Jack Jumper Ant Venom Immunotherapy Long-term Effectiveness Investigation

Jack Jumper ant (JJA) venom allergy is a uniquely Australian medical condition. It is the leading cause of venom allergy and affects up to three per cent of the population. 70 percent of people with JJA allergy will have another reaction on a repeat sting and this sensitivity appears to persist for many years.

Venom immunotherapy (VIT) has been shown to be a safe and effective treatment in the prevention of severe systemic allergic reactions (anaphylaxis) to future stings. It is currently offered to patients as standard care in Tasmania, South Australia and Victoria. However, whilst JJA VIT has been used for many years, there is a lack of evidence on the long-term benefit of the treatment and how it impacts patient quality of life.

This trial will offer patients who have completed a JJA VIT program (between 3 and \< 6-years duration) and have been off-treatment for at least 18-months and \< 5 years, to have a supervised JJA sting challenge and blood test to assess their JJA venom tolerance level. It will also ask them to complete a set of questionnaires at different timepoints to obtain a history of their exposure and reactions to JJA stings outside of the hospital setting (field stings), and to measure the impact of the completed VIT and knowledge of their sting challenge outcome on their quality of life and their behaviours around auto-injectors.

These measures will be used to explore the long-term effectiveness of JJA VIT and the impact of a sting challenge post VIT on a patient's quality of life.

This will be a prospective, multicentre, phase 4 clinical trial examining the long-term effectiveness (measured by response to an in-hospital JJA sting challenge, primary outcome) and impact on quality of life of JJA VIT involving 3 Australian tertiary hospital sites offering this treatment - Royal Hobart Hospital, Royal Adelaide Hospital and Monash Medical Centre.

Patients who have completed their JJA VIT (between 3 and \<6 years duration) at one of the 3 sites and off-treatment for at least 18 months and \< 5 years, will be invited to participate in the trial by their original treating site. A research team member will obtain informed e-consent and a booking for an in-clinic JJA sting challenge will be allocated. For all consented participants, quality of life (QoL), anxiety and depression scores, history of field sting reactions since treatment completion and attitudes toward adrenaline autoinjector carriage/usage will be collected via questionnaire at trial enrolment, sting challenge, 1-month post sting challenge and annually for 3-years. A blood sample will be collected immediately prior to the sting challenge at the in-clinic appointment. Participants will also be asked to consent to access retrospective data related to their completed JJA VIT course from their hospital clinical records.

Optional consents will also be sought from each participant for the collection of an extra tube of blood with the serum biobanked for future analysis, and the inclusion of their data in the National Allergy BioRepository (ALBI).

Eligibility Criteria:
Eligibility criteria

- Any adult (≥ 18 years) who has completed a JJA VIT program at one of the three participating sites.

Inclusion Criteria:

1. Completed a continuous program of JJA VIT of between 3 and \< 6 years duration.
2. Have ceased JJA VIT for ≥ 18 months but \< 5 years.
3. Have the ability to provide informed consent.

Exclusion Criteria:

1. Any person \< 18 years.
2. Any adult (≥ 18 years) who has not completed a continuous JJA VIT program of duration between 3 and \< 6 years.
3. Any adult (≥ 18 years) who has completed a continuous JJA VIT program of duration between 3 and \< 6 years but ceased JJA VIT \< 18 months or \> 5 years ago.
4. Any person who has a medical condition, that in the opinion of the investigator, may place them at increased risk if they were to have a sting challenge.
5. Unable to understand study requirements and provide informed consent.