Pandemic Labs, a Boston-based social media marketing agency, has relocated from Allston to expanded office space in Downtown Boston.

The company, which formerly occupied 1,500 square feet in Allston, has signed a lease for 3,911 square feet at 77 Summer St. in Downtown Boston.

Pandemic Labs will occupy the fifth floor of the 11-story, 46,069-square-foot standalone office building. The company’s move will be completed by February.

Brandon Leitner of Cresa Boston represented Pandemic Labs. The landlord, Synergy, was represented by Bonny Doorakian and David Cooney of NAI Hunneman.