Under the contract, Synteract will perform full service management of a pivotal Phase II trial of its new drug to treat glioblastoma multiforme - the most lethal form of brain cancer.
The terms of the contract were not disclosed.
Currently there are only two Food and Drug Administration (FDA)-approved therapies for brain cancer and the prognosis for patients with this disease is particularly poor.
Northwest's new trial drug, DCVax-Brain is a personalised therapeutic cancer vaccine using the patient's own dendritic cells (immune cells) with the patient's own tumour biomarkers (antigens).
"This Phase II trial has the potential to become one of the first cancer immunotherapies, an entirely new class of treatment for brain cancer," said Alton Boynton president of Northwest Biotherapeutics.
Two Phase I trials have already been carried out on the drug at out at UCLA in California, with the company heralding the results as "striking."
Data from the first trial demonstrated that patient survival on the drug was more than double that of patients receiving either of the two FDA-approved drugs.
The second trial, which has been ongoing since 2002, has six out of ten patients still surviving so far, with median survival not yet reached - five of which continue to be cancer-free, with no recurrence.
Survival times in this trial now range up to 44.4 months and are still continuing, said the firm.