normal distribution to calculate the probability (P-value) that our hypothesis is correct. To claim statistical significance of our results we required the P-value to be less than 0.05. Our study considered a total of 32 patients (24 males, 8 females, mean age, 51±13 years), whose 20 (18 males, 2 females, mean age, 54±15 years) received infliximab at longer intervals (10 weeks) and 12 (6 males, 6 females, mean age, 54±15 at the standard intervals (8 weeks). Among all these patients, the total relapses observed were 7 (22%).The group who received the treatment every 10 weeks showed a higher percentage (25%) of relapses, while in the second group, who received the treatment at standard intervals, only 2 patients had a worsening of psoriasis (17%). However, the calculated P-value was 0.28, so this difference cannot be considered statistically signi cant. Moreover, the presence of comorbidities is equally distributed across the two populations and cannot associated with an increased risk of relapses (Table 1). Patients in the group with prolonged interval administrations that experienced relapses returned to the conventional dose regime. None of the patients of the 10-week interval group received other treatments (such as methotrexate or acitretin) and no adverse ef- fects were reported among the two groups. The total annual cost for the drug administered at 10-week interval was 10,214 euros versus 12,732 euros of the drug at standard intervals, with total savings of 2,518 euros (19.8%) per year. Our results demonstrated that infliximab could be down-titrated without a significant increase risk of relapses. This is in contrast to previous studies about off-label use of other anti-TNF therapies in psoriasis, which demonstrated an important loss of effectiveness following the reduction of the treatment dose.2 Although the prolongation of infliximab’s dose intervals for psoriatic patients has not been investigated, rheumatologic studies showed that a dose reduction (ie, 3 mg/kg instead of 5 mg/kg) could sustain the treatment effects in low disease activity patients.1,3,4 Besides the previously demonstrated economical savings and the predictable long-term safety improvement (ie, increased risk of infection and non-melanoma skin cancer),5 the main advantage of this administration method may be the improving of the patient’s quality of life. Callis Duf n et al. showed that infliximab is one of the less appreciated drug by most patients,6 because it requires frequent hospitalizations. So, for patients with a low disease activity, it may be suitable prolonging the dose intervals. Limitations of our study include the retrospective non-interventional nature and the absence of a control group with the same patient characteristics (PASI 0 for 12 months). However, the PASI90 control group can be considered almost completely healed. Although not investigated in our study, the infliximab down-titration may have some undesirable effects, such as an increase in disease activity in the long term and the development of anti-drug antibodies. In fact, a serum concentration of an anti-TNF agent under the optimal levels seems to be associated to an increasing of antidrug antibody formation, even though it has not been clearly demonstrated.7 To our knowledge, there are no data so far about the effectiveness and safety of the infliximab down-titration in psoriatic patients. So, even if other prospective and interventional studies should be performed, the prolongation of infliximab’s dose intervals could Down-Titration of Infliximab:The Real-Life Use in Psoriatic Patients
December 2016 | Volume 15 | Issue 12 | Editorials | 1584 | Copyright © December 2016
Federico Bardazzi MD,a Camilla Loi MD,a Francesca Prignano MD,b Federica Ricceri MD,b Ferdinando Giordano PhD,c Annalisa Patrizi MD,a and Michela Magnano MDa
aDepartment of Specialized, Clinical and Experimental Medicine, Division of Dermatology, University of Bologna, Italy bDepartment of Medical-Surgical Critical Area, Section of Clinical, Preventive and Oncological Dermatology, University of Florence, Italy cDepartment of Physics, University of Catania and INFN, Italy
normal distribution to calculate the probability (P-value) that our hypothesis is correct. To claim statistical significance of our results we required the P-value to be less than 0.05. Our study considered a total of 32 patients (24 males, 8 females, mean age, 51±13 years), whose 20 (18 males, 2 females, mean age, 54±15 years) received infliximab at longer intervals (10 weeks) and 12 (6 males, 6 females, mean age, 54±15 at the standard intervals (8 weeks). Among all these patients, the total relapses observed were 7 (22%).The group who received the treatment every 10 weeks showed a higher percentage (25%) of relapses, while in the second group, who received the treatment at standard intervals, only 2 patients had a worsening of psoriasis (17%). However, the calculated P-value was 0.28, so this difference cannot be considered statistically signi cant. Moreover, the presence of comorbidities is equally distributed across the two populations and cannot associated with an increased risk of relapses (Table 1). Patients in the group with prolonged interval administrations that experienced relapses returned to the conventional dose regime. None of the patients of the 10-week interval group received other treatments (such as methotrexate or acitretin) and no adverse ef- fects were reported among the two groups. The total annual cost for the drug administered at 10-week interval was 10,214 euros versus 12,732 euros of the drug at standard intervals, with total savings of 2,518 euros (19.8%) per year. Our results demonstrated that infliximab could be down-titrated without a significant increase risk of relapses. This is in contrast to previous studies about off-label use of other anti-TNF therapies in psoriasis, which demonstrated an important loss of effectiveness following the reduction of the treatment dose.2 Although the prolongation of infliximab’s dose intervals for psoriatic patients has not been investigated, rheumatologic studies showed that a dose reduction (ie, 3 mg/kg instead of 5 mg/kg) could sustain the treatment effects in low disease activity patients.1,3,4 Besides the previously demonstrated economical savings and the predictable long-term safety improvement (ie, increased risk of infection and non-melanoma skin cancer),5 the main advantage of this administration method may be the improving of the patient’s quality of life. Callis Duf n et al. showed that infliximab is one of the less appreciated drug by most patients,6 because it requires frequent hospitalizations. So, for patients with a low disease activity, it may be suitable prolonging the dose intervals. Limitations of our study include the retrospective non-interventional nature and the absence of a control group with the same patient characteristics (PASI 0 for 12 months). However, the PASI90 control group can be considered almost completely healed. Although not investigated in our study, the infliximab down-titration may have some undesirable effects, such as an increase in disease activity in the long term and the development of anti-drug antibodies. In fact, a serum concentration of an anti-TNF agent under the optimal levels seems to be associated to an increasing of antidrug antibody formation, even though it has not been clearly demonstrated.7 To our knowledge, there are no data so far about the effectiveness and safety of the infliximab down-titration in psoriatic patients. So, even if other prospective and interventional studies should be performed, the prolongation of infliximab’s dose intervals could 
