Novacea

(NOVC)

shares fell hard Monday after the company terminated a late-stage study on its lead investigational cancer therapy and put another study on hold due to the imbalance of deaths between treatment arms.

The company and its partner,

Schering-Plough

(SPG) - Get Report

, said they ended the phase III Ascent-2 trial on prostate cancer drug Asentar after a higher death rate was observed in the arm of the study with Asentar plus taxotere compared to the standard treatment arm. While Novacea is analyzing the full data, it's also halted a phase II trial on Asentar for advanced pancreatic cancer.

"We believe our financial position is solid, with approximately $110 million in cash and receivables at the end of the third quarter of this year, which should help us withstand this setback," Chief Executive John Walker said in a conference call Monday morning.

Novacea fell $4.75, or 66%, to $2.44 in recent trading, while Schering-Plough was down 40 cents, or 1.3%, at $29.56.