The Debut of Inflammatory Musculoskeletal Pathology in Patients Receiving Anticancer Therapy with PD-1/PD-L1 Pathway Inhibitors
Authors: Koltakova A. D. , Lila A. M. , Alekseeva O. G. , Fedenko A. A. , Gridneva Y. V. , Olshanskaya A. S. 
Published: October 2022

Objective: to describe musculoskeletal immune-mediated adverse events (iAEs) associated with the therapy of solid tumors with immune checkpoint inhibitors (ICIs, inhibitors of the PD-1/PD-L1 pathway).

Patients and methods. 13 patients receiving ICIs therapy with musculoskeletal iAEs were examined. The average age of patients was 59±10 years. All cases had a histologically verified diagnosis of a malignant solid neoplasm: melanoma (n=5), kidney cancer (n=3), bladder cancer (n=2), non-small cell lung cancer (n=1), breast cancer (n=1), cervical cancer (n=1). All patients were prescribed inhibitors of the PD-1/PD-L1 signaling pathway: nivolumab (n=6), pembrolizumab (n=3), atezolizumab (n=3), prolgolimab (n=1). In 7 (54%) patients, in addition to musculoskeletal disorders, other AEs were also detected: thyroiditis (n=3), neuropathy (n=2), rash (n=1), dry syndrome (n=1), hepatitis (n=1). The median time from the start of antitumor immunotherapy (IT) to the onset of musculoskeletal pathology was 20 [9; 48] weeks.

Results and discussion. Clinical manifestations of musculoskeletal pathology included: synovitis in 9 (69%) patients, tenosynovitis in 11 (85%), enthesitis in 4 (31%), morning stiffness in the joints for more than 30 minutes in 4 (31%). In 11 cases, musculoskeletal pathology was persistent (in 9 patients with arthritis and 2 with periarthritis) and in 2 – transient. The knee (77%), shoulder (69%) and hand (54%) joints were most frequently affected, with bilateral involvement in 9 (69%) patients. Inflammatory changes in the joints were represented by mono- (n=1), oligo- (n=3) and polyarthritis (n=5), including those involving the small joints of the hands and/or feet (n=5) and predominantly affecting the joints of the lower limbs (n=3). In 3 patients with arthritis, periarticular changes dominated in clinical picture (in 2 patients with symmetrical polyarthritis and severe tenosynovitis, in another 1 patient – with RS3PE syndrome). The severity of musculoskeletal pathology was assessed using the CTCAE v5.0 toxicity criteria: grade 1 was documented in 2 (15.5%), grade 2 in 9 (69%), and grade 3 in 2 (15, 5%) patients. Laboratory workup revealed elevation of ESR ≥30 mm/h (median – 34 [14; 42] mm/h) in 7 out of 12 (58%) patients, elevation of CRP level >5 mg/l (median – 7.2 [4.6; 12.9] mg/l) – in 7 out of 10 (70%). In 7 out of 10 patients, antinuclear antibodies (Hep2) were detected in titers: 1:160 (n=2), 1:320 (n=3), 1:640 (n=2). Rheumatoid factor and antibodies to cyclic citrullinated peptide were not detected in any case. Therapy for musculoskeletal AEs included non-steroidal anti-inflammatory drugs (n=10), oral systemic glucocorticoids – GC (n=5), methotrexate – MT (n=1) and hydroxychloroquine (n=5), intra-articular administration of GC (n=1). Five patients with arthritis required long-term therapy (median duration – 12 [3; 12] months), in 1 patient with polyarthritis and severe tenosynovitis, antitumor IT was interrupted for the duration of the course of MTX treatment.

Conclusion. It has been shown that musculoskeletal iAEs have heterogeneous manifestations and may require long-term treatment and in rare cases, anticancer therapy interruption. Additional studies and close cooperation between rheumatologists and oncologists are needed to obtain a more complete understanding of the nature and spectrum of musculoskeletal AEs, to identify their clinical, laboratory and instrumental features, and to develop an management of patients algorithm.