Swedish Orphan Biovitrum (Sobi) has agreed a $1.7 billion merger deal to acquire CTI BioPharma and its recently-approved Vonjo drug for people with blood cancer myelofibrosis and severe thrombocytopenia
Seattle-based biotech CTI got accelerated approval from the FDA for Vonjo (pacritinib) just over a year ago to treat adults with intermediate- or high-risk primary or secondary myelofibrosis with low platelet counts, becoming the first drug in the US for this indication.
Around two-thirds of the approximately 21,000 myelofibrosis patients in the US develop cytopenia – either thrombocytopenia or anaemia – sometimes as a side effect of drug therapies for the cancer, such as Novartis and Incyte’s JAK1/2 inhibitor Jakafi (ruxolitinib). Around one-third of them have platelet counts below the threshold that makes the eligible for Vonjo treatment.
Analysts said on its approval that given CTI’s list price of around $245,000 per year for the drug before discounts, it could eventually become a blockbuster with sales in excess of $1 billion a year, thanks to its focus on patients for whom Jakafi isn’t an option. Last year, sales of Jakafi made around $2.4 billion.
Vonjo’s continued approval hinges on a confirmatory phase 3 trial – PACIFICA – which is due to generate results in the middle of 2025.
Sobi said the selective JAK2, IRAK1, and ACRV1 inhibitor will slot into its haematology portfolio alongside Doptelet (avatrombopag), an oral thrombopoietin receptor agonist for primary chronic immune thrombocytopenia (ITP) that it acquired via a $915 million takeover of Dova Pharma in 2019.
The Swedish company says it will help advance its strategy to build a franchise in rare haematology disorders, accelerate its revenue growth and firm up its margins. It plans to start a cash tender offer to buy up CTI’s shares at $9.10 per share, funded through debt.
“CTI represents a perfect fit for Sobi’s haematology franchise today, adding a powerful and highly differentiated new product that will make a significant difference for patients,” commented Guido Oelkers Sobi’s president and chief executive.
“There is a large unmet medical need within myelofibrosis, in particular for patients suffering from thrombocytopenia who are inadequately treated by existing medicines.”
Sobi’s involvement could re-invigorate development of Vonjo in Europe, where in 2019 CTI was forced to withdraw its marketing application after the EMA’s human medicines committee indicated it was likely to recommend against approval without more clinical data.
The drug was also delayed on its way to market in the US, thanks to an FDA clinical hold in 2016 that held up clinical trials, as well as a request by the regulator for another phase 3 trial two years later.