Have your CV and the JD in front of you as a point of reference. Do your research on the company. Know the therapeutic areas that they work in: marketed and pipeline products. Research recent news articles.
Prior to the call, review your CV and compare it to the requirements of the job description. Highlight the skills on your CV that align with the position and be able to address your skills/strengths/experiences in a concise way. Always be honest.
Smile while you are on the phone. It may sound silly but your smile comes across in your voice.
Thank the interviewer for their time and express your interest in moving to the next step.