The most common side effects with intravenous infusions are reactions related to the infusion (such as fever, chills and shivering) while most common serious side effects are infusion reactions, infections and heart-related problems.[16] Similar side effects are seen when it is injected under the skin, with the exception of reactions around the injections site (pain, swelling and rash), which occur more frequently with the skin injections.[16]
Rituximab is a chimericmonoclonal antibody against the protein CD20, which is primarily found on the surface of immune system B cells.[23] When it binds to this protein it triggers cell death.[18]
Rituximab is a chimeric monoclonal antibody targeted against CD20, a surfaceantigen present on B cells. It acts by depleting normal as well as pathogenic B cells while sparing plasma cells and hematopoietic stem cells, which do not express the CD20 surface antigen.[27]
In the United States, rituximab is indicated to treat:
In the European Union, rituximab is indicated for the treatment of follicular lymphoma and diffuse large B cell non-Hodgkin's lymphoma (two types of non-Hodgkin's lymphoma, a blood cancer);[16] chronic lymphocytic leukemia (CLL, another blood cancer affecting white blood cells);[16] severe rheumatoid arthritis (an inflammatory condition of the joints);[16] two inflammatory conditions of blood vessels known as granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA);[16] moderate to severe pemphigus vulgaris, an autoimmune disease characterised by widespread blistering and erosion of the skin and mucous membranes (the linings of internal organs). 'Autoimmune' means that the disease is caused by the immune system (the body's natural defences) attacking the body's own cells.[16]
Rituximab has been shown to be an effective rheumatoid arthritis treatment in three randomised controlled trials and is now licensed for use in refractory rheumatoid disease.[32] In the United States, it has been FDA approved for use in combination with methotrexate for reducing signs and symptoms in adult patients with moderately to severely active rheumatoid arthritis (RA) who have had an inadequate response to one or more anti-TNF-alpha therapy. In the European Union, the license is slightly more restrictive: it is licensed for use in combination with methotrexate in patients with severe active RA who have had an inadequate response to one or more anti-TNF therapy.[33]
The antibody binds to the cell surface protein CD20. CD20 is widely expressed on B cells, from early pre-B cells to later in differentiation, but it is absent on terminally differentiated plasma cells. Although the function of CD20 is unknown, it may play a role in Ca2+ influx across plasma membranes, maintaining intracellular Ca2+ concentration and allowing activation of B cells.
Rituximab is relatively ineffective in elimination of cells with low CD20 cell-surface levels.[60] It tends to stick to one side of B cells, where CD20 is, forming a cap and drawing proteins over to that side. The presence of the cap changes the effectiveness of natural killer (NK) cells in destroying these B cells. When an NK cell latched onto the cap, it had an 80% success rate at killing the cell. In contrast, when the B cell lacked this asymmetric protein cluster, it was killed only 40% of the time.[61]
Rituximab has a general regulatory effect on the cell cycle.
Preferential elimination of malignant B cells with high CD20 levels and high BCR signaling propensity, especially in chronic lymphocytic leukemia (CLL).[60]
It increases MHC II and adhesion molecules LFA-1 and LFA-3 (lymphocyte function-associated antigen).
Rituximab also induces a release of some chronic lymphocytic leukemia cells from immune niches, which might make them more sensitive to chemotherapy used in combination with an anti-CD20 antibody.[63]
The combined effect results in the elimination of B cells (including the cancerous ones) from the body, allowing a new population of healthy B cells to develop from lymphoid stem cells.
Rituximab binds to amino acids 170–173 and 182–185 on CD20, which are physically close to each other as a result of a disulfide bond between amino acids 167 and 183.[64]
Originally available for intravenous injection (e.g. over 2.5 hrs), in 2016, it gained EU approval in a formulation for subcutaneous injection for B-cell CLL/lymphoma (CLL).[71]
In June 2017, the US FDA granted regular approval to the combination of rituximab and hyaluronidase human (brand name Rituxan Hycela) for adults with follicular lymphoma, diffuse large B-cell lymphoma, and chronic lymphocytic leukemia.[72] The combination is not indicated for the treatment of non-malignant conditions.[31][72] The combination was approved based on clinical studies SABRINA/NCT01200758 and MabEase/NCT01649856.[31]
In September 2019, the US FDA approved rituximab injection to treat granulomatosis with polyangiitis and microscopic polyangiitis in children two years of age and older in combination with glucocorticoids (steroid hormones).[73] It is the first approved treatment for children with these rare vasculitis diseases, in which a person's small blood vessels become inflamed, reducing the amount of blood that can flow through them.[73] This can cause serious problems and damage to organs, most notably the lungs and the kidneys.[73] It also can impact the sinuses and skin.[73] Rituximab was approved by the FDA to treat adults with granulomatosis with polyangiitis and microscopic polyangiitis in 2011.[73]
In December 2021, the US FDA approved rituximab in combination with chemotherapy for children aged 6 months to 18 years with previously untreated, advanced stage, CD20-positive diffuse large B-cell lymphoma, Burkitt lymphoma, Burkitt-like lymphoma, or mature B-cell acute leukemia.[28][74] Efficacy was evaluated in Inter-B-NHL Ritux 2010, a global multicenter, open-label, randomized 1:1 trial of participants six months in age or older with previously untreated, advanced stage, CD20-positive diffuse large B-cell lymphoma, Burkitt lymphoma, Burkitt-like lymphoma, or B-cell acute leukemia.[74] Advanced stage was defined as stage III with elevated lactose dehydrogenase level (lactose dehydrogenase greater than twice the institutional upper limit of normal values) or stage IV B-cell non-Hodgkin's lymphoma or B-cell acute leukemia.[74] Participants were randomized to Lymphome Malin B chemotherapy that consisted of corticosteroids, vincristine, cyclophosphamide, high-dose methotrexate, cytarabine, doxorubicin, etoposide, and triple drug (methotrexate/cytarabine/corticosteroid) intrathecal therapy alone or in combination with rituximab or non-US licensed rituximab, administered as six infusions of rituximab IV at a dose of 375 mg/m2 as per the Lymphome Malin B scheme.[74]
Biosimilars are approved in the United States, India, the European Union, Switzerland, Japan, and Australia.[citation needed] The US FDA approved rituximab-abbs (Truxima) in 2018,[1][75][76] rituximab-pvvr (Ruxience) in 2019,[2] and rituximab-arrx (Riabni) in 2020.[3]
In July 2024, the Committee for Medicinal Products for Human Use of the European Medicines Agency adopted a positive opinion, recommending the granting of marketing authorization to Dr. Reddy's Laboratories / Holding GmbH for their rituximab biosimilar Ituxredi, intended for the treatment of non-Hodgkin's lymphoma, chronic lymphocytic leukemia, rheumatoid arthritis, granulomatosis with polyangiitis and microscopic polyangiitis and pemphigus vulgaris.[5] Ituxredi was authorized for medical use in the European Union in September 2024.[5][6] Dr Reddy's Rituximab biosimilar Reditux was approved in India in 2007.[77]
In 2014, Genentech reclassified Rituxan as a specialty drug, a class of drugs that are only available through specialty distributors in the US.[78] Because wholesalers discounts and rebates no longer apply, hospitals would pay more.[78]
Patents on rituximab have expired in the European Union[79][80][81] and in the United States.[82][83][84]Biosimilars were approved in the United States, India, the European Union, Switzerland, Japan, and Australia. The US FDA approved rituximab-abbs (Truxima) in 2018,[1][75][76] rituximab-pvvr (Ruxience) in 2019,[2] and rituximab-arrx (Riabni) in 2020.[3][85][86] Truxima and Riabni are approximately $3600 per 500 mg, wholesale - 10% less than Rituxan, while Ruxience is 24% less than Rituxan.[87][88] Dr Reddy's rituximab ituxredi retails for under 10,000 rupees ($118) per 100 mg in India.[89]
Rituximab has been reported as a possible cofactor in a chronic hepatitis E infection in a person with lymphoma. Hepatitis E infection is normally an acute infection, suggesting the drug in combination with lymphoma may have weakened the body's immune response to the virus.[92]
In 2009, a patient receiving methotrexate-induced B-cell depletion for cancer treatment, experienced a transient remittal of their myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) symptoms. While initial trials using Rituximab were promising, a phase 3 trial published in 2019 did not find an association between Rituximab treatment and improvements in ME/CFS.[93][94]
The efficacy and success of rituximab has led to some other anti-CD20 monoclonal antibodies being developed:
ocrelizumab, humanized (90%-95% human) B cell-depleting agent.
ofatumumab (HuMax-CD20) a fully human B cell-depleting agent.[96]
Third-generation anti-CD20s such as obinutuzumab have a glycoengineered Fc fragment (Fc)[97] with enhanced binding to Fc gamma receptors, which increase ADCC (antibody-dependent cellular cytotoxicity).[98] This strategy for enhancing a monoclonal antibody's ability to induce ADCC takes advantage of the fact that the displayed Fc glycan controls the antibody's affinity for Fc receptors.[99]
^ abc"Ituxredi EPAR". European Medicines Agency. 25 July 2024. Retrieved 27 July 2024. Text was copied from this source which is copyright European Medicines Agency. Reproduction is authorized provided the source is acknowledged.
^ abcdefgh"Mabthera EPAR". European Medicines Agency. 17 September 2018. Archived from the original on 9 September 2021. Retrieved 8 September 2021. Text was copied from this source which is copyright European Medicines Agency. Reproduction is authorized provided the source is acknowledged.
^"Mabthera PI". Union Register of medicinal products. 3 June 1998. Retrieved 5 July 2024.
^ abcdefgh"Rituximab". The American Society of Health-System Pharmacists. Archived from the original on 27 March 2016. Retrieved 8 December 2016.
^Tandan R, Hehir MK, Waheed W, Howard DB (August 2017). "Rituximab treatment of myasthenia gravis: A systematic review". Muscle & Nerve. 56 (2): 185–196. doi:10.1002/mus.25597. PMID28164324. S2CID19504332.
^Singer O, McCune WJ (May 2017). "Update on maintenance therapy for granulomatosis with polyangiitis and microscopic polyangiitis". Current Opinion in Rheumatology. 29 (3): 248–253. doi:10.1097/BOR.0000000000000382. PMID28306595. S2CID35805200.
^ abWorld Health Organization (2023). The selection and use of essential medicines 2023: web annex A: World Health Organization model list of essential medicines: 23rd list (2023). Geneva: World Health Organization. hdl:10665/371090. WHO/MHP/HPS/EML/2023.02.
^Saini KS, Azim HA, Cocorocchio E, Vanazzi A, Saini ML, Raviele PR, et al. (August 2011). "Rituximab in Hodgkin lymphoma: is the target always a hit?". Cancer Treatment Reviews. 37 (5): 385–390. doi:10.1016/j.ctrv.2010.11.005. PMID21183282.
^McGinley MP, Moss BP, Cohen JA (January 2017). "Safety of monoclonal antibodies for the treatment of multiple sclerosis". Expert Opinion on Drug Safety. 16 (1): 89–100. doi:10.1080/14740338.2017.1250881. PMID27756172. S2CID36762194.
^He D, Guo R, Zhang F, Zhang C, Dong S, Zhou H (December 2013). "Rituximab for relapsing-remitting multiple sclerosis". The Cochrane Database of Systematic Reviews (12): CD009130. doi:10.1002/14651858.CD009130.pub3. PMID24310855.
^Burton C, Kaczmarski R, Jan-Mohamed R (June 2003). "Interstitial pneumonitis related to rituximab therapy". The New England Journal of Medicine. 348 (26): 2690–1, discussion 2690–1. doi:10.1056/NEJM200306263482619. PMID12826649.
^Seyfizadeh N, Seyfizadeh N, Hasenkamp J, Huerta-Yepez S (January 2016). "A molecular perspective on rituximab: A monoclonal antibody for B cell non Hodgkin lymphoma and other affections". Critical Reviews in Oncology/Hematology. 97: 275–290. doi:10.1016/j.critrevonc.2015.09.001. PMID26443686.
^ abBorsky M, Hrabcakova V, Novotna J, Brychtova Y, Doubek M, Panovska A, et al. (December 2021). "Rituximab induces rapid blood repopulation by CLL cells mediated through their release from immune niches and complement exhaustion". Leukemia Research. 111: 106684. doi:10.1016/j.leukres.2021.106684. PMID34438120.
^"Biosimilars of Rituximab". Generics and Biosimilars Initiative. 14 April 2017. Archived from the original on 24 February 2024. Retrieved 29 April 2017.
^"Amgen Rituximab Biosimilar Gains FDA Approval". The Center For Biosimilars. 17 December 2020. Archived from the original on 23 April 2021. Retrieved 23 April 2021. The pharmaceutical company said Riabni will be marketed at a discount to the reference product of 23.7% below wholesale acquisition cost (WAC), or a WAC of $716.80 per 100 mg and $3584 per 500 mg single-dose vial. These costs are 15.2% less than the WAC for the biosimilar rituximab Truxima, Amgen said. The company added that Riabni's average sales price will be 16.7% below the current average for Rituxan.
^Contreras K, Orozco V, Puche E, González CA, García-Padilla P, Rodríguez MP, et al. (March 2022). "Cost-Effectiveness of Rituximab (Fixed Schedule vs Tailored Dose) Compared With Azathioprine Maintenance Therapy in Adults With Generalized Antineutrophil Cytoplasm Antibody-Associated Vasculitis in Colombia". Value in Health Regional Issues. 28: 98–104. doi:10.1016/j.vhri.2021.08.002. PMID34922060.
^Romero G, Ticchioni M, Cohen M, Rosenthal-Allieri MA, Mondot L, Lebrun Frenay C (March 2016). "Neuromyelitis optica: Contribution of therapeutic responses markers monitoring in patients given rituximab". Revue Neurologique. 172 (3): 220–224. doi:10.1016/j.neurol.2015.12.004. PMID26915311.
^Kriston L, Härter M, Hölzel L (March 2009). "Challenges in reporting meta-analyses of diagnostic accuracy studies". Letters. Annals of Internal Medicine. 150 (6): 430. doi:10.7326/0003-4819-150-6-200903170-00025. PMID19293085.
^Fluge Ø, Rekeland IG, Lien K, Thürmer H, Borchgrevink PC, Schäfer C, et al. (May 2019). "B-Lymphocyte Depletion in Patients With Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Randomized, Double-Blind, Placebo-Controlled Trial". Annals of Internal Medicine. 170 (9): 585–593. doi:10.7326/M18-1451. PMID30934066. S2CID91186383.
^Bonnan M, Ferrari S, Bertandeau E, Demasles S, Krim E, Miquel M, et al. (2014). "Intrathecal rituximab therapy in multiple sclerosis: review of evidence supporting the need for future trials". Current Drug Targets. 15 (13): 1205–1214. doi:10.2174/1389450115666141029234644. PMID25355180.