Ofatumumab

Key takeaways

Ofatumumab belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Ofatumumab to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Ofatumumab from memory before moving on to harder problems.

Reference excerpt

Ofatumumab is a fully human monoclonal antibody to CD20, which appears to provide rapid B-cell depletion. Under the brand name Kesimpta, it is approved for the treatment of multiple sclerosis in the United States as well as in the European Union and other regions. Under the brand name Arzerra, it is approved for the treatment of certain types of chronic lymphocytic leukemia (CLL) in the United States. It is sold by Novartis under license from Genmab. The most common side effects for ofatumumab (Kesimpta) include upper respiratory tract infection, headache, injection-related reactions, neutropenia, and local injection site reactions.

Medical uses Ofatumumab (Kesimpta 20 mg solution for injection in pre-filled syringe/pen) is indicated for the treatment of relapsing forms of multiple sclerosis in adults. The recommended dose is 20 mg of ofatumumab administered by subcutaneous injection with monthly dosing following loading. Treatment with ofatumumab has been shown to rapidly deplete B-cells which aids MS pathogenesis by influencing and regulating different autoimmune process such as T-cell production and APC activity. Ofatumumab (Arzerra 100 mg or 1000 mg concentrate for solution for infusion) is indicated for the treatment of untreated, relapsed, or refractory chronic lymphocytic leukemia (CLL). The recommended doses for treatment of CLL are higher than MS, with 1000 or 2000 mg infusions administered monthly depending on if the CLL is untreated, relapsed or refractory, following loading. Ofatumumab is under investigation as a potential treatment for follicular lymphoma, diffuse large B cell lymphoma and rheumatoid arthritis.

Adverse effects Adverse effects of ofatumumab (Kesimpta) by frequency: Very common (>10% frequency):

Upper respiratory tract infection Injection-related reactions (systemic) Injection-site reactions (local) Urinary tract infections Headache Common (1–10% frequency):

Back pain Blood immunoglobulin M decreased Oral herpes Adverse effects of ofatumumab (Arzerra) by frequency: Very common (>10% frequency):

Common (1–10% frequency):'

Uncommon (0.1-1% frequency):

Rare (<0.1% frequency):

Hepatitis B infection or reactivation Ofatumumab (Arzerra) has received a black box warning regarding the potential for it to cause progressive multifocal leukoencephalopathy and hepatitis B reactivation. Likewise it is also advised that doctors watch cautiously for small bowel obstruction, neutropenia, thrombocytopenia, infusion reactions or an increased risk for infection. For more information, please refer to the prescribing information or your doctor.

Interactions No formal drug interaction studies have been conducted with ofatumumab. Although it is advised that patients are not administered live virus vaccines (e.g. the oral polio vaccine) while undergoing treatment with ofatumumab due to the compromised ability to fight the attenuated viruses seen in patients being treated with ofatumumab. While on treatment with ofatumumab (Kesimpta), all immunizations should be administered according to immunization guidelines at least 4 weeks prior to initiation of ofatumumab for live or live-attenuated vaccines and, whenever possible, at least 2 weeks prior to initiation of ofatumumab for inactivated vaccines.

Mechanism Ofatumumab is a fully human anti-CD20 monoclonal antibody whose epitope is distinct from that of rituximab. Ofatumumab binds to a distinct epitope on small and large extracellular loops of CD20. The CD20 antigen is expressed on solely B cell lymphocytes. Compared with rituximab, ofatumumab binds more tightly to CD20 with a slower off-rate. It causes cytotoxicity in the cells that express CD20 by means of complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC).

History Ofatumumab was jointly developed by Danish biotech Genmab and GlaxoSmithKline GSK plc who entered into an agreement to co-develop and commercialize ofatumumab in 2006. It was approved as Arzerra for the treatment of chronic lymphocytic leukemia in the United States in October 2009. Ofatumumab (Arzerra) was then approved in the European Union in June 2010, in the United Kingdom in April 2010, and in Canada in August 2012. In 2014, Novartis acquired a number of GSK's oncology products, including the collaboration with Genmab and ofatumumab. For commercial reasons ofatumumab (Arzerra) was withdrawn from the Canadian market in 2017. It was withdrawn from the European Union in February 2019. Novartis removed it from all of the non-US markets and made it available only for compassionate use in those markets. Ofatumumab (Kesimpta) was approved for the treatment of relapsing forms of multiple sclerosis in adults in the United States in August 2020. EU approval was subsequently received in March 2021.

Society and culture

Economics Ofatumumab (Arzerra) was transitioned to an oncology access program to make it available at no cost to chronic lymphocytic leukemia patients in the U.S.

References

Illustrations

Worked examples

Example 1 — a first encounter with Ofatumumab

Start with the simplest possible case. Write down what Ofatumumab claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Ofatumumab before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Ofatumumab ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Ofatumumab

In research: Ofatumumab appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Ofatumumab in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Ofatumumab is common in secondary-school and first-year university syllabi. It links to neighbouring topics Drugs developed by GSK plc, Drugs developed by Novartis, Monoclonal antibodies for tumors, so understanding it makes those chapters shorter.
In everyday life: Look for Ofatumumab outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Ofatumumab in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Ofatumumab means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Ofatumumab out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Ofatumumab in simple terms?

Ofatumumab is a fully human monoclonal antibody to CD20, which appears to provide rapid B-cell depletion. Under the brand name Kesimpta, it is approved for the treatment of multiple sclerosis in the United States as well as in the European Union and other regions.

Why does Ofatumumab matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Ofatumumab?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Ofatumumab.