGL), and osteoclast differentiati ...

to be approved by the FDA. On 13 June 2013, the FDA approved denosumab for treatment of adults and skeletally mature adolescents with

that is unresectable or where resection would result in significant morbidity.

Europe

On 17 December 2009, the

Committee for Medicinal Products for Human Use The Committee for Medicinal Products for Human Use (CHMP), formerly known as Committee for Proprietary Medicinal Products (CPMP), is the European Medicines Agency's committee responsible for elaborating the agency's opinions on all issues regardin ...

(CHMP) issued a positive opinion for denosumab for the treatment of postmenopausal osteoporosis in women and for the treatment of bone loss in men with hormone ablation therapy for prostate cancer. Denosumab was approved for marketing by the European Commission on 28 May 2010.

References

External links

* * {{Portal bar , Medicine Amgen Monoclonal antibodies Osteoporosis drugs