What happened

AstraZeneca (AZN -0.29%) and Surface Oncology (SURF) shares both traded up on Monday, bucking the heavily bearish trend of the overall stock market. AstraZeneca closed the day more than 5% higher on the back of positive news about its cancer drug, while Surface Oncology slipstreamed behind it with a 3.2% gain.

So what

On Saturday, AstraZeneca provided an update about the phase 3 trial of its Imfinzi oncology drug in combination therapy for the treatment of one type of lung cancer.

The company said that, when administered with certain chemotherapies, Imfinzi "demonstrated a sustained, clinically meaningful overall survival (OS) benefit at three years for adults with extensive-stage small cell lung cancer (ES-SCLC) treated in the first-line setting."

Cancer attacking an organism.

Image source: Getty Images.

In combination therapy, the drug was responsible for reducing the risk of death by 29% compared to chemotherapy alone, AstraZeneca added. The new data also show that the combination therapy produced longer overall survival (OS) than in patients treated solely with chemotherapy, with the median OS being 12.9 months for the combination against 10.5 for chemotherapy alone.

The combination therapy regime "demonstrated a well-tolerated safety profile consistent with the known profile of the medicines," AstraZeneca added.

In the wake of the news, BTIG analyst Justin Zelin published a fresh research note reiterating his buy rating and a $17 per-share price target on Surface Oncology stock. In the note, Zelin wrote that the AstraZeneca trial results bode well for immune-enhancing antibody cancer products the clinical-stage biotech specializes in.

Now what

Imfinzi is a leading cancer treatment, and its performance in the latest AstraZeneca combination therapy trial is very encouraging since ES-SCLC is a particularly challenging form of the disease. Both AstraZeneca and Surface Oncology investors are right to be bullish about the future of the two companies' current and potentially upcoming cancer therapies.