Tag Archives: tofacitinib

Tofacitinib -Risks and Benefits in Rheumatoid Arthritis

Posted on by

Previously Tofacitnib, an oral Janus kinase inhibitor, has shown promise as an emerging treatment for inflammatory bowel disease (Tofacitinib –a JAK Inhibitor for UC | gutsandgrowth).  So, a recent large study in tofacitinib use in rheumatoid arthritis caught my attention, specifically with regards to the potential risks of treatment (NEJM 2014; 370: 2377-86).

This double-blind study randomly assigned 958 patients (mean age ~49 years) to receive 5 mg or 10 mg of tofacitinib twice daily or weekly methotrexate.  This study, called ORAL Start, examined the effectiveness of these drugs over a 24 month period in patients with active moderate-to-severe rheumatoid arthritis naive to therapeutic doses of methotrexate.

Key findings:

  • Among tofacitinib patients, 25.5% (5 mg group) and 37.7% (10 mg group) had an ACR 70 response at 6 months compared with 12.0% of methotrexate patients.  Results at 12 and 24 months were similar (Figure 1)
  • Adverse effects:
  1. 4% of tofacitinib patients developed herpes zoster compared with 1.1% of methotrexate patients
  2. 5 tofacitinib patients developed cases of cancer (three cases of lymphoma) compared with 1 case among patients receiving methotrexate
  3. Tofacitinib was associated with decreases in neutrophil/lymphoctye counts, increases in creatinine levels, increases in aminotransferases, and increases (16-22%) in LDL/HDL cholesterol levels
  4. Four deaths were noted among patients treated with tofacitinib compared with none in the methotrexate patients.

Related blog post: Source Article: Methotrexate Safety | gutsandgrowth

What you might not know about anti-TNF monitoring…

Posted on by

At a recent group dinner meeting, we had the opportunity to review therapeutic anti-TNF monitoring. In addition, we discussed emerging treatments for inflammatory bowel disease, like golimumab, tofacintinib and vedolizumab.

As noted in previous blog entries (see below), therapeutic anti-TNF monitoring can help adjust treatment.  Namely, if a patient loses response to therapy and has low trough levels of anti-TNF (Infliximab ❤ μg/mL, Adalimumab <8 μg/mL, or certolizumab <27.5 μg/mL) without antidrug antibodies (ADAs), then increasing the dose is likely to be effective.  However, if a patient has a therapeutic level and is not responding, changing to another agent and/or further investigation is worthwhile.

So, what information is new?

  • Only about 20% of patients who lose clinical response develop ADAs.  So, drug level, rather than ADAs, is most helpful.
  • For infliximab, adjusting dose 14 weeks into therapy to achieve a target trough level between 3-7 mcg/mL may be helpful.
  • Severe colitis patients may need higher initial doses (?as high as 20 mg/kg) due to potential for ‘antigen sink.’  This is due to notably higher clearance in the presence of low albumin, and high CRP.  Other factors that increase clearance include higher BMI and male gender.
  • About 1/2 of patients who receive higher doses due to severe disease may be able to deescalate dosage when improved. (?which half)
  • Currently, a reactive approach to checking levels is common in U.S. in part due to costs associated with checking trough levels and ADAs (as much as $2500).  That is, most commonly checking levels is undertaken in patients with suboptimal clinical response.  A proactive approach to achieve target levels may be shown to be helpful.
  • While studies have not shown higher adverse reactions with higher trough levels, there are a few clinical situations in which lower trough levels can be important.  In patients with psoriatic skin lesions and arthralgias, if trough levels are elevated, lowering the dose may be helpful.

Outstanding questions?

  • Should patients have drug levels checked when they are asymptomatic?
  • How does a practitioner account for variability among different laboratory assays?
  • What is the optimal target level for each anti-TNF agent? Is this different in Crohn disease compared with ulcerative colitis? Is the trough target level different in adults than children?
  • Is there a toxic level?
  • If a rapid test response were available, would checking drug levels be needed for hospitalized patients to assess anti-TNF rescue therapy?

Related blog links:

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition

Tofacitinib –a JAK Inhibitor for UC

Posted on by

There are definitely a lot of new therapies on the horizon for inflammatory bowel disease.  One of these agents is likely to be tofacitinib which has shown efficacy for active ulcerative colitis (NEJM 2012; 367: 616-24).

Background: Tofacitinib is a selective oral inhibitor of Janus kinase (JAK) which mediates activity for multiple cytokines, including interleukins 2, 4, 7, 9, 15, and 21.  Blockage of a common signaling molecule by these cytokines “should result in suppression of both T and B cells while maintaining regulatory T-cell function.  It has shown efficacy for organ allograft rejection, rheumatoid arthritis, and psoriasis.”  A previous small study by these investigators did not demonstrate efficacy in Crohn’s disease (Gastroenterology 2011; 140: Suppl: S124 Abstract).

Design: In this study which began as a double-blind, placebo-controlled, phase 2 trial, tofacitinib or placebo was given to 194 adult patients (from 51 centers in 17 countries) with moderate-to-severe active ulcerative colitis. Dosing for tofacitinib included groups receiving 0.5 mg, 3 mg, 10 mg, or 15 mg (all BID).  “The primary outcome was a clinical response at 8 weeks, defined as an absolute decrease from baseline in the score on the Mayo scoring system.”  Most of these patients had failed conventional therapy, including mesalamine, corticosteroids, immunosuppressants, and anti-TNF agents.

Results: At 8 weeks, the primary outcome with the highest doses (10 mg & 15 mg) of tofacitinib had clinical response rates of 61% (p=0.1) and 78% (p<0.001) respectively compared with a 42% placebo response.  Clinical remission (Mayo score ≤ 2) occurred in 48% and 41% respectively (both p<0.001) compared with 10% in placebo group.  Endoscopic remission was noted in 30% and 27% respectively (both p<0.001) compared with 2% of placebo group.

In addition, tofacitinib administration improved CRP values and fecal calprotectin concentrations (Figure 2 of article).

Potential adverse effects included the following

  • neutropenia (ANC 1000-1500) observed in three treated patients
  • two tofacitinib patients (10 mg group) developed abscesses
  • mild increases in LDL and HDL were noted and dose-related (these changes have been seen in rheumatoid arthritis patients as well)

Additional reference:

  • N Engl J Med 2012; 367:495-507 | August 9, 2012.  Tofacitinib for rheumatoid arthritis