In that study, researchers looked at the data from two already completed studies, the Vioxx Gastrointestinal Outcomes Research study (VIGOR) and Celecoxib Long-Term Arthritis Safety Study (CLASS), and concluded that both drugs might slightly increase the risk of cardiac events such as heart attack and stroke.

FORBES: Magazine Article

Schneider CK, Melmed RD, Barstow LE, Enriquez FJ, Ranger-Moore J, Ostrem JA. Oral Human Immunoglobulin for Children with Autism and Gastrointestinal Dysfunction: A Prospective, Open-Label Study.

FORBES: Anti-Vaccine Activists Apparently Immune To Science

The culprit: gastrointestinal perforations, a known side effect of Avastin, showed up in five of 44 patients in the study.

FORBES: Avastin Sales Could Still Hit $7 Billion Per Year