This multicentre, randomised, double-blind, dose-finding, active- and placebo-controlled Phase II clinical trial will evaluate the safety, efficacy, pharmacokinetic profile, and immunogenicity of KJ101 for the debridement of deep second-degree burns. The trial will provide supporting evidence for subsequent Phase III trials.

This multicentre, randomised, double-blind, dose-finding, active- and placebo-controlled Phase II clinical trial will evaluate the safety, efficacy, pharmacokinetic profile, and immunogenicity of KJ101 in the debridement of deep second-degree burns. The aim is to provide supporting evidence for subsequent Phase III clinical trial.

The study comprises four treatment groups: KJ101 at a dose of 800 U/mL; KJ101 at a dose of 1200 U/mL; an active comparator group receiving chymotrypsin at a dose of 800 U/mL; and a placebo control group.

Approximately 144 screened and qualified subjects will be randomised at a ratio of 1:1:1:1 to one of the four groups. All interventions will be administered locally to the target wound at the following frequencies: once daily prior to complete necrotic tissue debridement, and then every other day post-debridement.

Treatment will continue until complete wound healing is achieved (with a maximum treatment duration of 28 days), after which there will be a one-week safety follow-up period will be conducted.

Inclusion criteria:

1. Male and female subjects aged 18 to 65 years inclusive, who are neither pregnant nor lactating;
2. Clinically diagnosed with superficial or deep II degree burns within 72 hours of injury, with a total burn area of ≤30% TBSA. The target burn wound must be isolated or have distinguishable boundaries, with an area between 40 and 200 cm².
3. Subjects of childbearing age must agree to use effective and safe contraceptive methods during the treatment period and for three months after the final administration.

Exclusion criteria:

1. Individuals who are known to be allergic to any component of the test drug or who have a tendency to allergies.
2. Burns caused by specific factors, such as electrical or chemical burns.
3. Subjects with shock or inhalation lung injury;
4. Subjects with target wounds complicated by inflammatory skin diseases (e.g. atopic dermatitis, eczema or psoriasis), or who have undergone enzymatic debridement (e.g. with collagenase, papain, bromelain, chymotrypsin or trypsin).
5. Subjects who, during screening, are judged by the investigator to have other severe systemic infections requiring systemic treatment;
6. Abnormal liver or kidney function.