Secular Trends in the Cost of Immunosuppressants after Solid Organ Transplantation in the United States

Abstract

Background and objectives: Immunosuppressive medications are critical for maintenance of graft function in transplant recipients but can represent a substantial financial burden to patients and their insurance carriers.

Design, setting, participants, & measurements: To determine whether availability of generic immunosuppressive medications starting in 2009 may have alleviated some of that burden, we used Medicare Part D prescription drug events between 2008 and 2013 to estimate the average annualized per-patient payments made by patients and Medicare in a large national sample of kidney, liver, and heart transplant recipients. Repeated measures linear regression was used to determine changes in payments over the study period.

Results: Medicare Part D payments for two commonly used immunosuppressive medications, tacrolimus and mycophenolic acid (including mycophenolate mofetil and mycophenolate sodium), decreased overall by 48%-67% across organs and drugs from 2008 to 2013, reflecting decreasing payments for brand and generic tacrolimus (21%-54%), and generic mycophenolate (72%-74%). Low-income subsidy payments, which are additional payments made under Medicare Part D, also decreased during the study period. Out-of-pocket payments by patients who did not receive the low-income subsidy decreased by more than those who did receive the low-income subsidy (63%-79% versus 24%-44%).

Conclusions: The decline in payments by Medicare Part D and by transplant recipients for tacrolimus and mycophenolate between 2008 and 2013 suggests that the introduction of generic immunosuppressants during this period has resulted in substantial cost savings to Medicare and to patients, largely reflecting the transition from brand to generic products.

Keywords: Cost Savings; Drugs, Generic; Health Expenditures; Heart Transplantation; Immunosuppressive Agents; Insurance Carriers; Linear Models; Medicare Part D; Mycophenolic Acid; Prescription Drugs; Transplant Recipients; end-stage renal disease; heart disease; liver failure; tacrolimus; transplantation, kidney.

Graphical abstract

Figure 1.

Trends in Medicare Part D payments from 2008–2013. Average annualized Medicare Part D plan payments (2013 US dollars) for overall, brand-name, and generic (A) tacrolimus and (B) mycophenolic acid by organ type.

Figure 2.

Trends in low-income subsidy payments from 2008–2013. Average annualized payments (2013 US dollars) by the Medicare Part D low-income subsidy program for overall, brand-name, and generic (A) tacrolimus and (B) mycophenolic acid by organ type. Patients not receiving the low-income subsidy were excluded from this analysis.

Figure 3.

Trends in non-low-income subsidy patient payments from 2008–2013. Average annualized out-of-pocket payments (2013 US dollars) by patients not receiving the low-income subsidy for overall, brand-name, and generic (A) tacrolimus and (B) mycophenolic acid by organ type. Patients receiving the low-income subsidy were excluded from this analysis.

Figure 4.

Trends in low-income subsidy patient payments from 2008–2013. Average annualized out-of-pocket payments (2013 US dollars) by patients receiving the low-income subsidy for overall, brand-name, and generic (A) tacrolimus and (B) mycophenolic acid by organ type. Patients not receiving the low-income subsidy were excluded from this analysis.