Offering cash and more than four times the company's earlier valuation should allow Ultragenyx to win an acquisition battle for Dimension Therapeutics.
Its offer sets a new bar of $138m for a phase II haemophilia B gene therapy asset, and one that has been tested in only 24 people. As a rare disease player Ultragenyx might be unperturbed by the small patient numbers, but the question of whether Dimension’s DTX101 encodes a sufficiently powerful protein is another risk in the buyout swoop.
In offering $5.50 a share Ultragenyx topped an all-share offer from Regenxbio, which had spun out Dimension in 2013 to develop novel AAV vectors. The Regenxbio offer valued Dimension at $3.41 a share – before the offer Dimension’s share price stood at $1.20 and its market capitalisation at $30.1m.
Although it is active in rare diseases Ultragenyx has yet to enter into gene therapy. However, gene therapy looks to be fertile ground for companies seeking to treat haemophilia, where the promise of a once-and-done treatment could outweigh frequent infusions to prevent bleeds, and perhaps also command million-dollar reimbursement.
In haemophilia B, gene therapy seeks to encode production of factor IX, the absence of which means blood cannot clot. The biggest selling product in the space is Pfizer’s Benefix, a straight factor replacement.
To bleed or not to bleed
Two separate approaches have emerged: encoding normal human factor IX, or a mutated version called FIX-Padua first identified in an Italian patient that is a more potent clotting factor. This is the approach of Spark Therapeutics’s Pfizer-partnered SPK-9001 as well as Shire’s abandoned BAX 335 (New data Spark haemophilia B gene therapy battle, June 17, 2016).
With the leading two FIX-Padua candidates spoken for, gene therapy projects encoding wild-type protein are the next best thing. Uniqure has blazed a trail here – its increases in factor IX have been seen as modest compared with Spark’s FIX-Padua project, although more recently it has been able to demonstrate a reduction in bleeds as well as discontinuation of preventive factor IX infusions.
It could be that Ultragenyx is less interested in haemophilia than it is in Dimension's earlier stage metabolic disease candidates – a space with which it is more familiar. In that case, emerging data could make DTX101 a candidate for out-licensing, which, if successful, will make this acquistion look a little less expensive.