Roche's multiple sclerosis therapy ocrelizumab and AstraZeneca's cancer immunotherapy durvalumab have both been deemed breakthroughs by the FDA.
The US regulator awarded ocrelizumab the designation as a treatment for primary-progressive MS, a serious form of the disease that responds poorly to current therapies. It is the first MS drug to gain breakthrough status, which provides a quicker route through the development and review process for new drugs as well as a higher level of interaction with FDA staff.
The FDA made its decision on the back of positive results from the phase III ORATORIO study, which revealed that ocrelizumab significantly reduced disability progression and other markers of disease activity in secondary progressive MS patients compared to placebo.
Ocrelizumab targets CD20-positive B cells, a type of immune cell thought to play a central role in the destruction of the myelin sheath surrounding nerve cells that is the primary pathological feature of MS. Roche has indicated it plans to file for approval of the drug in its first markets in the first half of this year and says its proposed brand name for the drug is Ocrevus.
Decision Resources' analysts have suggested that an effective drug for progressive MS could become a $1bn product in that population alone. Meanwhile, Roche has also shown in the OPERA clinical trials that ocrelizumab is effective as a second-line therapy in the more common relapsing-remitting form of MS.
Meanwhile, AZ has revealed that the FDA granted breakthrough status for its PD-L1 inhibitor durvalumab (MEDI4736) for the treatment of patients with PD-L1 positive inoperable or metastatic urothelial bladder cancer whose tumour has progressed during or after one standard platinum-based regimen.
Once again this is a poorly served population with the standard of care remaining the old and often ineffective chemotherapy agent cisplatin, despite decades of research into new drugs.
The designation has been granted in light of a phase I trial (Study 1108) in patients with advanced metastatic urothelial bladder cancer, according to AZ. Durvalumab is currently being tested as a first-line therapy in this setting - both alone and in combination with tremelimumab - in the DANUBE trial.
Duvalumab is not the only drug in the PD-1/PD-L1 inhibitor category to be developed for bladder cancer. Merck & Co's Keytruda (pembrolizumab) and Roche's atezolizumab have both shown efficacy in clinical trials, with the latter awarded breakthrough status by the FDA in that indication last year.