Background: A glycerol throat spray containing cold-adapted cod trypsin (GCTS) deactivates common cold virus in vitro and decreases pharyngeal rhinovirus load after inoculation in humans. We relied on early self-diagnosis and evaluated two different scales to detect a treatment effect in naturally occurring common colds. Methods: Adults were enrolled in this randomised, prospective, parallel group, single-blind study to begin treatment six times daily at first sign of a common cold or were assigned to a non-treated group. Jackson′s symptom scale and the 9-item Wisconsin Upper Respiratory Symptom Survey (WURSS)-21 quality of life (QoL) domain were recorded daily by subjects and area under the curve over 12 days (AUC1-12) calculated. Results: Treatment resulted in reduced symptoms with an AUC1-12 of 45.1 ± 32.5 for Jackson scores compared to 53.8 ± 35.7 in the controls (p=0.023). AUC1-12 for the 9-item WURSS-21 QoL domain was likewise improved, 113.6 ± 107.7 and 152.7 ± 126.3 (p=0.006), respectively. During the first four days fewer of the treated subjects (35.3%) used rescue medication than did the control group (50.4%, p=0.014). Conclusions: Reduction in common cold symptoms was seen with treatment with a glycerol throat spray containing cold-adapted cod trypsin. This effect was best detected with the 9-item WURSS-21 QoL domain.

ColdZyme® Mouth Spray (ColdZyme) is intended to reduce the probability of catching a cold and/or can help shorten the duration of a cold, if used at an early stage of the infection, by forming a barrier on the pharyngeal mucous membrane. The user experience of ColdZyme on naturally occurring common cold infections was evaluated in competitive athletes training professionally or on an amateur level. Thirteen athletes completed weekly electronic surveys on occurrence of common colds, cold severity and user experience over the course of 3 months. The 13 participants reported in total 15 cold incidents with an average duration of 7.4 days. The average cold severity was 31.2 on a visual-analogue scale (VAS) ranging from 0 (mildest possible cold) to 100 (worst possible cold). The overall user satisfaction with ColdZyme was high. 81% of the reported colds were experienced to be milder and/or shorter than usual. None of the participants reported "No effect". Out of the participants who reported absence of a cold in the previous week, 69% reported a positive answer to the question if ColdZyme had prevented them from catching a cold in the previous week. Conclusion: The present study evaluated prevention and alleviation of naturally occurring common cold in athletes, and demonstrated that ColdZyme may be an easy and practical way for competitive athletes to prevent or reduce infections of the common cold virus and corresponding unwanted absence from training and competition. Due to the lack of a comparator group, a placebo effect cannot be excluded.

Background A glycerol throat spray containing cold-adapted cod trypsin (GCTS) deactivates common cold virus in vitro and decreases pharyngeal rhinovirus load after inoculation in humans. We relied on early self-diagnosis and evaluated two different scales to detect a treatment effect in naturally occurring common colds. Methods Adults were enrolled in this randomised, prospective, parallel group, single-blind study to begin treatment six times daily at first sign of a common cold or were assigned to a non-treated group. Jackson’s symptom scale and the 9-item Wisconsin Upper Respiratory Symptom Survey (WURSS)-21 quality of life (QoL) domain were recorded daily by subjects and area under the curve over 12 days (AUC1-12) calculated. Results Treatment resulted in reduced symptoms with an AUC1-12 of 45.1 ± 32.5 for Jackson scores compared to 53.8 ± 35.7 in the controls (p = 0.023). AUC1-12 for the 9-item WURSS-21 QoL domain was likewise improved, 113.6 ± 107.7 and 152.7 ± 126.3 (p = 0.006), respectively. During the first four days fewer of the treated subjects (35.3%) used rescue medication than did the control group (50.4%, p = 0.014). Conclusions Reduction in common cold symptoms was seen with treatment with a glycerol throat spray containing cold-adapted cod trypsin. This effect was best detected with the 9-item WURSS-21 QoL domain.

Background Previous clinical and in vitro investigations have supported the efficacy of a glycerol throat spray containing cold-adapted cod trypsin (ColdZyme) against respiratory viruses causing the common cold bycreating a protective mucosal barrier shown to deactivate common cold virus in vitro and decrease pharyngeal rhinovirus load. Methods and findings This was a double-blind, randomized, parallel-group, placebo-controlled study conducted at 10 German sites to evaluate the efficacy of the medical device ColdZyme, a glycerol mouth spray containing cold-adapted cod trypsin for a naturally occurring common cold versus placebo spray. 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. Jackson’s symptom scale and the 9-item Wisconsin Upper Respiratory Symptom Survey-21 (WURSS-21) quality of life (QoL) domain and a sore throat scale were recorded daily by subjects, as well as any use of allowed rescue treatment. 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). The demographic profile of the treatment groups were comparable with 68.1% female and almost all subjects being Caucasian (98.4%). The age ranged between 18 and 70 years with a mean age of 41.3 (±14.4) years. 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 by 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 A robust safety profile for ColdZyme was demonstrated throughout the study. Conclusion The safety and tolerability of ColdZyme have been confirmed in a large study population and further establishes evidence of a faster recovery from common cold symptoms. Early self-diagnosis and early use of ColdZyme mouth spray is a safe alternative for treatment of naturally occurring colds.

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