Earlier in February, Pfizer said it would close operations at the site.
The US based drug maker’s intent was to outsource some R&D activities and colleagues at the site to a contract research organisation.
However, after a rigorous diligence process, the negotiations with strategic partners did not prove to be viable.
The decision to retain its presence on the site is expected to support the development of drugs in mid and late-stage pipeline.
Annette Doherty will take over from Ruth McKernan as the new site director at Sandwich.
McKernan will become chief scientific officer at the company’s Pain and Sensory Disorders Unit ‘Neusentis’ in Cambridge, UK.
McKernan said retaining this core group at Sandwich will provide extra time for complex commercial negotiations with potential investors.
Sandwich Economic Development Task Force chairman Paul Carter said securing 350 jobs on site by Pfizer is a step in the right direction and is positive news.
"We must now work with Pfizer and their marketing agent CBRE to secure further investors and businesses on-site, and encourage inward investment and occupancy in a whole array of business activity," Carter said.