Demographics and baseline clinical features of enrolled patients
Among the 123 RA patients screened, 117 entered to the induction stage with a median age of 58.4 years and 81.2% female. 67 patients achieved DAS28-CRP<3.2 within 12 weeks after initiating MTX and TNFi treatment and then were randomized. There were 24, 21 and 22 patients in group A, B and C in the randomization stage, respectively (Figure 1). 50 patients failed in entering the randomization stage due to adverse events (4 patients), lost to follow up (1 patients), protocol violation (1 patients) and no achievement of DAS28-CRP<3.2 (44 patients). During 60-week follow-up in randomization stage, there were 5 patients dropped out (Figure 1). The baseline demographics and clinical features of 67 enrolled patients are demonstrated in Table 2.
Table 2
Comparison of baseline characteristics and outcomes among patients of the three groups in the randomization stage.
| Group A (n=24) | Group B (n=21) | Group C (n=22) | P value |
Age [year, median (min-max)] | 59.7 (22-72) | 59.9 (31-70) | 53.04 (29-72) | 0.327 |
Gender (F%) | 18 (75.0%) | 17 (81.0%) | 13 (59.1%) | 0.260 |
BMI (mean±SD) | 23.3±3.1 | 23.6±3.3 | 24.1±4.5 | 0.787 |
Disease duration [months, median (min-max)] | 37 (6-253) | 64 (12-300) | 81 (7-336) | 0.080 |
TJC [median (min-max)] | 2(0-5) | 1.5(0-6) | 1(0-5) | 0.434 |
SJC [median (min-max)] | 1(0-4) | 0.5(0-2) | 0(0-3) | 0.194 |
PGA [median (min-max)] | 20 (10-45) | 30 (5-70) | 20 (0-50) | 0.099 |
EGA [median (min-max)] | 20 (10-45) | 30 (10-70) | 20 (0-50) | 0.105 |
ESR [median (min-max)] | 18(2-100) | 15(4-46) | 19(2-45) | 0.889 |
CRP [median (min-max)] | 3.01(1.22-30.7) | 3.3(1.59-34.28) | 4.18(1.14-60.1) | 0.814 |
RF [IU/ml, median (min-max)] | 161(0-1930) | 31.2(0-1010) | 50.8(0-3414) | 0.191 |
Anti-CCP | 20 (90.9%) | 17 (85%) | 18 (90%) | 0.819 |
DAS28-CRP [median (min-max)] | 2.88(1.71-3.19) | 2.97(1.81-3.19) | 2.74(1.34-3.19) | 0.728 |
DAS28-ESR (mean±SD) | 3.20±0.54 | 3.06±0.63 | 2.79±0.93 | 0.247 |
SDAI [median (min-max)] | 8.71(2.45-12.55) | 9.40(3.23-16.16) | 7.51(0.18-4.14) | 0.089 |
CDAI [median (min-max)] | 8.5(2-12) | 8.75(3-16) | 6(0-14) | 0.056 |
HAQ (mean±SD) | 3.5(0-55) | 5.5(0-21) | 1(0-16) | 0.081 |
EQ-5D | 0.869(0.505-0.961) | 0.826(0.505-0.961) | 0.872(0.591-0.961) | 0.321 |
PD [median (min-max)] | 0(0-4) | 1.5(0-27) | 0.5(0-5) | 0.030 |
GS [median (min-max)] | 3.5(0-15) | 4(0-40) | 2.5(0-23) | 0.263 |
Relapse | 9 (40.9%) | 7 (35%) | 17 (85%) | 0.001 |
Duration of LDA/remission before relapse (weeks) | 44.2±20.5 | 40.5±23.9 | 25.1±16.3 | 0.010 |
Sharp Score Progression | | | | |
BE | 0(0-2) | 0(0-3) | 0.5(0-6) | 0.179 |
JSN | 1(0-3) | 1(-1-7) | 1(-1-8) | 0.751 |
mTSS | 1(0-4) | 1(-1-9) | 1.5(-1-14) | 0.938 |
Note: BMI: body mass index; TJC: tender joint count; SJC: swollen joint count; PGA: patient global assessment; EGA: evaluator global assessment; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; RF: rheumatoid factor; anti-CCP: anti-cyclic citrullinated protein; DAS: disease activity score; SDAI: simplified disease; activity index; CDAI: clinical disease activity index; HAQ-DI: Health Assessment Questionnaire-Disability Index; EQ-5D: Euro Qol five dimension questionnaire; PD: power Doppler; GS: gray scale; LDA: low disease activity; BE: bone erosion; JSN: joint space narrow; mTSS: mean total sharp score. |
Predictive factors for achievement of LDA with TNFi and MTX treatment within 12 weeks
Sixty-seven out of 117 (57.3%) patients achieved LDA after initiating TNFi plus MTX treatment within 12 weeks. Comparing with 44 patients who did not achieve LDA, the patients who achieved LDA had lower proportion of female, shorter disease duration, fewer baseline TJC, lower baseline disease activity and lower baseline HAQ-DI (Table 3). Multiple logistic regression analysis showed that male gender and few TJC were predictive factors for the achievement of LDA with TNFi and MTX treatment within 12 weeks (Table S2).
Table 3
Comparison of baseline characteristics between patients achieved and not achieved DAS28-CRP<3.2 in the induction stage.
| Total patients enrolled in the induction stage (n=111) | Patients achieved DAS28-CRP<3.2 (n=67) | Patients not achieved DAS28-CRP<3.2 (n=44) | P value |
Age [year, median (min-max)] | 58.4(22-72) | 59.0(22-72) | 57.0(24-72) | 0.356 |
Gender (F%) | 91 (81.2%) | 48 (71.6%) | 43 (97.7%) | 0.001 |
BMI (mean±SD) | 23.8±3.8 | 23.6±3.6 | 23.9±4.0 | 0.578 |
Disease duration [months, median (min-max)] | 76(6-408) | 62(6-336) | 114(6-408) | 0.053 |
TJC [median (min-max)] | 10(1-28) | 8(2-18) | 12.5(1-28) | 0.002 |
SJC [median (min-max)] | 4(0-21) | 4(0-21) | 5(0-18) | 0.095 |
PGA [median (min-max)] | 60 (20-90) | 60 (20-90) | 70 (20-90) | 0.354 |
EGA [median (min-max)] | 60 (10-90) | 50 (10-90) | 60 (20-90) | 0.058 |
ESR [median (min-max)] | 33(2-170) | 4(2-105) | 33(6-170) | 0.345 |
CRP [median (min-max)] | 15.0(1.27-143) | 14.7(1.27-104) | 14.9(1.42-138) | 0.693 |
RF positive (%) | 81 (73.0%) | 48 (71.6%) | 33 (75%) | 0.697 |
Anti-CCP positive (%) | 96 (86.5%) | 60 (89.6%) | 36 (81.8%) | 0.371 |
DAS28-CRP [median (min-max)] | 5.11(3.41-7.89) | 4.74(3.50-7.89) | 5.47(3.41-7.47) | 0.004 |
DAS28-ESR (mean±SD) | 5.68±1.15 | 5.41±1.12 | 6.05±1.10 | 0.004 |
SDAI [median (min-max)] | 27.42(10.76-69.39) | 24.46(11.48-69.39) | 35.85(10.76-62.6) | 0.003 |
CDAI [median (min-max)] | 26(9-62) | 24(10-62) | 33(9-57) | 0.004 |
HAQ-DI (mean±SD) | 1.03±0.60 | 0.90±0.57 | 1.25±0.60 | 0.003 |
PD [median (min-max)] | 2 (0-38) | 2 (0-38) | 2 (0-20) | 0.710 |
GS [median (min-max)] | 6 (0-56) | 5 (0-56) | 6 (0-37) | 0.312 |
Note: BMI: body mass index; TJC: tender joint count; SJC: swollen joint count; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; RF: rheumatoid factor; anti-CCP: anti-cyclic citrullinated protein; DAS: disease activity score; SDAI: simplified disease; activity index; CDAI: clinical disease activity index; HAQ-DI: Health Assessment Questionnaire-Disability Index; |
The clinical features of patients at randomization and their clinical outcomes in three groups
Eventually, 67 patients entered the randomization stage, with a median age of 59 years and 71.6% female. At randomization, their clinical features were similar among three groups, except for a bit higher PD score in group B. During follow-up of 60 weeks, relapse was observed in 10/22 (45.5%), 7/20 (35%) and 17/20 (85%) patients in three groups, respectively (Figure 2). The relapse rates in group A and group B were comparable (p=0.491), however both higher than that in group C (p=0.019, p=0.004, respectively). Interestingly, the LDA maintenance duration before relapse was significantly shorter in group B than that in group A and group C (9.5±5.3 weeks vs. 21.2±10.0 weeks, p=0.014; 9.5±5.3 weeks vs.19.0±7.0 weeks, p=0.004), although no difference was found between group A and group C (p=0.623).
For those patients who did not relapse, the disease activity assessed by DAS28-CRP, DAS28-ESR, CDAI and SDAI, as well as HAQ-DI and EQ-5D was all comparable among three groups at week 60 (Table S3).
The radiological outcomes of the patients in three groups
The modified Sharp score was evaluated by X-ray of bilateral wrists and hands. The bone erosion score, joint space narrowing score and modified total sharp score were comparable among three groups at baseline. The changes of all these radiological scores at the end of week 60 from baseline were similar among three groups.
48 out of 67 patients received ultrasound examination at randomization and 20 non-flared patients received repeated ultrasound scan at week 60. Overall, the proportion of patients with PD synovitis was significantly decreased (p=0.010), but not with GS synovitis (p=0.294). Further analysis in separate groups showed that both total PD score and GS score were significantly decreased in patients of group B and the proportion of patients with PD synovitis was also significantly decreased in group B only (p<0.001) (Table S4). In patients of group A, only GS score was decreased, whereas, neither PD nor GS synovitis was improved in patients of group C (Table S5).
The cost-effectiveness and cost-utility analysis among three groups
Direct cost-effectiveness analysis and total cost-effectiveness analysis are shown in Figure S3. The cost-effectiveness and cost-utility analysis for the three therapeutic strategies are presented in Table S6 and Table S7. The triple therapy had the lowest average direct cost-effectiveness ratio, total cost-effectiveness ratio, direct cost-utility ratio and total cost-utility ratio. Compared to MTX monotherapy, both TNFi maintenance and triple therapy had cost-effectiveness, but only triple therapy had cost-utility, when ¥100000 was taken as the threshold of willingness to pay (WTP). Compared to triple therapy, TNFi maintenance therapy had neither cost-effectiveness nor cost-utility.
The tornado analysis indicated that the most influential parameter was the cost of TNFi. The ICER was decreased from ¥3.0 million per QALY to ¥0.278 million per QALY if the cost of TNFi was reduced from ¥1300 to ¥100 per week (Figure S4).
TNFi maintenance therapy would gain better net monetary benefit of utility when the TNFi cost per week was reduced to ¥130.54 or less (Figure S5), and better net monetary benefit of effectiveness (evaluated by relapse-free rate) when the weekly cost was ¥399.16 or less (Figure S6).
The adverse effects
All the 117 patients were included for the safety analysis. There were 62 (55.6%) patients with various adverse events, including elevated aminotransferase (27, 23.1%), upper respiratory tract infection (18, 15.4%), rash (14, 12.0%), gastro-intestinal symptoms (10, 8.5%), leukocytopenia (8, 6.8%), pruritus (6, 5.1%), urinary tract infection (2, 1.7%), pneumonia (2, 1.7%), and hyperlipidemia, periodontitis, edema of lower extremities, herpes zoster, anemia, new onset hypertension (1 each, 0.9%), respectively. In the induction stage, 4 patients withdrew from the study due to adverse events (1each with pneumonia, severe skin allergy, herpes zoster, and liver damage with leukocytopenia). No severe adverse events were observed.
Among the 67 patients enrolled into the randomization stage, adverse reactions were observed in 37 (55.2%) patients, which was similar to that in total safety set. Most adverse effects were comparable among the three groups, except for more frequent gastro-intestinal symptoms in patients of group A than group B [p=0.011] and group C [p=0.001] (Table 4). No dropout due to adverse events occurred in the randomization stage.
Table 4
Adverse effect among the three groups.
| Group A (n=24) | Group B (n=21) | Group C (n=22) | P value |
Total adverse events | 12 (50%) | 12 (57.2%) | 13 (59.1%) | 0.807 |
Liver damage | 5 (20.8%) | 7 (33.3%) | 6 (27.3%) | 0.640 |
Upper respiratory tract infection | 3 (12.5%) | 7 (33.3%) | 6 (27.3%) | 0.217 |
Rash | 1 (4.2%) | 1 (4.8%) | 2 (9.1%) | 0.761 |
Gastrointestinal involvement | 8 (33.3%) | 1 (4.8%) | 0 | 0.001 |
Pruritus | 1 (4.2%) | 1 (4.8%) | 1 (4.5%) | 0.995 |
Leukocytopenia | 3 (12.5%) | 2 (9.5%) | 1 (4.5%) | 0.615 |
Urinary tract infection | 0 | 1 (4.8%) | 1 (4.5%) | 0.405 |
Anemia | 1(4.2%) | 0 | 0 | 0.353 |
Hyperlipide | 0 | 0 | 1 (4.5%) | 0.323 |
Paradentitis | 0 | 0 | 1 (4.5%) | 0.323 |