Conference: 2010 International PHA Conference and Scientific Sessions
Release Date: 06.24.2010
Presentation Type: Abstracts
Beckmann J1, Lynch J2, Purl H3, Emerson E4, Allen A5, Frutiger K6, Traiger G7.
1. Harbor UCLA Medical Center, Torrance, CA, USA
2. Arizona Pulmonary Specialists, Phoenix, AZ, USA
3. Baylor College of Medicine, Houston, TX, USA
4. Gilead Sciences, Foster City, CA, USA
5. University California at Davis Medical Center, Sacramento, CA, USA
6. University of Rochester, Rochester, NY, USA
7. University of California, Los Angeles, Los Angeles, CA, USA
PURPOSE: To assess whether LabSync provides an indirect benefit of improving 12 month persistency rates in those taking AMBRISENTAN for pulmonary arterial hypertension.
BACKGROUND: AMBRISENTAN is a selective endothelin receptor antagonist (ERA) indicated for the treatment of PAH. Like all ERA therapies, Ambrisentan is available only through a special restricted distribution program that requires monthly liver function tests for all patients and monthly pregnancy tests for female patients of childbearing potential. LabSync is a voluntary, web-based service designed to assist health care providers with the monthly laboratory work associated with Ambrisentan treatment. LabSync facilitates communication with patients, physicians and laboratory facilities to coordinate lab orders, resolve insurance issues, send patient appointment reminders, and provide lab results directly to office staff. The Ambrisentan Education and Access Program (LEAP) supports patients using Ambrisentan but not necessarily using LabSync. A previous retrospective 9 month study showed that patients enrolled in LabSync had more days on therapy and fewer missed refills than those not enrolled (Beckmann J et al., 2009 PH Research Network Symposium). A second analysis of the LabSync database was conducted to further understand Ambrisentan persistency of patients enrolled in the program for up to 12 months.
METHODS: An independent, retrospective analysis of patients enrolled in LabSync and control subjects on Ambrisentan but not enrolled in LabSync was conducted to look at persistency of use with ambrisentan therapy. Patients were divided into those with at least 6 months of therapy and those with 12 or more months of therapy as of December 2009. Patients were matched for age, gender, geographic location, treatment center, total number of shipments received, days since most recent shipment (prior to LabSync enrollment), and LEAP enrollment month. The percentage of patients within a cohort remaining on therapy after 12 months was defined as the persistency rate, and the total number of patients on Ambrisentan therapy at any given month was defined as the on-therapy rate. Subgroup analyses were performed for those patients new to therapy and for patients who received care outside of a PH specialty center.
RESULTS: The matched cohorts included 628 LabSync patients and 1251 control patients with 6 months of data, and 328 LabSync patients and 659 control patients with 12 months of data. At month 12, 84% of LabSync vs 73% of control patients were on therapy (p = 0.0002). Of the patient cohort whose persistency was tracked, 78% of LabSync patients vs 57% of control patients remained on therapy after 12 months (p=0.0069). LabSync patients also missed fewer refills than control patients (5.4% vs 10.7%; p = 0.006). Furthermore, 77% of new LabSync patients were on AMBRISENTAN therapy at month 12, compared to 61% of controls (p = 0.0015). LabSync patients who received care outside of a PH specialty center had higher on-therapy rates at month 6 (90% vs 80%; p = 0.0047) compared to matched controls.
CONCLUSIONS: Patients enrolled in LabSync showed greater persistency with Ambrisentan as evidenced by more days on therapy and fewer missed refills compared to those not enrolled. This effect was preserved out to 12 months. Building on previous findings that compliance improvements were seen regardless of age and sex (Beckmann J et al., 2009 PH Research Network Symposium), this analysis demonstrates that enrollment in LabSync may be beneficial to populations of patients where compliance is especially critical, including patients just starting Ambrisentan therapy and those who receive care outside of a PH specialty center which may not have the same resources to support patients. Future research on whether LabSync helps to improve outcomes of this serious and progressive disease should be considered.