Pfizer's Ibrance may have competition to breathing down its neck. But the drug giant intends to keep its lead with contender Ibrance, and on that front, it’s appealing to physicians and their prescribing habits with its latest regulatory win.
Friday, the FDA converted Ibrance’s accelerated nod to a regular approval and widened the number of antihormonal therapies that could be administered alongside. Previously, only Novartis’ Femara (letrozole) was approved to accompany the first-in-class CDK 4/6 inhibitor, but the new indication lets Ibrance pair up with any aromatase inhibitor to treat for previously untreated patients with advanced HR-positive, HER2-negative breast cancer.
It’s a tweak that “really makes it a bit easier for physicians to now have their prescribing practice in line with the label," Mace Rothenberg, chief development officer for oncology at Pfizer, explained in an interview. Studies over the years have suggested that “there’s equivalence between the major ones”—Femara and AstraZeneca’s Arimidex (anastrozole)—yet some doctors “for one reason or another were reluctant to change their practice,” he said.
Those doctors are the ones who may now find Ibrance more appealing.
“For physicians who are used to using anastrazole, this actually makes it easy to add Ibrance to that rather than having to use it with an aromatase inhibitor that they’re less familiar with,” Rothenberg said. And while it’s unclear how many doctors and patients the change might affect, “we’re trying to remove as many barriers to prescribing Ibrance appropriately as possible.”
Since winning a quick FDA go-ahead in early 2015, Ibrance has been prescribed by nearly 10,000 doctors to roughly 50,000 breast cancer patients. Still, the med is not the choice for a “substantial” number of doctors, Rothenberg said. Some may think their patients are doing fine on their aromatase inhibitor alone and don’t need the side effects that an additional med can bring, he explained.
Pfizer, however, has found that Ibrance adds an additional benefit in every patient subset it’s examined. So as it looks to expand the med's reach, its task “really is trying to convince those physicians that even in patients they think can do well, they can do better with Ibrance,” Rothenberg said.
Meanwhile, Ibrance is fending off some new competition in Novartis’ Kisqali, which launched mid-March under a flex-pricing model that helped it undercut the Pfizer hotshot. The med is available at three different prices that match its three different doses, a unique feature Novartis wanted to play up in the marketplace.
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“What this allows is very good flexibility for the physician and the patient. They can dose reduce mid-cycle, and they don’t have to write a new prescription and everything that goes along with that,” the Swiss drugmaker’s EVP of U.S. oncology, Bill Hinshaw, said in a recent interview.
“The physicians and the nurses that we’re engaging with ... very much appreciate the dosing convenience. They think, and we think, that that’s an important part of a patient’s journey,” Hinshaw added.
And then there’s abemaciclib, the Eli Lilly candidate that recently posted placebo-beating progression-free survival data in a phase 3 study that’ll back up the company’s Q2 filing. Credit Suisse analyst Vamil Divan, for one, predicts a 90% probability of success for the prospect, with 2023 global sales of $1.6 billion, he wrote to clients last month.
Rothenberg stressed that though Pfizer has “been the leader in this field, we are not standing still.” The company is examining Ibrance in women in earlier-stage breast cancer, and it’s got trials running in head and neck cancer and pancreatic cancer, too.
“Every drug that tries to enter in this space has a very high bar to live up to in order to be as widely accepted and well received as Ibrance has been,” he said, adding that “we’re really committed to this area and retaining market leadership in this field.”