Biogen’s oral multiple sclerosis product Tecfidera has been a massive earner for the company, but is facing challenges to its patents. The company’s now filed a follow-up in the US to try to defend its franchise.
The new drug – diroximel fumarate (BIIB098) – is partnered with Alkermes and has been developed to improve the safety profile of Tecfidera (dimethyl fumarate), particularly with regard to its gastrointestinal tolerability.
It has been filed via the truncated 505(b)(2) US regulatory pathway, which allows it to reference Tecfidera data in the application dossier, and Biogen and Alkermes are hoping for a possible launch for relapsing forms of MS towards the end of 2019 or in early 2020. If approved, Biogen intends to sell it under the brand name Vumerity.
BIIB098, formerly known as ALKS 8700 and licensed by Biogen in 2017, has been filed for approval on the back of the EVOLVE-MS-1 study which showed it was bioequivalent to Tecfidera, along with pharmacokinetic bridging studies comparing the two drugs. Biogen is also enrolling patients a head-to-head tolerability study versus Tecfidera with data due in mid-2019.
So far, Alkermes says it has seen discontinuation rates with the new drug at below 1%, well below the 6%-7% reported in trials of Tecfidera. However, a recent ‘real-world’ study conducted in Sweden found that a majority of Tecfidera patients at one clinic – around 57% – had stopped using the drug and switched to an alternative after two years.
The tolerability issue hasn’t held back Tecfidera commercially, however, with quarterly sales currently running at more than $1bn, despite tougher competition overall in the MS market.
While the GI tolerability of Tecfidera has been recognised as an issue for some time, analysts are divided on the potential role of BIIB098, with some suggesting that the side effects are fairly manageable and can recede with time. Others maintain that BIIB098 will win patients new to therapy, even if patients already managed on Tecfidera are less likely to switch.
Alkermes pocketed a $50m milestone payment from Biogen on the strength of preliminary comparative tolerability data, and will get another $150m if the drug is approved by the FDA.
Just when Tecfidera might become vulnerable to generic competition isn’t yet clear. In October, a US federal appeals court upheld a ruling that Biogen’s patents on the drug are valid, rejecting a challenge by Danish drugmaker Forward Pharma, with which it had reached a deal to delay generic competition five years ago.
Biogen said the ruling meant it had protection against generics in the US until 2028, although Forward Pharma has said it may appeal. In the meantime, a patent opposition lawsuit is ongoing in Europe.
Earlier this month Indian drugmakers Lupin Labs and Shilpa Medicare both won tentative FDA approval for generic dimethyl fumarate capsules, although they have not indicated when they intend to place the products on the market.