Clovis Oncology CEO Patrick Mahaffy told CNBC he's been the underdog for most of his career.
"It probably would be fun to be an overdog one time," he said in an interview Monday from the American Society of Clinical Oncology meeting, where the biotech company presented data on its experimental drug for lung cancer, CO-1686, that will compete with a similar one from British drug giant AstraZeneca.
Tuesday's not that day. Clovis' stock recently hit a fresh 52-week low and was recently down 16 percent, adding to Monday's losses, on concerns AstraZeneca's experimental medicine, AZD9291, will edge Clovis' out. (For the latest Clovis stock quote, click here.)
Citi analyst Yaron Werber downgraded Clovis' stock Tuesday to "neutral" from "buy," writing: "We now have more clarity on AZD9291 and its profile looks comparatively better than CO-1686. With a cleaner profile, no major toxicity issues, and possible ... path to market ahead of CO-1686, we have to re-assess our previous view on the stock as CO-1686 will likely not offer any tangible benefits based on the current profile."
Questions arose at the conference over the side effect profiles of both drugs—AstraZeneca's is associated with "interstitial lung disease-like" effects and rash in some patients, while Clovis' is linked to high blood sugar for some. At an investor event over the weekend, Mahaffy noted three patients started on insulin while taking CO-1686, prompting some to say the drug causes diabetes.