INtREPUS is a large pharmaceutical company and a direct competitor to Massive Dynamic.
It's pharmaceutical research division was headed by David Esterbrook, and has worked on a wide range of controversial projects: Prenatal gene therapy, human animal hybridization studies, viral warfare - "All the fun stuff" according to Charlie Francis.
INtREPUS was holding illegal drug trials. They kidnapped Emily Kramer and held her for two weeks, then released her, which led to the incident at Holly's Diner. They also held Claire Williams captive. Olivia Dunham confronts Esterbrook at a conference in Manhattan. After slyly probing him for information, Olivia reveals herself as an FBI agent. Olivia saves Claire, then confronts Esterbrook at INtREPUS. She says they have a statement from his employee admitting that Esterbrook supplied her with the facility and the equipment to transform Emily and Claire into weapons, then arrest him.
A radio announcer reports the news of Esterbrook's detainment causing INtREPUS' stock value to fall considerably, while the stock value of Massive Dynamic, INtREPUS' leading competitor, has risen just as remarkably. ("The Cure")
Later, Warren Blake, an INtREPUS employee, was murdered by the Jellyfish Toxin. He had formerly worked on the Jellyfish project and was murdered as a vendetta for the research he had previously been involved in.
- INtREPUS appears on a coffee mug next to a compact LCD TV broadcasting a live news report of Daniel Chin on WPKW. ("Power Hungry")
- Their slogan as seen on their posters is "Treating & Curing your family for over 20 years". ("The Cure")