- Shire disclosed another win for its rare disease business on Thursday with positive results coming in from a late-stage study of its drug lanadelumab.
- The investigational medicine aims to treat hereditary angioedema (HAE), an uncommon disorder that causes intermittent swelling of various body parts and is particularly dangerous when it affects the throat, as it can lead to suffocation. When that swelling occurs, it is referred to as an HAE attack.
- In the Phase 3 HELP study, patients taking 300 mg of lanadelumab once every two weeks demonstrated an 87% reduction in average number of HAE attacks versus those on placebo. The drug also didn't trigger any serious adverse events in the trial, according to a May 18 statement from Shire. A Biologics License Application for the candidate is scheduled for filing either late this year or in early 2018.
There are only a handful of treatments targeting HAE and its symptoms on the market, and Shire owns most of them. Already in its arsenal are Cinryze (C1 esterase inhibitor [human]), Firazyr (icatibant) and Kalbitor (ecallantide), which the Dublin-based drugmaker snagged through the $5.9 billion acquisition of Dyax in late 2015. Together, those therapies had $366 million in revenues during the first quarter.
Buying Dyax also put Shire in control of DX-2930, later renamed lanadelumab. Though Kalbitor was already on the market by the time it came under Shire's control, it was the clinical-stage drug that really stood out as a potential revenue driver. Industry analysts have pegged peak annual sales for lanadelumab at $2 billion. Kalbitor, meanwhile, brought in just $11.7 million from January to March.
Part of the candidate's appeal is its differentiated mechanism of action. Unlike Cinryze, Kalbitor and other approved HAE drugs — such as CSL Behring's Berinert and Salix's Ruconest — lanadelumab doesn't inhibit C1 esterase.
Instead, it binds to and hinders plasma kallikreins, part of a group of enzymes responsible for chopping up other proteins. One class of proteins that plasma kallikreins interact with is kininogens, which spur inflammation in the body. Firazyr is another plasma kallikrein inhibitor, though it specifically targets the a protein call bradykinin.
The early results from HELP help affirm the effectiveness of such treatments in HAE patients. The trial had 125 participants, 56% of which were on prophylaxis regimens for the disease and 65% of which were experiencing at least three attacks monthly. It also had three experimental arms that tested a range of doses: 300 mg bi-weekly, 300 mg every four weeks and 150 mg every four weeks.
Shire touted that, regardless of dose, all patients treated with its drug reported no HAE attacks during the 26-week study period. A less-frequent dosing schedule would likely give lanadelumab a competitive edge over some other medications if it makes it to market, as well as a more favorable adherence profile.
Shire stock rose Thursday morning following news of the positive results. Shares traded at $188.21, up more than 3% from the previous day's close.