Zorzi et al. compared the effectiveness of infliximab (IFX) and adalimumab (ADA) in 93 Crohn's disease (CD) patients. No differences were found in obtaining and maintaining remission, as well as steroid-sparing effects with IFX vs. ADA. Although interesting, these data are from a national referral centre. Data from primary care are still lacking.
We studied our population suffering from CD and naïve to anti-tumour necrosis factor-alpha (TNFα) therapy from January 2005 to December 2011. Forty-four patients (20 IFX and 24 ADA) were managed as out-patients in two primary care centres in South Italy (Apulia region). Disease activity was assessed by Harvey-Bradshaw Index (HBI): clinical response was defined as reduction of the HBI score ≥5 points from baseline value. Clinical remission was defined as HBI score ≤5 points. Loss of response was defined as an increase in HBI score >5 points from the last value, despite intensified infusion regimens.
Induction was completed in 18 (90%) patients in the IFX group and in all patients in the ADA group. At the end of induction, clinical remission was achieved in 16/18 (88.9%) patients in the IFX group and in four (16.7%) in the ADA group (P = 0.0001). In the remaining 20 patients in the ADA group, 18 patients had clinical response (HBI reduction ≤5 points) at the end of the induction regimen, and achieved clinical remission after a median (range) of 3 (2–6) months. Two patients did not obtain clinical remission and underwent surgery 6 and 12 months after starting therapy with ADA.
All IFX patients (18/20) and ADA patients (22/24) obtaining clinical remission/clinical response underwent scheduled treatment to maintain/obtain remission. Patients were followed up for a median of 18 (range: 6–72) months. In particular, median follow-up was 39 (range: 8–72) months in IFX group and 12 (4–48) months in ADA group. No statistically significant difference was found between the two groups at the end of follow-up (P = 0.341) (see Figure 1).
After univariate analysis, positive predictors of clinical remission were HBI <10 (P = 0.039), and the presence of mild or moderate inflammation at endoscopy (P = 0.013). On the contrary, no characteristics of patients at inclusion influenced the persistence either of clinical remission or mucosal healing during follow-up. Finally, both drugs were safe, with mild adverse events in only 6.8% of the overall population (10.0% of IFX, and 4.2% of ADA), and did not require suspension of treatment. This favourable safety profile may be explained by more severe disease treated by secondary-tertiary centres, and patients taking multiple therapies with higher risk of drug-induced reactions.
The strength of these data is that they come from primary care, and that we found for the first time that IFX seems to be faster than ADA in obtaining clinical remission, even if no difference between these biologics was found in long-term maintenance of clinical remission. Our results are similar to those of Zorzi et al., confirming that the effectiveness of these antibodies is similar in both primary and secondary-tertiary centres.