Analysts have been reflecting on the US approval granted to Human Genome Sciences and GlaxoSmithKline's lupus drug Benlysta and what it means for patients and the two companies.
Unsurprisingly, HGS shares ended the day up 13.5% at $29.03 after the US Food and Drug Administration gave the green light to Benlysta (belimumab), making it the first new treatment to be approved for lupus in 56 years. It is also likely to be a very lucrative one.
Benlysta will cost around $35,000 per patient per year and Navid Malik, an analyst at Matrix Group, noted that it will enjoy "a low-risk threat from generics in the foreseeable future". The US market is estimated to be anywhere between 300,000 and 1.5 million lupus patients and he forecasts peak sales for Benlysta of £1 billion, "which may be conservative". Some analysts have forecast peak sales of $3.6 billion.
Mr Malik added that "from a sentiment perspective, this is an important milestone for GSK" as it presents further evidence of delivery from its pipeline and "demonstrates a strong degree of innovation, given the complex path that has faced Benlysta on its way to final approval". The green light from the FDA has put HGS in the spotlight as a takeover target, but when asked by PharmaTimes World News whether GSK may be tempted to make a bid, he said it is unlikely.
Any move by GSK would only be justified if it made good economic sense, eg if the royalties it pays out to HGS became too high. However Mr Malik noted that in terms of pipeline, the two companies are working together on darapladib (discovered by GSK based on HGS technology) which is in Phase III for atherosclerosis and if that gets to market, "there probably could be a serious discussion".
James Wentworth, healthcare analyst at Datamonitor, said that "with a fairly wide label, Benlysta will help to make lupus the next billion dollar autoimmune market". He expects approval in Europe later this year but "this presents a lower commercial opportunity".
Mr Wentworth notes that HGS has been building up stock of the drug and the firm has stated it has about a year’s worth of inventory, "enough for approximately 50,000 patients". He expects Benlysta will remain the only marketed US biologic for lupus "for at least the next three years", though "there is competition looming with several Phase III agents in development", led by UCB’s epratuzumab.