Approval makes Xiidra the apple of Shire’s eye

The FDA go-ahead for Shire’s dry eye drug Xiidra is not only a relief after a chequered path to approval, but should also help the group reduce its reliance on its ADHD franchise. Xiidra is easily the company’s most valuable pipeline asset and is expected to be Shire’s second biggest seller in 2022 behind ADHD drug Vyvanse (see table below).

To get there, Xiidra will need to capture market share from Allergan’s Restasis – which might not be too difficult, as Xiidra’s label cites a quicker onset of action and the fact it can treat both the signs and symptoms of dry eye disease. Restasis, meanwhile, is only approved to treat the signs.

Shire has not yet given pricing details but Leerink analysts expect Xiidra to cost about the same as Restasis, at around $300 per prescription, while Evercore ISI’s Umer Raffat believes a premium could be justified.

How well Shire does at luring away Allergan’s customers could depend on its pricing strategy: Xiidra will benefit from a better label, but payers might still prefer Restasis if it is much cheaper.

But the drug could also appeal to more patients, with Leerink saying the treatable patient population could number nine million versus the one million currently using Restasis. And the overall market is even bigger: Mr Raffat noted that around 54 million people in the US suffer from dry eye disease, and that around 16 million are seeking treatment.

Dry your eyes mate

The decision is a turnaround for Shire, which last October received an FDA rejection for Xiidra – then known as lifitegrast – after mixed data from the phase III Opus-1 and Opus-2 trials.

Not long after, the Opus-3 study succeeded on its single primary endpoint, eye dryness; although there were doubts at the time, this must have been enough for approval (Shire keeps it simple and gets dry eye win, October 27, 2015). 

Shire has also prevailed in another of its goals, preventing itself being acquired with its own purchase of Baxalta, which finally completed in June. However, the companies’ joint pipelines post-Xiidra’s approval look rather thin, with no more blockbusters-in-waiting according to EvaluatePharma sellside forecasts.

The biggest R&D project is Shire’s hereditary angioedema candidate lanadelumab, which is set to overtake the group’s existing HAE therapy Cinryze by 2022; followed by adult ADHD drug SHP465, which could help stem losses in its Adderall franchise (More than ever Shire needs unusual focus on ADHD franchise, June 30, 2016). 

Baxalta’s biggest contribution is partner CTI Biopharma’s myelofibrosis candidate pacritinib, which looks unlikely to meet this forecast due to its ongoing FDA clinical hold. It also brings pancreatic cancer drug Onivyde, developed by Merrimack but licensed to Baxalta in Europe, where it is expecting approval anytime now.

While Xiidra’s approval is a boost for Shire, it exposes an uncomfortably bare pipeline. Maybe it’s already time for more M&A.

To contact the writer of this story email Madeleine Armstrong in London at [email protected] or follow @medtech_ma on Twitter