European Physician Survey of EGFR Inhibitor Prescribing Patterns

The survey will be conducted for 3 rounds in months 0, 12, and 24 after the first interview.

Before the beginning of each round, a sampling list will be created by Amgen.

In each round of the survey, potential participating oncologists will be sampled from each country's sampling list through random sampling and reached through telephone, letter or email. During the initial contact, the oncologists will be assessed for their eligibility to participate in the study by using a standardized screening questionnaire.

The initial contact and screening of potential participating oncologists will continue until a total of 150 eligible oncologists agree to participate in each round. The number of oncologists sampled in each country will be proportional to the use of Vectibix in each country and the number of oncology physicians estimated to prescribe Vectibix. Each eligible oncologist can only participate in 1 of the 3 rounds of survey.

Study staff will then conduct the survey with each of the identified eligible oncologists over the telephone, using a standardized questionnaire. Information about their awareness of the correct indication and appropriate administration of Vectibix and their experience in the administration of Vectibix treatment in the previous 6 months will be collected. We will make every attempt to collect the correct information from participating oncologists. This may require at least two phone calls to allow an oncologist to review their notes in order to report the correct data.

Physician Inclusion Criteria:

• Must be a practicing oncology specialist
• Must treat at least 3 new or continuing patients with metastatic colorectal cancer in the last quarter
• Must have prescribed Vectibix within the last 6 months to metastatic colorectal cancer patients

Exclusion criteria

• Must not have taken part in this study previously
• Must not have participated in Amgen study number 20101120.