[Updated 1/17/19, 8:50 a.m. See below.] An experimental Amgen osteoporosis drug that had sparked concern about cardiovascular side effects has won the backing of an FDA advisory panel.
A total of 15 panelists on Thursday voted that the benefits of the drug, romosozumab (Evenity), outweigh its risks, and are enough to support its approval. But many of those panelists also said the drug should carry a warning on its label, and that the FDA should require Amgen (NASDAQ: AMGN) to conduct more studies to better understand the heart risks.
Three other panelists voted that the drug’s benefits support approval, but for a different patient population than the one Amgen proposes. One panelist voted against approval. The FDA is not obligated to follow an advisory panel’s recommendations, though the advice is taken under consideration. It’s unclear when a decision will happen. At least one company claims the partial government shutdown is delaying FDA review of its drug. An Amgen spokeswoman was unable to provide a target date for an FDA decision on romosozumab.
Osteoporosis is a disease that reduces the density of bones, making them more likely to break. It affects an estimated 10 million Americans, while another 44 million Americans have low bone density that increases the risk of developing the disease, according to the National Osteoporosis Foundation. Standard treatment includes a class of generic drugs called bisphonates, which slow bone loss.
Romosozumab, an antibody drug administered once monthly by injection, was developed to increase the density of bones and reduce the chance of fractures. In Phase 3 results released in 2017, Amgen and partner UCB reported that patients treated with the drug showed fewer fractures compared to patients treated with a bisphonate alone.
But the data also showed a higher risk of a major cardiovascular problems, such as a heart attack or stroke, in the group treated with the Amgen drug. Those risks were enough to prompt the FDA to reject the drug in 2017 and ask Amgen to provide more data.
In its initial application in 2017, Amgen sought approval for its drug as a treatment for all postmenopausal women at risk of fracture. The company’s resubmission last year, which included data from two additional Phase 3 studies, has narrowed the drug’s proposed scope to women whose history of broken bones, or failure to respond to other therapies, puts them at high risk of additional fractures. In documents Amgen filed with the FDA, the company also said a warning could be placed on the drug’s label to flag the potential cardiovascular risks. On Wednesday, many panelists agreed with the suggestion; some said the warning could eventually be removed after further study clarifies the drug’s risks.
[Paragraph added with analyst comment.] In a research note, RBC Capital Markets analyst Kennen MacKay wrote that the committee vote is a positive sign for the potential approval of romosozumab, but the key question is its commercial opportunity. Panelists noted that there is an overlap between those at high risk of fracture and those at high risk of a major cardiovascular event—and both increase with age. That could slow the initial launch of the drug, MacKay said.
Amgen is trying to compete against other osteoporosis drugs developed to strengthen bones. Waltham, MA-based Radius Health (NASDAQ: RDUS) won FDA approval in 2017 for its osteoporosis drug abaloparatide (Tymlos). The Radius drug, a once-daily injection, generated $64.8 million in sales through the first three quarters of 2018.
Both Radius and Amgen are trying to take market share from Eli Lilly (NYSE: LLY), whose osteoporosis drug teriparatide (Forteo), generated more than $1.1 billion in worldwide sales last year through the third quarter. Patents for that injectable drug, which was approved in 2002, are set to expire this year, opening the door for generic drug makers to sell their versions of the therapy.