Swedish Orphan Biovitrum AB (Sobi) has agreed to acquire US-based Dova Pharmaceuticals in a transaction valued up to $915m.

Dova Pharmaceuticals was established in 2016 to commercialise Doptelet, a second generation small-molecule thrombopoietin receptor (TPO) agonist indicated to treat thrombocytopenia by increasing platelet count.

Under the deal, Sobi will begin a tender offer to purchase all outstanding shares of Dova for $27.50 per share in cash, as well as the right to an additional $1.50 upon approval of Doptelet for use in chemotherapy-induced thrombocytopenia by the US Food and Drug Administration (FDA).

The deal is expected to be concluded in the fourth quarter of this year, giving Sobi rights to Doptelet. The FDA has approved the drug for low platelet counts caused by chronic immune thrombocytopenia (ITP) and chronic liver disease (CLD).

Sobi has said that it will retain Dova’s 125 employees after the deal closes.

The acquisition will broaden the scope of Sobi’s product portfolio into haematology, enhancing the company’s commercial presence in the US.

Dova Pharmaceuticals president and CEO David Zaccardelli said: “We are extremely pleased to announce this merger with Sobi, which we believe will continue the expansion of Doptelet in the US and provide the necessary resources to maximise Doptelet’s availability to patients in both the US and internationally.”

The European Commission has also granted marketing authorisation for Doptelet to treat severe thrombocytopenia in adult patients with CLD who are scheduled to undergo an invasive procedure. Next year, European filing for the chronic ITP indication is expected.

Sobi CEO and president Guido Oelkers said: “The cadence of upcoming launches and approvals across indications and regions that Doptelet provides, enables us to further accelerate growth in our haematology franchise.

“There is a large unmet medical need within thrombocytopenia and for us, this is a great opportunity to be able to give patients access to new and improved treatments.”