Efficacy and safety of a 7-week immunotherapy protocol with
aluminium hydroxide absorbed hymenoptera venom
To the Editor,
Hymenoptera venom allergy can cause life threatening anaphylaxis in
patients sensitised to wasp and bee venom. Venom immunotherapy is
effective in 77%‐84% of patients treated with honeybee venom and in
91%‐96% of patients receiving vespid venom1. Adverse
events are usually rare and mild, and symptoms occur in only
4.3%‐11.4% of patients during the updosing1.
A variety of therapy regimes exist for the updosing phase, from
conventional, rush, ultrarush or clustered
modalities1,2. Current conventional protocols are
time‐consuming for patients, and some patients decline the potentially
life-saving treatment due to the time commitment required for
immunotherapy. Adverse events appear to be less frequent in conventional
protocols during the updosing phase compared to rush and ultrarush
protocols1,2; however, patients may remain unprotected
for weeks as it takes considerable time to reach the maintenance dose.
The only licensed venom immunotherapy product in the UK is Alutard SQ®
(ALK Abelló) for Vespula and Apidae venom. The SPC recommends updosing
with a 7-week clustered protocol or 15- or 25-week conventional
protocol.
To enhance the acceptance of treatment and increase compliance, we
reduced the length of the SPC protocol. Another significant factor was
the COVID-19 pandemic, which significantly reduced outpatient capacity
to comply with social distancing.
Based on previous data using the same product3, we
introduced a shorter updosing protocol with 8 injections in 7 weeks and
monitored its efficacy and safety. We used this in a wider age range of
patients, including one patient with indolent mastocytosis and more
patients with severe sting reactions.
Seventy‐four patients aged 17 to 85 years with a history of a systemic
sting reaction to vespid and apidae stings grade 2-4 were included
(Table 1). Further information about patient selection and the updosing
protocol is in supplementary file S1.
We managed to retain all the patients during updosing and maintenance,
and no dose reduction was needed.
During updosing, there were no objective systemic adverse reactions
recorded. Only one objective systemic adverse reaction was documented
during maintenance, which was mild and limited to the skin. There were 6
incidences of mild and subjective systemic reactions during updosing and
maintenance, which included symptoms of feeling hot, dizzy and itchy.
The symptoms were treated with additional antihistamines with no change
in regime required. We had a lower incidence of systemic reactions at
1.4% compared to Schrautzer et al3, who reported
objective systemic reactions in 3.9% of patients during just the
updosing phase.
9.5% of our patient cohort reported large localised reactions
throughout both the updosing and maintenance phase, which generally only
occurred once or twice during the full treatment course.
The prevalence of cardiovascular disease and treatment with
beta-blockers were not related to the occurrence of side effects.
Reactions to field stings were monitored to assess efficacy as sting
challenges are not performed in the UK. 20 patients had field stings and
all reported localised reactions. Some patients were stung by multiple
insects (such as one patient who was stung by 19 insects at one time)
and this was more common in beekeepers.
We have extended the work of Schrautzer et al3 and
demonstrated the efficacy and safety of their 7-week protocol in a large
group of patients in a real-world setting. We have also demonstrated
safety and efficacy of the 7-week protocol for Alutard SQ® apidae
immunotherapy. Our data includes a larger group of patients with more
severe reactions. Interestingly, our data also shows a lower number of
reactions to immunotherapy treatment.
The quicker updosing protocol improved patients’ acceptance of treatment
and increased the efficiency of our immunotherapy clinic in terms of
time and cost for patients, and medical staff.