Pfizer, like many big companies today, is being choosy and taking its time hiring candidates. (They may also be indecisive, or both.) That was my experience. The recruiter had told me they'd already spoken to a dozen candidates, and were still "figuring out what the job was" based on who they met.
Process;
Initial phone interview with hiring manager: job responsibilities, qualities they look for (fast moving, hard worker, smart, etc.), culture (same as qualities), asked about work history, describe my experience relevant to their needs.
In person interview with HR: behavioral questions, management style, work style, culture I like to work in, etc.
In person interview with business "client" -- skills relevant to their situation; past work experience. This was the only person I met who showed any of the "Pfizer arrogance" that others told me about, making several unfavorable comparisons of numerous pharma companies (including my former employer) vs. Pfizer. Definitely saw Pfizer as the model for the industry.
In person interview with hiring manager: same questions as phone interview.
Outcome:
Recruiter told me after my final interview that all "went well." Then a few days later that they're "still interested, but still interviewing." Last I heard 6 months after that, they still hadn't hired for the position.
Advice:
Expect a long process.
Know the company -- its business and culture.
Be somewhat deferential, especially if coming from another pharma company. Like it or not, Pfizer people think very highly of their position in the industry.
Be prepared to help them define the job you're interviewing for.