Hockey commentator don Cherry describes COLD-fX, the popular cold and flu remedy made by Edmonton-based CV Technologies Inc., as a “beauty.” And from a marketing point of view, it certainly is.

According to ACNielsen, COLD-fX now ranks as the country’s best-selling cold and flu remedy. Toronto-based Marketing Magazine and the TSX Venture Exchange both named CV Technologies its company of the year for 2005. (The company has since graduated from the venture exchange to the senior Toronto Stock Exchange.)

But it is still not clear how effective the product is. Two professors at the University of British Columbia faculty of pharmaceutical sciences recently reviewed three of the company’s clinical trials and expressed concern the company has been selectively using the results to make “misleading” promotional claims.

The first two trials, which were combined, involved about 200 nursing home patients. Half took COLD-fX, which is made from ginseng, and half took a placebo. Based on these results, the company claims that COLD-fX reduces colds, flus and respiratory illness by 89%.

But professors James McCormack and Peter Loewen, who are experts at analysing clinical trials, noted that the trials showed no difference in the incidence of cold or flu, as measured by symptoms. It was only by looking at a subset of those illnesses — flus that were confirmed by laboratory analysis — that there was a significant difference between the two groups: 9% for the placebo group vs only 1% for the COLD-fX group.

The absolute difference of 8% translates into a relative difference of 89%, but the professors say that it is misleading to state that COLD-fX reduces colds, flus and respiratory illness by 89% because there was no difference in the incidence of those who reported feeling sick.

McCormack and Loewen also noted there was no significant difference in the percentage of subjects who caught at least one cold. It was only by looking at something they didn’t originally intend to look at — those who caught more than one cold — that they noticed a difference: 22.8% for the placebo group vs only 10% for the COLD-fX group (an absolute reduction of 12.8%, which translates into a relative reduction of 56%). Based on this result, the company stated: “COLD-fX prevents recurrent cold and flu infections by 56%.”

The company dismissed the professors’ analysis as containing “errors” and “misleading information.” However, both professors stand behind their original comments.

The study also looked at several secondary endpoints and found the severity of cold symptoms was less in subjects who took COLD-fX, and the duration of cold symptoms was an average 2.4 days, or 31% shorter. McCormack and Loewen note that these results are inconsistent with the two earlier trials, which showed no effect on the severity or duration of colds. However, they agree that “if these results are real, then there might indeed be a meaningful effect for consumers.”

The company notes that both studies were peer reviewed and published in reputable medical journals. But it agrees that more follow-up trials are needed. It is currently conducting a much broader trial involving 720 subjects and it will spend up to $30 million over the next three years attempting to obtain U.S. Food and Drug Administration approval to market COLD-fX as an over-the-counter cold and flu remedy. To its credit, the company is one of the few natural health product manufacturers making a strong effort to prove the efficacy of its products. IE