Merck buys ArQule and BTK drug for $2.7bn

Merck & Co. has announced it is to snap up ArQule for $2.7 billion, just as the US biotech announced new data from a blood cancer drug that could be used after rival therapies fail.

There are already Bruton’s tyrosine kinase (BTK) inhibitor class drugs on the market – Janssen/AbbVie’s Imbruvica (ibrutinib) has been on the market since 2013 after a first approval in mantle cell lymphoma (MCL) and has since been approved in numerous blood cancer indications.

AstraZeneca’s Calquence (acalabrutinib) followed and has been approved in MCL and chronic lymphocytic leukaemia (CLL).

Calquence has already wowed the American Society of Hematology (ASH) with some stunning data in CLL in combination with Roche’s Gazyva – and now US Merck is trying to get in on the BTK act with this “bolt on” acquisition.

Merck & Co., known as MSD outside the US, has agreed to buy ArQule for $20 per share, bringing with it the BTK inhibitor ARQ 531.

Massachusetts-based ArQule’s lead candidate, ARQ 531 is a novel oral BTK inhibitor that is in phase 2 trials for treatment of B-cell cancers.

Merck said ARQ 531 is a highly selective, reversible inhibitor that blocks both wild-type BTK and the C481S mutant form of the enzyme that is commonly associated with resistance to other BTK inhibitors.

In early clinical trials, ARQ 531 demonstrated a manageable safety profile and early signs of anti-tumour activity in relapsed or refractory chronic lymphocytic leukaemia and Richter’s Transformation.

Final data from a phase 1 study of ARQ 531 was presented at ASH, and Merck has agreed to buy all outstanding shares in ArQule in the agreement announced simultaneously.

There are other oral kinase inhibitors in ArQule’s pipeline along with ARQ 531, described by Merck’s research chief Dr Roger Perlmutter as “a compelling candidate for the treatment of B-cell malignancies.”

The acquisition represents a considerable turnaround for ArQule, which had previously been trying to develop the c-MET inhibitor tivantinib, but had met a series of trial failures.