Drugmaker Bristol-Myers Squibb said it bought rights to a mid-stage fibrosis drug and its privately held developer for up to $1.25 billion, boosting its pipeline for drugs that treat tissue scarring.

The deal gives Bristol-Myers access to Promedior’s lead experimental drug, PRM-151, which is being tested to treat two types of fibrosis.

PRM-151 is undergoing trials as a treatment for the lung condition, idiopathic pulmonary fibrosis, and a form of blood disorder called myelofibrosis.

Myelofibrosis, a condition that affects the bone marrow, is classified as a rare disease by the US National Institutes of Health.

Bristol-Myers has four experimental fibrosis drugs in its pipeline, two of them in mid-stage and two in early studies.

Promedior’s mid-stage studies of its fibrosis drug are expected to begin in the next few weeks, Bristol-Myers said on Monday.

Lexington, Massachusetts-based Promedior is backed by healthcare investors including British drugmaker Shire Plc .

Bristol-Myers said rights to buy Promedior could be exercised after the completion of either of the studies. The deal includes an upfront cash payment of $150 million for the right to acquire Promedior. – Reuters