Mel Gibson on health: what the evidence says · JRE #2254

What the evidence says 01 / RECORD

AZT (azidothymidine, zidovudine) was synthesized in 1964 by Jerome Horwitz and screened as a candidate anticancer drug; it was set aside because it failed to show meaningful antitumor efficacy against the cancers it was tested on, not because trials showed it killed cancer patients faster than their disease. Two decades later, in the mid-1980s, researchers repurposed the same compound after discovering it potently inhibited HIV reverse transcriptase, and a 1987 placebo-controlled trial (Fischl et al., NEJM) led to its approval as the first antiretroviral drug for HIV/AIDS. Peer-reviewed pharmacology literature describes AZT plainly as "a failed anticancer drug from the 1960s" that was later found effective against HIV, with no claim in the scientific record that it was withdrawn from cancer use for causing faster death than cancer. AZT does carry real, well-documented toxicities (bone marrow suppression, anemia) at the high doses used in early HIV trials, which may be the origin of loose public claims like this one, but that toxicity issue arose in its HIV use, not as the stated reason for cancer-drug discontinuation. The claim misrepresents the documented history of the drug.