Safety and Efficacy of Tofacitinib vs Methotrexate in the Treatment of Psoriatic Arthritis

Title Safety and Efficacy of Tofacitinib vs Methotrexate in the treatment of Psoriatic Arthritis- An Open Label Randomized single center study Psoriatic arthritis is defined as an inflammatory arthropathy associated with skin psoriasis and usually negative for rheumatoid factor. Till date, many NSAIDs, corticosteroids, DMARDs have been used, but the safety and efficacy issues demands more researches. The prevalence of PsA worldwide is about 1%-2% and among patients with psoriasis ranges from 7% to 42%. The pathogenesis of PsA involves many cytokines. Tofacitinib is an oral Janus Kinase (JAK) inhibitor with immunomodulatory and anti-inflammatory mechanism. It binds to JAK and prevents the activation of the JAK-signal transducers and activators of transcription (STAT) signaling pathway which ultimately decreases the production of pro-inflammatory cytokines, and prevents both inflammatory response and the inflammation-induced damage. It has shown better efficacy in many diseases like Rheumatoid Arthritis, Axial spondyloarthropathies, Psoriasis, Psoriatic Arthritis, Alopecia areata, dry eye disease.

This prospective, open label, randomized study will be conducted in inpatient and outpatient departments of Rheumatology, BSMMU, Dhaka, Bangladesh in 110 adult volunteers (\>18 years) of both genders diagnosed as psoriatic arthritis. Patients will be divided equally into two groups, Group A will be put on Tofacitinib 5 mg twice daily and Group B will be put on Methotrexate weekly in increasing dose with maximum dose of 25 mg weekly. Groups will be divided on the basis of randomization by random number table. Patients with inadequate response to highest dose of MTX or Tofacitinib 5 mg BD at the end of 3 months will be put on Tofacitinib 5 mg BD or Tofacitinib 10 mg BD respectively. The patients not eligible for therapy will not be included in the study. Patients will be followed up at 1, 3 and 6 months. Baseline characteristics will be monitored and recorded at 3 and 6 months.

The clinical information of the study subjects will be recorded in a structured history, clinical examination and questionnaire. All subjects will be enrolled after having informed written consent. The participants will enjoy every right to participate or withdraw from the study at any point of time. Response to Tofacitinib will be expressed in mean, standard deviation and percentage. Ethical clearance will be taken from the Institutional Review Board (IRB) of BSMMU.

Background:

Methotrexate, an anti-folate drug, is a widely accepted and commonly used DMARD for the treatment of PsA. Tofacitinib is a JAK inhibitor, and relatively new drug for this condition.

Aims:

To assess and compare safety and efficacy of Tofacitinib and Methotrexate in the treatment of PsA.

Methodology:

This open label, randomized, prospective study was conducted in Department of Rheumatology, BSMMU, Dhaka for 1½ years from September, 2017 to February, 2019. 61 patients, aged \>18 years with the diagnosis of PsA for ≥3 months were randomized into two groups. 29 patients (Tofacitinib 5mg BD) and 32 patients (MTX from 15 mg/week to 25 mg/week over 1 month) were enrolled and followed-up at the end of 1, 3 and 6 months. Primary endpoint was ACR 20 response at the end of 3 months. Patients who achieved treatment target on the basis of DAPSA score at the end of 3 months were allowed to continue previuos treatment and assessed for safety and efficacy till 6 months. Patients not achieving treatment target in Tofacitinib group were put on Tofacitinib 10 mg BD and in MTX group were put on Tofacitinib 5 mg BD. These patients were followed-up for safety and efficacy at the end of 6 months. Secondary outcome measures were EULAR response, 66/68 joints SJC/TJC, VAS for pain, ESR, CRP, DAPSA, DAS28, PASI, PASI 75 response, MASES and HAQ-DI. Safety assessment was done on the basis of clinical history, examination and laboratory findings at each follow-up. Ethical clearance was obtained from IRB, BSMMU at the beginning. Statistical analysis was done using chi-square test, Fisher's exact test, paired sample t-test and independent sample t-test. Missing data were dealt with intention to treat (ITT) analysis.

Eligibility Criteria:
Inclusion Criteria:

1. Male or female patients more than 18 years
2. Psoriatic arthritis \> 3 months with peripheral involvement diagnosed on the basis of CASPAR criteria
3. Unresponsive to more than 2 NSAIDs at maximum recommended doses for more than 4 weeks, i.e 2 weeks for each NASID

5. Patients with active disease 6. PsA with or without extra-articular features like enthesitis, dactylitis and nail changes

Exclusion Criteria:

1. Systemic infections requiring hospital admission during the past 6 months
2. A history of active infectious disorders (including active or latent tuberculosis), and/or a history of chronic or recurrent serious infective diseases, opportunistic infections
3. Hemoglobin (Hb) \< 9 g/dl
4. White blood cell count \< 3000, Neutrophil count \< 1000, Platelet count \< 100000
5. Live vaccines within 3 months prior to the first dose
6. Serum creatinine \> upper limit of normal reference range
7. GFR less than 50 mL/min
8. Alanine aminotransaminase (ALT) more than 2 times of ULN
9. Pregnant or breast feeding, females of child-bearing potential not using highly effective contraception
10. New York Heart Association Class III and IV congestive heart failure
11. Evidence or history of malignancy, with the exception of adequately treated or excised non-metastatic basal or squamous cell cancer of the skin or cervical carcinoma in situ
12. Any lymphoproliferative disorder, history of lymphoma, leukemia, or signs and symptoms suggestive of current lymphatic disease