Thousands of results from clinical trials of cancer drugs were unleashed Wednesday evening ahead of the year's biggest event in cancer research, ASCO, or the American Society of Clinical Oncology meeting.
Among them were early data on AstraZeneca's experimental lung cancer drug, known as AZN9291. The medicine is designed to help patients whose cancer has mutated out of the reach of other drugs, a population for whom no medicines are approved.
And it's a key part of AstraZeneca's defense that Pfizer's $106 billion bid undervalues its prospects; the British company said earlier this month that the drug could draw about $3 billion in peak annual sales, compared with analysts' estimates of $1 billion to $2 billion.
In the study results released Wednesday, AZN9291 shrank tumors in more than half, or 51 percent, of the 177 patients in the study. The drug has been designated a "breakthrough therapy" by the U.S. Food and Drug Administration, a status designed to speed the path of important medicines to market.
So, a win for AstraZeneca, right?
Not so fast. While the data were well-received by analysts, some pointed to a similar drug from a much smaller biotech that may be even stronger.