Allergy expects resolution of US clinical hold on Ragweed vacc

UK-based Allergy Therapeutics says that the treating physician who reported the adverse event that put its Ragweed vaccine on clinical hold in the USA has stated that, pending further tests, in her opinion, the patient's symptoms resulted from an alternative diagnosis, of a condition which would be unrelated to the study vaccine.

The company also continues to collaborate fully with the US Food and Drug Administration to provide new data as it is accumulated, and remains confident that, following its ongoing reviews, the agency will accept the alternative diagnosis.

Owing to the approaching pollen season, Allergy Therapeutics' ongoing Phase III Ragweed trial (R301) has had to be definitively moved to the observation phase. Prior to the clinical hold, 992 patients had been recruited onto this study, 92% of the target of 1,074. Of these, approximately 300 have received all four injections and can therefore be considered to be participating in the study per protocol. Although the UK firm anticipates that useful data will be collected from this study, it is sufficiently compromised that it is highly unlikely to reach its primary endpoint. Therefore, conclusion of the Ragweed program will require a further study to complete the patient numbers, probably to be conducted next year.