Pfizer, Astellas and Johnson & Johnson envision a wide-open new field ahead for their blockbuster prostate cancer drugs, and its patients whose disease hasn't yet spread through the body.
Both companies are putting up new data that could open the gates. But a high-stakes market scrum lies ahead—and it's likely to include a formidable generic competitor.
In abstracts released ahead of the ASCO’s Genitourinary Cancers Symposium this weekend, Pfizer and Astellas unveiled details of the Prosper study, which tested Xtandi in patients with nonmetastatic prostate cancer. J&J also rolled out similar numbers on its late-stage candidate apalutamide, intended as a follow-up to its big-selling Zytiga therapy.
And the key word is "similar." The results out of the two studies didn't match up exactly—and researchers caution that true head-to-head comparisons are only possible in head-to-head clinical trials—but they were close. Xtandi added to hormonal therapy held off metastasis by 36.6 months at the median, a 21.9-month improvement over hormonal treatments alone. The J&J candidate delivered 40.5 metastasis-free months, a 24.3-month improvement over current therapy. That's a difference of 2.4 months between the two drugs' survival advantages.
Without details on secondary endpoints, which the companies will unveil during full presentations later this week, and without longer-term data showing whether living longer metastasis-free will help patients live longer, period—well, the conclusions to be made at this point are limited. And it's always a gamble predicting how payers and prescribers will react to a new drug—apalutamide is up for FDA approval within the next few months—or a new indication, as Xtandi is hoping for.
But you can bet that Pfizer and Astellas on one side and J&J on the other will try to get as much mileage as possible out of their respective sets of data, because they're worth several billion dollars in sales, analysts say. Evaluate Pharma figures that apalutamide can bring in $1.6 billion in 2022. Xtandi—which delivered a combined $2.59 billion for Astellas and Pfizer last year—is set to grow to $4.71 billion in 2022, EP has said, putting it among the top 15 best-selling cancer drugs that year, according to data compiled for FiercePharma last year.
The new indication based on Prosper would be “a significant expansion for the drug,” Astellas SVP and oncology chief Steven Benner said in an interview with FiercePharma last year. “If it works out as expected, it’s a way to bring Xtandi to a new patient population.”
But there's a cloud over that picture:J&J's own Zytiga, and the earlier-than-expected generics threatened for later this year. The U.S. Patent Trial and Appeal Board invalidated Zytiga's 2027 patent last month, after an inter partes review challenge by would-be generics maker Argentum Pharmaceuticals. If that decision stands, Zytiga copies could hit the market as soon as October.
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J&J is doing everything it can to fight the decision, of course. "We believe the '438 patent is valid and will continue to vigorously defend it," J&J said in a statement at the time—and reiterated the same when it released fourth-quarter earnings last week. Zytiga delivered $1.23 billion in 2017 sales, $402 million of that in the U.S.
And Pfizer executives say they're not worried about Zytiga copycats in any case. One of Xtandi's selling points from the beginning is that it doesn't need to be paired with steroids, as Zytiga is. Albert Bourla, Pfizer's COO, ticked off Xtandi's perceived advantages during the company's fourth-quarter earnings call.
"There are differences between Xtandi and Zytiga safety, there are differences in terms of dosing frequency, there are differences in terms of requirements for steroid administration, and there are also very different monitoring acquirements," Bourla said, according to a Seeking Alpha transcript.
He went on to tout the company's FDA filing for a new indication based on the Prosper data. Xtandi is also at the center of "more studies that are coming in the earlier setting," Bourla noted. "So, of course, we will continue monitoring the market, but we are not right now concerned about Zytiga generics."
Meanwhile, Zytiga and Xtandi remain in a hot contest for share. Zytiga got a big sales boost in the fourth quarter from the Latitude study revealed at the European Society for Medical Oncology meeting in September, which supported Zytiga plus prednisone, along with standard hormone therapy, for previously untreated patients. Zytiga grew to $402 million in the quarter, up 61% year over year, which helped fuel a 12.8% annual increase.
"It’s really being driven by the Latitude data, where we are seeing an increase not only in the market growth but then ... almost 5 points of [market] share for Zytiga in terms of comparisons to the prior year," said Joseph Wolk, J&J's VP of investor relations, during the company's earnings call last month. The metastatic prostate cancer market grew by 25%, J&J said, and Zytiga itself has captured more than a third of that market.
Xtandi grew, too, Bourla said, and the numbers show it. The drug saw a 12% year-over-year boost, to $168 million, and that was 22% higher than third-quarter sales.
Bourla credited a push toward marketing to urologists in addition to oncologists, and couldn't resist comparing Xtandi to Zytiga in that group of prescribers.
"The number of urologists actively prescribing Xtandi continues to grow and reached an all time high of 1,700 in this quarter, which is more than three times the number of urologists that are prescribing Zytiga, for example," he said.
And this was after Bourla admitted last year that Xtandi was growing "below our expectations in the U.S." Turning that around with a combination of marketing and a new indication is obviously job one for Pfizer, having paid $14 billion for Medivation in 2016 to get its hands on Xtandi and a PARP inhibitor, talazoparib. And Astellas, its marketing partner, has its own hopes for the drug, including forthcoming data on patients with hormone-sensitive disease.
“This is an example where we just need to get additional data out that will help show the benefits of Xtandi in additional patient populations,” Benner said.