Biogen announced the start of a global Phase 3b clinical trial to evaluate the efficacy and safety of extended interval dosing (EID) with Tysabri (natalizumab) in patients with relapsing-remitting multiple sclerosis (RRMS).
Results of the six-week dosing interval will be compared with the approved standard interval dosing (SID) regimen, which consists of intravenous injections (300 mg) every four weeks.
Tysabri is a humanized monoclonal antibody therapy believed to prevent immune cells from crossing the blood-brain barrier, subsequently preventing lesions on the brain and spinal cord. The treatment is approved by the U.S. Food and Drug Administration and the European Medicines Agency, and has shown an ability to reduce MS relapse rates.
However, prolonged treatment with Tysabri has been linked to an increased risk of progressive multifocal leukoencephalopathy (PML), a rare opportunistic and potentially deadly viral infection caused by the John Cunningham virus (JCV).
The two-year Phase 3b NOVA trial (NCT03689972) is a follow-up of the retrospective TOUCH Prescribing Program that compared Tysabri-associated PML risk between EID and SID regimens. The findings showed that EID treatment was significantly associated with a reduced risk of PML compared with SID.
NOVA will enroll approximately 480 RRMS patients — the first patient has now been enrolled — to further evaluate the efficacy and benefit-risk profile of Tysabri EID on patients previously treated with SID for one year. The outcomes from the EID group will be compared with patients receiving continued SID treatment. The primary objective of the trial is the number and size of new brain lesions.
“For more than a decade, natalizumab has been considered a highly effective treatment option for patients with relapsing forms of MS,” Alfred Sandrock, Jr., MD, PhD, executive vice president and chief medical officer at Biogen, said in a press release.
“The NOVA study may generate valuable data that we hope will answer questions for the scientific community about the efficacy of [Tysabri] when its dosing schedule is extended to every six weeks, and in conjunction with prior safety analyses, may inform on the drug’s benefit-risk profile,” he added.
Besides the U.S. and the European Union, Tysabri is approved in more than 80 countries, including Canada, Australia and Switzerland. The therapy has been used as an RRMS treatment for more than 10 years, including in nearly 191,000 patients.