Two preservationist groups have dropped a lawsuit challenging the City of Chicago’s decision to deny landmark status to the old Prentice Women’s Hospital.

Northwestern University plans to demolish the building in Chicago’s Streeterville neighborhood to make way for a new biomedical research facility. The decision to drop the lawsuit clears the way for Northwestern to carry through on it plans.

Christina Morris, a senior field officer for the National Trust for Historic Preservation, said her organization and Landmarks Illinois still maintain that the 18-month landmarks process for old Prentice had “significant flaws.” Those include a November vote by the Commission on Chicago Landmarks that both granted the building preliminary landmark status and took it away in the same day.

In a hearing on the lawsuit, Cook County Circuit Judge Neil Cohen, who issued a stay in the matter, called the commission’s action “arbitrary” and “nontransparent” at the time.

But ultimately, Morris said the preservation groups didn’t feel like anything more positive could come from continuing the lawsuit.

“We felt that we had done as much as we possibly could to demonstrate the significance of the building and ways to reuse,” Morris said. “We just couldn’t see that we’d have any other outcome.”

Old Prentice  was designed in the 1970s by Chicago architect Bertrand Goldberg, who’s better known for designing Marina City along the Chicago River.

“Even though we’re disappointed the building wasn’t granted landmark status, we think some good things have come of it,” Morris said. “Press coverage has raised awareness of Bertrand Goldberg’s legacy and it started an incredible discussion of the importance of modern architecture across the country.”

Northwestern plans to move forward with the city to build a research facility on the site on East Superior Street. The new building would be connected to an existing research building, Alan Cubbage, a university spokesperson said.

Northwestern will conduct an international design competition for the research facility.

Cubbage said the building will be the “linchpin” of the university’s biomedical research on diseases such as cancer, Parkinson’s and Alzheimer’s for decades to come.

“We’re very much looking forward to the next step – bringing a wonderful signature building to our campus and moving forward,” Cubbage said.

Morris said that although the preservationists lost this battle, they gained important support and resources through the process.

“We feel preservation is a really important component of a healthy, economically vibrant, interesting city,” Morris said. “We will continue to work with our partners to preserve the best of Chicago’s architectural heritage.”

ehirst@tribune.com