Evolution of Immune Checkpoint Blockade-Induced Myocarditis Over 2 Years.

Ipilimumab and nivolumab for melanoma induced smoldering myocarditis remitting with steroids. Rechallenge with nivolumab produced steroid-refractory myocarditis confirmed by electron microscopy. Tacrolimus and mycophenolate transiently reduced inflammation, but antithymocyte globulin induced remission. Cardiomyopathy with fatty infiltration ensued, but the patient succumbed to rampant melanoma progression after lymphocyte depletion. (Level of Difficulty: Advanced.).

Correlates of response and outcomes with talimogene laherperpvec.

BACKGROUND AND OBJECTIVES: Patients with in-transit or limited cutaneous metastatic melanoma may benefit from intralesional injections with talimogene laherparepvec (TVEC), a modified oncolytic herpesvirus. However, its use in patients with adverse prognostic scores in a real-life clinical setting has not been studied. METHODS: We performed a two-center retrospective analysis of 40 patients with metastatic melanoma treated with TVEC from 2015-2017. Demographics, overall response, and survival after therapy were noted. RESULTS: Overall, there was a durable response rate of 40%; median progression-free survival (PFS) was 10.5 months and median overall survival (OS) was not reached. Bulky disease was associated with decreased OS (15.7 months vs not reached, P < .05) and mPFS (2.3 months vs not reached, P < .05), when compared with smaller tumors. Poor performance status (ECOG 2-3) was associated with worse OS (10.2 months vs not reached, P < .05) and PFS (2.1 months vs not reached, P < .05) compared to patients with ECOG 0-1. There was no difference in the outcomes with age greater than 75 or with prior therapies. Adverse events were relatively tolerable. CONCLUSIONS: These findings demonstrate that TVEC is an effective and safe treatment for metastatic melanoma in a real-life clinical setting, and suggest parameters to aid in appropriate therapy selection for optimal response.

Clinical characterization of colitis arising from anti-PD-1 based therapy.

Colitis is a frequent, clinically-significant immune-related adverse event caused by anti-programmed death-1 (PD-1). The clinical features, timing, and management of colitis with anti-PD-1-based regimens are not well-characterized. Patients with advanced melanoma that received either anti-PD-1 monotherapy ("monotherapy") or combined with ipilimumab ("combination therapy") were screened from 8 academic medical centers, to identify those with clinically-relevant colitis (colitis requiring systemic steroids). Of 1261 patients who received anti-PD-1-based therapy, 109 experienced colitis. The incidence was 3.2% (30/937) and 24.4% (79/324) in the monotherapy and combination therapy cohorts, respectively. Patients with colitis from combination therapy had significantly earlier symptom onset (7.2 weeks vs 25.4 weeks, p < 0.0001), received higher steroid doses (median prednisone equivalent 1.5 mg/kg vs 1.0 mg/kg, p = 0.0015) and experienced longer steroid tapers (median 6.0 vs 4.0 weeks, p = 0.0065) compared to monotherapy. Infliximab use and steroid-dose escalation occurred more frequently in the combination therapy cohort compared to monotherapy. Nearly all patients had resolution of their symptoms although one patient died from complications. Anti-PD-1 associated colitis has a variable clinical presentation, and is more frequent and severe when associated with combination therapy. This variability in checkpoint-inhibitor associated colitis suggests that further optimization of treatment algorithms is needed.

Quantitative Spatial Profiling of PD-1/PD-L1 Interaction and HLA-DR/IDO-1 Predicts Improved Outcomes of Anti-PD-1 Therapies in Metastatic Melanoma.

Purpose: PD-1/L1 axis-directed therapies produce clinical responses in a subset of patients; therefore, biomarkers of response are needed. We hypothesized that quantifying key immunosuppression mechanisms within the tumor microenvironment by multiparameter algorithms would identify strong predictors of anti-PD-1 response.Experimental Design: Pretreatment tumor biopsies from 166 patients treated with anti-PD-1 across 10 academic cancer centers were fluorescently stained with multiple markers in discovery (n = 24) and validation (n = 142) cohorts. Biomarker-positive cells and their colocalization were spatially profiled in pathologist-selected tumor regions using novel Automated Quantitative Analysis algorithms. Selected biomarker signatures, PD-1/PD-L1 interaction score, and IDO-1/HLA-DR coexpression were evaluated for anti-PD-1 treatment outcomes.Results: In the discovery cohort, PD-1/PD-L1 interaction score and/or IDO-1/HLA-DR coexpression was strongly associated with anti-PD-1 response (P = 0.0005). In contrast, individual biomarkers (PD-1, PD-L1, IDO-1, HLA-DR) were not associated with response or survival. This finding was replicated in an independent validation cohort: patients with high PD-1/PD-L1 and/or IDO-1/HLA-DR were more likely to respond (P = 0.0096). These patients also experienced significantly improved progression-free survival (HR = 0.36; P = 0.0004) and overall survival (HR = 0.39; P = 0.0011). In the combined cohort, 80% of patients exhibiting higher levels of PD-1/PD-L1 interaction scores and IDO-1/HLA-DR responded to PD-1 blockers (P = 0.000004). In contrast, PD-L1 expression was not predictive of survival.Conclusions: Quantitative spatial profiling of key tumor-immune suppression pathways by novel digital pathology algorithms could help more reliably select melanoma patients for PD-1 monotherapy. Clin Cancer Res; 24(21); 5250-60. ©2018 AACR.

Talimogene laherparepvec: First in class oncolytic virotherapy.

Oncolytic viruses represent a novel drug class in which native or modified viruses mediate tumor regression through selective replication within and lysis of tumor cells as well as induction of systemic antitumor immunity capable of eradicating tumor at distant, uninjected sites. Talimogene laherparepvec (TVEC) is a type I herpes simplex virus genetically modified to preferentially replicate in tumor cells, enhance antigen loading of MHC class I molecules and express granulocyte-macrophage colony-stimulating factor to increase tumor-antigen presentation by dendritic cells. It is presently the only oncolytic virus approved by the FDA with an indication for advanced melanoma based upon improved durable response rate in a randomized, phase III trial. Clinical trials are underway in melanoma investigating TVEC as neoadjuvant monotherapy and in combination with checkpoint inhibitors for unresectable disease as well as in an array of other malignancies. It is appropriate to review TVEC's biology mechanism of action, clinical indication and future directions as a prototype of the burgeoning class of oncolytic viruses.

Chronic granulomatous dermatitis induced by talimogene laherparepvec therapy of melanoma metastases.

Talimogene laherparepvec (TVEC) is the first oncolytic viral immunotherapy approved by the FDA, for advanced melanoma consisting of genetically modified herpes simplex type 1 virus which selectively replicates causing tumor lysis, expressing granulocyte macrophage-colony stimulating factor (GM-CSF) and activating dendritic cells. Intratumoral injection of TVEC produces objective response in 41% of stage IIB-IV M1a melanoma. However, clinical response assessment can be problematic due to immune-related inflammation at established tumor sites. Herein, we report 5 cases of granulomatous dermatitis developing at sites of TVEC injection associated with pathologic complete response in 4 of 5 patients. Over 5 months, TVEC injections were administrated in a median of 20 tumors per patient for 9 median doses prior to biopsy of persistent, indurated nodules. Granulomatous dermatitis with melanophages and melanin pigment incontinence was observed in all samples without evidence of melanoma cells in 4 patients. The fifth patient was rendered melanoma-free by resection of the 1 nodule out of 4 with persistent tumor. Repetitive administration of TVEC or other oncolytic viral immunotherapies mimicking unresolved infection can produce granulomatous inflammation confounding assessment of the degree of tumor response and need for additional TVEC therapy. Tumor biopsies are encouraged after 4 to 6 months of TVEC administration to differentiate melanoma from granulomatous inflammation. Patients with confirmed granulomatous dermatitis replace continued with remained in remission after treatment discontinuation. Inflammatory nodules typically regress spontaneously.

Smoldering myocarditis following immune checkpoint blockade.

BACKGROUND: Severe myocarditis associated with electrical conduction abnormalities and occasionally heart failure has been well documented following treatment with immune checkpoint blockade with an estimated incidence of less than 1%. However, the incidence, early detection, and management of less severe immune-related myocarditis are unknown since most immunotherapy trials have not included routine cardiac monitoring. Herein, we provide the first description of subclinical or smoldering myocarditis with minimal signs and symptoms following immune checkpoint blockade with a single dose of ipilimumab and nivolumab. CASE PRESENTATION: Our patient was diagnosed with immune checkpoint blockade-induced myocarditis based upon an acute rise in serum cardiac troponin I beginning 2 weeks after the initial dose of ipilimumab/nivolumab consistent with the reported median onset of clinical myocarditis at 17 days, as well as a lack of other causes despite extensive cardiac evaluation. The patient initially presented with intractable nausea with no known gastrointestinal etiology. High dose glucocorticoid therapy led to rapid resolution of nausea and a four-fold decrease in troponin I over 4 days. Serum troponin I spiked again following a steroid taper to 13 times the upper limit of normal with endomyocardial biopsy revealing collagen fibrosis and lymphocytic inflammation predominantly comprised of CD8+ T cells consistent with chronic smoldering myocarditis. Serum anti-striated muscle antibodies were also detected with no evidence of rhabdomyolysis. Serum cardiac troponin I levels as an indicator of ongoing myocyte damage gradually improved with chronic prednisone at 10 mg daily. Late addition of intravenous immunoglobulin was associated with rapid normalization of creatine kinase-myocardial band. CONCLUSIONS: This case demonstrates that subclinical, smoldering myocarditis may occur following immune checkpoint blockade, with evidence of both humoral and cell-mediated immunity responsive to corticosteroid therapy. This experience supports early monitoring for myocarditis with serial electrocardiograms and serum troponin I determinations in large, prospective cohorts of patients receiving combination immune checkpoint blockade as early detection and initiation of immunosuppression may forestall fulminant presentation of this disease and limit myocardial damage.

Primary Intraosseous Smooth Muscle Tumor of Uncertain Malignant Potential: Original Report and Molecular Characterization.

We report the first case of primary intraosseous smooth muscle tumor of uncertain malignant potential (STUMP) which is analogous to borderline malignant uterine smooth muscle tumors so designated. The tumor presented in the femur of an otherwise healthy 30-year-old woman. Over a 3-year period, the patient underwent 11 biopsies or resections and 2 cytologic procedures. Multiple pathologists reviewed the histologic material including musculoskeletal pathologists but could not reach a definitive diagnosis. However, metastases eventually developed and were rapidly progressive and responsive to gemcitabine and docetaxel. Molecular characterization and ultrastructural analysis was consistent with smooth muscle origin, and amplification of unmutated chromosome 12p and 12q segments appears to be the major genomic driver of this tumor. Primary intraosseous STUMP is thought to be genetically related to leiomyosarcoma of bone, but likely representing an earlier stage of carcinogenesis. Wide excision and aggressive follow-up is warranted for this potentially life-threatening neoplasm.

Radiotherapy to Control Limited Melanoma Progression Following Ipilimumab.

Durable local control of irradiated cancer and distant abscopal effects are presumably immune mediated. To evaluate the role of radiotherapy (RT) for limited progression after anti-CTLA4 checkpoint inhibition, medical records of all patients with surgically incurable stage III or IV melanoma from a single institution who received ipilimumab as first-line immunotherapy and subsequent RT were reviewed. Sixteen patients who received RT to all sites of limited melanoma progression were analyzed. Eight patients with an incomplete initial response to ipilimumab received RT to new or progressive disease, whereas the remaining 8 patients with a complete initial response to ipilimumab received RT to sites of subsequent recurrence. The median interval from ipilimumab initiation to start of RT was 30 weeks (range, 15-130 wk), a timeframe where delayed response to ipilimumab is rare. The RT dose was predominantly 30 Gy in 5 fractions (41%) or 36 Gy in 6 fractions (26%). Brain radiation was limited to stereotactic radiosurgery in a single patient. The median local control with RT was 31.4 months. The median disease control was 18.7 months, defined as the interval from completion of RT to the start of additional systemic therapy known to impact survival (anti-programmed death-1 or targeted BRAF therapy), hospice enrollment, or death. The overall survival at 1 and 2 years was 87% and 61%, respectively. Seven patients (44%) had no evidence of melanoma at median follow-up of 29.5 months since completion of RT with no additional therapy. This series supports use of RT to limited sites of progression following ipilimumab as an alternative to other systemic treatments such as anti-programmed death-1 antibodies.