Study to Evaluate Safety, Tolerability and Explorative Efficacy of DM-101PX in Birch Pollen Allergic Participants

Inclusion Criteria: * Either sex or any race, aged 18 to 65 years * Good general health * A documented clinical history of moderate to severe birch pollen induced allergic rhinitis or rhinoconjunctivitis with symptoms that interfere with daily activities or sleep and remain bothersome despite the use of relevant symptomatic medication, and have been present over at least 2 previous birch pollen seasons * Birch pollen specific IgE ≥ 0.7 kU/L * Positive SPT to birch pollen allergen, with wheal diameter ≥ 3 mm * Body weight ≥ 50 kg and body mass index within the range of 18-35 kg/m2 Exclusion Criteria: * History or findings on physical examination of any significant disease or disorder which, in the opinion of the Investigator, could put the subject at risk because of participation in the trial, influence the results of the trial or subject's ability to participate in the trial * Current diagnosis of persistent asthma, or moderate to severe asthma requiring GINA Step 2 or higher treatment, or asthma partially controlled or uncontrolled according to GINA classification in the 6 months before screening * Significant rhinitis, sinusitis, significant and/or severe allergies not associated with the birch pollen season * History of asthma deterioration that resulted in emergency treatment or hospitalization in the past 12 months before screening, or a life-threatening asthma attack at any time in the past * A Forced Expiratory Volume in one second (FEV1) ≤ 75% of predicted value * History of severe drug allergy, severe angioedema, or systemic allergic reaction of Grade 3 or grater, according to World Allergy Organization (WAO) scale, due to any cause