Drugmaker Pfizer on Monday announced a $2.26 billion deal to acquire Canadian drug developer Trillium Therapeutics (TRIL).

Pfizer will buy the remaining outstanding shares for $18.50 apiece. Shares of Trillium on Monday closed at $17.59, up $11.50, or 188.83%.

Trillium was valued at less than $50 million at the beginning of 2020. In September 2020, Pfizer invested $25 million in Trillium stock.

Trillium's official website says that it targets "CD47, a molecule that tumors frequently use to evade the immune system. CD47 is a 'don’t eat me' signal that blocks the ability of macrophages to phagocytose and destroy tumor cells."

“The proposed acquisition of Trillium builds on our strong track record of leadership in Oncology, enhancing our hematology portfolio as we strive to improve outcomes for people living with blood cancers around the globe,” said Andy Schmeltz, global president and general manager of Pfizer Oncology.

The purchase will allow Pfizer access to two cancer drugs that are in the early stages of clinical testing specifically for a range of blood cancers.

The drugs would be targeting lymphoma and certain tumors by going into deeper research on how to block cancer cells from not being destroyed by the immune system.

“Our deep experience in understanding the science of blood cancers, along with the diverse knowledge base we have developed across our growing hematology portfolio of eight approved and investigational therapies, provide us with a foundation to advance these important potential medicines to patients who need them,” Schmeltz said.

More than 1 million people were diagnosed with a form of blood cancer in 2020, while 700,000 people died from blood cancer. Blood cancers account for 6% of all cancers.