Originally published by our sister publication Specialty Pharmacy Continuum
Adults with primary immunodeficiency diseases (PIDDs) who self-administered immunoglobulin replacement therapy (IgRT) at home had significantly lower infection rates and reduced use of antibiotics compared with those not employing home-based care with the medication, according to new data from a large managed care database.
Although IgRT is the standard of care for PIDDs, data on treatment patterns and healthcare resource use in patients who begin subcutaneous injections at home are limited, noted Caroline Geremakis, MD, of Takeda Pharmaceuticals, and colleagues, in the poster study (103), which they presented at the IgNS 2024 National Conference, in Washington, D.C.
The primary objective of the study was to investigate outcomes associated with the use of immune globulin subcutaneous (human), 20% solution (Cuvitru, Takeda), referred to as Ig20Gly in the analysis. The data came from Komodo Health, a company that helps leverage patient data for research. The study was independently reported and neither funded nor endorsed by Takeda, Dr. Geremakis noted.
Dr. Geremakis and colleagues reviewed data from 732 adults with PIDDs with at least two healthcare claims for the subcutaneous medication. The primary outcomes were treatment patterns (adherence, persistence, discontinuation and switching), healthcare resource use (outpatient visits, emergency department visits, inpatient hospital stays and outpatient prescriptions), incidence of infections and antibiotic use.
Two time periods were included for analysis: a baseline period of one year prior to the start of therapy, and then approximately one year of active treatment. Overall, the incidence of infection was significantly lower during Ig20Gly therapy than during the baseline period (83.1% vs. 89.9%; P<0.001). This difference appeared across severe infections, ear and sinus infections, and respiratory infections, the investigators reported.
Consistent with those rates of infection, antibiotic use was more common before Ig20Gly initiation than during active therapy (86.9% vs. 81.4%; P<0.001).
Compliance Findings
Approximately two-thirds of the patients adhered to their Ig20Gly therapy, one-fourth discontinued and 28% switched to a new IgRT, the researchers noted. The mean duration of treatment was 22.4 months. Healthcare resource use was not significantly different before and after initiation of home Ig20Gly, although other outpatient visits that were not office- or hospital-based were higher after starting therapy. The increase in other outpatient visits, including home visits, may reflect the learning curve for Ig20Gly, according to the researchers.
“The discontinuation of therapy by approximately one-quarter of patients could stem from multiple factors including, but not limited to, provider decisions involving patient preference, seasonality, immunoglobulin G [IgG] levels and other clinical parameters that are not typically captured within claims data, thereby limiting recommendations on how this could be mitigated,” Dr. Geremakis told Specialty Pharmacy Continuum.
Still, the lower incidence of infection and antibiotic use in the “real-world” setting of the study confirms that “Ig20Gly is effective in reducing infection rates,” she said.
The findings were limited by several factors related to the use of claims data, including the lack of data on patient preferences, seasonality, IgG levels and other clinical parameters, Dr. Geremakis noted. Thus, additional research may be required to further validate these study findings. “However, this type of real-world research continues to build on the knowledge base in the scientific community,” she said.
Expert Takeaways
Analyzing real-world prescribing data for patient outcomes is always helpful, said Leslie Myers, PharmD, IgCP, an independent Ig expert who was not involved in the study, in an interview. However, she agreed that the study’s use of claims data does not yield a complete picture. Questions include why the patients stopped therapy, whether because of insurance constraints or pharma incentives, she noted. More information on each patient/data set could yield clarification, in addition to other insights.
“Also, the population chosen, adult PIDD patients, can sometimes be a challenging one [to analyze], depending on when they were diagnosed,” Dr. Myers said. Patients diagnosed at an early age, for example, become accustomed to therapy and enjoy the independence of subcutaneous Ig once they can self-administer, she explained.
Some barriers to Ig home therapy that might have prompted discontinuation include fear of self-infusion, dexterity, visual difficulty and the ability to self-manage supplies and resources needed to complete the infusion, Dr. Myers noted. However, she added that most of these barriers can be overcome by additional teaching if patients are willing to push through.
“Dexterity and visual difficulties are slightly harder to overcome,” Dr. Myers said. Additional teaching mechanisms for administration can help with dexterity—such as different types of pumps or prefilled syringes—but they are not available for all products, she noted. However, simply placing a blank white piece of paper behind the syringe can make it easier to see markings, she added.
As for the decline in infections documented in the current study, “it’s to be expected,” Dr. Myers said. She added, however, that it shines light on the need for more information to determine why patients discontinue Ig therapy at home against doctors’ orders, and how clinicians can help prevent it.
The sources reported no relevant financial disclosures.
