Add-back therapy use and its impact on LA persistence in patients with endometriosis

Abstract

Objectives:

Persistence and compliance in women with endometriosis who are receiving gonadotropin-releasing hormone agonists (GnRH-a) may be limited by its hypoestrogenic side effects. Use of concomitant therapy with norethindrone acetate (NA), estrogen, estrogen/progestin combinations, or other progestin (i.e., ‘add-back therapy’ [ABT]) is recommended to alleviate these side effects. This retrospective study evaluated ABT utilization and its effect on compliance and persistence in patients with endometriosis taking the GnRH-a leuprolide acetate (LA) depot suspension.

Methods:

A retrospective analysis of a large pharmacy claims database identified patients who started LA therapy from 2002 to 2004 for the treatment of endometriosis. Patients were identified as having received ABT if they started 7 days before, or within 45 days of the last LA fill.

Results:

A total of 1285 women with endometriosis who began using LA were identified with 12 months of evaluable data: 211 (16.4%) used concomitant NA therapy, 116 (9.0%) used concomitant estrogen-based therapy, 28 (2.2%) used concomitant combination estrogen- and progestin-based therapies, 56 (4.4%) used concomitant progestin-based therapy, and 874 (68.0%) did not use any ABT. Mean (±SD) LA persistence in women receiving NA-based ABT was 5.83 ± 2.98 months, compared with 4.25 ± 2.62 months for those not using ABT (P < 0.0001). Average medication possession ratio was 0.43 ± 0.20 for women receiving NA-based ABT versus 0.32 ± 0.18 for those not receiving any ABT (P < 0.0001). Patients < 30 years of age were most likely to continue therapy longer and have greater compliance compared with the older age group cohorts (P < 0.01). Patients who used ABT continued to do so for 3.79 ± 3.21 months.

Limitations:

Limitations of this study include those associated with the use of retrospective claims databases: It does not include any information regarding the patient’s pain symptoms, disease severity, or other factors, which could correlate to compliance and persistence.

Conclusions:

Among women using LA therapy for endometriosis, only 32% used any type of ABT, and these patients had significantly higher persistence and compliance with LA therapy compared to no ABT user group.

Key words::

• Add-back therapy
• Endometriosis
• Hormones
• Leuprolide acetate
• Medication adherence
• Medication compliance
• Norethindrone acetate
• Retrospective studies

Transparency

Declaration of funding

This article was funded through a grant from TAP Pharmaceutical Products Inc., Lake Forest, IL, USA, which became part of Abbott Laboratories, Abbott Park, IL, USA.

Declaration of financial/other relationships

M.J.F., S.E.M., and K.C. have disclosed that they are employees of Abbott and have also disclosed that they are Abbott stockholders. M.J.F. and K.C. were employees of TAP at the initiation of this project. R.A.B. and J.E.S. have disclosed that they have served as consultants to Abbott and TAP in conjunction with this research.

Some peer reviewers receive honoraria from CMRO for their review work. The peer reviewers of this paper have disclosed that they have no relevant financial relationships.

Acknowledgment

The authors have disclosed that they had no outside editorial assistance in preparing this manuscript.

All authors provided input to the study design and interpretation of results, and reviewed and commented on drafts of the manuscripts. R.A.B. and M.J.F. conducted the analysis and developed the initial drafts of the manuscript.