Week 28 – FACT

“Febuxostat Compared with Allopurinol in Patients with Hyperuricemia and Gout”

aka the Febuxostat versus Allopurinol Controlled Trial (FACT)

N Engl J Med. 2005 Dec 8;353(23):2450-61. [free full text]

Gout is thought to affect approximately 3% of the US population, and its prevalence appears to be rising. Gout occurs due to precipitation of monosodium urate crystals from supersaturated body fluids. Generally, the limit of solubility is 6.8 mg/dL, but local factors such as temperature, pH, and other solutes can lower this threshold. A critical element in the treatment of gout is the lowering of the serum urate concentration below the limit of solubility, and generally, the accepted target is 6.0 mg/dL. The xanthine oxidase inhibitor allopurinol is the most commonly used urate-lowering pharmacologic therapy. Allopurinol rarely can have severe or life-threatening side effects, particularly among patients with renal impairment. Thus drug companies have sought to bring to market other xanthine oxidase inhibitors such as febuxostat (trade name Uloric). In this chronic and increasingly burdensome disease, a more efficacious drug with fewer exclusion criteria and fewer side effects would be a blockbuster.

The study enrolled adults with gout and a serum urate concentration of ≥ 8.0 mg/dL. Exclusion criteria included serum Cr ≥ 1.5 mg/dL or eGFR < 50 ml/min (due to this being a relative contraindication for allopurinol use) as well as a the presence of various conditions or use of various drugs that would affect urate metabolism and/or clearance of the trial drugs. (Patients already on urate-lowering therapy were given a two week washout period prior to randomization.) Patients were randomized to treatment for 52 weeks with either febuxostat 80mg PO daily, febuxostat 120mg PO daily, or allopurinol 300mg PO daily. Because the initiation of urate-lowering therapy places patients at increased risk of gout flares, patients were placed on prophylaxis with either naproxen 250mg PO BID or colchicine 0.6mg PO daily for the first 8 weeks of the study. The primary endpoint was a serum urate level of < 6.0 mg/dL at weeks 44, 48, and 52. Selected secondary endpoints included percentage reduction in serum urate from baseline at each visit, percentage reduction in area of a selected tophus, and prevalence of acute gout flares weeks requiring treatment.

762 patients were randomized. Baseline characteristics were statistically similar among all three groups. A majority of the patients were white males age 50+ who drank alcohol. Average serum urate was slightly less than 10 mg/dL. The primary endpoint (urate < 6.0 at the last three monthly measurements) was achieved in 53% of patients taking febuxostat 80mg, 62% of patients taking febuxostat 120mg, and 21% of patients taking allopurinol 300mg (p < 0.001 for each febuxostat groups versus allopurinol). Regarding selected secondary endpoints:

1) The percent reduction in serum urate from baseline at the final visit was 44.73 ± 19.10 in the febuxostat 80mg group, 52.52 ± 19.91 in the febuxostat 120mg group, and 32.99 ± 15.33 in the allopurinol 300mg group (p < 0.001 for each febuxostat group versus allopurinol, and p < 0.001 for febuxostat 80mg versus 120mg). 2) The percentage reduction in area of a single selected tophus was assessed in 156 patients who had tophi at baseline. At week 52, the median percentage reduction in tophus area was 83% in febuxostat 80mg patients, 66% in febuxostat 120mg patients, and 50% in allopurinol patients (no statistical difference per authors, p values not reported). Additionally, there was no significant reduction in tophus count in any of the groups. 3) During weeks 1-8 (in which acute gout flare prophylaxis was scheduled), 36% of patients in the febuxostat 120mg sustained a flare, whereas only 22% of the febuxostat 80mg group and 21% of the allopurinol group sustained a flare (p < 0.001 for both pairwise comparisons versus febuxostat 120mg). During weeks 9-52 (in which acute gout flare prophylaxis was no longer scheduled), a similar proportion of patients in each treatment group sustained an acute flare of gout (64% in the febuxostat 80mg group, 70% in the febuxostat 120mg group, and 64% in the allopurinol group). Finally, the incidence of treatment-related adverse events was similar among all three groups (see Table 3). Treatment was most frequently discontinued in the febuxostat 120mg group (98 patients, versus 88 patients in the febuxostat 80mg group and 66 patients in the allopurinol group; p = 0.003 for comparison between febuxostat 120mg and allopurinol).

In summary, this large RCT of urate-lowering therapy among gout patients found that febuxostat, dosed at either 80mg or 120mg PO daily, was more efficacious than allopurinol 300mg in reducing serum urate to below 6.0 mg/dL. Febuxostat was not superior to allopurinol with respect to the tested clinical outcomes of tophus size reduction, tophus count, and acute gout flares. Safety profiles were similar among the three regimens.

The authors note that the incidence of gout flares during and after the prophylaxis phase of the study “calls attention to a well-described paradox with important implications for successful management of gout: the risk of acute gout flares is increased early in the course of urate-lowering treatment” and the authors suggest that there is “a role for more sustained prophylaxis during the initiation of urate-lowering therapy than was provided here” (2458).

A limitation of this study is that its comparator group, allopurinol 300mg PO daily, may not have represented optimal use of the drug. Allopurinol should be uptitrated q2-4 weeks to the minimum dose required to maintain the goal serum urate of < 6.0 mg/dL (< 5.0 if tophi are present). According to UpToDate, “a majority of gout patients require doses of allopurinol exceeding 300 mg/day in order to maintain serum urate < 6.0 mg/dL.” In the United States allopurinol has been approved for doses of up to 800 mg daily. The authors state that “titration of allopurinol would have compromised the blinding of the study” (2459) but this is not true – blinded protocolized titration of study or comparator drugs has been performed in numerous other RCTs and could have been achieved simply at greater cost to and effort from the study sponsor (which happens to be the drug company TAP Pharmaceuticals). The likelihood that such titration would have shifted the results toward a null effect does not go unnoted. Another limitation is the relatively short duration of the trial – follow-up may have been insufficient to establish superiority in clinical outcomes, given the chronic nature of the disease.

In the UK, the National Institute for Health and Care Excellence (NICE), the agency tasked with assessing cost-effectiveness of various medical therapies, recommended as of 2008 that febuxostat be used for the treatment of hyperuricemia in gout “only for people who are intolerant of allopurinol or for whom allopurinol is contraindicated.”

Of note, a recent study funded by Takeda Pharmaceuticals demonstrated the non-inferiority of febuxostat relative to allopurinol with respect to rates of adverse cardiovascular events in patient with gout and major pre-existing cardiovascular conditions.

Allopurinol started at 100mg PO daily and titrated gradually to goal serum urate is the current general practice in the US. However, patients of Chinese, Thai, Korean, or “another ethnicity with similarly increased frequency of HLA-B*5801” should be tested for HLA-B*5801 prior to initiation of allopurinol therapy, as those patients are at increased risk of a severe cutaneous adverse reaction to allopurinol.

Further Reading/References:
1. FACT @ ClinicalTrials.gov
2. UpToDate “Pharmacologic urate-lowering therapy and treatment of tophi in patients with gout”
3. NICE: “Febuxostat for the management of hyperuricemia in people with gout”
4. “Cardiovascular Safety of Febuxostat or Allopurinol in Patients with Gout.” N Engl J Med. 2018 Mar 29;378(13):1200-1210.

Summary by Duncan F. Moore, MD

Image Credit: James Gilray, US Public Domain, via Wikimedia Commons

Week 42 – BeSt

“Clinical and Radiographic Outcomes of Four Different Treatment Strategies in Patients with Early Rheumatoid Arthritis (the BeSt Study).”

Arthritis & Rheumatism. 2005 Nov;52(11):3381-3390. [free full text]

Rheumatoid arthritis (RA) is among the most prevalent of the rheumatic diseases with a lifetime prevalence of 3.6% in women and 1.7% in men [1]. It is a chronic, systemic, inflammatory autoimmune disease of variable clinical course that can severely impact physical functional status and even mortality. Over the past 30 years, as the armamentarium of therapies for RA has exploded, there has been increased debate about the ideal initial therapy. The BeSt (Dutch: Behandel-Strategieën “treatment strategies”) trial was designed to compare, according to the authors, four of “the most frequently used and discussed strategies.” Regimens incorporating traditional disease-modifying antirheumatic drugs (DMARDs), such as methotrexate, and newer therapies, such as TNF-alpha inhibitors, were compared directly.

The trial enrolled 508 DMARD-naïve patients with early rheumatoid arthritis. Pertinent exclusion criteria included history of cancer and pre-existing laboratory abnormalities or comorbidities (e.g. elevated creatinine or ALT, alcohol abuse, pregnancy or desire to conceive, etc.) that would preclude the use of various DMARDs. Patients were randomized to one of four treatment groups. Within each regimen, the Disease Activity Score in 44 joints (DAS-44) was assessed q3 months, and, if > 2.4, the medication regimen was uptitrated to the next step within the treatment group.

Four Treatment Groups

  1. Sequential monotherapy: methotrexate (MTX) 15mg/week, uptitrated PRN to 25-30mg/week. If insufficient control, the following sequence was pursued: sulfasalazine (SSZ) monotherapy, leflunomide monotherapy, MTX + infliximab, gold with methylprednisolone, MTX + cyclosporin A (CSA) + prednisone
  2. Step-up combination therapy: MTX 15mg/week, uptitrated PRN to 25-30mg/week. If insufficient control, SSZ was added, followed by hydroxychloroquine (HCQ), followed by prednisone. If patients failed to respond to those four drugs, they were switched to MTX + infliximab, then MTX + CSA + prednisone, and finally to leflunomide.
  3. Initial combination therapy with tapered high-dose prednisone: MTX 7.5 mg/week + SSZ 2000 mg/day + prednisone 60mg/day (tapered in 7 weeks to 7.5 mg/day). If insufficient control, MTX was uptitrated to 25-30 mg/week. Next, combination would be switched to MTX + CSA + prednisone, then MTX + infliximab, then leflunomide monotherapy, gold with methylprednisolone, and finally azathioprine with prednisone.
  4. Initial combination therapy with infliximab: MTX 25-30 mg/week + infliximab 3 mg/kg at weeks 0, 2, 6, and q8 weeks thereafter. There was a protocol for infliximab-dose uptitration starting at 3 months. If insufficient control on MTX and infliximab 10 mg/kg, patients were switched to SSZ, then leflunomide, then MTX + CSA + prednisone, then gold + methylprednisolone, and finally AZA with prednisone.

Once clinical response was adequate for at least 6 months, there was a protocol for tapering the drug regimen.

The primary endpoints were: 1) functional ability per the Dutch version of the Health Assessment Questionnaire (D-HAQ), collected by a blinded research nurse q3 months and 2) radiographic joint damage per the modified Sharp/Van der Heijde score (SHS). Pertinent secondary outcomes included DAS-44 score and laboratory evidence of treatment toxicity.

At randomization, enrolled RA patients had a median duration of symptoms of 23 weeks and median duration since diagnosis of RA of 2 weeks. Mean DAS-44 was 4.4 ± 0.9. 72% of patients had erosive disease. Mean D-HAQ score at 3 months was 1.0 in groups 1 and 2 and 0.6 in groups 3 and 4 (p < 0.001 for groups 1 and 2 vs. groups 3 and 4; paired tests otherwise insignificant). Mean D-HAQ at 1 year was 0.7 in groups 1 and 2 and 0.5 in groups 3 and 4 (p = 0.010 for group 1 vs. group 3, p = 0.003 for group 1 vs. group 4; paired tests otherwise insignificant). At 1 year, patients in group 3 or 4 had less radiographic progression in joint damage per SHS than patients in group 1 or 2. Median increases in SHS were 2.0, 2.5., 1.0, and 0.5 in groups 1-4, respectively (p = 0.003 for group 1 vs. group 3, p < 0.001 for group 1 versus group 4, p = 0.007 for group 2 vs. group 3, p < 0.001 for group 2 vs. group 4). Regarding DAS-44 score: low disease activity (DAS-44 ≤ 2.4) at 1 year was reached in 53%, 64%, 71%, 74% of groups 1-4, respectively (p = 0.004 for group 1 vs. group 3, p = 0.001 for group 1 vs. group 4, p not significant for other comparisons). There were no group differences in prevalence of adverse effects.

Overall, among patients with early RA, initial combination therapy that included either prednisone (group 3) or infliximab (group 4) resulted in better functional and radiographic improvement than did initial therapy with sequential monotherapy (group 1) or step-up combination therapy (group 2). In the discussion, the authors note that given the treatment group differences in radiographic progression of disease, “starting therapy with a single DMARD would be a missed opportunity in a considerable number of patients.” Contemporary commentary by Weisman notes that “the authors describe both an argument and a counterargument arising from their observations: aggressive treatment with combinations of expensive drugs would ‘overtreat’ a large proportion of patients, yet early suppression of disease activity may have an important influence on subsequent long‐term disability and damage.”

Fourteen years later, it is a bit difficult to place the specific results of this trial in our current practice. Its trial design is absolutely byzantine and compares the 1-year experience of a variety of complex protocols that theoretically have substantial eventual potential overlap. Furthermore, it is difficult to assess if the relatively small group differences in symptom (D-HAQ) and radiographic (SHS) scales were truly clinically significant even if they were statistically significant. The American College of Rheumatology 2015 Guideline for the Treatment of Rheumatoid Arthritis synthesized the immense body of literature that came before and after the BeSt study and ultimately gave a variety of conditional statements about the “best practice” treatment of symptomatic early RA. (See Table 2 on page 8.) The recommendations emphasized DMARD monotherapy as the initial strategy but in the specific setting of a treat-to-target strategy. They also recommended escalation to combination DMARDs or biologics in patients with moderate or high disease activity despite DMARD monotherapy.

References / Additional Reading:
1. “The lifetime risk of adult-onset rheumatoid arthritis and other inflammatory autoimmune rheumatic diseases.” Arthritis Rheum. 2011 Mar;63(3):633-9. [https://www.ncbi.nlm.nih.gov/pubmed/21360492]
2. BeSt @ Wiki Journal Club
3. “Progress toward the cure of rheumatoid arthritis? The BeSt study.” Arthritis Rheum. 2005 Nov;52(11):3326-32.
4. “Review: treat to target in rheumatoid arthritis: fact, fiction, or hypothesis?” Arthritis Rheumatol. 2014 Apr;66(4):775-82. [https://www.ncbi.nlm.nih.gov/pubmed/24757129]
5. “2015 American College of Rheumatology Guideline for the Treatment of Rheumatoid Arthritis” Arthritis Rheumatol. 2016 Jan;68(1):1-26
6. RheumDAS calculator

Summary by Duncan F. Moore, MD

Image Credit: Braegel, CC BY 3.0, via Wikimedia Commons

Week 19 – RAVE

“Rituximab versus Cyclophosphamide for ANCA-Associated Vasculitis”

by the Rituximab in ANCA-Associated Vasculitis-Immune Tolerance Network (RAVE-ITN) Research Group

N Engl J Med. 2010 Jul 15;363(3):221-32. [free full text]

ANCA-associated vasculitides, such as granulomatosis with polyangiitis (GPA, formerly Wegener’s granulomatosis) and microscopic polyangiitis (MPA) are often rapidly progressive and highly morbid. Mortality in untreated generalized GPA can be as high as 90% at 2 years (PMID 1739240). Since the early 1980s, cyclophosphamide (CYC) with corticosteroids has been the best treatment option for induction of disease remission in GPA and MPA. Unfortunately, the immediate and delayed adverse effect profile of CYC can be burdensome. The role of B lymphocytes in the pathogenesis of these diseases has been increasingly appreciated over the past 20 years, and this association inspired uncontrolled treatment studies with the anti-CD20 agent rituximab that demonstrated promising preliminary results. Thus the RAVE trial was performed to compare rituximab to cyclophosphamide, the standard of care.

Population:
ANCA-positive patients with “severe” GPA or MPA and a Birmingham Vasculitis Activity Score for Wegener’s Granulomatosis (BVAS/WG) of 3+.

notable exclusion: patients intubated due to alveolar hemorrhage, patients with Cr > 4.0

Intervention:
rituximab 375mg/m2 IV weekly x4 + daily placebo-CYC + pulse-dose corticosteroids with oral maintenance and then taper

Comparison:
placebo-rituximab infusion weekly x4 + daily CYC + pulse-dose corticosteroids with oral maintenance and then taper

Outcome:
primary end point = clinical remission, defined as a BVAS/WG of 0 and successful completion of prednisone taper

primary outcome = noninferiority of rituximab relative to CYC in reaching 1º end point

authors specified non-inferiority margin as a -20 percentage point difference in remission rate

subgroup analyses (pre-specified) = type of ANCA-associated vasculitis, type of ANCA, “newly-diagnosed disease,” relapsing disease, alveolar hemorrhage, and severe renal disease

secondary outcomes: rate of disease flares, BVAS/WG of 0 during treatment with prednisone at a dose of less than 10mg/day, cumulative glucocorticoid dose, rates of adverse events, SF-36 scores


Results
:
197 patients were randomized, and baseline characteristics were similar among the two groups (e.g. GPA vs. MPA, relapsed disease, etc.). 75% of patients had GPA. 64% of the patients in the rituximab group reached remission, while 53% of the control patients did. This 11 percentage point difference among the treatment groups was consistent with non-inferiority (p < 0.001). However, although more rituximab patients reached the primary endpoint, the difference between the two groups was statistically insignificant, and thus superiority of rituximab could not be established (95% CI -3.2 – 24.3 percentage points difference, p = 0.09). Subgroup analysis was notable only for superiority of rituximab in relapsed patients (67% remission rate vs. 42% in controls, p=0.01). Rates of adverse events and treatment discontinuation were similar among the two groups.

Implication/Discussion:
Rituximab + steroids is as effective as cyclophosphamide + steroids in inducing remission in severe GPA and MPA.

This study initiated a major paradigm shift in the standard of care of ANCA-associated vasculitis. The following year, the FDA approved rituximab + steroids as the first-ever treatment regimen approved for GPA and MPA.  It spurred numerous follow up trials, and to this day expert opinion is split over whether CYC or rituximab should be the initial immunosuppressive therapy in GPA/MPA with “organ-threatening or life-threatening disease” (UpToDate).

Further Reading/References:
1. “Wegener granulomatosis: an analysis of 158 patients” (1992)
2. RAVE at ClinicalTrials.gov
3. “Challenges in the Design and Interpretation of Noninferiority Trials,” NEJM (2017)
4. “Clinical Trials – Non-inferiority Trials”
5. UpToDate,“Initial Immunosuppressive Therapy in Granulomatosis with Polyangiitis and Microscopic Polyangiitis
6. Wiki Journal Club
7. 2 Minute Medicine

Summary by Duncan F. Moore, MD