Changes in Management After 18F-DCFPyL PSMA PET in Patients Undergoing Postprostatectomy Radiotherapy, with Early Biochemical Response Outcomes

Prostate-specific membrane antigen (PSMA) tracers have increased sensitivity in the detection of prostate cancer, compared with conventional imaging. We assessed the management impact of ¹⁸F-DCFPyL PSMA PET/CT in patients with prostate-specific antigen (PSA) recurrence after radical prostatectomy (RP) and report early biochemical response in patients who underwent radiation treatment. Methods: One hundred patients were enrolled into a prospective study, with a prior RP for prostate cancer, a PSA of 0.2-2.0 ng/mL, and no prior treatment. All patients underwent diagnostic CT and PSMA PET/CT, and management intent was completed at 3 time points (original, post-CT, and post-PSMA) and compared. Patients who underwent radiotherapy with 6-mo PSA response data are presented. Results: Ninety-eight patients are reported, with a median PSA of 0.32 ng/mL (95% CI, 0.28-0.36), pT3a/b disease in 71.4%, and an International Society of Urological Pathology grade group of at least 3 in 59.2%. PSMA PET/CT detected disease in 46.9% of patients, compared with 15.5% using diagnostic CT (PSMA PET, 29.2% local recurrence and 29.6% pelvic nodal disease). A major change in management intent was higher after PSMA than after CT (12.5% vs. 3.2%, P = 0.010), as was a moderate change in intent (31.3% vs. 13.7%, P = 0.001). The most common change was an increase in the recommendation for elective pelvic radiation (from 15.6% to 33.3%), nodal boost (from 0% to 22.9%), and use of concurrent androgen deprivation therapy (ADT) (from 22.9% to 41.7%) from original to post-PSMA intent because of detection of nodal disease. Eighty-six patients underwent ¹⁸F-DCFPyL-guided radiotherapy. Fifty-five of 86 patients either did not receive ADT or recovered after ADT, with an 18-mo PSA response from 0.32 to 0.02 ng/mL; 94.5% of patients had a PSA of no more than 0.20 ng/mL, and 74.5% had a PSA of no more than 0.03 ng/mL. Conclusion: ¹⁸F-DCFPyL PET/CT has a significant impact on management intent in patients being considered for salvage radiotherapy after RP with PSA recurrence. Increased detection of disease, particularly in the pelvic lymph nodes, resulted in increased pelvic irradiation and concurrent ADT use. Early results in patients who are staged with ¹⁸F-DCFPyL PET/CT show a favorable PSA response.

POS0123 NEUROPATHIC PAIN SYMPTOMS IN INFLAMMATORY HAND OSTEOARTHRITIS(OA) LOWERS HEALTH RELATED PHYSICAL QUALITY OF LIFE AND MAY REQUIRE ANOTHER APPROACH THAN ANTI-INFLAMMATORY TREATMENT

Background:

Pain is a common, difficult to manage symptom in hand osteoarthritis (OA). Multiple pain mechanisms may play a role in hand OA.

Objectives:

To investigate presence of neuropathic pain symptoms in patients with inflammatory hand OA, characteristics of those patients, their impact on health related quality of life (HR-QoL), and the influence of anti-inflammatory treatment on neuropathic pain symptoms.

Methods:

Data from a randomised, double-blind, placebo-controlled trial of prednisolone including 92 patients with hand OA fulfilling ACR criteria were used. At baseline patients had signs of synovial inflammation, a VAS finger pain of ≥30 mm and who flared ≥20 mm upon NSAID washout. The primary endpoint was VAS finger pain (0-100) at week 6.

Neuropathic pain symptoms were measured at baseline and week 6 using the validated painDETECT questionnaire, consisting of questions on pain quality, pain intensity over time and radiating pain. Scores range -1 to 38 and patients are classified as having unlikely (<13), indeterminate (13-18) and likely (>18) neuropathic pain. HR-QoL was measured with physical component scale (PCS) of Short-Form 36 (SF36; 0-100), comorbidities with the Self-administered Comorbidities Questionnaire (SCQ; 0-45), radiographic severity with Kellgren-Lawrence (KL) sum score (0-120), and treatment response with OMERACT-OARSI responder criteria.

Association of patient characteristics with neuropathic pain symptoms was analysed with univariate and multivariate ordinal logistic regression, with painDETECT as dependent variable. Association of neuropathic pain symptoms with HR-QoL was analysed with multivariate linear regression, adjusted for age, sex, BMI, VAS finger pain, SCQ score and KL sum score, with PCS as dependent variable. Response of neuropathic pain symptoms and VAS pain to prednisolone was analysed with generalised estimating equations. Association of neuropathic pain symptoms at baseline with response to treatment was analysed using χ2-tests and GEE.

Results:

91 patients had complete painDETECT data at baseline (mean painDETECT score 12.8 [SD 5.9]). Scores were <13 in 53%, 13-18 in 31% and >18 in 16%. Higher painDETECT score categories were associated with less radiographic damage, more comorbidities, female sex and higher VAS finger pain in multivariate analysis. (table 1)

Table 1.

Ordinal logistic regression with painDETECT categories as dependent variable

VariablesMean (SD) N=91 (100%)Odds ratio (95% CI)Age64 (9)0.96 (0.90 to 1.02)Female sex; N (%)72 (79%)3.84 (1.19 to 12.39)*BMI; median (SD)27 (24 to 29)0.97 (0.89 to 1.06)SCQ score; median (SD)2 (1 to 5)1.04 (1.04 to 1.36)*VAS finger pain53.8 (2.1)1.02 (1.00 to 1.04)*KL sum score37 (16)0.96 (0.93 to 1.00)*

*p<0.05. BMI = body mass index. SCQ = Self-administered comorbidities questionnaire. VAS = visual analog scale. KL= Kellgren-Lawrence.

Patients with painDETECT scores >18 had a lower HR-QoL (PCS -6.5 [95%CI -10.4 to -2.6]) than those with painDETECT scores <13.

PainDETECT scores remained unchanged throughout the trial in both prednisolone-treated and placebo-treated patients, and there was no between-group difference at week 6. VAS pain improved more in the prednisolone group than in the placebo group (mean between-group difference -16.5 [95%CI -26.1 to -6.9]) (figure 1). No association between the presence of neuropathic pain symptoms at baseline and OMERACT-OARSI response to treatment was found.

Conclusion:

Patients with inflammatory hand OA and additional neuropathic pain symptoms are more often female and have more comorbidities, and report a lower QoL, than those without. Neuropathic pain symptoms seem unresponsive to anti-inflammatory therapy. Clinicians should be aware of neuropathic pain symptoms in their patients as they might benefit from additional, specific treatment.

Acknowledgements:

The authors thank all patients for their participation in the HOPE study, and participating rheumatologists for inclusion of patients in the HOPE study. We also thank research nurses B.A.M.J. van Schie-Geyer and S. Wongsodihardjo, and technicians J.C. Kwekkeboom and E.I.H. van der Voort, for their contributions.

Disclosure of Interests:

Coen van der Meulen: None declared, Lotte van de Stadt: None declared, Féline Kroon: None declared, Marion Kortekaas: None declared, Annelies Boonen Speakers bureau: Lecture for UCB; paid to department., Consultant of: Yes. Advisory board meetings at Galapagos, Eli Lilly and Abvvie; paid to department., Grant/research support from: Yes. Grants by Celgene and Abbvie; paid to department., Stefan Böhringer: None declared, Marieke Niesters: None declared, Monique Reijnierse: None declared, Frits Rosendaal: None declared, Naghmeh Riyazi: None declared, M. Starmans: None declared, Franktien Turkstra: None declared, Jende van Zeben: None declared, Cornelia Allaart: None declared, Margreet Kloppenburg Consultant of: For Abbvie, Pfizer, Levicept, GlaxoSmithKline, Merck-Serono, Kiniksa, Flexìon, Galapagos, Jansen, CHDR and local investigator of industry-driven trial (Abbvie). All fees were paid to the institution., Grant/research support from: Grant by the Dutch Arthritis Society

POS0609 A TOCILIZUMAB DOSING STRATEGY IN RHEUMATOID ARTHRITIS PATIENTS WITH STABLE DISEASE AIMING TO PREVENT OVERTREATMENT AND UNNECESSARY COSTS

Background:

Tocilizumab (TCZ) is a humanized interleukin 6 (IL-6) antibody that competitively inhibits IL-6 signalling by binding both membrane-bound and soluble IL-6 receptors. The EULAR recommends the use of TCZ, as a biological disease-modifying antirheumatic drug (DMARD), as second line therapy in rheumatoid arthritis (RA) when conventional DMARDs have failed achieving treatment target. The labelled dosing regimen for TCZ in RA is 8mg/kg (maximum 800mg) every 4 weeks. A TCZ predose serum concentration (TCZpsc) >1mg/L normalizes C-reactive protein, while clinical trials found mean TCZpsc of 19.9 ±17.0 mg/L in patients receiving the standard regimen. On the basis of these data, it can be hypothesized that cost-effectiveness of therapy can be improved.

Objectives:

In this study we evaluated TCZpsc in stable RA-patients to determine whether the TCZ 8mg/kg dose could be lowered while meeting the minimal required concentration for effective blockage of the IL-6 inflammatory cascade.

Methods:

Adult RA patients with stable disease (i.e. at least 3 months without treatment change) treated with intravenous TCZ were investigated in a prospective cohort study. TCZpsc before two different TCZ infusions over time was assessed. A validated ELISA was used to measure TCZpscs, immunogenicity was measured by quantifying human antibodies using antigen-binding tests (radioimmunoassay).

A population pharmacokinetic (PK) model was constructed using maximum a posteriori Bayesian estimation applied on the available PK data in the literature combined with the collected data on dosing and predose concentrations in the study patients. Body surface area, creatinine clearance and gender were included as covariates in the model. A patient individual dose tapering strategy was predicted based on the derived model.

The target TCZpsc was set on 8-10mg/L taking the measurement error of 15%, the use of the entire content of the vials and intra-individual variation into consideration.

Results:

A total of 44 patients were included [median (IQR) age: 63 (58-72), 75% female, mean (SD) DAS28-ESR: 1.5 (0.8)]. Half of the patients received TCZ in combination with a conventional DMARD, 32% used methotrexate (MTX). Patients received 7.7 ±0.8mg/kg (range 5.7-9.7) TCZ. Mean TCZpsc was 27.6 ±12.6mg/L. The intra-individual variance of TCZpsc was low; mean difference in individual TCZpscs was 0.56 (5.2)mg/L. Higher dosages (in mg/kg) were significantly associated with higher TCZpsc (regression coefficient 7.32 95%CI 2.73;11.9), suggesting overtreatment. No drug-neutralizing auto-antibodies were measured. Co-treatment with MTX did not influence the median TCZpsc (21.0mg/L versus 26.5mg/L without MTX, p=0.84).

According to the measured TCZpsc, TCZ dosage could be lowered in 36 patients (92%). In a 28-days regimen, target-TCZpsc would be reached with a 0.4-4.6mg/kg dose-reduction (Figure 1). Extending the interval between two administrations would lead to low TCZpsc (<1mg/L).

Figure 1.

Intended dose reduction related to the measured tocilizumab predose serum concentration

Considering the aimed average dose-reduction of 2.1 mg/kg per administration, efficacy would be expected to maintain (TCZpsc >1 mg/L) while reducing yearly costs with ±€3.900,- per patient. On average patients were started on TCZ treatment 63 months (SD26) earlier. As maximum efficacy of TCZ treatment can be achieved after 3 months, TCZpsc-guided dose reduction 3 months after start could have resulted in a total drug cost reduction of ±€750.000,- in our study population (±€19.500,- per patient).

Conclusion:

Measured TCZpsc under standard TCZ therapy was much higher than the minimal required concentration. These results suggest that the labelled TCZ dose leads to overtreatment and unnecessary costs in patients with stable RA. The TCZpsc seems supportive as an instrument for dose reduction strategies. Future prospective studies should assess its use in TCZ dose adjustment and confirm whether treatment efficacy is maintained.

Disclosure of Interests:

None declared

Patterns of disease detection using [18F]DCFPyL PET/CT imaging in patients with detectable PSA post prostatectomy being considered for salvage radiotherapy: a prospective trial

PURPOSE

Prostate-specific membrane antigen (PSMA) PET/CT is increasingly used in patients with biochemical recurrence post prostatectomy to detect local recurrence and metastatic disease at low PSA levels. The aim of this study was to assess patterns of disease detection, predictive factors and safety using [¹⁸F]DCFPyL PET/CT versus diagnostic CT in patients being considered for salvage radiotherapy with biochemical recurrence post prostatectomy.

METHODS

We conducted a prospective trial recruiting 100 patients with detectable PSA post prostatectomy (PSA 0.2-2.0 ng/mL) and referred for salvage radiotherapy from August 2018 to July 2020. All patients underwent a PSMA PET/CT using the [¹⁸F]DCFPyL tracer and a diagnostic CT. The detection rates of [¹⁸F]DCFPyL PET/CT vs diagnostic CT were compared and patterns of disease are reported. Clinical patient and tumour characteristics were analysed for predictive utility. Thirty-day post-scan safety is reported.

RESULTS

Of 100 patients recruited, 98 were suitable for analysis with a median PSA of 0.32 ng/mL. [¹⁸F]DCFPyL PET/CT was positive 46.4% and equivocal 5.2%, compared to 15.5% positivity for diagnostic CT. Local recurrence was detected on [¹⁸F]DCFPyL PET/CT in 28.5%, nodal disease in 27.5% and bony metastases in 6.1% of patients. Both ISUP grade group (p < 0.001) and pre-scan PSA (p = 0.029) were significant predictors of [¹⁸F]DCFPyL PET/CT positivity, and logistic regression generated probabilities combining the two showed improved prediction rates. No significant safety events were reported post [¹⁸F]DCFPyL administration.

CONCLUSIONS

[¹⁸F]DCFPyL PET/CT increases detection of disease in patients with biochemical recurrence post prostatectomy compared to diagnostic CT. Patients being considered for salvage radiotherapy with a PSA >0.2 ng/mL should be considered for [¹⁸F]DCFPyL PET/CT scan.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry Number: ACTRN12618001530213 ( http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375932&isReview=true ).

AB0230 STATINS TO PREVENT RHEUMATOID ARTHRITIS: INCONCLUSIVE RESULTS OF THE STAPRA TRIAL

Background:

Persons at high risk for developing rheumatoid arthritis (RA) may benefit from a low-risk pharmacological intervention aimed at primary prevention. Statins are safe and widely-used drugs; previous studies demonstrated disease-modifying effects of statins in RA patients1as well as an association between statin use and a decreased risk of RA development2.

Objectives:

We designed a multi-center, randomized, double-blind, placebo-controlled trial to investigate if atorvastatin use for 3 years could prevent arthritis.

Methods:

Persons at high risk for RA, defined by the presence of arthralgia and anti-citrullinated protein antibody (ACPA) concentration >3xULN or both ACPA and rheumatoid factor (RF), were randomized to atorvastatin 40 mg daily or placebo for 3 years. Eligible participants were ≥18 years, had no indication for lipid-lowering therapy and had no clinical synovitis. The primary endpoint was development of clinical arthritis. Our goal was to include 220 patients, based on an anticipated 30% risk reduction by atorvastatin. Analysis was by intention-to-treat.

Results:

189 patients were screened, 175 were eligible, but only 67 persons were included of whom 62 were randomized (figure 1). The main reason for non-inclusion was unwillingness to use study medication (n=58, 54%). Inclusion was stopped after 38 months due to the low inclusion rate. Analyses were performed 1 year after inclusion stop. Mean follow up was 18 (0-36) months. Mean age was 48 years and 74% of participants were female. 14 persons (23%) developed clinical arthritis: 8/31 (26%) in the atorvastatin group and 6/31 (19%) in the placebo group (HR 0.8, 95% CI 0.3-2.2) after a median period of 7.5 (IQR 5.3-21.8) months (atorvastatin) and 4 (0-14.8) months (placebo). In the atorvastatin group, 17 persons completed the study according to protocol, 6 dropped out and 8 continued follow-up after prematurely stopping study medication. In the placebo group, 16 persons completed the study according to protocol, 11 dropped out and 4 continued follow-up after prematurely stopping study medication. Median duration of study medication use was 9 (6-26) months (atorvastatin group) and 8 (3-17) months (placebo group).

Conclusion:

The results of this trial are inconclusive due to severe difficulties with patient inclusion and low treatment adherence. The difficulty to enter and retain participants in this prevention trial is highly relevant given the current interest in treating RA in an ever earlier phase. At-risk individuals’ perceptions should be taken into account when designing preventive trials and will be important in optimizing acceptance and adherence to preventive treatment. Currently we are finalizing research into the motivation and barriers for participation in different primary prevention trials of RA and the willingness to initiate different types of preventive treatment in individuals in the at-risk phase of RA.

References:

[1]McCary et al. Lancet. 2004; 19;363(9426):2015-21

[2]Chodick G et al. PLoS Med. 2010;7(9):e1000336

Disclosure of Interests:

Laurette van Boheemen: None declared, S.A. Turk: None declared, M.H. van Beers - Tas: None declared, W.H. Bos Grant/research support from: abbvie, sanofi, roche, celgene, ucb, novartis, Speakers bureau: abbvie, Sanofi, eli lilly, Diane Marsman: None declared, E.N. Griep: None declared, M. Starmans: None declared, C.D. Popa: None declared, A.M. van Sijl: None declared, Maarten Boers: None declared, Michael Nurmohamed Grant/research support from: Not related to this research, Consultant of: Not related to this research, Speakers bureau: Not related to this research, Dirkjan van Schaardenburg: None declared

OP0057 SEX SPECIFIC DIFFERENCES IN EARLY PSORIATIC ARTHRITIS

Background:

Although the prevalence of Psoriatic Arthritis (PsA) is the same in men and women, women experience a higher burden of disease (pain, disability, fatigue) (1).The persistent belief that women tend to over-report their symptoms compared to men may also contribute to under or delayed diagnosis in women. The clinical pattern of PsA also differs, with men presenting more commonly with peripheral and axial joint damage and women being affected more frequently by polyarthritis (2). Furthermore, most disease activity measures contain pain and quality of life measurement metrics that may perform differently by sex. As a result, this may affect the clinician’s perception of disease severity, influence management decisions and subsequently introduce sex bias in prescribing.

Objectives:

To assess sex-related differences in baseline demographics, disease characteristics and evolution over 1 year in patients with newly diagnosed PsA.

Methods:

Our study is embedded in the Dutch south-west Early Psoriatic Arthritis prospective cohort study. We described patient characteristics using simple descriptive analysis techniques. For the comparison across sexes and baseline and 1 year follow up, appropriate tests depending on the distribution were used.

Results:

273 men and 294 women with no significant differences in age and ethnicity were included. Women reported significantly longer duration of symptoms before diagnosis and significantly fewer of them were in paid employment at baseline. Oligoarthritis was the most common pattern of arthritis in both sexes. Polyarthritis and enthesitis were more prevalent in women who also presented at baseline a significantly higher tender joint count (Fig.1) than men but no difference in swollen joint count.

Figure 1.

Longitudinal evolution of TJC68, Pain, VAS global, BRAF for men and women in the first year of PsA.

All composite indices (CPDAI, DAPSA, GRACE, MDA, Psoriatic ArthritiS Disease Activity Score) showed significantly worse results in women at baseline. Women also suffered more frequently from comorbid medical conditions, fatigue and anxiety, and reported more severe limitations in function and worse quality of life.

At 12 months women, despite the improvement they made, reported significantly higher levels of pain compared to men. Although MDA rates increase over time for both sexes,(Fig.2), it remained significantly more prevalent among men (19.0% vs 11.1% at inclusion,p<0.05, and 58.1% vs 35.7%,p<0.00, at T12). DAPSA was significantly higher in women at both timepoints and a significantly higher percentage of men presented remission according to DAPSA score at 12 months.

Figure 2.

Longitudinal evolution of composite measures for men and women in the first year of PsA.

Conclusion:

After 1 year of follow-up women didn’t surpass their baseline disadvantages and despite the improvement, they still present higher disease activity, more pain and lower functional capacity than men. The nature of these findings may advocate a need for sex specific adjustment of treatment strategies and evaluation in psoriatic arthritis as sex-related difference in outcome persisted over time.

References:

[1]Eder L, Thavaneswaran A, Chandran V, Gladman DD. Gender difference in disease expression, radiographic damage and disability among patients with psoriatic arthritis. Annals of the rheumatic diseases. 2013;72(4):578-82.

[2]Orbai AM, Perin J, Gorlier C, Coates LC, Kiltz U, Leung YY, et al. Determinants of Patient-Reported Psoriatic Arthritis Impact of Disease: An Analysis of the Association with Gender in 458 Patients from 14 Countries. Arthritis care & research. 2019.

Disclosure of Interests:

Evangelia Passia: None declared, Marijn Vis Grant/research support from: Novartis, Pfizer – grant/research support, Consultant of: AbbVie, Celgene Corporation, Eli Lilly, Novartis, Pfizer – consultant, Laura C Coates: None declared, Anushka Soni Grant/research support from: Oxford-UCB prize fellowship, Speakers bureau: Janssen and Abbvie, Ilja Tchetverikov: None declared, Andreas Gerards: None declared, Lindy-Anne Korswagen: None declared, Marc R Kok Grant/research support from: BMS and Novartis, Consultant of: Novartis and Galapagos, Wiebo van der Graaff: None declared, Josien Veris-van Dieren: None declared, Natasja Denissen: None declared, F. Fodili: None declared, M. Starmans: None declared, Yvonne Goekoop-Ruiterman: None declared, M. van Oosterhout: None declared, Jolanda Luime: None declared

Physical activity and body composition in patients with ankylosing spondylitis

OBJECTIVE

Patients with ankylosing spondylitis (AS) are at risk for accelerated muscle loss and reduced physical activity. Accurate data are needed on body composition and physical activity in this patient group. The purpose of this study was to investigate body composition and objectively assessed physical activity in patients with AS.

METHODS

Twenty-five AS patients (15 men, mean ± SD age 48 ± 11 years) were compared with 25 healthy adults matched for age, sex, and body mass index. Body composition was measured using a 3-compartment model based on air-displacement plethysmography to assess body volume and deuterium dilution to assess total body water. The fat-free mass index (FFMI; fat-free mass divided by height squared) and the percent fat mass (%FM) were calculated. Daily physical activity was assessed for 7 days using a triaxial accelerometer and physical fitness with an incremental test until exertion on a bicycle ergometer. Blood samples were taken to determine C-reactive protein (CRP) level and tumor necrosis factor α.

RESULTS

Accelerometer output (kilocounts/day) showed the same physical activity level for patients and controls (mean ± SD 319 ± 105 versus 326 ± 66). There was no difference in the FFMI or %FM between the patients and controls. Physical activity was positively related to the FFMI (partial R = 0.38, P = 0.01) and inversely related to CRP level (R = -0.39, P < 0.01), independent of group. CRP level was inversely related to the FFMI, but the effect was less strong than with physical activity (partial R = -0.31, P = 0.03).

CONCLUSION

Daily physical activity may help preserve fat-free mass in patients with AS.