A development entity led by Millennium Partners subsidiary Cargo Ventures is moving ahead with plans for a Seaport East life science development one-seventh the size originally envisioned.

ICCNE filed a project notification form with the Boston Planning & Development Agency Monday for a 381K SF, 10-story building at 2 Harbor St. The developer had originally planned for a 2.7M SF complex spread across several properties, connected to South Station by a new, $100M aerial gondola network.

That plan ran aground after Millennium Partners failed to strike a land deal last year with a neighboring tenant that would have cleared a path for the project's full build-out.

ICCNE was still planning for a 900K SF version of the project as recently as this summer, but it filed a letter of intent last month saying the 381K SF version would be able to navigate Boston’s approvals process more easily.

“We are entitling a building that could be approved and built quickly versus focusing on a larger project,” Cargo Ventures CEO Jacob Citrin said in a statement last month. “We remain confident in the Boston market. The leasing market is vibrant and we want to capture that momentum.”

The latest scaled-down version of 2 Harbor St. is expected to house 1,500 workers when completed. The developer also plans to pay more than $2.5M into Boston’s affordable housing fund and nearly $500K into a city job training fund.