Prior Authorizations, Trial Gaps Hinder Glomerular Disease Drug Access

New therapies for glomerular diseases continue to reach the market, but limited pediatric data, insurer denials, unrepresentative trials, and global affordability gaps keep many patients from receiving them, panelists said during a clinical practice session at the American Society of Nephrology (ASN) Kidney Week 2026 meeting, held in Denver, Colorado.

“How do we provide and afford access to our patients, the people that really matter and who ultimately benefit from these scientific advances?” asked comoderator Leslie P. Wong, MD, MBA, FASN, executive vice president and chief clinical officer at Rochester Regional Health in Rochester, New York, in introducing the session.

Anna R. Gaddy, MD, FASN, associate professor of medicine at the Medical College of Wisconsin in Milwaukee, served as comoderator. The session came a day after the FDA granted accelerated approval to ravulizumab (Ultomiris; Alexion, AstraZeneca Rare Disease) to reduce proteinuria in adults with primary IgA nephropathy (IgAN) at risk for disease progression,¹ and months after a similar accelerated approval for atacicept (Trutakna; Vera Therapeutics) in July.²

Children Wait Years for Access to New Kidney Therapies

Susan L. Furth, MD, PhD, executive vice president and chief scientific officer at Children’s Hospital of Philadelphia, discussed the challenges of translating new kidney therapies to pediatric patients. She said pediatric trial data in kidney disease trail adult data by 13 years on average, and that only about 15% of IgAN intervention trials include pediatric-aged patients.

“At this juncture of time, this kind of lag is just not acceptable,” Furth said.

Furth pointed to the rarity of pediatric glomerular disease, slow progression that forces reliance on surrogate end points, and limited incentives for companies to develop therapies for ultra-rare pediatric conditions. She noted that the Best Pharmaceuticals for Children Act and the Pediatric Research Equity Act were meant to encourage pediatric studies, but that waivers and deferrals mean some therapies are not adequately tested in children.

As solutions, she highlighted extrapolation from adult efficacy data, master protocols and platform trials, and real-world evidence, including an electronic health record algorithm across PEDSnet children’s hospitals that identified almost 5000 children with glomerular disease. Dosing and exposure data still require studies in children, she said, because “children are not just little adults.”

Prior Authorization Denials Are Rarely Appealed

Lisa M. Latts, MD, MS, MBA, MPH, head of clinical at Bridge and founder and principal of LML Health Solutions, addressed prior authorizations, Risk Evaluation and Mitigation Strategies, and site exemptions.

“FDA approval is only the starting line,” Latts said, noting that a drug must clear formulary placement, policy criteria, prior authorization, and affordability before a patient fills it. She cited a study published in JAMA that found insurers rejected 40.7% of initial fill attempts for single-source branded drugs in 2024, up from 24.3% in 2018, and that 48.4% of rejected fills were not followed by a fill of the drug or a same-class alternative within 90 days.³

Latts said the largest opportunity lies in appeals. In 2024, Medicare Advantage insurers made 52.8 million prior authorization determinations and denied 7.7% fully or partially, yet only 11.5% of denials were appealed, and 80.7% of appeals were fully or partially overturned.⁴ She urged clinicians to learn whether a drug falls under the pharmacy or medical benefit, submit complete documentation the first time, accept peer-to-peer calls, and request a same-specialty reviewer on appeal.

“Complete data gets approved. Missing data gets a delay,” she said. She also pointed clinicians to template appeal letters in the ASN Glomerular Diseases Collaborative Compendium and recommended submitting requests electronically, noting that 47% of drug prior authorizations are still sent by phone, fax, or mail. For patients who cannot afford copays, she recommended checking lower-cost alternatives, manufacturer assistance, copay foundations, and hospital financial aid before the patient even reaches the pharmacy.

Real-World Evidence Shows a Trial Representation Gap

John J. Sim, MD, FASN, professor of clinical science at the Kaiser Permanente Bernard J. Tyson School of Medicine, examined how real-world evidence can complement trials.

In unpublished data from Kaiser Permanente Southern California, 273 of 1039 patients with IgAN (26.3%) met trial-style thresholds of a urine protein-to-creatinine ratio of at least 0.75 g/g and an estimated glomerular filtration rate of at least 20 mL/min/1.73 m², he said. In a published analysis from the same health system, 173 of 926 (18.7%) patients with primary, genetic, or undetermined focal segmental glomerulosclerosis (FSGS) met criteria modeled on the phase 3 ACTION3 (NCT0518364) trial.⁵ About 12% of patients with IgAN in the health system were receiving newer therapies as of January 2026, with higher use among trial-eligible patients.

Sim also shared unpublished data on the harms of older approaches. Corticosteroids were the initial treatment for 94% of 253 treated patients with IgAN and 91% of 228 treated patients with primary FSGS. In all, 45 patients with IgAN (17.8%) and 46 with FSGS (20.2%) had at least 1 serious infection requiring hospitalization or an emergency department visit. In IgAN, infection rates were highest among patients with less than 6 months of cumulative immunosuppression (13.2 per 100 patient-years; P = .01 across duration groups), which Sim attributed to clinicians stopping treatment early after an infection, meaning some patients may have missed the full benefit. He called for real-world research to capture patient- and caregiver-reported outcomes that structured data miss.

“Representation is a gap,” Sim concluded. “A very small proportion of our patients are included in these clinical trials. The real-world evidence will hopefully complement some of that evidence gap that I just discussed. But ultimately, all these things are complementary to each other because we're really after precision medicine in terms of which drugs should be given to our patients.”

Global Access to Kidney Disease Drugs Hinges on Affordability

Hernán Trimarchi, MD, PhD, FASN, head of the Division of Nephrology and Renal Transplantation at Hospital Británico de Buenos Aires in Argentina, covered barriers to global access. He said chronic kidney disease trial participation is concentrated in North America and Europe, where about 15% of the world’s population lives, and that participating in a trial does not ensure a country will gain access to the drug once open-label extensions end.

Newer IgAN therapies are available in only a few countries, he said, and in some low-income settings a month’s supply of a kidney drug can exceed a month’s salary, “so the availability does not imply its affordability either,” Trimarchi said.

“Ideally, the drug should be commercialized in those countries in which the drug has been tested. I think that would be fair,” Trimarchi said. “We need affordability. It is key for us to achieve access to new therapies.”

Across the session, panelists described access barriers that persist after FDA approval, from the lag in pediatric data to prior authorization denials that often go unappealed and trial populations that reflect a small share of real-world patients. They pointed to approaches already within reach, including extrapolation and platform trials for children, complete documentation and appeals for coverage, real-world evidence that captures patient-reported outcomes, and commercialization in the countries where drugs are tested.

References

1. Ultomiris received accelerated approval in the US as first and only C5 complement inhibitor to reduce proteinuria in adults with primary immunoglobulin A nephropathy. News release. AstraZeneca. October 21, 2026. Accessed October 22, 2026. https://www.astrazeneca.com/media-centre/press-releases/2026/ultomiris-approved-in-us-in-igan.html

2. Hohmann E. FDA approves atacicept for IgA nephropathy. AJMC^®. July 7, 2026. Accessed October 22, 2026. https://www.ajmc.com/view/fda-approves-atacicept-for-iga-nephropathy

3. Levy JF, Alexander GC, Vabson B, Ippolito BN. Formulary-related insurance denials of single-source branded drugs in the United States. JAMA. Published online July 9, 2026. doi:10.1001/jama.2026.8702

4. Biniek JF, Sroczynski N, Freed M, Neuman T. Medicare Advantage insurers made nearly 53 million prior authorization determinations in 2024. KFF. January 28, 2026. Accessed October 22, 2026. https://www.kff.org/medicare/medicare-advantage-insurers-made-nearly-53-million-prior-authorization-determinations-in-2024/

5. Munis MA, Chen Q, Smith A, Garcia CL, Fuller D, Sim JJ. Real-world eligibility for FSGS clinical trials: insights from a US health system. Clin Kidney J. 2025;19(2):sfaf377. doi:10.1093/ckj/sfaf377