Session Information
Session Type: Abstract Submissions (ACR)
Background/Purpose: The ADACTA trial found that biologic naïve patients with severe active RA who are methotrexate (MTX) intolerant or in whom continued MTX treatment is inappropriate, achieved a significant benefit after 24 weeks on tocilizumab (TCZ) 8mg/kg IV every 4 weeks monotherapy vs. 40mg adalimumab (ADA) every 2 weeks monotherapy. The objective of our study was to estimate the cost-effectiveness of TCZ vs. ADA used as monotherapy (mono) for RA from the U.S. payer perspective.
Methods: We compared treatment initiation with TCZ (8mg/kg every 4 weeks) mono vs. two different dose regimens of ADA mono: 1) 40mg weekly, 2) 40mg every 2 weeks. Efficacy for TCZ and ADA every 2 weeks was obtained from ADACTA. Efficacy for ADA weekly was estimated by adjusting upward the ADA response in ADACTA, using a ratio of response rates for ADA weekly:ADA every 2 weeks derived from the 2004 van de Putte et al. study, which evaluated both doses of ADA mono. For the 6-month trial period, we calculated the incremental cost per additional ACR20, 50, 70 responder, and low disease activity score (LDAS) achieved for TCZ vs. ADA (“6-month model”). We also used a patient-level simulation model (10,000 patients, 2,000 simulations) to estimate the lifetime incremental cost per quality-adjusted life year (QALY) of initiating treatment with TCZ vs. ADA mono (“life-time model”). In this model, both drugs are followed by an etanercept-certolizumab-palliative care sequence. Non-responders discontinue at 6 months; responders experience a constant probability of discontinuation thereafter. Discontinued patients go to the next treatment in the sequence. Trial-based ACR responses are linked to changes in HAQ scores at 6 months. HAQ remains constant while on biologics and is mapped to utility to estimate QALYs using pooled data from TCZ trials (Diamantopoulos 2012). Costs are derived from published sources and include drug treatment, monitoring, and direct medical resource utilization (derived from HAQ score; Kobelt 1999). Costs and QALYs were discounted at 3%. Sensitivity analyses were performed to test the robustness of the model results.
Results: In the 6-month and lifetime models, TCZ 8mg/kg mono had higher ACR response rates and QALYs, respectively, and lower costs compared with ADA mono 40mg weekly (Table). Compared with ADA 40mg every 2 weeks, the 6-month incremental cost for TCZ ranged from $2,077 per additional LDAS achiever to $4,509 per additional ACR70 responder; in the lifetime model the incremental cost-effectiveness ratio was $49,195/QALY. Based on one-way sensitivity analyses, model results were most sensitive to changes in drug costs and ACR response rates.
Conclusion: TCZ (8mg/kg every 4 weeks) mono dominates (more effective and less costly) ADA (40mg weekly) mono and is cost-effective compared to ADA (40mg every 2 weeks) mono, from a US payer perspective, in patients with severe RA for whom methotrexate treatment is not appropriate.
|
TCZ Monotherapy |
ADA Monotherapy |
Difference: TCZ Mono-ADA mono |
Incremental Cost-effectiveness Ratio (ICER) |
|
|
Comparison 1: Life-time Cost/QALY for TCZ Mono 8mg/kg every 4 weeks vs. ADA Mono 40mg every week |
||||
|
Costs |
$202,707 |
$270,779 |
($68,072) |
|
|
Life-years |
16.13 |
16.09 |
0.04 |
|
|
QALYs |
7.49 |
7.35 |
0.14 |
TCZ Dominates ADA weekly (more effective, less costly) |
|
Comparison 1a: 24-week ICERs for clinical outcomes- TCZ Mono 8mg/kg every 4 weeks vs. ADA Mono 40mg every week |
||||
|
Costs |
$13,758 |
$25,512 |
($11,754) |
|
|
ACR20 |
65% |
57% |
8% |
TCZ Dominates ADA weekly (more effective, less costly) |
|
ACR50 |
47% |
44% |
3% |
|
|
ACR70 |
33% |
27% |
6% |
|
|
Comparison 2: Life-time Cost/QALY for TCZ Mono 8mg/kg every 4 weeks vs. ADA Mono 40mg every 2 weeks |
||||
|
Costs |
$202,707 |
$186,064 |
$16,643 |
|
|
Life-years |
16.13 |
16.05 |
0.08 |
|
|
QALYs |
7.49 |
7.15 |
0.34 |
$49,195/QALY |
|
Comparison 2a: 24-week ICERs for clinical outcomes- TCZ Mono 8mg/kg every 4 weeks vs. ADA Mono 40mg every 2 weeks |
||||
|
Costs |
$13,758 |
$13,100 |
$658 |
|
|
ACR20 |
65% |
49% |
16% |
$4,220/ACR20 resp |
|
ACR50 |
47% |
28% |
19% |
$3,393/ACR50 resp |
|
ACR70 |
33% |
18% |
15% |
$4,509/ACR70 resp |
|
LDAS |
52% |
20% |
32% |
$2,077/LDAS |
Disclosure:
J. J. Carlson,
Genentech, Inc,
5;
S. Ogale,
Genentech, Inc.,
3;
F. Dejonckheere,
Roche Pharmaceuticals,
3;
S. Sullivan,
Genentech, Inc,
5.
« Back to 2012 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/cost-effectiveness-of-tocilizumab-monotherapy-vs-adalimumab-monotherapy-in-the-treatment-of-severe-active-rheumatoid-arthritis/