Latest therapeutic advances in musculoskeletal disease from the ACR 2015 annual conference

The American College of Rheumatology (ACR) annual meeting was held in San Francisco from 7 to 11 November 2015. It attracted over 13,000 scientific attendees and they were treated to the presentation of 3270 abstracts. The following Therapeutic Advances highlights are, of necessity therefore, highly selective, based in part on the selection made by the ACR press team and in part on the biases of the first author. The topics chosen are listed according to the primary disorder covered by the presented abstract.

Osteoarthritis

Osteoarthritis remains one of the few rheumatic disorders without disease-modifying therapies, that is, treatments which alter the natural course of the disease. There were no breakthroughs presented at ACR but in a 2-year randomized controlled trial (RCT) comparison between 1200 mg of chondroitin sulphate (CS) and 200 mg of celecoxib, Pelletier (IRRM, Montréal, QC, Canada) and colleagues reported benefit of CS over 12 and 24 months compared with celecoxib on cartilage loss as assessed by magnetic resonance imaging (MRI) cartilage volume [Pelletier et al. 2015]. Although data were shown for a completer analysis, it was reported that essentially similar effects occurred in an intention-to-treat analysis. The significant benefit in the CS group on cartilage loss was primarily at the medial compartment but there was no significant difference in symptom relief. On the face of it, therefore, this nutraceutical might be considered to have some disease-modifying effect but significant cartilage loss occurred over a 12- and 24-month period in both groups suggesting that CS will have a very limited (if any) role as a sole disease-modifying agent in osteoarthritis.

Intra-articular corticosteroids in osteoarthritis are frequently used for short-term symptomatic relief but when used frequently there have been concerns about more rapid joint destruction. McAlindon (Tufts Medical Center, Boston, MA, USA) and colleagues reported results from a 2-year RCT of 3-monthly intra-articular (IA) triamcinolone (40 mg) versus IA saline [Driban et al. 2015]. They demonstrated that symptom control was no better between active and placebo treatments when assessed at the 3-monthly visits. While structural outcome measures in MRI showed no differences in structural progression between the two groups, overall there was no difference in symptomatic relief of the 3-monthly injections over placebo indicating that there is little, if any, clinical value in giving regular 3-monthly IA corticosteroids in treating knee osteoarthritis.

In the absence of disease-modifying drugs, the management of osteoarthritis remains primarily pain relief, lifestyle modification and often physiotherapy-driven exercise programmes. The latter have not been frequently assessed using a standard RCT approach. Nery (Universidade Federal de Sao Paulo, Sao Paulo, Brazil) and colleagues presented results from a 12-week RCT of a structured exercise regime for hand osteoarthritis compared with standard care [Nery et al. 2015]. They showed benefit in terms of reduced pain and improved function as assessed as part of composite endpoint measures, the latter being assessed as secondary endpoints. Although, in an intention-to-treat analysis, the primary endpoint of pain assessed by the American pain scale (NPS) did not show statistical significance, this trial gave some reassurance that a grip-strengthening exercise regime for those with moderate-to-severe hand osteoarthritis will have clinical benefit.

Rheumatoid arthritis therapies

Janus Kinases (JAK) are a family of signalling proteins which mediate signal transduction of a variety of cytokines. Inhibitors of JAK, that are small molecules and can be administered orally, have been in development for some years. An inhibitor of JAK3, tofacitinib, has been marketed for the treatment of rheumatoid arthritis in the USA since 2012 but, as yet, it has not been approved for use in Europe by the CMEA.

Several studies of JAK 1 and 2 inhibitors were presented at the conference. Fleischmann (Metroplex Clinical Research Center, Dallas, TX, USA) and colleagues presented a phase III study of barictinib 4 mg daily in early rheumatoid arthritis, and demonstrated that baricitinib alone or in combination with methotrexate (MTX) was superior in terms of ACR 20, 50 and 70 responses at both 24 and 52 weeks follow up compared with MTX alone [Fleischmann et al. 2015]. The response was very rapid, showing up within the first week in terms of a number of indices including swollen and tender joint counts. C-reactive protein (CRP) fell rapidly into the normal range and, if it normalized, there was improved radiological damage prevention even in the monotherapy with the barictinib group compared with MTX alone.

Genovese (Stanford University Medical Center, Palo Alto, CA, USA) and colleagues presented results of a subgroup and post hoc analysis of a previous phase III study of baritinib (RA-BEACON), which he had presented at EULAR in 2015 [Genovese et al. 2015a, 2015b]. In the original study, oral baricitinib produced a rapid and sustained clinical improvement over 24 weeks among patients with long-standing rheumatoid arthritis. The post hoc analysis demonstrated that baricitinib was successful regardless of which unsuccessful biologic drug had been used previously.

Westhovens (KU Leuven, Leuven, Belgium) and colleagues presented data from a 6-month phase IIB trial of a JAK 1 inhibitor, filgotinib, where six differing doses were compared with placebo in patients with active rheumatoid arthritis treated for 24 months (Westhovens et al. 2015). All patients were on MTX. The higher doses, especially 200 mg daily, either in single 200 mg or two 100 mg dosing, showed significant benefit compared with MTX alone. No serious adverse events were reported, especially with no serious infections. Kavanaugh (University of California San Diego, La Jolla, CA, USA) presented further data from a monotherapy filgonitib study compared with placebo, which showed clear improvements in ACR 20, 50 and 70 over 12–24 weeks [Kavanaugh et al. 2015b].

A pragmatic randomized trial of nonresponders to first anti-tumour necrosis factor (anti-TNF) therapy was presented by Gottenberg (Hautepierre, Strasbourg, France) and colleagues. Patients were randomized to either a second anti-TNF or a non-TNF-targeted biologic selected by the investigator (abatacept, rituximab or tocilizumab). The primary efficacy outcome was reaching a DAS-28 of 3.2 at 6 months. There were 150 patients randomized to each arm with 33 patients receiving abatacept, 41 rituximab, 70 tocilizumab in the non-TNF-targeted biologic arm. Significant superiority on reaching a DAS-28 of 3.2 was shown in the second arm but there was no significant difference between the chosen drugs [Gottenberg et al. 2015].

In a second abstract based on the same study, those who had developed anti-TNF antibodies to the first anti-TNF therapy did just as well with a second anti-TNF as those receiving a non-TNF-targeted biologic suggesting that the minority of patients who develop anti-TNF drug antibodies could be usefully switched to another anti-TNF rather than switching to a non-TNF targeted biologic [Candon et al. 2015].

The DRESS study evaluated in a randomised controlled, open-label, noninferiority strategy trial, whether tapering of anti-TNF therapy (adalimumab or etanercept) compared with usual care led to excess major flare [van Herwaarden et al. 2015]. While it showed that tapering was noninferior to usual care with regard to major flaring it might lead to a slight increase in radiological disease progression. den Broeder (Sint Maartenskliniek, Nijmegen, Netherlands) and colleagues presented results of a follow-up study, examining the relationships between disease activity in those tapering cases versus usual care [den Broeder et al. 2015]. The study demonstrated no differences in major flares between the two groups but there was a large increase in short-term flares in the tapering group versus usual care leading to a small but significant increase in mean weighted DAS28CRP scores in the tapering group compared with controls. The excess progression was associated with mean time weighted DAS28 indicating that to minimize disease progression, tapering of anti-TNF therapy should be monitored by careful monitoring of disease activity and perhaps repeated radiographic analysis.

There was a series of abstracts presented on the hot-topic of the relative efficacy of biosimilars compared with their parent compounds in the management of rheumatoid arthritis. Such drugs have not yet been widely approved in the USA or Europe but the evidence of relative efficacy presented suggests that it will not be too long until these do reach the marketplace. Cohen (Metroplex Clinical Research Center, Dallas, TX, USA) and colleagues presented the results of a phase III study of efficacy and safety of ABP 501 compared with adalimumab in subjects with moderate-to-severe rheumatoid arthritis and demonstrated, at the 24-week endpoint, equivalent improvements in ACR 20, 50 and 70 with the two therapies with near identical safety and immunogenicity results [Cohen et al. 2015]. Emery (University of Leeds, Leeds, UK) and colleagues presented the 52-week assessment results from a phase III trial of an etanercept biosimilar (SB4) compared with etanercept reference product (ETN; Enbrel®) in patients with moderate-to-severe rheumatoid arthritis [Vencovsky et al. 2015]. The 24-week results [Emery et al. 2015] had already shown efficacy and safety equivalence between the drugs and at 52-week efficacy, including radiographic progression and safety were comparable between SB4 and ETN but the immunogenicity profile was improved in the SB4 arm.

Similar 12-month results were presented on an infliximab biosimilar (SB2) by Smolen (Medical University of Vienna, Vienna, Austria) and colleagues [Choe et al. 2015a], reporting further on the 6-month data published [Choe et al. 2015b] comparing the biosimilar with the reference product. Similar to the previous presentation, 52-week efficacy (including radiographic progression and safety) were comparable but in this study so was the immunogenicity data. The longest study reported was a 72-week phase I trial of CT-P10, a rituximab biosimilar presented by Yoo (Hanyang University Hospital for Rheumatic Diseases, Seoul, South Korea) and colleagues [Yoo et al. 2015]. This was a 2:1 randomized study of CT-P10 and rituximab in anti-TNF intolerant or treatment-failure rheumatoid arthritis subjects. Initial 24-week data of a first treatment cycle (two infusions at fortnightly intervals) was presented at ACR in 2013. A second treatment cycle was given to those requiring retreatment due to returned disease activity at variable intervals from week 24 to 48 and final assessment made 24 weeks later. There were near identical benefits in DAS-28 scores after the first cycle, and no significant differences after the second cycle, either in terms of efficacy or safety, were noted.

Rheumatoid arthritis comorbidities

Comorbidities associated with rheumatoid arthritis, such as cardiovascular disease, cancer and infection, are significant determinants of excess mortality in the disease. As many of these comorbidities are driven in part by a chronic inflammatory response, the question to be considered is whether raised mortality rates are changing in response to improved management of the disease? Two studies presented attempted to address this issue.

A population-based cohort of patients with rheumatoid arthritis in British Columbia was reported by Lacaille (University of British Columbia, Vancouver, BC, Canada) [Lacaille et al. 2015]. She reported an earlier onset cohort (1996–2000) and later onset cohort (2001–2006) and both were followed for 5 years or mortality which ever occurred first. There were almost 2500 rheumatoid arthritis and matched controls. Compared with controls, all-cause mortality showed significant decreases in the later-onset cohort. Cardiovascular disease, cancer and infection mortality were all increased in the earlier-onset cohort, albeit deaths from infection were very low in both rheumatoid arthritis and controls. The differences in mortality compared with controls disappeared in the later onset cohort although the follow up is short for a mortality study. While the biological determinants of the improvement in mortality remain speculative (and were not examined in the study), it is possible that either improved management of rheumatoid arthritis or improved management of comorbidities or perhaps a combination of both is responsible.

Psoriatic arthritis

Kavanaugh (University of California San Diego, La Jolla, CA, USA) and colleagues presented further results, following up data from an RCT published on the IL17-A inhibitor, secukinumab, the FUTURE 2 study [McInnes et al. 2015; Kavanaugh et al. 2015a], used in psoriatic arthritis and active skin psoriasis. Higher response rates were noted with TNF inhibitor-naïve patients as opposed to those patients who had received TNF inhibitor at 24 and 52 weeks in ACR 20, 50 and 70 especially with the two higher doses of the drug: that is, 150 and 300 mg doses given subcutaneously on a weekly basis. There was less obvious difference in skin scores in TNF inhibitor-naïve versus previous TNF-exposed patients but HAQ score benefits were more marked in the latter. How this trend data will be used when the drug arrives in the clinic is less clear unless secukinumab is permitted to be used as a first biologic in those with psoriatic arthritis.

A 2-year follow-up of the FUTURE 1 trial published in the New England Journal of Medicine [Mease et al. 2015a] was presented by Mease (Swedish Medical Center, Seattle, WA, USA) and colleagues [Mease et al. 2015b]. In this study, secukinumab was used in a loading fashion with continued therapy given at two doses monthly subcutaneously. The 12-month beneficial effects as published were maintained through 2 years of monthly dosing at both the 75 and 150 mg doses with minimal radiological progression.

Fatigue and rheumatic diseases

A total of 187 abstracts were presented which dealt with the issue of fatigue which occurs in almost every rheumatic disease in excess of that in the general population. There were increasing data to indicate that in rheumatoid arthritis, fatigue is an important determinant of outcome and that it is not always responsive to intensive anti-inflammatory therapy. This implies that alternative factors other than just inflammatory disease activity are associated with fatigue. However, Cappelli (Johns Hopkins University, Baltimore, MD, USA) and colleagues showed from a prospective cohort of 165 participants (82% female with mean age of 56 years), that anti-CCP negativity was a robust independent predictor of greater fatigue and may be associated with greater impairments in disability and participation [Cappelli et al. 2015].

ACR guidelines for the management of rheumatoid arthritis

Finally ACR guidelines for the management of rheumatoid arthritis were launched officially at the conference having just been published online (see http://www.rheumatology.org/Practice-Quality/Clinical-Support/Clinical-Practice-Guidelines/Rheumatoid-Arthritis). The process of production and the need for an update since 2012 was discussed by the first author, Javinder Singh from Birmingham, Alabama. The new guideline included new thoughts on the use of glucocorticoids in early and established rheumatoid arthritis and determination on the use of new therapies, including for the first time a JAK inhibitor, tofacitinib. The latter is FDA approved but has not yet received approval from European Regulatory authorities.

For the first time the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to rate the quality of evidence and a group consensus process was used to grade the strength of recommendations (either strong or conditional). A strong recommendation indicated that clinicians are certain that the benefits of an intervention far outweigh the harms (or vice versa). A conditional recommendation denoted uncertainty over the balance of benefits and harms or more significant variability in patient values and preferences.

The guideline covers the use of traditional disease-modifying antirheumatic drugs (DMARDs), biologic agents, tofacitinib, and glucocorticoids in early (<6 months) and established (⩾6 months) rheumatoid arthritis. In addition, it provides recommendations on using a treat-to-target approach, tapering and discontinuing medications, and the use of biologic agents and DMARDs in patients with hepatitis, congestive heart failure, malignancy, and serious infections. The guideline also addressed supplementary issues to treatment including the use of vaccines in patients starting/receiving DMARDs or biologic agents, screening for tuberculosis in patients starting/receiving biologic agents or tofacitinib, and laboratory monitoring for traditional DMARDs. The guideline includes 74 recommendations: 23% are strong and 77% are conditional. The relevance of the guideline to the standard for management of rheumatoid arthritis in the USA and beyond will be covered in a future article to be published in Therapeutic Advances in Musculoskeletal Disease.