Baxter scores but Roche’s secret weapon waits in the wings

No sooner did Baxter score a win with its long-acting haemophilia A project BAX 855, enabling it to compete with Biogen Idec’s recently approved Eloctate, than a new challenger has appeared – at least if a super-bullish analysis by UBS is to be believed.

As the norm moves away from treating bleeding episodes towards preventive care Baxter now has a good shot at staying in the game against Biogen, as well as Bayer and Novo Nordisk. But the possibility that Roche’s ACE 910 could shake up the entire space, as UBS thinks, will have to be considered, though it is still very early days.

Indeed, ACE 910 (emicizumab), a bispecific anti-factor IXa/factor X antibody that aims to replicate the co-factor function of factor VIII, is barely in phase II, and phase I data are expected at December’s ASH meeting. But the project “could make all current factor VIII and VII products obsolete”, UBS’s Alexandra Hauber wrote yesterday.

Before this becomes a consideration, of course, the market is set to change dramatically with the advent of long-acting factor VIIIs like Baxter’s BAX 855 (Adynovate).

Yesterday Baxter said the open-label phase II/III Prolong-Ate study showed prophylactic BAX 855 to be superior to on-demand BAX 855, cutting annualised bleeding rates from 41.5 to 1.9. The efficacy result was not a huge surprise, and safety was seen as the more important parameter.

Baxter said no patients developed inhibitors to BAX 855, and no treatment-related adverse events, including hypersensitivity, were reported. The project will be filed with the US FDA before the end of the year, while an extension trial continues and a phase III paediatric study is initiated.

But this space is becoming crowded. Novo’s N8-GP and Bayer’s BAY 94-9027 – like BAX 855 these are pegylated factor VIIIs – are in phase III, while Biogen’s Eloctate, which extends the life of factor VIII via an fc fusion protein, was approved in the US in June. EvaluatePharma consensus for 2020 sales of Eloctate, BAY 94-9027, BAX 855 and N8-GP is $1.3bn, $402m, $302m and $292m respectively.

“Unparalleled efficacy”

All four are dosed intravenously between twice a week and once every five days, but in phase I ACE 910 was given just once weekly, and via more convenient subcutaneous injection. This, coupled with “unparalleled efficacy” in phase I, could give the Roche project an advantage, UBS says.

Moreover, the analysts see the risk of developing inhibitors as low, and say the bispecific antibody could be easier and cheaper to manufacture than factor VIII – one of the most complex and possibly largest of recombinant proteins. ACE 910 was discovered by Chugai, the majority-owned Roche subsidiary that the Swiss company has been rumoured to be interested in acquiring fully.

UBS thinks ACE 910 could enter pivotal trials next year and be launched in 2018 at the earliest – a remarkably bullish stance on its speed of development – as well as generating peak sales of CHF7bn ($8bn). This barely credible claim – consensus is for just $2m in 2020 – is tempered only marginally by the caveat that it is not adjusted for development risk.

At ASH Roche plans to present comprehensive data from all the dosing cohorts of an 18-patient phase I trial. Much more evidence is needed before even a fraction of the CHF7bn estimate begins to look like it is close to reality.

Project Study Trial ID
BAX 855 159-pt, phase II/III (Prolong-Ate) NCT01736475
ACE 910 18-pt, phase I/II, open-label extension JapicCTI-132195

To contact the writer of this story email Jacob Plieth in London at [email protected] or follow @JacobEPVantage on Twitter

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