Efficacy and safety of AP-Bio®(KalmCold®) in participants with uncomplicated upper respiratory tract viral infection (common cold) - A phase III, double-blind, parallel group, randomized placebo-controlled trial.

Introduction: Kalmegh (Andrographis paniculata) is commonly used for treating uncomplicated Upper Respiratory Tract Infection (URTI) in complementary and alternative system of medicine. AP-Bio®(KalmCold®) is a standardized extract derived from the leaves of A. paniculata. This study was proposed to evaluate its efficacy using validated scales and objective measures.

Methods: Participants were randomized in a ratio of 1:1:1 to receive either AP-Bio® 200 mg/day, AP-Bio® 400 mg/day or placebo for 7 days. The primary outcome measure was Wisconsin Upper Respiratory Symptom Survey (WURSS-21) score. The secondary outcome measures were nasal mucous weight, nasal muco-ciliary clearance function and Interleukin-8 in nasal wash, as well as safety and tolerability.

Results: A total of n = 331 participants were screened and N = 300 participants were enrolled. The absolute WURSS-21 global score [mean (Standard Deviation - SD)] in the AP-Bio® 400 mg group [5.70 (5.31)] was less than the AP-Bio® 200 mg group [5.81 (4.83)] on Day-3. However, it was much higher in the placebo group [9.55 (14.27)]. AP-Bio® 400 mg group (Mean Difference - MD [Standard Error - SE] = -3.85 [1.52]; 95% CI = -6.85, - 0.85; adjusted p = 0.034) and 200 mg group (MD [SE] = -3.74 [1.51]; 95% CI = -6.73, - 0.76; adjusted p = 0.038) had significantly lower score than placebo. Similarly, on Day-3, the change in global score from baseline was significantly better in the AP-Bio® 400 mg group (MD [SE] = -3.91; [1.82] 95% CI = -7.50, - 0.32; adjusted p = 0.038) and AP-Bio® 200 mg group (MD [SE] = -3.84 [1.97]; 95% CI = -7.72, - 0.04; adjusted p = 0.044) in comparison to the placebo group. Nasal mucous weight, tissue paper counts used, and interleukin-8 showed a trend towards AP-Bio® groups having a favourable outcome when compared with placebo but did not reach statistical significance due to a small sample size. None of the study participants complained of any adverse physical symptoms. However, incident eosinophilia was noted in n = 20 participants on day 3. (n = 6 in AP-Bio® 200 mg group, n = 7 in Ap-Bio® 400 mg group and n = 13 in placebo group; p = 0.181).

Conclusions: Participants in both the AP-Bio® dose groups showed positive tendency towards resolution of URTI symptoms when compared with placebo on Day-3 but not on Day-5 and Day-7.