Please assess the completion status of the following clinical trial:

Trial Title: Efficacy and Safety of Birch Pollen Immunotherapy in Local Allergic Rhinitis

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: SINGLE
- Phase: PHASE3
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* well document symptoms of rhinitis during birch pollen season~* positive nasal provocation test to birch~* negative results of skin prick tests to inhalant allergen including: D. pteronyssius, D. farinae, grass pollen, birch, hazel, alder Alternaria, and cat.~* negative results of serum total and allergen specific IgE against mentioned allergens.~Exclusion Criteria:~* diagnosis of bronchial asthma, non-allergic rhinitis (especially senile or vasomotor rhinitis) and severe non-stable diseases. All subjects were required to abstain from anti-allergy drugs and glucocorticoid nasal drops for at least 6 weeks prior to the start of the study.

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Purethal Birch immunotherapy (Type: ACTIVE_COMPARATOR): Purethat Birch intervention and symptomatic treatment for 24 months
- placebo and symptomatic treatment (Type: PLACEBO_COMPARATOR): placebo intervention and symtomatic treatment during 24 months

Based on this trial design, predict the completion outcome and termination type (if applicable).