The path to approval was long and winding for a new class of medicines called hypoxia-inducible factor prolyl hydroxylase (HIF-PH) inhibitors. And even after GSK clinched regulatory victory earlier this month, its Jesduvroq may have a hard time swaying doctors in the real world, according to a Spherix Global Insights poll.
In early February, Jesduvroq won an FDA approval to treat patients with anemia caused by chronic kidney disease (CKD) who’ve been on dialysis for at least four months.
GSK had hoped to gain an approval to treat patients who don’t require dialysis, but the FDA ruled the drug’s safety hadn't been established in that population.
According to market research firm Spherix, many nephrologists “expressed frustration at this outcome,” given the belief that the “greatest value” of oral HIF-PH inhibitors is in CKD patients who aren’t on dialysis.
With that in mind, Spherix surveyed 110 nephrologists in early February to take doctors’ pulse on the new GSK med. The initial findings suggest nephrologists are “divided regarding their receptivity to the drug’s recent approval.”
While some nephrologists look forward to having another treatment option, others have taken a more cautious approach, expressing disappointment with the “limited utility of application based on the restrictive label.”
Over the past few years, the HIF-PH inhibitor landscape has been “turbulent,” Spherix noted. Despite high-profile misses in the field, a “consistent one-third” of nephrologists appear to be “‘HIF-PH supporters,'" according to Spherix.
That said, the bulk of remaining physicians are “more cautious” and are likely to be “highly selective” when it comes to Jesduvroq prescribing.
GSK is committed to bringing Jesduvroq to the right patients “as quickly as reasonably possible,” a company spokesperson said over email, adding that GSK is working with dialysis organizations to provide education on the clinical outcomes of the new drug and to potentially make the drug available to those organizations’ patients.
Meanwhile, given that 87% of dialysis patients are on Medicare, GSK is submitting filings to the Centers for Medicare & Medicaid Services to facilitate “timely reimbursement and access to Jesduvroq,” she added.
The HIF-PH inhibitor class—which also includes AstraZeneca and Fibrogen’s roxadustat plus Akebia and Otsuka’s vadadustat—hasn’t had much success in the past. Those other members of the class suffered high-profile FDA rejections over the last two years.
As for Jesduvroq, the drug carried an “elevated estimated” risk for heart attack and stroke in non-dialysis patients, the FDA noted in pre-advisory committee briefing documents back in October. In its approved format, the medicine sports a boxed warning highlighting increased risk of blood clotting complications, including death, heart attack and stroke as well as blood clots in the lungs, legs or dialysis access site.
Most of the doctors Spherix polled agreed with the FDA’s decision to slap a warning on Jesduvroq limiting the drug’s use to prevalent dialysis.
Still, with Jesduvroq’s launch looming, plus potential for other HIF-PH meds to file new drug application packages at the FDA, the anemia of the CKD landscape is “certain to change,” Spherix noted.
Elsewhere, Akebia, AstraZeneca and GSK’s drugs are already duking it out overseas in Japan, which has endorsed approvals for vadadustat, roxadustat and daprodustat. In Japan, GSK’s drug carries the name Duvroq, where it's approved to treat patients with renal anemia. AstraZeneca’s roxadustat, for its part, is also approved in China and Europe as Evrenzo.