EntreMed Inc. (NASDAQ:ENMD) reported Monday that its losses widened in the second quarter, driven by high expenses related to research and development, though shares remained flat as the pharmaceutical company said it progressed on a compound that demonstrated antitumor activity in preclinical trials for ovarian cancer patients.

The developer of therapeutics for the treatment of cancer posted a net loss of $4.9 million, or 62 cents a share, compared with a loss of $3.1 million, or 46 cents a share, in the same quarter last year.

Earnings were driven into the red by nearly $4 million in research and development costs.

The Rockville, Maryland-based company said it saw no revenues for the second quarter, though as of June 30 it had cash and short-term investments totaling approximately $8 million.

EntreMed CEO Michael M. Tarnow said the second quarter was “pivotal” for the company.

“We achieved a critical milestone with the initiation of the multi-center Phase 2 study for ENMD-2076 in ovarian cancer patients,” he said. “The Phase 2 study is being conducted at six prestigious cancer centers within the U.S. and Canada and all sites are currently enrolling patients.”

ENMD-2076 has demonstrated in preclinical studies significant antitumor activity, the company said.

“We remain encouraged and enthusiastic about the progress of the ENMD-2076 clinical program and are working hard to meet our development objectives for this exciting compound,” Tarnow said.