This is a single centre, double-blind, randomised, three-period crossover phase 1 trial in subjects with type 1 diabetes mellitus (T1DM). Each subject will be randomly allocated to a sequence of three treatments, i.e. two single subcutaneous doses of BioChaperone® Glucagon (BC Glucagon) formulation 1, BioChaperone® Glucagon formulation 2 and GlucaGen® HypoKit®, each at the fixed doses of 50 µg and 1 mg on 3 separate dosing visits.

Following trial drug administration, pharmacokinetics (PK) and pharmacodynamics (PD) assessments will be carried until 4 hours. Safety will be assessed during all the trial period.

The total trial maximum duration for the individual subject will be up to 10 weeks.

Inclusion Criteria:

• Male or female patients aged between 18 and 64 years (both inclusive)
• Type 1 diabetes mellitus (as diagnosed clinically) ≥ 12 months prior to the screening visit
• Treated with daily insulin for T1DM ≥ 12 months prior to the screening visit
• Stable insulin treatment at least 3 months prior to the screening visit
• Stable disease with HbA1c <9.0 %
• C peptide <=0.30 nmol/L
• Body mass index (BMI) < 30.0 kg/m2

Exclusion Criteria:

• Type 2 Diabetes mellitus
• Previous participation in this trial. Participation is defined as being randomised
• Receipt of any medicinal product in clinical development within 60 days prior to this trial
• Clinically significant abnormal haematology, biochemistry, urinalysis, or coagulation screening tests, as judged by the Investigator considering the underlying disease
• Known or suspected hypersensitivity to the trial products or related products
• Severe hypoglycaemic events within one month prior to screening, as judged by the investigator
• Recent administration of glucagon (within 3 months prior to Screening)
• Clinically relevant diabetic complications as judged by the investigator
• Women of child bearing potential not willing to use contraceptive methods