Roche has announced positive new data from the Phase IIIb CASTING trial of Ocrevus (ocrelizumab) in patients with relapsing-remitting multiple sclerosis (RRMS). Ocrevus is a recombinant monoclonal antibody (mAb) that gained FDA approval for the treatment of both RRMS and primary progressive multiple sclerosis (PPMS) on March 28, 2017. The brand entered the US market in Q2 2017 and reached blockbuster status in its first full year on the market, making it one of the most successful product launches.
The CASTING study was a two-year, open-label study to evaluate the effectiveness and safety of Ocrevus in patients with RRMS who had a suboptimal response to an adequate course of disease-modifying treatment (DMT). The new data showed that after two years of treatment with Ocrevus, following switching from prior therapy, 75% of RRMS patients showed no symptoms of the disease. This confirmed that Ocrevus is a highly effective treatment option for people with RRMS who experienced a suboptimal response to their prior DMT. These new data will be presented at MSVirtual2020, the eighth joint Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS)-European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) meeting.
Ocrevus has several notable clinical attributes supporting its strong market uptake, including high efficacy that is comparable to that of Biogen’s Tysabri (natalizumab) and superior to that of EMD Serono’s Rebif (IFNβ-1a), infrequent dosing via intravenous (IV) infusion every six months, and an absence of serious side effects such as the increased risk for progressive multifocal leukoencephalopathy (PML), which is associated with the long-term use of immunosuppressants such as Tysabri. These new data further reinforce Ocrevus as a highly effective treatment for people with multiple sclerosis (MS).
The launch of Ocrevus enabled Roche to enter the lucrative MS market and will help the company to diversify its existing drug portfolio, which is largely focused on the immuno-oncology space. Ocrevus’ high efficacy at reducing relapses and good safety profile translated into a rapid uptake in RRMS patients. Although Ocrevus is the first and only approved drug for the treatment of PPMS, it is not a curative treatment. Ocrevus has modest efficacy at slowing disease progression in a subset of PPMS patients (active forms), but it might not work as well in advanced patients who have a high disability and little inflammation (non-active forms).
Other anti-CD20 mAbs will compete with Ocrevus due to their more convenient subcutaneous (SC) formulations, such as Novartis’ Kesimpta (ofatumumab), which received FDA approval in August. As Kesimpta is a second-in-class anti-CD20 DMT, Novartis will need to demonstrate its clinical advantage in order to differentiate it from Ocrevus, which holds an established position in the market. Current clinical data suggest that Kesimpta’s efficacy and safety will be comparable. As such, its uptake will be generated through its advantages in terms of patient convenience. Kesimpta has an SC formulation that allows for self-administration, compared to IV-administered Ocrevus, and it also requires less frequent administration. Despite this, Kesimpta is still second-in-class and is unlikely to reach the same market share as Ocrevus in RRMS.