A multicentre, international, randomised, double-blind, placebo controlled study to demonstrate the clinical efficacy and safety of subcutaneous immunotherapy with gpASIT+™ in patients with grass pollen-induced allergic rhinoconjunctivitis during two successive pollen seasons

INTERVENTION: Product Name: gpASIT+™ Pharmaceutical Form: Solution for injection INN or Proposed INN: gpASIT+™ Other descriptive name: POLLEN PEPTIDES Concentration unit: µg/ml microgram(s)/millilitre Concentration type: equal Concentration number: 100‐ Pharmaceutical form of the placebo: Solution for injection Route of administration of the placebo: Subcutaneous use CONDITION: Therapeutic area: Diseases [C] ‐ Ear, nose and throat diseases [C09] Treatment of seasonal grass pollen‐induced rhinoconjunctivitis ; MedDRA version: 20.0 Level: LLT Classification code 10019170 Term: Hay fever System Organ Class: 100000004870 PRIMARY OUTCOME: Main Objective: To demonstrate the clinical efficacy of grass pollen‐ASIT+™ (gpASIT+™) following subcutaneous administration to patients suffering from grass pollen‐induced allergic rhinoconjunctivitis, as assessed with the combined symptom and medication score (CSMS) during the peak of the 2019 grass pollen season. Primary end point(s): The primary efficacy endpoint will be the average daily CSMS collected during the peak of the grass pollen season. The daily CSMS is the sum of the daily symptom score and the daily RMS calculated from the data recorded in the eDiary. Secondary Objective: • To confirm the clinical efficacy of gpASIT+™ as assessed with the CSMS during the entire 2019 grass pollen season;; • To confirm the clinical efficacy of gpASIT+™ as assessed with the Rhinoconjunctivitis Total Symptom Score (RTSS) and subscores, the Rescue Medication Score (RMS) and the rate of “well days”, during the 2019 grass pollen season (both peak and entire season);; • To confirm the safety and clinical tolerability of gpASIT+™ treatment;; • To confirm the induction of key immunological effects in serum after treatment with gpASIT+™;; • To assess patients’ quality of life and the health economics impact of treatment with gpASIT+™ during the pollen season. Timepoint(s) of evaluation of this end point: Over the peak of the grass pollen season. SECONDARY OUTCOME: Secondary end point(s): Secondary efficacy endpoints are: ; • CSMS over the entire grass pollen season; ; • RTSS (i.e. the sum of ESS and NSS) over the peak period and the entire grass pollen season; RMS over the peak period and the entire grass pollen season; ; • Symptom subscores (ESS and NSS) over the peak period and the entire grass pollen season; ; • TSS (the sum of the ESS, NSS and lung symptom score) over the peak period and the entire grass pollen season (in asthmatic patients only); ; • Use of rescue medication to relieve asthma symptoms over the peak period and the pollen season; ; • Number (%) of “well days” over the peak period and the entire grass pollen season; ; • RQLQ(S); ; • PGE assessment. Timepoint(s) of evaluation of this end point: Over the peak period and the entire pollen season INCLUSION CRITERIA: 1) Female or male patients aged 18 to 64 years (inclusive); 2) Signed and dated Informed Consent Form (ICF) by a legally competent patient; 3) Good physical and mental health according to medical history, physical examination and vital signs; 4) Female patients who are: a. Not of childbearing potential, defined as: amenorrhea or post‐menopausal (natural spontaneous amenorrhea for at least 12 months, or at least 6 weeks following surgical menopause), OR b. Naturally or surgically sterile (hysterectomy; bilateral salpingectomy or oophorectomy; bilateral tubal ligation with surgery at least 6 weeks prior to study screening), OR c. Non‐pregnant, non‐lactating with negative blood pregnancy test at the Screening visit and using at least one of the following contraceptive methods: i. Stable hormonal contraceptive for =90 days prior to the study (if <90 days prior to the study, additional use of a double barrier method is required until 90 da