Swedish Orphan Biovitrum AB (Sobi) announced Wednesday morning that it is acquiring CTI BioPharma, a Seattle-based company focused on developing treatments for rare diseases and blood cancers, for $1.7 billion.

Sobi’s acquisition is set to bolster its hematology franchise with the addition of Vonjo, a novel oral kinase inhibitor that treats myelofibrosis. 

The differentiated product received accelerated approval from the Food and Drug Administration in February 2022 for trating adults with intermediate or high-risk primary or secondary myelofibrosis.

As part of the deal, Sobi received committed debt financing from both Bank of America and Danske bank, with the company adding that up to half of the merger consideration is expected to be refinanced through an issuance of ordinary shares. There will be preferential rights for existing Sobi shareholders after the close of the transaction.

Additionally, Investor AB, the company’s main shareholder, undertook a vote in favor of the implementation of the rights.

If approved, Sobi’s acquisition subsidiary will be merged into CTI.

“There is a large unmet medical need within myelofibrosis, in particular for patients suffering from thrombocytopenia who are inadequately treated by existing medicines,” Sobi CEO Guido Oelkers said in a statement. “The combination of the talented team at CTI, together with Sobi’s broad US and global haematology capabilities, will help get this much needed new therapy to patients faster and more effectively. The acquisition of CTI is the latest in a series of transformative transactions Sobi has conducted to build its leading rare haematology franchise.”

Ultimately, Sobi expects the CTI purchase to be “highly accretive” to its revenue and margins, starting in the near-term. Sobi also stated that it views the addition of Vonjo as being “highly complementary” to its existing portfolio, specifically Doptelet, which the company purchased from Dova Pharmaceuticals for $915 million in 2019.

Still, the launch of Vonjo hasn’t been stellar, according to Evaluate Pharma, which projects that revenues from the drug will reach $822 million by 2028, the year before its patents start to expire. Evaluate Pharma noted that this figure is below CTI’s takeover valuation.

The company said a detailed time plan will be announced in the future.