A hidden tab in an Excel spreadsheet published nine months ago has wiped $12 billion off Amgen’s market cap. The tab contains data on bone density changes in patients who received Amgen’s obesity prospect MariTide in a phase 1 trial.
Amgen published data from the study in the journal Nature Metabolism in February. The paper makes no mention of bone density. Amgen also shared the source data in Excel spreadsheets. At first glance, none of the spreadsheets contain bone density data either. However, one of the files contains hidden tabs that can be revealed by right-clicking on one of the visible tabs.
The tabs remained hidden until an analyst at Cantor Fitzgerald spotted them and published a note about the bone density data this week. Three of the hidden tabs contain femur, lumbar and hip DEXA bone density scan data. A fourth tab, called “DEXA cohort 9 four,” contains patient-level data for the top MariTide dose.
Cantor analyst Olivia Brayer called the data a “big unknown” in a research note, according to CNBC, and suggested bone density is a potential risk of GIPR antagonists such as MariTide. Amgen’s share price fell 7% in the wake of Brayer’s note, wiping $12 billion off the biotech’s market cap.
However, Jefferies analyst Michael Yee called the bone density finding a “non-issue” in a note published in response to the brouhaha, arguing that “the data is all over the place.” Amgen weighed in with its own statement on the data.
“As previously stated, Amgen does not see an association between the administration of MariTide and bone mineral density changes,” the biotech said. “The phase 1 study results do not suggest any bone safety concern or change our conviction in the promise of MariTide. We look forward to sharing the phase 2 topline data later this year.”
One hidden tab shows that, on average, patients who received the highest dose of MariTide lost around 4% of their bone mineral density across 12 weeks of treatment. Another tab shows patient-level data for the four people on the highest dose, showing both the tiny number of subjects involved and providing evidence the overall decline was driven by one participant.
Investors appeared to regain confidence after having time to look into the data. Amgen’s share price was up 3.6% before the market opened on Wednesday, erasing around half of the losses triggered by the note. The magnitude of the stock drop on such scant evidence gives an indication of the importance investors are placing on MariTide as Amgen heads toward phase 2 readout that is expected this year.