Treatment for Rheumatoid Arthritis
is an autoimmune disease that results in a chronic, systemic inflammatory
disorder that may affect many tissues and organs, but principally attacks flexible
(synovial) joints. It can be a disabling and painful condition, which can lead to
substantial loss of functioning and mobility if not adequately treated. In addition
of non-pharmacological treatments like physical therapies, Altebrel™
and Zytux™ may help your patient to manage the disease very well
so that the symptoms relieve, joint damage decreases, and overall functional abilities improves.
Altebrel™is the biosimilar product with the generic name of Etanercept.
It is used for treatment of several autoimmune diseases like Rheumatoid Arthritis, Psoriasis Arthritis,
and Spondyloarthritis. Etanercept is a fusion protein consisting from one FC part of antibody and two TNF receptors.
Etanercept is produced in CHO cells which are genetically engineered. It is a glycoprotein with molecular
weight of 150 KDa which is expressed in CHO cell as a homo-dimer protein, containing 934 amino acids,
and secreted into culture media. After several steps of purification, Etanercept is formulated the same way as original brand medicine.
Altebrel™ is a human recombinant injectable product that is identified by the following data:
Recommended International Nonproprietary Name of Active ingredient (INN):
Chemical Abstracts Service (CAS) registry:
Etanercept is a homo-dimeric protein. Each monomer is composed of an extra cellular receptor
part which is banded to human TNFα with FC part of immunoglobulin IgG1.
Etanercept manufacturing is based on the expression of a protein recombinant technology
using Chinese Hamster Ovary (CHO) cell. This molecule is composed of 934 amino acids with weight of 150 KDa and acts as a TNFα Blocker.
TNFα is a kind of cytokine which is produced by monocytes and macrophages and increases white cells flow to the site of inflammation.
According to this function besides some other related mechanisms, TNFα could increase inflammation. Therefore, Etanercept decreases
inflammation responses through inhibiting the mentioned TNFα mechanism which is completely effective in the treatment of autoimmune
diseases like Rheumatoid arthritis.
This medicine is produced as prefilled syringes containing solution form with two different dosages: 25 mg and 50 mg.
Zytux™ in combination with methotrexate (MTX) is indicated for the treatment
of adult patients with moderate to severe active rheumatoid arthritis after failing one or more treatments
with tumor necrosis factor (TNF) inhibitors.
Mechanism of action
Rituximab is a monoclonal chimeric (mouse/human) antibody which binds specifically
to the transmembrane antigen CD20 located on pre-B and mature B lymphocytes, but not on hematopoietic
stem cells, pro-B cells, normal plasma cells or other normal tissue. The antigen is expressed on >95%
of all B cell non-Hodgkin’s lymphomas. After antibody binding, CD20 does not internalize, nor is it
shed from the cell membrane. CD20 does not circulate in plasma as free antigen and thus does not compete
for antibody binding. Studies
to date have found no connection between the intensity of CD20 expression on the malignant cells and the treatment response.
Rituximab binds to the CD20 antigen on
B lymphocytes and causes B cell lysis. Possible mechanisms of cell lysis are complement-dependent cytotoxicity (CDC) together
with antibody-dependent cellular cytotoxicity (ADCC) and induction of apoptosis.
Peripheral B cell counts fell below normal after the first dose of Zytux™. In patients treated for hematological malignancy,
B cells began to regenerate within 6 months of completing therapy, with values
reverting to normal within 9 to 12 months of completing therapy. Rituximab
sensitizes drug-resistant human B cell lymphoma lines to the cytotoxic effects of some chemotherapy agents.
Active substance: rituximab
Excipients: sodium citrate, polysorbate 80, sodium chloride and water for injection.
PHARMACEUTICAL FORM AND AMOUNT OF ACTIVE INGREDIENT PER UNIT:
Zytux™ 100: Each 10 ml vial contains 100 mg rituximab (rituximab conc. 10mg/ml)
Zytux™ 500: Each 50 ml vial contains 500 mg rituximab (rituximab conc. 10mg/ml)