The Safety and Efficacy of Intralymphatic Immunotherapy in Pollen Allergic Adolescents and Young Adults With Asthma: A Randomized Placebo-controlled Trial
Phase: PHASE2
Conditions: Rhinitis, Asthma, Allergy
Sponsor: Karolinska Institutet

Intralymphatic immunotherapy in pollen-allergic young adults with 
rhinoconjunctivitis and mild asthma: A randomized trial 
 
Date: 24/11 2019.  
 
 

 
Study outline 
All eligible allergic patients at the allergy clinics at the Karolinska University Hospital in 
Solna/Huddinge, Stockholm, Sweden, were screened and enrolled in the study during the 
inclusion period January 1, 2013, and December 31, 2015. Inclusion criteria were age 16 to 
45 years, confirmed allergy to birch and/or timothy grass pollen together with 
rhinoconjunctivitis and mild asthma (controlled asthma [asthma control test score > 19] and a 
positive methacholine challenge), and otherwise healthy. Exclusion criteria were troublesome 
allergy to mites and animal dander, disease in the upper airways including sinusitis and 
nonallergic rhinitis, uncontrolled asthma, pregnancy, breast-feeding, other illnesses, and drug 
abuse. Unfortunately, the required number of patients (60 according to the power calculation; 
see the Statistical Analysis section below) was not reached because of narrow inclusion 
criteria. The study was randomized, double-blind, placebo-controlled, and performed between 
2013 and 2017. Before each treatment period, an assistant prepared sealed opaque envelopes 
for both active and placebo treatments to achieve a final 1:1 ratio. After the first year of the 
study, it was revealed that 3 actively treated patients had to be excluded and therefore, 
patients were randomized 2:1, active:placebo, for the remainder of the study to achieve the 
1:1 ratio. The envelopes were randomly mixed, and an independent nurse drew 1 envelope for 
each patient and prepared the medical product according to the envelope at all 3 injection 
visits. The active allergen extracts could not be distinguished from placebo. Using this 
method, all the participants, physicians who administered the interventions, and study staff 
who evaluated the outcomes remained blinded until the follow-up visit after the first pollen 
season was completed. 
Assessment of clinical parameters 
Clinical parameters were evaluated before the start of the treatment, in the fall after the first 
pollen season, and in the fall after the second pollen season (active group only). Treatment 
effect was evaluated by asking the patients to compare their allergic symptoms during the last 
pollen season with the pollen season before treatment on a visual analogue scale ranging from 
0 (unchanged symptoms, no improvement) to 10 (total symptom relief, complete recovery). 
Asthma control 4 weeks before follow-up was estimated with the asthma control test, where a 
score of 19 or less suggests poorly controlled asthma.E1 Quality of life was assessed using the 
Juniper Asthma Quality of Life Questionnaire, giving a score ranging from 1 to 7, and a 
change in score of 0.5 points is considered clinically relevant.E2 Modified SSs and MSsE3 were 
calculated taking into account the frequency: daily (4 points); every second day (3 points); 1 
to 3 days per week (2 points); occasionally (1 point); never (0 points), for the following 
symptoms: blocked nose, rhinorrhea, fatigue, sneezing, and asthma symptoms, and for the 
following medications used: local and systemic antihistamines, nasal steroids, asthma 
medication, and eye drops. A maximum score of 20 points for symptoms and 16 points for 
medication could be obtained. 
Nasal provocation tests (NPTs) were performed with a commercially available birch or grass 
extract, Aquagen 100,000 SQ-E/mL (ALK-Abelló, Copenhagen, Denmark), according to a 
modified Lebel protocol.E4 One spray dose, 0.1 mL of the extract (10,000 SQ-E), was 
deposited in each nostril. Symptoms during NPTs were scored according to the Lebel scoring 
scale before and 5, 15, and 30 minutes after administration by a trained research nurse. The 
scoring system identifies nasal, eye, and ear symptoms: rhinorrhea, nasal pruritus, nasal 
congestion, ocular pruritus, watery eyes, and itchy ears, each graded on a scale from 0 to 3 

points, and a total score was summarized after subtracting the starting score (maximum score 
is 54 + the number of sneezes). 
Fraction of exhaled nitric oxide, FEV1, and forced vital capacity were measured according to 
international guidelines.E5 Bronchial hyperresponsiveness to a challenge with methacholine 
was assessed, and the dose of methacholine causing a 20% reduction in FEV1 (PD20) was 
calculated.E6 
Assessment of serum antibodies 
Blood was taken at each visit, and serum and plasma were collected for immunological 
analyses. Allergen-specific IgE level was measured by ImmunoCAP (Phadia, Thermo 
Scientific, Uppsala, Sweden) for birch (t3) and timothy grass (g6) pollen according to the 
manufacturer’s instructions. A cutoff level ≥ 0.35 kUA/L was considered positive. In addition, 
IgG to birch/timothy grass pollen and IgG4 to birch/timothy grass pollen were measured by 
ImmunoCAP, with the cutoff 2 mg/L for IgG and 0.05 mg/L for IgG4. 
Outcomes 
The primary outcome of the study was the change in symptoms score after NPT. The 
secondary outcomes were SSs and MSs, changes in response to a bronchial challenge with 
methacholine (PD20), treatment effect measured on a visual analogue scale, changes in quality 
of life, changes in allergen-specific serum immunoglobulin levels, incidence of adverse 
events, changes in asthma symptom scores, changes in pulmonary function measurement 
(FEV1 and forced vital capacity), and changes in airway inflammation assessed by fraction of 
exhaled nitric oxide. 
Adverse events and patient analysis 
Four patients were removed or left the study before analysis of results; 3 patients (active 
group) were excluded after the first treatment period because of deviations from the treatment 
protocol, and 1 patient (placebo) left the study after the first treatment period, before the 
follow-up (see Fig E1). 
No adrenaline was needed during the study. In total 91 injections were given, 55 with active 
treatment and 36 with placebo. A total of 69 mild side effects (pain, redness, itch or swelling 
at injection site, sneezing, and tiredness) within 24 hours after injection were reported. Fifty-
nine of these were reported from 13 patients receiving active treatment, and 10 from 5 
placebo-treated patients. In the active group, 1 patient suffered from generalized urticaria 15 
minutes after injection and 1 patient reported increased asthma symptoms the day after 
injection. 
Eleven patients (6 receiving active and 5 placebo treatments) did not have full analysis data 
sets. In the active treated group, 1 patient reported side effects after the first treatment period 
(eczema) and declined the booster dose. This patient completed the follow-up after the first 
pollen season and is included in the analysis. One patient was diagnosed with sarcoidosis 3 
months after the booster injection. After careful medical investigation by a physician in 
respiratory medicine, no causal relationship could be established. The patient participated in 
the final follow-up but did not take part in NPT and methacholine challenge and is not 
included in the analysis of spirometry and quality of life for that time point. In addition, 1 
patient did not perform the NPTs and 3 did not answer the symptoms and medication 
questionnaires. In the placebo-treated group, 1 patient did not perform the NPT at the follow-

up after the first pollen season, another did not perform the spirometry measurements at the 
follow-up after the first pollen season, and 3 patients did not answer the symptoms and 
medication questionnaires. 
Statistical analysis 
A power calculation was performed with a 2-sample t test for the primary outcome variable of 
NPT response. We expected 30% improvement in nasal symptoms in the active group at the 
NPT 6 to 9 months after treatment compared with the placebo group, based on a previous 
study,E7 and we assumed a mean of 18 in the placebo group and a mean of 14 ± 5.5 in the 
active group. Aiming at a power of 0.80 and using a type 1 error rate α level of .05, the 
calculated sample size was 60 in total. Data are presented as median ± interquartile range. 
Mann-Whitney U test was used for comparisons between placebo and active treatments. 
Wilcoxon matched pairs signed rank test was used within the active and placebo groups to 
compare before treatment to after the first pollen season and after the second pollen season. 
A Pvalue ≤ 0.05 was considered significant. Data were analyzed using Graphpad Prism v 
8.0.2 (Graphpad Software, La Jolla, Calif; www.graphpad.com).