Abatacept in early polymyalgia rheumatica (ALORS): a proof-of-concept, randomised, placebo-controlled, parallel-group trial

BACKGROUND

Medium-dose glucocorticoids can improve symptoms in nearly all patients with polymyalgia rheumatica. According to its good safety profile, abatacept could be used instead of glucocorticoids in early polymyalgia rheumatica. We aimed to determine whether the efficacy of abatacept is sufficient to justify larger studies in early polymyalgia rheumatica.

METHODS

To evaluate whether abatacept allows low disease activity without glucocorticoids in early polymyalgia rheumatica, we conducted a proof-of-concept, randomised, double-blind, placebo-controlled, parallel-group trial. Participants were recruited from five centres in France (in Brest, Le Mans, Morlaix, Dinan and Saint Malo, and Strasbourg) and were included if they had recent-onset (<6 months) polymyalgia rheumatica with a C-reactive protein (CRP) polymyalgia rheumatica activity score (PMR-AS) of more than 17 without any signs or symptoms of giant cell arteritis (clinical and [18F]fluorodeoxyglucose PET-CT evaluation). Participants were randomly assigned (1:1) to receive weekly subcutaneous abatacept (125 mg) or matching placebo, with glucocorticoid rescue therapy allowed in cases of high disease activity, for 12 weeks, and then glucocorticoid treatment based on disease activity, until week 36. Investigators, patients, outcome assessors, and sponsor personnel were masked to group assignments. The primary endpoint was low disease activity (CRP PMR-AS ≤10) at week 12 without glucocorticoids and without rescue treatment. The study was powered to demonstrate a 60% difference in response rates between groups. Open-ended adverse events were collected at each visit by clinicians and were categorised following system organ class classification after study completion. The ALORS trial is registered with ClinicalTrials.gov, NCT03632187.

FINDINGS

34 patients (22 women and 12 men) were randomly assigned between Dec 13, 2018, and Oct 21, 2021. All patients who had been randomly assigned were included in the analysis. The primary endpoint was reached by eight (50%) of 16 patients in the abatacept group and four (22%) of 18 patients in the placebo group (relative risk 2·2 [0·9-5·5]); crude p=0·15; adjusted p=0·070). Eight (50%) patients in the abatacept and 15 (83%) in the placebo group had adverse events. Four patients (one [6%] in the abatacept group and three [17%] in the placebo group) had serious adverse events. There were no deaths or new safety concerns.

INTERPRETATION

This study suggests that the effect of abatacept alone is not strong enough to justify larger studies in early polymyalgia rheumatica. This is only a first step in deciding whether a larger study should be conducted in early polymyalgia rheumatica and does not exclude a potential effect of abatacept in glucocorticoid-dependent polymyalgia rheumatica.

FUNDING

BMS Pharma France.

PET-Based Radiogenomics Supports KEAP1/NFE2L2 Pathway Targeting for Non-Small Cell Lung Cancer Treated with Curative Radiotherapy

PURPOSE/OBJECTIVE(S)

Radiotherapy (RT) is one of the major treatment options for localized lung cancer. Either delivered in normo- or moderate/highly hypofractionated regimens, use of RT is increasing especially thanks to the development of stereotactic radiotherapy (SBRT). RT is associated with a higher risk of local relapse when compared with surgery but with a preferable toxicity profile. The KEAP1/NFE2L2 mutational status has been proven as significantly correlated with local relapse in patients treated with RT. Several (33) transcriptomic features were previously identified as dependent from the KEAP1/NFE2L2 mutational status. However, these genetic and transcriptomic tests are rarely performed because of their cost and lack of availability. Prediction of the KEAP1/NFE2L2 mutational status on non-invasive modalities such as imaging could help in further personalizing each therapeutic strategy.

MATERIALS/METHODS

Due to the small size of patients with both mutation status (MutKEAP1-NFE2L2) and PET/CT, a first model (RNASeq) predicting the mutation status (MutRNASeq) using the 33 previously identified transcriptomic features was developed on patients from the TCGA-LUSC, TCGA-LUAD, CPTAC-LSCC and CPTAC-LUAD cohorts (770 patients) and externally validated on the NSCLC-Radiogenomics cohort (117 patients). Narrowing the patients to those with an available PET/CT, a second model (RNAPET) was then built and internally validated to predict the previously MutRNASeq probability using PET/CT-extracted radiomics features. The RNAPET model was then validated on an external cohort of 151 patients treated with curative radiotherapy for a localized non-small cell lung cancer (VMAT cohort). For each model, features were combined using a neural network approach (Multilayer Perceptron) within a statistical software modeler. Performances were evaluated based on the ROC-features as well as decision curve analysis.

RESULTS

The RNASeq model resulted in a C-Index of 0.82, Sensitivity (Se) of 70.3% and Specificity (Sp) of 93.4% in the validation cohort. Regarding the PET/CT-based prediction on a training cohort of 101 patients, the retained RNAPET model resulted in an AUC of 0.90 (p < 0.001). With a probability threshold of 20% and applied to the testing cohort, the RNAPET model achieved a C-Index of 0.7 with respective Se/Sp of 60.0% and 80.9% for the prediction of the MutRNASeq. The same radiomics model was validated on the VMAT cohort as patients were significantly stratified based on their risk of locoregional (LR) relapse with a hazard ratio of 2.61 (p = 0.02).

CONCLUSION

Our three-step approach enables the prediction of the MutKEAP1-NFE2L2 using PET/CT-extracted radiomics features and efficiently classified patient at risk of LR relapse in an external cohort treated with radiotherapy. This first evidence should be further evaluated on larger cohorts, and implemented in LR risk prediction models.

Psoas proximal insertion as a simple and reliable landmark for numbering lumbar vertebrae on MRI of the lumbar spine

OBJECTIVE

To evaluate the value of psoas muscle proximal insertion for correct numbering of the lumbar vertebrae in MRI, in particular in case of lumbosacral transitional vertebra (LSTV).

METHODS

Two radiologists assessed 477 MRI scans of the lumbar spine with a sagittal localizer sequence on the whole spine for numbering vertebrae caudally from C2. Proximal insertion of the psoas was determined as the most proximal vertebra with psoas over half of its body on coronal T2 STIR sequence. The last lumbar vertebra was named considering both its number and the presence or absence of LSTV according to Castellvi classification. These same parameters were also assessed on 207 PET-CT scans of another cohort including the whole spine.

RESULTS

Proximal insertion of the psoas was L1 in 94.1% of cases: 98.5% in case of modal anatomy, 81.4% in case of LSTV, and 51.7% in case of missing or supernumerary lumbar vertebra without LSTV. There was no statistically significant difference between MRI and CT data. The inter-reader agreement for determination of psoas proximal insertion was excellent (kappa = 0.96).

CONCLUSION

Proximal insertion of the psoas muscle is a helpful marker for correct numbering of the lumbar vertebrae in MRI and to detect a complete lumbosacral segmentation anomaly.

KEY POINTS

• Proximal insertion of the psoas muscle can be easily identified on a coronal T2 STIR sequence. • Psoas proximal insertion on the spine almost always designates the first lumbar vertebra and is helpful to accurately number all lumbar vertebrae, especially in case of lumbosacral transitional vertebra. • Conversely, when psoas muscle does not insert five lumbar bodies above the apparent lumbosacral joint, the probability of variation in the number of lumbar vertebrae is high.

Comparison of positron emission tomography and lymphangiography in the diagnosis of infradiaphragmatic Hodgkin's disease

PURPOSE

To evaluate the respective roles of positron emission tomography using 18F-fluorodeoxyglucose (FDG-PET) and lymphangiography (LAG) in staging Hodgkin's disease (HD) patients with negative contrast-enhanced infradiaphragmatic computed tomography (CT).

MATERIAL AND METHODS

28 patients underwent FDG-PET and LAG at initial staging. Concordant positive findings on both tests were regarded as actual HD locations and concordant negative findings as true negative. In case of discrepancy, the reference was biopsy or magnetic resonance imaging (MRI).

RESULTS

Concordant results were obtained in 26 patients (24 negative, two positive). In two of the 24 negative patients, PET showed additional lesions in the spleen and one celiac lymph node (one patient), and in the right kidney and the right iliac crest (one patient). Discordant results were obtained in two patients. Both methods indicated infradiaphragmatic involvement in different locations in one patient. In the other, PET was falsely positive (PET done within 24 hours after a negative LAG), which was confirmed by biopsy (benign inflammatory, probably due to LAG medium).

CONCLUSION

FDG-PET and LAG gave comparable results, making invasive LAG unnecessary. Furthermore, LAG, when performed before PET, can be responsible for false-positive PET results.