Rituximab (Rituxan) Archive
Third PML case reported with Rituximab(11/07/10)
A case of progressive multifocal leukoencephalopathy (PML) has been reported in a rheumatoid arthritis patient taking rituximab (Rituxan) who had not previously received anti- tumor necrosis factor therapy, according to the FDA and the drug’s manufacturer.
The case is the third seen with rituximab in rheumatoid arthritis, according to a “Dear Healthcare Professional” letter issued by Genentech. The previous two were seen in patients who had received anti-TNF drugs earlier.
PML causes inflammation in the brain, which has been fatal in about half of patients. It is caused by reactivation of latent JC virus infection, presumably a result of immune suppression.
Other biologic drugs targeting immune system components have been linked to PML, as well, including natalizumab (Tysabri) and efalizumab (Raptiva).
Both those drugs were removed from the U.S. market after cases of PML appeared, although natalizumab was later reintroduced with a strict risk evaluation and mitigation strategy. (See Raptiva Yanked from U.S. Market and Tysabri (natalizumab) Allowed Back to Market with Restrictions)
“Physicians should consider PML in any patient being treated with Rituxan who presents with new onset neurologic manifestations,” Genentech’s letter said. “Consultation with a neurologist, brain MRI, and lumbar puncture should be considered as clinically indicated.”
The most recent case involved a 73-year-old woman who had received two doses of rituximab in February 2009. Symptoms developed four to six months later, Genentech said.
The woman had also taken leflunomide, hydroxychloroquine, and prednisone — but not anti-TNF drugs such as infliximab (Remicade) or Etanercept (Enbrel).
The letter did not indicate whether she had survived.
Genentech said about 100,000 rheumatoid arthritis patients have received rituximab, apparently putting the risk much lower than with natalizumab.
The risk of PML with natalizumab has been estimated at about one case per 1,000 patients receiving the drug for two years.
Source: Discuss Pharmacy Copyright 2010 Discuss Pharmacy (11/07/10)
OBJECTIVE: B cells and the humoral immune system have been implicated in the pathogenesis of multiple sclerosis (MS). This study sought to evaluate the efficacy, safety, and tolerability of add-on therapy with rituximab, a monoclonal antibody that depletes circulating B cells, in subjects with relapsing MS with breakthrough disease defined by clinical and MRI activity (Class III evidence).
METHODS: Thirty subjects with a relapse within the past 18 months despite use of an injectable disease-modifying agent, and with at least 1 gadolinium-enhancing (GdE) lesion on any of 3 pretreatment MRIs, received rituximab administered at 375 mg/m(2) weekly x 4 doses. Three monthly posttreatment brain MRI scans were obtained beginning 12 weeks after the first infusion. Multiple Sclerosis Functional Composite (MSFC) and Expanded Disability Status Scale (EDSS) were obtained at baseline and throughout the post-treatment follow-up.
RESULTS: GdE lesions were reduced after treatment with rituximab, with 74% of posttreatment MRI scans being free of GdE activity compared with 26% free of GdE activity at baseline (p < 0.0001). Median GdE lesions were reduced from 1.0 to 0, and mean number was reduced from 2.81 per month to 0.33 after treatment (88% reduction). MSFC improved as well (p = 0.02). EDSS remained stable.
CONCLUSION: Rituximab add-on therapy was effective based upon blinded radiologic endpoints in this phase II study. In combination with standard injectable therapies, rituximab was well-tolerated with no serious adverse events. B-cell-modulating therapy remains a potential option for treatment of patients with relapsing MS with an inadequate response to standard injectable therapies.
CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that add-on rituximab reduces gadolinium-enhancing brain lesions in multiple sclerosis.
Source: Neurology. 2010 Jun 8;74(23):1860-7. & Pubmed PMID: 20530322 (08/06/10)
AAN - Rituximab may be an effective treatment for secondary progressive Multiple Sclerosis(19/04/10)
Targeting B cells implicated in progressive multiple sclerosis with rituximab (Rituxan) therapy might help patients diagnosed with the disease, according to data from a small study reported here.
"This study shows that rituximab could be an effective treatment in a subgroup of patients with secondary progressive multiple sclerosis," Carolina Ionete, MD, of the University of Massachusetts Medical School in Worcester, wrote in a poster presentation abstract for the annual meeting of the American Academy of Neurology.
However, Ionete said that before clinicians begin using the monoclonal antibody in patients with multiple sclerosis, a larger scale study will be required.
Her study scrutinized outcomes in 10 patients who had documented diagnoses of secondary progressive multiple sclerosis without relapses.
Rituximab targets CD20, a protein expressed on most B cells -- believed to be part of the cascade of molecular events involved in the inappropriate autoimmune functioning that is the hallmark of multiple sclerosis.
Ionete and colleagues determined to evaluate the clinical response to rituximab in the treatment of secondary progressive multiple sclerosis in a retrospective study that used chart reviews to identify patients who received rituximab for treatment of secondary progressive multiple sclerosis at the UMass medical center.
All of the patients were treated with intravenous rituximab 1 gram, repeated in two weeks.
Five patients received a second cycle of rituximab at six months, and five patients did not receive the second cycle. Of the latter group, two had adverse reactions, two did not respond to treatment, and one has still had less than one year of follow-up.
Ionete reviewed the patients' neurological examination, Expanded Disability Status Scale (EDSS), 25-foot walk, and modified nine-hole peg test which was performed at baseline, and then at three months, six months and 12 months.
Magnetic resonance imaging scans which recorded new or enlarged T2 lesions and new T1 gadolinium enhancing lesions were collected at baseline and at 12 months.
The patients who received the second cycle of rituximab at six months showed mean extended disability status scale improvement. Their mean baseline scores were 5.4 on the EDSS, and those scores improved to 4.4 at 12 months (P=0.0032).
Ionete also observed improvement in times for the 25-foot walk at month 12 in all five patients who received the second cycle at six months. Four out of five patients showed improvement in the modified nine-hole peg test. The mean time to perform the test at baseline was 17.14 sec, which decreased to 13.94 sec at 12 months.
The researchers did not see changes in the magnetic resonance imaging activity over the 12 month period in any of the patients.
Ionete disclosed financial relationships with Bayer Healthcare, Teva Neuroscience, EMD Serono and Biogen Idec.
Other authors disclosed financial relationships with other industry entities including Berlex and Genentech.
Primary source: American Academy of Neurology
Source reference: Ionete C, et al "Rituximab in secondary progressive multiple sclerosis -- one year follow up" AAN 2010; Abstract P02.147.
Source: Medpage Today © 2004-2010 MedPage Today, LLC(19/04/10)