mAbs can be modified for delivery of a toxin, radioisotope, cytokine or other active conjugate or to design bispecific antibodies that can bind with their Fab regions both to target antigen and to a conjugate or effector cell. Every intact antibody can bind to cell receptors or other proteins with its Fc region. MAbs approved by the FDA for cancer include: Alemtuzumab Bevacizumab Cetuximab Dostarlimab Gemtuzumab ozogamicin Ipilimumab Nivolumab Ofatumumab Panitumumab Pembrolizumab Ranibizumab Rituximab Trastuzumab Autoimmune diseases Monoclonal antibodies used for autoimmune diseases include infliximab and adalimumab, which are effective in rheumatoid arthritis, Crohn's disease, ulcerative colitis and ankylosing spondylitis by their ability to bind to and inhibit TNF-α. Basiliximab and daclizumab inhibit IL-2 on activated T cells and thereby help prevent acute rejection of kidney transplants. Omalizumab inhibits human immunoglobulin E (IgE) and is useful in treating moderate-to-severe allergic asthma. Examples of therapeutic monoclonal antibodies Monoclonal antibodies for research applications can be found directly from antibody suppliers, or through use of a specialist search engine like CiteAb. Below are examples of clinically important monoclonal antibodies. COVID-19 In 2020, the monoclonal antibody therapies bamlanivimab/etesevimab and casirivimab/imdevimab were given emergency use authorizations by the US Food and Drug Administration to reduce the number of hospitalizations, emergency room visits, and deaths. In September 2021, the Biden administration purchased billion worth of Regeneron monoclonal antibodies at $2,100 per dose to curb the shortage. As of December 2021, in vitro neutralization tests indicate monoclonal antibody therapies (with the exception of sotrovimab and tixagevimab/cilgavimab) were not likely to be active against the Omicron variant. Over 2021–22, two Cochrane reviews found insufficient evidence for using neutralizing monoclonal antibodies to treat COVID-19 infections. The reviews applied only to people who were unvaccinated against COVID‐19, and only to the COVID-19 variants existing during the studies, not to newer variants, such as Omicron. Side effects Several monoclonal antibodies, such as bevacizumab and cetuximab, can cause different kinds of side effects. These side effects can be categorized into common and serious side effects. Some common side effects include: Dizziness Headaches Allergies Diarrhea Cough Fever Itching Back pain General weakness Loss of appetite Insomnia Constipation Among the possible serious side effects are: Anaphylaxis Bleeding Arterial and venous blood clots Autoimmune thyroiditis Hypothyroidism Hepatitis Heart failure Cancer Anemia Decrease in white blood cells Stomatitis Enterocolitis Gastrointestinal perforation Mucositis See also List of monoclonal antibodies References Further reading 2019 Historical overview of monoclonal