Early intervention with ColdZyme mouth spray after self-diagnosis of common cold: a randomized, double-blind, placebo-controlled study

Abstract

Background A glycerol throat spray containing cold-adapted cod trypsin creates a protective barrier and is known to deactivate common cold virus in vitro and decrease pharyngeal rhinovirus load after inoculation in humans. Early self-diagnosis and use of the medical device ColdZyme indicate a safe alternative for treatment in naturally occurring common colds. Methods This was a double-blind, randomized, parallel-group, placebo-controlled study conducted at ten German sites to evaluate the efficacy of the medical device ColdZyme, a glycerol mouth spray containing cold-adapted cod trypsin, for naturally occurring common cold, versus placebo. Adults experiencing a minimum of three common colds during the previous year, but otherwise healthy, were enrolled to begin treatment with the mouth spray or placebo six times daily at first sign of a common cold. Jacksons symptom scale and the 9-item Wisconsin Upper Respiratory Symptom Survey-21 (WURSS-21) quality of life (QoL) domain and sore throat scale were recorded daily by subjects, as well as any use of allowed rescue treatment. The trial is registered at ClinicalTrials.gov, number NCT03794804. Results Between January and April 2019, 701 subjects were enrolled and randomly assigned to the ColdZyme group (n=351) or the placebo group (n=350). Of the 701 subjects, 438 (62.5%) subjects developed symptoms typical of common cold, and all 438 started study treatment (n=220 in the ColdZyme group and n=218 in the placebo group). There were no differences between the groups in primary and major secondary endpoints, however, the assessment using the WURSS-21 QoL domain and Jackson score suggests a slightly faster recovery with ColdZyme, as symptoms and complaints affecting the quality of life were shortened about 1 day. The beneficial effect of ColdZyme was particularly noticeable on the fifth day of the common cold. A positive difference between treatment groups was also seen for the subjects assessments of global efficacy of the investigational product, and a robust safety profile for ColdZyme was demonstrated throughout the study. Conclusion The safety and tolerability of ColdZyme have been confirmed in a larger study population, while establishing evidence of a slightly faster recovery from common cold symptoms. Keywords: glycerol, (cod) trypsin, common cold, quality of life, oral spray, colds viruses