What happened

Shares of Novocure (NVCR 1.90%) were sliding 15.1% lower as of 11:05 a.m. EDT on Thursday. The decline came after the company announced final results from its phase 2 study evaluating a combination of its Tumor Treating Fields (TTFields) therapy with sorafenib in treating advanced liver cancer.

So what

Based on the sell-off of the biotech stock today, you might think that Novocure reported horrible results from its phase 2 study. That really wasn't the case, though.

The company said the disease control rate (the percentage of patients whose tumors shrank or remained stable over a period of time) was 76%. Novocure announced that the objective response rate (the percentage of patients whose tumors shrank or disappeared) was 9.5% in the intent-to-treat population. Both results were much higher than the historical controls.

Scientist looking through a microscope.

Image source: Getty Images.

Novocure's results looked better for patients who completed at least 12 weeks of treatment with its TTFields therapy. The disease control rate for these patients was 91% with an objective response rate of 18%.

While these results weren't bad, investors hoped they'd be even better. However, Novocure chief scientific officer Uri Weinberg said that the company was "very encouraged" by the phase 2 results "especially in light of the poor prognosis of the study population and low treatment exposure."

Now what

Novocure now plans to move forward with a randomized controlled clinical study of TTFields in treating liver cancer. Weinberg said that the company is "especially interested in the potential to use TTFields together with immunotherapy" in treating the aggressive type of cancer.