Portage Biotech (PRTG) reported late Thursday "encouraging" efficacy data in a murine mesothelioma model with PORT-7 given as a single agent or in combination with anti-PD-1 antibody.

The data showed both single agent activity, and more than 90% inhibition of tumor growth when PORT-7 was combined with an anti-PD1 antibody in a murine model of mesothelioma, it said.

"This is the first report of antitumor activity against mesothelioma using a selective A2B receptor inhibitor," Portage said, adding that it's making preparations to start a first-in-human trial.

The shares more than doubled in after-hours activity.