I think that I need more context to the question. I think that I am confused with the premise of the question. It seems to me that greater regulation of tobacco products would impact the competitive advantage of all producers. This would include Philip Morris, so it would not be adding to their advantage, but actually hurting them. On another level, I think that more detail would have to be given about the nature of "regulation." Economic regulation might be different from public health notification. I am not certain where I stand on the first instance, but I am definitely in favor of divulging all relevant information regarding the health consequences of tobacco products, such as its nature of addiction as well as any additives that are added into the product.
That's hard to say, given that we don't the know the content or purpose of the regulation you describe in your question. Cigarettes and other tobacco products are already heavily regulated in the United States, in terms of their manufacture and content, how they can be advertised and to whom, licensing requirements to sell tobacco, and what age you have to be to buy them. The only way I could see more regulation adding to a company such as Philip Morris' competitive advantage would be if the products they currently have in the pipeline already comply with the new regulations. In that case, the advantage would be short term, and I would be fine with the regulations giving them that advantage, as long as those regulations also better protected consumers and the public.
Also keep in mind that most tobacco companies, American and otherwise, have a more reliable customer base in Europe and Asia than in the US, where a much higher percentage of the population smokes, and make the bulk of their profits elsewhere, where laws passed in America do not apply.