Forum Moderators: not2easy
For instance, to use a well-known company many people are familiar with, and that guards its IP - Apple Computers - they will allow you to include the word "Mac" in the domain name, if it's about their products, and as long as you don't represent yourself as being associated/endorsed with them.
However, they will not allow you to use the word "Apple" in a domain name if it's about their products (some sites get away with this, although it's clear from a glance that they are not associated or endorsed by Apple, but Apple is clear that you are not supposed to).
I'm not saying Pfizer has something similar, but it wouldn't surprise me if they have this information available.
Check rulings at ArbForum.com and WIPO.int to verify.
Some day, some one, will be subjected to more than just a letter or an arbitration. Someday BigCorp will sue someone for the specific purpose of bankrupting the domain holder and making an example of him/her.
Keep that in mind as you plan your strategy.
Always better to ask the directly concerned party rather than asking some unrelated webmasters.
Ask the company.