Exam 3 Dosage Forms for Biologics Flashcards
What are biologics?
medications that are derived from or produced by living organisms
What are examples of biologics?
recombinant proteins, peptides, blood factors, vaccines, oligonucleotides, and cell based therapies
What are other names for biologics?
biotech drugs, biopharmaceuticals, large molecule drugs
What is the importance of biologics?
- of the top 200 drugs by sales in 2018, 73 (37%) were biologics
- in 2003, only 5 of the top 100 were biologics → dramatic increase!
- there are more than 100 biologics on the market, with hundreds more in development
In 2018, what is the breakdown of the biologics in the top 200 (73 of them) and their types?
monoclonal antibodies (MAbs) and their derivatives → 35
cytokines → 8
insulins → 9
peptides → 7
vaccines → 7
other → 7 (enzymes, oligos, toxins like Botox, blood factors)
What is the largest class of biologics?
monoclonal antibodies (MAbs)
What are monoclonal antibodies?
- very large proteins that have MW of over 150,000
- interacts with antigens at the antigen binding site
- CHO is the sugar portion of the molecule and is important for how it’s processed in the body
- has 4 amino acid chains → 2 light and 2 heavy which are linked by disulfide bonds
- contains mostly beta sheets, little alpha helices
- top half of antibody is antigen binding portion and bottom half has biological activity
What are some properties of MAbs?
- glycoproteins, high beta sheet content
- MW around 150,000 daltons
- quaternary structure → 2 light chains (L) and two heavy chains (H) linked by SS bonds
- antigen binding occurs through the variable domain (V) at the complementary determining region (CDR)
- the constant (C) domain (the base arm of Y) helps determine biodistribution, plasma half life
What are some examples of MAbs?
Humira, Herceptin, Avastin
What are the five different kind of MAb derivatives?
- chimeric monoclonal antibody → top is mouse derived and bottom is human derived → example is Remicade aka infliximab
- humanized monoclonal antibody
- human recombinant antibody → example is adalimumab aka Humira AND golimumab aka Simponi
- humanized Fab fragment → example is certolizumab pegol aka Cimzia
- human recombinant receptor/Fc fusion protein (fusion protein takes stem of MAb and attach to 2 receptors) → example is etanercept aka Enbrel
What are antibody drug conjugates (ADC)?
- a growing class of MAb-based drugs in development
- combine target specificity of MAb with efficacy of small molecule drug
- can use MAb fragments rather than whole MAb
What are the elements of an ADC?
- antibody → specific for tumor associated antigen that has restricted expression on normal cells
- linker → attaches the cytotoxic agent to the antibody (is usually fragile but newer linker systems are designed to be stable in circulation and release the cytotoxic agent inside targeted cells)
- cytotoxic agent → designed to kill target cells when internalized and released
What is the mechanism behind ADC?
takes the green ball (toxin) and links it to the antibody so that it might recognize antigens/receptors on cancer cells → like a trojan horse where it is a toxic molecule to cancer cells
What type of formulations are ADCs most typically found in?
freeze dried or lyophilized (since the linker is unstable and fragile)
What are some things to know about cytokines?
- includes interleukins, interferons, erythropoietins (are associated with doping scandals)
- MW of about 30,000 daltons or less → smaller than MAbs
- high alpha helix content (4 helix bundle)
What are some examples of cytokines?
Neulasta, Epogen, Avonex, Rebif, Humatrope