Tustin-based Peregrine Pharmaceuticals Inc.’s shares continued their roller-coaster ride today after yesterday’s steep drop-off.

Shares of the drug developer rose 44% in midday trading to a market value of about $171 million.

Peregrine shares fell by more than 70% yesterday after company officials told analysts that they shouldn’t rely on clinical data about bavituximab, which it is developing as a lung cancer treatment.

The drug maker said Monday that it discovered what it called “major discrepancies” between some patient sample test results and other data in a mid-stage trial data.

Peregrine’s collapse followed a big share jump in early September after it said patients who were treated with bavituximab in the trial lived twice as long as those who only received chemotherapy.