On January 2, shares of Trillium Therapeutics (TRIL) sold for a little over $1. Now in December, those same shares sell for more than $15. What caused the stock to skyrocket so far, so fast?

Trillium's science focuses on shutting off the CD47 protein in cancer cells. This protein allows cancer cells to remain invisible to your body's immune system. By shutting off the CD47 protein, your body's immune system can now see the cancer and will kill it.

Sculpture of body's immune system attacking a cancer cell.

Image source: Trillium Therapeutics

Back in March, Gilead Sciences acquired a biotech called Forty Seven for $4.9 billion. Forty-Seven was the first company to focus on shutting down the CD47 protein. The acquisition set off a wave of excitement about the biotechs working in this area. A company called ALX Oncology had an IPO, and the stock quickly doubled. But no company has thrived as much as Trillium.

The biotech has two cancer drugs in early trials, TTI-621 and TTI-622, targeting solid tumors and heme malignancies. What distinguishes Trillium's drugs is that they do not bind to healthy red blood cells (which also have the CD47 protein). 

Forty Seven's drug, magrolimab, is highly effective when used in a cocktail with azacitidine. In a clinical trial used in patients with MDS (a cancer of the blood) 91% of patients achieved an objective response, and 42% had complete remission). Magrolimab is less-impressive as a monotherapy, with an objective response rate of 10%. So far, TTI-622 is showing objective response rates three times higher than magrolimab in blood cancers.

While it's very early, right now this molecule appears to be best-in-class as a monotherapy. And Trillium, with a $1.5 billion market cap, has plenty of room to run higher.