Glaxo, with products including Nicorette, Breathe Right, weight-loss treatment Alli and Aquafresh and Sensodyne toothpastes, is the No. 2 drug company with sales of $6.3 billion last year. If WPP has indeed snared the business, it would follow two big wins for the holding company, which also recently got work from computer manufacturer Dell and South Korea's LG Electronics.