Potential Approval of HIF-PH Inhibitors in Dialysis Patients

As approval for hypoxia-inducible factor (HIF) prolyl hydroxylase (PH) inhibitors for the treatment of anemia nears, focus has turned to access for patients on dialysis. According to Meghan Staudt, MBA, and colleagues at Spherix Global Insights, Exton, Pennsylvania, dialysis centers have influence over access.

The researchers conducted an analysis comparing the evolution of Parsabiv® (Amgen) from approval and inclusion under TDAPA (transitional drug add-on payment adjustment) to being reimbursed within the bundle as an analogue for the path the HIF-PH inhibitors may face. Results of the analysis were reported during a poster session at the NKF SCM22 in a poster titled What to Expect with the Potential Approval of HIF-PH Inhibitors in Dialysis.

The analysis examined responses from more than 200 nephrologists who completed a HIPAA-compliant, online tool. Relevant data included demographic profiles, attitudinal responses, and brand share estimates quarterly from 2017 through 2021.

Vadadustat, the HIF-PH in the pipeline at Akebia Therapeutics, Inc., is the first in line for FDA approval. In dialysis, vadadustat has higher familiarity among nephrologists than Parsabiv did pre-approval (29% vs 16%, respectively). The percentage of nephrologists who anticipate trialing a HIF-PH inhibitor immediately in dialysis is low (8%); however, it is higher than Parsabiv at a similar time pre-launch (3%).

Barriers to using HIF-PH inhibitors are similar to those seen with Parsabiv: the top barriers for both drugs are largely related to access. Many nephrologists anticipate dialysis center protocols will dictate the use of HIF-PH inhibitors; similarly, most reported experiencing formulary issues with Parsabiv.

When asked about the use of HIF-PH inhibitors in dialysis, 48% of responding nephrologists said they expected their dialysis center to primarily use erythropoiesis-stimulating agents (ESAs), 22% expect equal ESA and HIF-PH inhibitor use, and 21% expect only use of ESAs. Fifty percent of the responding nephrologists said they were concerned about safety with HIF-PH inhibitors.

While nephrologists expect that most dialysis patients treated for anemia will be on ESAs, more than 80% anticipate using HIF-PH inhibitors in dialysis. In comparison, Parsabiv’s user base rose past 80%, reaching peak share 2 years after approval under TDAPA. However, once Parsabiv was added to the Medicare bundle payment, its share eroded over time.

In conclusion, the authors said, “Vadadustat, if approved, may end up on a similar path as Parsabiv, with dialysis center protocols governing use, Although familiarity with vadadustat may aid its uptake in dialysis, safety concerns ring loud and will be a hurdle the HIF-PH inhibitor class will need to battle.”

Source: Staudt M, Malone S, Robinson J. What to expect with the potential approval of HIF-PH inhibitors in dialysis. Abstract of a poster presented at the National Kidney Foundation 2022 Spring Clinical Meetings (Abstract #179), Boston, Massachusetts, April 6-10, 2022.