Immune checkpoint inhibitor-induced inflammatory arthritis persists after immunotherapy cessation

Chronic Immune-Related Adverse Events Following Adjuvant Anti-PD-1 Therapy for High-risk Resected Melanoma

Importance

Agents targeting programmed cell death 1 (PD-1)/PD ligand 1 (PD-L1) improve long-term survival across many advanced cancers and are now used as adjuvant therapy for resected stage III and IV melanomas. The incidence and spectrum of chronic immune-related adverse events (irAEs) have not been well defined.

Objective

To determine the incidence, time course, spectrum, and associations of chronic irAEs arising from adjuvant anti-PD-1 therapy.

Design, Setting, and Participants

This retrospective multicenter cohort study was conducted between 2015 and 2020 across 8 academic medical centers in the United States and Australia. Patients with stage III to IV melanomas treated with anti-PD-1 in the adjuvant setting were included.

Main Outcomes and Measures

Incidence, types, and time course of chronic irAEs (defined as irAEs persisting at least 12 weeks after therapy cessation).

Results

Among 387 patients, the median (range) age was 63 (17-88) years, and 235 (60.7%) were male. Of these patients, 267 (69.0%) had any acute irAE, defined as those arising during treatment with anti-PD-1, including 52 (19.5%) with grades 3 through 5 events; 1 patient each had fatal myocarditis and neurotoxicity. Chronic irAEs, defined as those that persisted beyond 12 weeks of anti-PD-1 discontinuation, developed in 167 (43.2%) patients, of which most (n = 161; 96.4%) were mild (grade 1 or 2) and most persisted until last available follow-up (n = 143; 85.6%). Endocrinopathies (73 of 88; 83.0%), arthritis (22 of 45; 48.9%), xerostomia (9 of 17; 52.9%), neurotoxicities (11 of 15; 73.3%), and ocular events (5 of 8; 62.5%) were particularly likely to become chronic. In contrast, irAEs affecting visceral organs (liver, colon, lungs, kidneys) had much lower rates of becoming chronic irAEs; for example, colitis became chronic in 6 of 44 (13.6%) cases, of which 4 of 6 (66.7%) resolved with prolonged follow-up. Age, gender, time of onset, and need for steroids were not associated with the likelihood of chronicity of irAEs.

Conclusion and Relevance

In this multicenter cohort study, chronic irAEs associated with anti-PD-1 therapy appear to be more common than previously recognized and frequently persisted even with prolonged follow-up, although most were low grade. The risks of chronic irAEs should be integrated into treatment decision-making.

Treatment of rheumatic immune-related adverse events due to cancer immunotherapy with immune checkpoint inhibitors-is it time for a paradigm shift?

Immunotherapy has revolutionized cancer treatment during the last years. Several monoclonal antibodies that are specific for regulatory checkpoint molecules, that is, immune checkpoint inhibitors (ICIs), have been approved and are currently in use for various types of cancer in different lines of treatment. Cancer immunotherapy aims for enhancing the immune response against cancer cells. Despite their high efficacy, ICIs are associated to a new spectrum of adverse events of autoimmune origin, often referred to as immune-related adverse events (irAEs), which limit the utility of these drugs. These irAEs are quite common and can affect almost every organ. The grade of toxicity varies from very mild to life-threatening. The pathophysiological mechanisms behind these events are not fully understood. In this review, we will summarize current evidence specifically regarding the rheumatic irAEs and we will focus on current and future treatment strategies. Treatment guidelines largely support the use of glucocorticoids as first-line therapy, when symptomatic therapy is not efficient, and for more persistent and/or moderate/severe degree of inflammation. Targeted therapies are higher up in the treatment pyramid, after inadequate response to glucocorticoids and conventional, broad immunosuppressive agents, and for severe forms of irAEs. However, preclinical data provide evidence that raise concerns regarding the potential risk of impaired antitumoral effect. This potential risk of glucocorticoids, together with the high efficacy and potential synergistic effect of newer, targeted immunomodulation, such as tumor necrosis factor and interleukin-6 blockade, could support a paradigm shift, where more targeted treatments are considered earlier in the treatment sequence.

[Rheumatic immune adverse events related to immune checkpoint inhibitors-(IrAEs related to ICI)]

New anti-cancer therapeutics have been developed in the recent years and dramatically change prognosis and patient management. Either used alone or in combination, immune checkpoint inhibitors (ICI), such as anti-CTLA-4 and anti-PD1/PD-(L)1, act by removing T-cell inhibition to enhance their antitumor response. This change in therapeutic targets leads to a break in immune-tolerance and a unique toxicity profile resulting in immune complications. These side effects, called Immune-Related Adverse Events (IrAEs), can affect all organs, with a wide range of clinical and biological presentations and severity. Various rheumatic and musculoskeletal manifestations have been reported in the literature, ranging from mild arthralgia, polymyalgia rheumatica, to genuine serodefined rheumatoid arthritis and myositis. Tolerance studies suggest some correlations between IrAEs occurrence and tumor response. Assessment of patient musculoskeletal status prior to the start of the ICI is warranted. Management of rheumatic IrAEs does not usually request ICI discontinuation, exception for myositis or very severe forms where it should be discussed. Treatment relies on non-steroidal anti-inflammatory drugs (NSAIDs) or low dose glucocortioids (<20mg per day). Dose should be adjusted according to severity. The use of disease modifying anti-rheumatic drugs (DMARDs), either conventional and/or biological should be very cautious and result from a shared decision between oncologist and rheumatologist to best manage dysimmunitary complications without hampering the antitumor efficacy of ICI.

TNF in the era of immune checkpoint inhibitors: friend or foe?

Immune checkpoint inhibitors (ICIs) are effective in the treatment of patients with advanced cancer and have emerged as a pillar of standard cancer care. However, their use is complicated by adverse effects known as immune-related adverse events (irAEs), including ICI-induced inflammatory arthritis. ICI-induced inflammatory arthritis is distinguished from other irAEs by its persistence and requirement for long-term treatment. TNF inhibitors are commonly used to treat inflammatory diseases such as rheumatoid arthritis, spondyloarthropathies and inflammatory bowel disease, and have also been adopted as second-line agents to treat irAEs refractory to glucocorticoid treatment. Experiencing an irAE is associated with a better antitumour response after ICI treatment. However, whether TNF inhibition can be safely used to treat irAEs without promoting cancer progression, either by compromising ICI therapy efficacy or via another route, remains an open question. In this Review, we discuss clinical and preclinical studies that address the relationship between TNF, TNF inhibition and cancer. The bulk of the evidence suggests that at least short courses of TNF inhibitors are safe for the treatment of irAEs in patients with cancer undergoing ICI therapy. Data from preclinical studies hint that TNF inhibition might augment the antitumour effect of ICI therapy while simultaneously ameliorating irAEs.

Delayed immune-related adverse events with anti-PD-1-based immunotherapy in melanoma

BACKGROUND

Immune-related adverse events (irAEs) typically occur within 4 months of starting anti-programmed cell death protein 1 (PD-1)-based therapy [anti-PD-1 ± anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4)], but delayed irAEs (onset >12 months after commencement) can also occur. This study describes the incidence, nature and management of delayed irAEs in patients receiving anti-PD-1-based immunotherapy.

PATIENTS AND METHODS

Patients with delayed irAEs from 20 centres were studied. The incidence of delayed irAEs was estimated as a proportion of melanoma patients treated with anti-PD-1-based therapy and surviving >1 year. Onset, clinical features, management and outcomes of irAEs were examined.

RESULTS

One hundred and eighteen patients developed a total of 140 delayed irAEs (20 after initial combination with anti-CTLA4), with an estimated incidence of 5.3% (95% confidence interval 4.0-6.9, 53/999 patients at sites with available data). The median onset of delayed irAE was 16 months (range 12-53 months). Eighty-seven patients (74%) were on anti-PD-1 at irAE onset, 15 patients (12%) were <3 months from the last dose and 16 patients (14%) were >3 months from the last dose of anti-PD-1. The most common delayed irAEs were colitis, rash and pneumonitis; 55 of all irAEs (39%) were ≥grade 3. Steroids were required in 80 patients (68%), as well as an additional immunosuppressive agent in 27 patients (23%). There were two irAE-related deaths: encephalitis with onset during anti-PD-1 and a multiple-organ irAE with onset 11 months after ceasing anti-PD-1. Early irAEs (<12 months) had also occurred in 69 patients (58%), affecting a different organ from the delayed irAE in 59 patients (86%).

CONCLUSIONS

Delayed irAEs occur in a small but relevant subset of patients. Delayed irAEs are often different from previous irAEs, may be high grade and can lead to death. They mostly occur in patients still receiving anti-PD-1. The risk of delayed irAE should be considered when deciding the duration of treatment in responding patients. However, patients who stop treatment may also rarely develop delayed irAE.

Steroid-refractory dermatologic and pulmonary toxicity in a patient on rituximab treated with pembrolizumab for progressive urothelial carcinoma: a case report

BACKGROUND

Increasingly widespread use of programmed cell death protein 1 (PD-1) immune checkpoint inhibitors (ICIs) for treatment of a variety of progressive malignancies continues to reveal a range of immune-related adverse events (irAEs), necessitating immunosuppressive therapy for management. While a single course of systemic corticosteroids may be sufficient for many irAEs, no clear standard-of-care guidelines exist for steroid-refractory cases. We present an unusual case of a patient who developed several steroid-refractory novel irAEs on pembrolizumab despite ongoing B cell-directed immunosuppressive therapy with rituximab, who ultimately noted resolution of symptoms with tacrolimus, a T-cell-directed immunosuppressant.

CASE PRESENTATION

This 72-year-old Caucasian man with Waldenstrom's macroglobulinemia and myelin-associated glycoprotein (MAG) immunoglobulin M (IgM) antibody-associated neuropathy was being treated with maintenance rituximab and intravenous immunoglobulin when he was started on pembrolizumab (2.26 mg/kg) for metastatic urothelial cancer 31 months after surgery and adjuvant chemotherapy. After his third dose of pembrolizumab, he developed a painful blistering papular rash of the distal extremities. He received two more doses of pembrolizumab before he also developed diarrhea, and it was held; he was initiated on 1 mg/kg prednisone for presumed ICI-induced dermatitis and colitis. Skin biopsy 10 weeks after cessation of pembrolizumab and taper of steroids to 20  mg daily revealed a unique bullous erythema multiforme. He was then admitted with dyspnea and imaging concerning for necrotizing pneumonia, but did not respond to antibiotic therapy. Bronchoscopy and biopsy revealed acute fibrinous organizing pneumonia. His symptoms failed to fully respond to multiple courses of high-dose systemic corticosteroids and a trial of azathioprine, but pneumonia, diarrhea, and skin rash all improved markedly with tacrolimus. The patient has since completed his therapy for tacrolimus, continues off of ICI, and has not experienced a recurrence of any irAEs, though has more recently experienced progression of his cancer.

CONCLUSION

Despite immunosuppression with rituximab and intravenous immunoglobulin, two immunomodulators targeting B cells, ICI cessation, and systemic corticosteroid therapy, our patient developed two high-grade unusual irAEs, bullous erythema multiforme and acute fibrinous organizing pneumonia. Our patient's improvement with tacrolimus can offer critical insight into the pathophysiology of steroid-refractory irAEs.

Lactate modulation of immune responses in inflammatory versus tumour microenvironments

The microenvironment in cancerous tissues is immunosuppressive and pro-tumorigenic, whereas the microenvironment of tissues affected by chronic inflammatory disease is pro-inflammatory and anti-resolution. Despite these opposing immunological states, the metabolic states in the tissue microenvironments of cancer and inflammatory diseases are similar: both are hypoxic, show elevated levels of lactate and other metabolic by-products and have low levels of nutrients. In this Review, we describe how the bioavailability of lactate differs in the microenvironments of tumours and inflammatory diseases compared with normal tissues, thus contributing to the establishment of specific immunological states in disease. A clear understanding of the metabolic signature of tumours and inflammatory diseases will enable therapeutic intervention aimed at resetting the bioavailability of metabolites and correcting the dysregulated immunological state, triggering beneficial cytotoxic, inflammatory responses in tumours and immunosuppressive responses in chronic inflammation.

Rheumatic Complications of Immune Checkpoint Inhibitors

Immune checkpoint inhibitors activate the immune system to combat cancer. In doing so, however, they can cause immune-related adverse events (irAEs), including rheumatic syndromes, such as inflammatory arthritis, polymyalgia rheumatica, and myositis. This article reviews rheumatic irAEs that may be encountered in the general medicine practice and provides guidance to support prompt recognition, referral, and treatment of these patients.

Adverse events induced by immune checkpoint inhibitors

Immune checkpoint inhibitors have revolutionized the treatments of cancers but are also associated with immune related adverse events that can interfere with their use. The types and severity of adverse events vary with checkpoint inhibitors. A single mechanism of pathogenesis has not emerged: postulated mechanisms involve direct effects of the checkpoint inhibitor, emergence of autoantibodies or autoreactive T cells, and destruction by toxic effects of activated T cells. Several host factors such as genotypes, preexisting autoimmune disease, inflammatory responses and others may have predictive value. Ongoing investigations seek to identify ways of modulating the autoimmunity without affecting the anti-tumor response with agents that are specific for the autoimmune mechanisms.

First use of tofacitinib to treat an immune checkpoint inhibitor-induced arthritis

Immune checkpoint inhibitors have revolutionised cancer treatment; however, immune-related adverse events do occur, with up to 7% developing inflammatory arthritis. Common rheumatoid arthritis therapies such as methotrexate, prednisolone and biologics have been used to treat this arthritis in small, uncontrolled case series with varying success. In this case of personalised medicine, we report the first use of tofacitinib, a small molecular inhibitor of the Janus kinase-signal transducer and activator of transcription pathway, to treat checkpoint inhibitor-related inflammatory arthritis. This resulted in a rapid clinical response and complete, sustained remission of the arthritis with associated marked reduction in synovial molecular and cellular immune response.

Treatment of immune checkpoint inhibitor-induced inflammatory arthritis

PURPOSE OF REVIEW

This review summarizes the current evidence on treatment strategies for inflammatory arthritis because of cancer treatment with immune checkpoint inhibitors (ICI), prognosis of ICI-induced arthritis, and management of patients with preexisting inflammatory arthritis receiving ICI therapy.

RECENT FINDINGS

Inflammatory arthritis is the most common rheumatic immune-related adverse event observed in patients receiving ICI therapy. Most patients can successfully be treated with low doses of corticosteroids or conventional synthetic disease modifying anti-rheumatic drugs (DMARDs). A small minority will develop severe symptoms requiring biologic therapy including TNF inhibitors and IL-6 receptor inhibitors. Many cases of inflammatory arthritis will resolve with cessation of ICI therapy. Some patients will develop persistent arthritis despite discontinuation. Patients with preexisting inflammatory arthritis (e.g. rheumatoid arthritis) commonly flare on ICI therapy, but can usually be managed with corticosteroids.

SUMMARY

Inflammatory arthritis following ICI therapy for cancer is relatively common and the practicing rheumatologist should be able to recognize and manage it in conjunction with Oncology. The majority of patients respond to corticosteroids, but some will need treatment with conventional synthetic or biologic DMARDs. Additional studies should investigate the effects of immunosuppression on tumor response and the use of ICI therapy in patients with preexisting autoimmune disease.

The PD-1:PD-L1 axis in Inflammatory Arthritis

The activation of antigen specific T cells during an immune response is a tightly regulated process at the level of both costimulatory and coinhibitory receptors. One such coinhibitory receptor or checkpoint inhibitor which has received much attention in the field of oncology is the programmed cell death protein 1 (PD-1). Blockade of PD-1 or its ligand PD-L1 has proven successful in the treatment of a wide variety of cancers, therefore highlighting an important role for this pathway in anti-tumour immune responses. However, a caveat of PD-1 therapy and boosting anti-tumour immune responses is the development of self-reactive T cells which can lead to the induction of various autoimmune or inflammatory diseases, referred to as immune- related adverse events (irAEs). The emergence of rheumatological irAEs such as Inflammatory Arthritis (IA) in recent years has highlighted the importance of PD-1 in maintaining self-tolerance. Furthermore, the emergence of rheumatology related irAEs raises an important question as to how defects in this pathway can contribute to spontaneous rheumatological disease. In this review, we describe the biological distribution, function and regulation of the PD-1 pathway, its potential role in IA and irAE related IA.

EULAR points to consider for the diagnosis and management of rheumatic immune-related adverse events due to cancer immunotherapy with checkpoint inhibitors

BACKGROUND

Rheumatic and musculoskeletal immune-related adverse events (irAEs) are observed in about 10% of patients with cancer receiving checkpoint inhibitors (CPIs). Given the recent emergence of these events and the lack of guidance for rheumatologists addressing them, a European League Against Rheumatism task force was convened to harmonise expert opinion regarding their identification and management.

METHODS

First, the group formulated research questions for a systematic literature review. Then, based on literature and using a consensus procedure, 4 overarching principles and 10 points to consider were developed.

RESULTS

The overarching principles defined the role of rheumatologists in the management of irAEs, highlighting the shared decision-making process between patients, oncologists and rheumatologists. The points to consider inform rheumatologists on the wide spectrum of musculoskeletal irAEs, not fulfilling usual classification criteria of rheumatic diseases, and their differential diagnoses. Early referral and facilitated access to rheumatologist are recommended, to document the target organ inflammation. Regarding therapeutic, three treatment escalations were defined: (1) local/systemic glucocorticoids if symptoms are not controlled by symptomatic treatment, then tapered to the lowest efficient dose, (2) conventional synthetic disease-modifying antirheumatic drugs, in case of inadequate response to glucocorticoids or for steroid sparing and (3) biological disease-modifying antirheumatic drugs, for severe or refractory irAEs. A warning has been made on severe myositis, a life-threatening situation, requiring high dose of glucocorticoids and close monitoring. For patients with pre-existing rheumatic disease, baseline immunosuppressive regimen should be kept at the lowest efficient dose before starting immunotherapies.

CONCLUSION

These statements provide guidance on diagnosis and management of rheumatic irAEs and aim to support future international collaborations.

Toxicities from immunotherapy: From clinical trials to real-world clinical practice

In recent years, immunotherapy has become an important pillar of cancer treatment, with high response rates regardless of tumour histology or baseline mutations. However, immune activation associated with check-point inhibitors is not selective and a large variety of immune-related adverse events have been associated with anti-PD1, anti-PD-1/L-1 and anti-CTLA-4 agents. Though diagnosis and treatment of these toxicities have been established according to the recommendations from clinical trials and in line with the autoimmune disorders that they mimic, increasing real-world data is coming up showing that these adverse events may have differential characteristics and management, especially in terms of the use of corticoids, second-line treatments, salvage therapy for life-threatening cases and reintroduction of immunotherapy. Herein we present a comprehensive review of current recommendations and real-world data on the main immune-related adverse events of immunotherapy.

Expert Perspective: Immune Checkpoint Inhibitors and Rheumatologic Complications

Rheumatologists increasingly receive consults for patients treated with immune checkpoint inhibitors (ICIs) for cancer. ICIs can cause inflammatory syndromes known as immune-related adverse events (IRAEs). Several rheumatic IRAEs have been reported, including inflammatory arthritis, polymyalgia rheumatica, and myositis. For patients who present with musculoskeletal symptoms while receiving ICI therapy, it is important to have an algorithm for evaluation. The differential diagnosis includes a range of musculoskeletal syndromes, such as crystalline arthritis, mechanical issues, and osteoarthritis, in addition to IRAEs. After diagnosing a rheumatic IRAE, rheumatologists must work with the patient and the oncologist to form a treatment plan. Treatment of IRAEs is guided by severity. Evidence for management is limited to observational studies. Inflammatory arthritis and polymyalgia rheumatica are treated with nonsteroidal antiinflammatory drugs in mild cases, glucocorticoids for moderate-to-severe cases, and sometimes require other disease-modifying antirheumatic drugs. Myositis due to ICIs can be accompanied by myocarditis or myasthenia gravis. Glucocorticoids and withholding the ICI are usually required to treat myositis; some patients with severe myositis require intravenous immunoglobulin or plasmapheresis. Further research is needed to optimize treatment of IRAEs that does not compromise the antitumor effect of ICIs.

Identification and Classification of Polymyalgia Rheumatica (PMR) and PMR-Like Syndromes Following Immune Checkpoint Inhibitors (ICIs) Therapy: Discussion Points and Grey Areas Emerging from a Systematic Review of Published Literature

Background: Polymyalgia Rheumatica (PMR) is one of the most frequent rheumatologic immune-related adverse effects (IRAEs) in cancer patients following therapy with immune checkpoint inhibitors (ICIs). Atypical findings in many patients often lead to diagnosing PMR-like syndromes. Materials and methods: The aim of our research was to review reported diagnoses of PMR and PMR-like syndromes following ICIs therapy, and assess whether they can be redefined as adverse drug reaction (ADR). In line with PRISMA guidelines, we carried out a systematic search on three main bibliographic databases, based on a combination of subject headings and free text. We included all studies and case-reports published after 2011 (when FDA approved the use of the first ICI) describing the association of PMR or PMR-like syndromes with all types of ICIs therapy. We excluded reviews, conference abstracts, comments, secondary articles, and non-English language studies. Results: We reviewed data from seven studies and eight case-reports, involving a total of 54 patients. Limitations included: the small size of all studies; only one retrospective study used validated criteria for PMR; most reports assessed IRAEs by clinical judgment only and did not seek validation through assessment scales. To date, it remains a conundrum whether IRAEs-PMR is identical to the idiopathic form of the disease, or whether it should be considered a subset of the disease or a new entity. Conclusions: Our review indicates that the relationship between PMR and ICIs therapy is yet to be clearly understood and defined and that future research should remedy the current limits in study design.

Impact of COVID-19 on patients with rheumatic complications of cancer immunotherapy: results of a registry survey

Immune checkpoint inhibitors (ICI) block negative regulatory molecules, such as CTLA-4, PD-1 and PD-L1, in order to mount an antitumor response. T cells are important for antiviral defense, but it is not known whether patients with cancer treated with ICI are more or less vulnerable to viral infections such as COVID-19. Furthermore, immunosuppressive treatment of immune-related adverse events (irAE) may also impact infection risk. Rheumatic irAEs are often persistent, and can require long-term treatment with immunosuppressive agents. The aim of this study was to determine the incidence of COVID-19 infection and assess changes in ICI and immunosuppressive medication use among patients enrolled in a prospective rheumatic irAE registry during the height of the COVID-19 pandemic. On April 16 2020, following the ‘surge’ of COVID-19 infections in the New York Tri-State area, we sent a 23-question survey to 88 living patients enrolled in a single institutional registry of patients with rheumatic irAE. Questions addressed current cancer and rheumatic irAE status, ICI and immunosuppressant medication use, history of COVID-19 symptoms and/or diagnosed infection. A follow-up survey was sent out 6 weeks later. Sixty-five (74%) patients completed the survey. Mean age was 63 years, 59% were female, 70% had received anti-PD-(L)1 monotherapy and 80% had had an irAE affecting their joints. Six patients (10%) had definite or probable COVID-19, but all recovered uneventfully, including two still on ICI and on low-to-moderate dose prednisone. Of the 25 on ICI within the last 6 months, seven (28%) had their ICI held due to the pandemic. In patients on immunosuppression for irAE, none had changes made to those medications as a result of the pandemic. The incidence of COVID-19 was no higher in patients still on ICI. Ten percent of rheumatic irAE patients developed COVID-19 during the NY Tri-state ‘surge’ of March–April 2020. Oncologists held ICI in a quarter of the patients still on them, particularly women, those on anti-PD-(L)1 monotherapy, and those who had had a good cancer response. The incidence of COVID-19 was no higher on patients still on ICI. None of the patients on disease-modifying antirheumatic drugs or biological immunosuppressive medications developed COVID-19.

Arthralgia Induced by BRAF Inhibitor Therapy in Melanoma Patients

Simple Summary

BRAF inhibitors (BRAFi) are standard of care for BRAF-mutated metastatic melanoma (MM). One of the most common side effects is arthralgia, for which a high incidence has been described, but whose clinical presentation and management have not yet been characterized. The aim of this retrospective study was to assess the patterns and clinical course of this drug-induced joint pain and to discuss a potential pathogenesis based on our clinical findings. In our cohort of patients treated with BRAFi between 2010 and 2018, 48 of 154 (31%) patients suffered from new-onset joint pain, which primarily affected small joints with a symmetrical pattern, as can be observed in patients affected by rheumatoid arthritis, the most frequent rheumatic and musculoskeletal disease. Most cases were sufficiently treated by non-steroidal anti-inflammatory drugs; however, some patients required dose reduction or permanent discontinuation of the BRAFi. Interestingly, we found that the occurrence of arthralgia was associated with better tumor control.

Abstract

Introduction: BRAF inhibitors (BRAFi), commonly used in BRAF-mutated metastatic melanoma (MM) treatment, frequently cause arthralgia. Although this is one of the most common side effects, it has not been characterized yet. Methods: We retrospectively included all patients treated with BRAFi +/− MEK inhibitors (MEKi) for MM at the National Center for Tumor Diseases (Heidelberg) between 2010 and 2018 and reviewed patient charts for the occurrence and management of arthralgia. The evaluation was supplemented by an analysis of frozen sera. Results: We included 154 patients (63% males); 31% (48/154) of them reported arthralgia with a median onset of 21 days after the start of the therapy. Arthralgia mostly affected small joints (27/36, 75%) and less frequently large joints (19/36, 53%). The most commonly affected joints were in fingers (19/36, 53%), wrists (16/36, 44%), and knees (12/36, 33%). In 67% (24/36) of the patients, arthralgia occurred with a symmetrical polyarthritis, mainly of small joints, resembling the pattern typically observed in patients affected by rheumatoid arthritis (RA), for which a role of the MAPK signaling pathway was previously described. Patients were negative for antinuclear antibodies, anti-citrullinated protein antibodies, and rheumatoid factor; arthritis was visible in 10 of 13 available PET–CT scans. The development of arthralgia was linked to better progression-free survival and overall survival. Conclusion: Arthralgia is a common side effect in patients receiving BRAFi +/− MEKi therapy and often presents a clinical pattern similar to that observed in RA patients. Its occurrence was associated with longer-lasting tumor control.

Nebenwirkungen immunonkologischer Therapien

Immunonkologische Therapien und insbesondere die Immuncheckpoint-Inhibitoren (ICPi) als Hauptvertreter dieser neuen Substanzklasse kommen bei zunehmender Anzahl von soliden und teils auch hämatologischen Tumorentitäten und Indikationen zum Einsatz. Die relativ hohen (Langzeit-)Tumoransprechraten auch in fortgeschrittenen und therapierefraktären Stadien haben die therapeutischen Möglichkeiten der Onkologie geradezu revolutioniert. Gleichzeitig bringt der zunehmende Einsatz von ICPi auch neue Herausforderungen: Immunonkologische Therapien verursachen ein breites Spektrum an autoimmunen Nebenwirkungen, sogenannten „immune-related adverse events“ (irAEs), die teilweise klassischen Autoimmunopathien ähneln und jedes Organsystem betreffen können. Die große Mehrheit der ICPi-behandelten Patienten erlebt ein irAE an mindestens einem Organsystem und davon weisen ca. 5–20% ein rheumatisches irAEs auf. Diese sind interessanterweise mit einem besseren Tumoransprechraten bei ICPi-Therapie assoziiert und können entweder die Erstmanifestation einer klassischen entzündlich-rheumatischen Erkrankung oder auch nur eine transiente Nebenwirkung mit spezifischen Charakteristika sein. Zweifelsohne wird das interdisziplinäre Management immunvermittelter Nebenwirkungen auch den Rheumatologen in den nächsten Jahren zunehmend beschäftigen. Der vorliegende Artikel fasst die Erkenntnisse zum klinischen Management von irAEs für den praktizierenden Rheumatologen zusammen.

Balancing Cancer Immunotherapy Efficacy and Toxicity

Anti-programmed cell death-1 receptor/programmed cell death-1 receptor ligand-directed therapies are transforming cancer care, with durable antitumor responses observed in multiple cancer types. Toxicities arising from therapy are autoimmune in nature and may affect essentially any organ system. The immunologic basis of such toxities is complex, with contributions from T-cell activation and autoantibody generation. Although less recognized, hypersensitivity reactions are also possible. Although most toxicities resolve with systemic corticosteroids, some require second-line immunosuppression. Furthermore, the safety of drug rechallenge is not well characterized, with variable rates of toxicity flares arising with re-exposure. Herein, we review toxicities of immune checkpoint inhibitor therapies, particularly focusing on issues that allergists/immunologists may clinically encounter, including interstitial nephritis, skin toxicity, and risks associated with immunotherapy rechallenge.

Higher Checkpoint Inhibitor Arthritis Disease Activity may be Associated With Cancer Progression: Results From an Observational Registry

OBJECTIVE

To describe clinical features associated with cancer outcomes of patients with immune checkpoint inhibitor (ICI)-associated arthritis.

METHODS

Observational study of patients with ICI-arthritis enrolled in a single-center registry. Arthritis phenotype and activity, medications, and cancer status were recorded at every visit. We used descriptive statistic, and Kaplan-Meier curves using two-sided log-rank test and Cox regression analysis were used to identify factors associated with cancer progression-free survival (PFS).

RESULTS

Forty-two patients with ICI-arthritis were followed for a median (interquartile range [IQR]) of 7.4 (1.7, 14.7) months. Fifty-seven percent were female, 33% had melanoma, and 69% received anti-programmed death ligand 1 monotherapy. Median time from ICI initiation to arthritis onset was 2.8 (0.8, 11.2) months. Sixty-two percent had a rheumatoid arthritis (RA)-like small-joint presentation; 27% of all patients were rheumatoid factor and/or cyclic citrullinated peptide positive. Median (IQR) Clinical Disease Activity Index (CDAI) on presentation was 15 (8, 24); 62% required systemic glucocorticoids, 55% required disease-modifying antirheumatic drugs (DMARDs), and 69% had ongoing arthritis at 6 months. Arthritis led to ICI discontinuation in five patients. In univariate analysis, baseline CDAI, DMARD use, earlier arthritis onset, and longer duration of follow-up were associated with shorter PFS. In multivariable Cox regression analysis controlling for DMARD use and time to arthritis onset, CDAI was a significant predictor of cancer progression (hazard ratio 1.09, 95% confidence interval [CI] 1.00-1.19, P = 0.05) CONCLUSION: ICI-arthritis most commonly presents with an RA-like phenotype. High disease activity, as measured by CDAI, may portend cancer progression.

Immune checkpoint inhibitor-induced inflammatory arthritis: identification and management

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have proved to be groundbreaking in the field of oncology. However, immune system overactivation from ICIs has introduced a novel medical entity known as immune-related adverse events (irAEs), that can affect any organ or tissue. ICI-induced inflammatory arthritis (ICI-IIA) is the most common musculoskeletal irAE and can lead to significant morbidity and limitation in anti-cancer therapy.

AREAS COVERED

In this review, the authors focus on ICI-IIA. Relevant articles were identified through PubMed searches, spanning 2010 to the present. The authors detail the current understanding of its pathogenesis, diagnostic evaluation, and management strategies.

EXPERT OPINION

ICI-IIA is a complex irAE that we are just beginning to understand mechanistically and pathologically. It often presents later in the disease course than other irAEs and, due to various reasons, is under-recognized. In some patients, ICI-IIA may become a chronic disease, which distinguishes it from most irAEs that resolve after ICI discontinuation. Multiple important questions still demand further research including which patients may develop ICI-IIA? What are possible diagnostic and prognostic markers? Do anti-arthritis therapies interfere with the anti-tumor response? and when should steroid-sparing agents be initiated? Close collaboration and shared decision-making between oncologists, rheumatologists, and the patient are essential when managing this particular irAE.

Immune checkpoint inhibitor toxicities: systems-based approaches to improve patient care and research

Immune checkpoint inhibitors (ICIs) have now been approved in numerous and diverse cancer types and combination regimens. Effective recognition and treatment of ICI toxicities, which might occur acutely, affect any organ system, and produce many distinct clinical syndromes, have emerged as essential goals of ICI management. Thus, developing robust diagnostic and management approaches for ICI toxicity across the health-care system is an urgent and unmet clinical need. In this Personal View, we describe barriers to high-quality care that have constrained the most effective management of patients with cancer receiving ICI treatment. We review education initiatives to enhance patient and physician awareness, which is necessary given the broad spectrum of ICI toxicities often experienced by patients, and assess various systems-based approaches that maximise the chances of appropriate management. In addition, we describe research pipelines that broaden evidence-based approaches and the pathobiology of these novel events. Developing effective, systematic approaches for the recognition and treatment of ICI toxicities will continue to grow in importance as these agents proliferate in cancer care.

Immune checkpoint inhibitor-induced musculoskeletal manifestations

Immune checkpoint inhibitors (ICI) associate with a wide range of immune-related adverse events (Ir-AE), including musculoskeletal manifestations. We aimed at identifying all studies reporting musculoskeletal Ir-AE. An electronic (Medline, Scopus and Web of Science) search was performed using two sets of key words. The first set consisted of: arthritis, musculoskeletal, polymyalgia rheumatica and myositis. The second set consisted of: anti-PD-1, anti-PD-L1, anti-CTLA-4, ipilimumab, tremelimumab, pembrolizumab, nivolumab, atezolizumab, avelumab and durvalumab. We identified 3 prospective studies, 17 retrospective studies and 4 case series reporting 363 patients in total. Combined data from all three prospective studies provide a prevalence rate of 6.13%. Most patients were males (59.68%) and the vast majority (73%) were on programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) inhibitors. Most studies report a median time of ≤ 12 weeks from first ICI administration to symptom onset. The main clinical phenotypes reported were: (a) inflammatory arthritis (57.57%), (b) myositis (14.04%) and (c) polymyalgia rheumatica (PMR) (12.12%). A total of 256 patients required steroids (70.52%) and 67 patients (18.45%) were treated with DMARDs. Positive auto-antibodies and family history of any autoimmune disease were present in 18.48% and 19.04% of cases, respectively. Only a few patients (19%) had to discontinue treatment due to musculoskeletal Ir-AE. Two prospective studies show that significantly more patients with musculoskeletal Ir-AE exhibit a favorable oncologic response compared to patients not exhibiting such manifestations whereas retrospective studies show that 77.22% of patients with musculoskeletal Ir-AE have a good tumor response. One out of 15 patients treated with ICI will develop musculoskeletal Ir-AE; in most cases the severity of these manifestations is mild/moderate and usually ICI may be continued. Rheumatologists should familiarize with this new clinical entity and develop relevant therapeutic algorithms.

Kidney retransplantation after anti-programmed cell death-1 (PD-1)-related allograft rejection

In this report, we describe the first kidney retransplantation performed after anti-programmed cell death-1 (PD-1)-related allograft rejection. In 2014, we administered pembrolizumab (anti-PD-1) for ~9 months to a 57-year-old kidney transplant recipient with metastatic cutaneous squamous cell carcinoma (CSCC). The patient experienced both a complete antitumor response and T cell-mediated allograft rejection requiring reinitiation of hemodialysis. Four-and-a-half years after initiating pembrolizumab, the patient remained without evidence of CSCC relapse and received a kidney transplant from a living-unrelated donor. Ten-and-a-half months after kidney retransplantation, the allograft is functioning well and the patient's CSCC remains in remission. This case illustrates the potential for PD-1 blockade to bring about durable immune-mediated tumor control in chronically immunosuppressed patients, and begins to address the feasibility of kidney retransplantation in patients who have previously received immune checkpoint inhibitor therapy for cancer. Results from this and future cases may help elucidate mechanisms of antitumor immunity and allograft tolerance, and inform updates to transplant decision models. Our report also underscores the need for clinical trials testing novel immunotherapy combinations in solid organ transplant recipients designed to uncouple antitumor and anti-allograft immunity.

Immune checkpoint inhibitor-induced inflammatory arthritis: a qualitative study identifying unmet patient needs and care gaps

Background

Patients treated for cancer with immune checkpoint inhibitors (ICI) may develop autoimmune adverse events, including ICI-induced inflammatory arthritis (IA). ICI-induced IA treatment requires balancing immune activation to fight cancer and immune modulation to control autoimmunity. Our objective was to learn how patients experience ICI-induced IA and potentially conflicting treatment decisions.

Methods

Semi-structured interviews were conducted with participants with rheumatologist-diagnosed ICI-induced IA recruited from a longitudinal cohort. The interview guide probed the experience of diagnosis and treatment, symptoms and impact of ICI-induced IA, coping mechanisms, and treatment decision-making. Two researchers used an iterative coding process to identify themes through inductive thematic analysis and consensus. An overarching conceptual framework was derived from the qualitative analysis to identify care gaps perceived by patients, and inform future research.

Results

Fourteen patients with ICI-induced IA participated in semi-structured interviews. Five overarching themes were identified: an awareness gap leading to delay in diagnosis of IA, descriptors of ICI-induced IA and relationship to other adverse events, emotional and quality-of-life impact of IA, fear and decision-making, and contextual factors including social support.

Conclusions

As reported by patients, ICI-induced IA had a significant functional and emotional impact, even as compared to cancer and other ICI-induced side effects. Increasing awareness and integrated care of ICI-induced IA, and increasing social support are key targets for improving patient care. Additionally, more data on cancer outcomes in patients requiring immunomodulation for ICI-induced IA would help address fear and uncertainty for patients, and better support them through therapeutic decisions.

Immune Checkpoint Inhibition-Does It Cause Rheumatic Diseases? Mechanisms of Cancer-Associated Loss of Tolerance and Pathogenesis of Autoimmunity

Mechanisms of immune checkpoints and their role in autoimmunity are discussed in the context of immune checkpoint inhibitor (ICI) therapy for cancer. The updated clinical spectrum of immune-related adverse events (irAEs), with an in-depth discussion of rheumatic irAEs, is presented. The relationship between ICI-induced loss of self-tolerance in cancer and the implications for understanding of irAEs, rheumatic irAEs in particular, is overviewed.

Immune checkpoint inhibitors in women with gynecologic cancers: Practical considerations

Immune checkpoint inhibitors are an exciting new class of cancer therapeutics. Recently, a PD-1 inhibitor has been approved by the Food and Drug Administration for several indications that are relevant to patients with gynecologic malignancies. In this review, we explore the clinical considerations for the use of checkpoint inhibitor therapy in this population. Specifically, we will discuss the approved indications, recommended dosing, clinical monitoring while on treatment, common adverse events, and treatment of adverse events should they arise. Additionally, we will review mechanisms of resistance and other challenges associated with the use of checkpoint inhibitors. We will conclude with a discussion of possible future directions for immunotherapy in women with gynecologic cancers.

Immunotherapies and Metastatic Cancers: Understanding Utility and Predictivity of Human Immune Cell Engrafted Mice in Preclinical Drug Development

Metastases cause high mortality in several cancers and immunotherapies are expected to be effective in the prevention and treatment of metastatic disease. However, only a minority of patients benefit from immunotherapies. This creates a need for novel therapies that are efficacious regardless of the cancer types and metastatic environments they are growing in. Preclinical immuno-oncology models for studying metastases have long been limited to syngeneic or carcinogenesis-inducible models that have murine cancer and immune cells. However, the translational power of these models has been questioned. Interactions between tumor and immune cells are often species-specific and regulated by different cytokines in mice and humans. For increased translational power, mice engrafted with functional parts of human immune system have been developed. These humanized mice are utilized to advance understanding the role of immune cells in the metastatic process, but increasingly also to study the efficacy and safety of novel immunotherapies. From these aspects, this review will discuss the role of immune cells in the metastatic process and the utility of humanized mouse models in immuno-oncology research for metastatic cancers, covering several models from the perspective of efficacy and safety of immunotherapies.

Immune checkpoint inhibitor-induced inflammatory arthritis: a novel clinical entity with striking similarities to seronegative rheumatoid arthritis

OBJECTIVE

To determine the clinical and serologic similarities and differences between inflammatory arthritis induced by immune checkpoint inhibitors (IA-irAE) and rheumatoid arthritis (RA).

METHODS

In this retrospective cross-sectional comparative study, 20 patients with IA-irAE were age and sex matched to 40 seropositive and 40 seronegative RA patients. Electronic medical records were reviewed from diagnosis of inflammatory arthritis through May 2019. Arthritis characteristics, treatment, and relevant laboratory and serologic studies were captured.

RESULTS

Clinically, IA-irAE differed from seropositive and seronegative RA with respect to disease duration (4.18 versus 11.59 and 13.3 months, respectively, p = 0.005 (IA-irAE vs seropositive RA), p = 0.002 (IA-irAE vs seronegative RA)), polyarticular joint involvement at presentation (75% versus 97.5% and 100%, p = 0.013, p = 0.003), absence of erosive changes (5.9% vs 43.6% and 53.8%, p = 0.005, p = 0.001), mean prednisone dose (24.7 mg versus 16.53 mg and 15.68 mg, p = 0.008, p = 0.005), and use of methotrexate (5.0% versus 85.0% and 70.0%, p < 0.0001, p < 0.0001). Serologically, IA-irAE closely resembled seronegative RA. ANA positivity was seen in a minority of patients and did not differ significantly between all groups; however, the ANA staining pattern (speckled) was similar between IA-irAE and seronegative RA (100% versus 75%, respectively) and was not commonly observed in seropositive RA (18.2%).

CONCLUSION

IA-irAE is a new subset of IA that resembles seronegative RA immunologically. Our findings suggest that further study of IA-irAE might provide a window into underlying pathogenic mechanisms of early-stage seronegative RA. Key Points • Comprehensive comparison of clinical features between inflammatory arthritis irAE (IA-irAE) and regular rheumatoid arthritis indicates IA-irAE as a new subset of inflammatory arthritis. • IA-irAE resembles seronegative RA immunologically, suggesting that study of IA-irAE may provide a window into underlying pathogenic mechanisms of early-stage seronegative RA.

Rheumatic Manifestations in Patients Treated with Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that activate the immune system, aiming at enhancing antitumor immunity. Their clinical efficacy is well-documented, but the side effects associated with their use are still under investigation. These drugs cause several immune-related adverse events (ir-AEs), some of which stand within the field of rheumatology. Herein, we present a literature review performed in an effort to evaluate all publicly available clinical data regarding rheumatic manifestations associated with ICIs. The most common musculoskeletal ir-AEs are inflammatory arthritis, polymyalgia rheumatica and myositis. Non-musculoskeletal rheumatic manifestations are less frequent, with the most prominent being sicca, vasculitides and sarcoidosis. Cases of systemic lupus erythematosus or scleroderma are extremely rare. The majority of musculoskeletal ir-AEs are of mild/moderate severity and can be managed with steroids with no need for ICI discontinuation. In severe cases, more intense immunosuppressive therapy and permanent ICI discontinuation may be employed. Oncologists should periodically screen patients receiving ICIs for new-onset inflammatory musculoskeletal complaints and seek a rheumatology consultation in cases of persisting symptoms.

Autoimmune complications of immunotherapy: pathophysiology and management

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that target inhibitory molecules, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), or its ligand, programmed cell death protein ligand 1 (PD-L1), and lead to immune activation in the tumor micro-environment. ICIs can induce durable treatment responses in patients with advanced cancers, but they are commonly associated with immune related adverse events (irAEs) such as rash, colitis, hepatitis, pneumonitis, and endocrine and musculoskeletal disorders. Almost all patients experience some form of irAE, but high grade irAEs occur in approximately half of those on combination therapy (eg, anti-CTLA-4 plus anti-PD-1), and up to one quarter receiving ICI monotherapy. Fatal irAEs occur in approximately 1.2% of patients on CTLA-4 blockade and 0.4% of patients receiving PD-1 or PD-L1 blockade, and case fatality rates are highest for myocarditis and myositis. IrAEs typically occur in the first three months after ICI initiation, but can occur as early as one day after the first dose to years after ICI initiation. The mainstay of treatment is with corticosteroids, but tumor necrosis factor inhibitors are commonly used for refractory irAEs. Although ICIs are generally discontinued when high grade irAEs occur, ICI discontinuation alone is rarely adequate to resolve irAEs. Consensus guidelines have been published to help guide management, but will likely be modified as our understanding of irAEs grows.

Immunotherapy in Underrepresented Populations of Patients with Cancer: Do We Have Enough Evidence at Present? A Focus on Patients with Major Viral Infections and Autoimmune Disorders

The safety and activity of immune checkpoint inhibitors have been characterized in interventional and observational studies. However, only small studies have specifically investigated these agents in patients who are excluded or underrepresented in clinical trials, frequently referred to as "special populations" or "underrepresented populations." These include older adults, those with dysregulated immune activation, patients with a compromised immune function, and those carrying major viral infections, lymphoproliferative diseases, and major organ dysfunctions. Therefore, there remains substantial uncertainty regarding the use of immune checkpoint inhibitors in these specific settings. The Network of Italian Supportive Care in Oncology has carried out a multidisciplinary project, with the contribution of oncologists and other specialists, to retrieve the existing evidence on the use of immunotherapy in patients with solid and hematological cancers with the final aim to provide an expert guidance. The results of this effort are presented in this article, which is focused on patients with major viral infections or those with immune dysregulation/autoimmune diseases, and could be useful to guide decisions in clinical practice and to design prospective clinical trials focusing on the use of immunotherapy in these populations. IMPLICATIONS FOR PRACTICE: Substantial uncertainty remains regarding the use of immune checkpoint inhibitors in "underrepresented" patients, such as older adults, those with dysregulated immune activation, and patients with a compromised immune function, major viral infections, lymphoproliferative diseases or major organ dysfunctions. The Network of Italian Supportive Care in Oncology has carried out a multidisciplinary project to retrieve the existing evidence on the use of immunotherapy in underrepresented patients with cancer in order provide an expert guidance. The results of this effort, with a focus on patients with major viral infections or those with immune dysregulation/autoimmune diseases, are presented in this article and could be useful to guide decisions both in clinical practice and to design clinical trials.

Immune checkpoint inhibitor-induced inflammatory arthritis as a model of autoimmune arthritis

The development of inflammatory arthritis in patients receiving immune checkpoint inhibitor therapy is increasingly recognized due to the growing use of these drugs for the treatment of cancer. This represents an important opportunity not only to define the mechanisms responsible for the development of this immune-related adverse event and to ultimately predict or prevent its development, but also to provide a unique window into early events in the development of inflammatory arthritis. Knowledge gained through the study of this patient population, for which the inciting event is known, could shed light into the pathogenesis of autoimmune arthritis. This review will highlight the clinical and immunologic features of these entities to define common elements for future study.

Clinical Characteristics and Treatment of Immune-Related Adverse Events of Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) have been changing the paradigm of cancer treatment. However, immune-related adverse effects (irAEs) have also increased with the exponential increase in the use of ICIs. ICIs can break up the immunologic homeostasis and reduce T-cell tolerance. Therefore, inhibition of immune checkpoint can lead to the activation of autoreactive T-cells, resulting in various irAEs similar to autoimmune diseases. Gastrointestinal toxicity, endocrine toxicity, and dermatologic toxicity are common side effects. Neurotoxicity, cardiotoxicity, and pulmonary toxicity are relatively rare but can be fatal. ICI-related gastrointestinal toxicity, dermatologic toxicity, and hypophysitis are more common with anti- CTLA-4 agents. ICI-related pulmonary toxicity, thyroid dysfunction, and myasthenia gravis are more common with PD-1/PD-L1 inhibitors. Treatment with systemic steroids is the principal strategy against irAEs. The use of immune-modulatory agents should be considered in case of no response to the steroid therapy. Treatment under the supervision of multidisciplinary specialists is also essential, because the symptoms and treatments of irAEs could involve many organs. Thus, this review focuses on the mechanism, clinical presentation, incidence, and treatment of various irAEs.

Clinical Characteristics and Treatment of Immune-Related Adverse Events of Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) have been changing the paradigm of cancer treatment. However, immune-related adverse effects (irAEs) have also increased with the exponential increase in the use of ICIs. ICIs can break up the immunologic homeostasis and reduce T-cell tolerance. Therefore, inhibition of immune checkpoint can lead to the activation of autoreactive T-cells, resulting in various irAEs similar to autoimmune diseases. Gastrointestinal toxicity, endocrine toxicity, and dermatologic toxicity are common side effects. Neurotoxicity, cardiotoxicity, and pulmonary toxicity are relatively rare but can be fatal. ICI-related gastrointestinal toxicity, dermatologic toxicity, and hypophysitis are more common with anti- CTLA-4 agents. ICI-related pulmonary toxicity, thyroid dysfunction, and myasthenia gravis are more common with PD-1/PD-L1 inhibitors. Treatment with systemic steroids is the principal strategy against irAEs. The use of immune-modulatory agents should be considered in case of no response to the steroid therapy. Treatment under the supervision of multidisciplinary specialists is also essential, because the symptoms and treatments of irAEs could involve many organs. Thus, this review focuses on the mechanism, clinical presentation, incidence, and treatment of various irAEs.

The relationships between cancer and autoimmune rheumatic diseases

Links between autoimmune rheumatic diseases and cancer continue to be elucidated. In this review, we explore this complex, bidirectional relationship. First, the increased risk of cancer across the breadth of the autoimmune rheumatic diseases is described. The magnitude of risk and types of tumors seen can differ by the type of autoimmune disease, timing of disease course, and even clinical and laboratory features within a particular autoimmune disease, suggesting that targeted cancer screening strategies can be considered. Multiple mechanisms linking autoimmune rheumatic diseases and cancer are discussed, including the development of autoimmunity in the context of naturally occurring anti-tumor immune responses and malignancy arising in the context of inflammation and damage from autoimmunity. Immunosuppression for rheumatic disease can increase risk for certain types of cancers. Finally, immune checkpoint inhibitors, a type of cancer immunotherapy, which cause a variety of inflammatory syndromes of importance to rheumatologists, are reviewed.

A Case of Severe Seronegative Inflammatory Arthritis due to Nivolumab and Review of the Literature

Immune-checkpoint inhibitors (ICIs) have revolutionized the treatment of cancer, yet therapy is often hampered by immune-related adverse events (irAEs) which range from mild to severe life-threatening events. Musculoskeletal (MSK) irAEs leading to discontinuation of ICIs are uncommon but increasingly recognized. We report a challenging case of severe immune-related seronegative inflammatory arthritis due to nivolumab in a patient with stage IV metastatic adenocarcinoma.