Phase 1/2 trial of avelumab combined with utomilumab (4-1BB agonist), PF-04518600 (OX40 agonist), or radiotherapy in patients with advanced gynecologic malignancies.

BACKGROUND: Immune checkpoint blockade has shown mixed results in advanced/recurrent gynecologic malignancies. Efficacy may be improved through costimulation with OX40 and 4-1BB agonists. The authors sought to evaluate the safety and efficacy of avelumab combined with utomilumab (a 4-1BB agonist), PF-04518600 (an OX40 agonist), and radiotherapy in patients with recurrent gynecologic malignancies. METHODS: The primary end point in this six-arm, phase 1/2 trial was safety of the combination regimens. Secondary end points included the objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors and immune-related Response Evaluation Criteria in Solid Tumors, the disease control rate (DCR), the duration of response, progression-free survival, and overall survival. RESULTS: Forty patients were included (35% with cervical cancer, 30% with endometrial cancer, and 35% with ovarian cancer). Most patients (n = 33; 83%) were enrolled in arms A-C (no radiation). Among 35 patients who were evaluable for efficacy, the ORR was 2.9%, and the DCR was 37.1%, with a median duration of stable disease of 5.4 months (interquartile range, 4.1-7.3 months). Patients with cervical cancer in arm A (avelumab and utomilumab; n = 9 evaluable patients) achieved an ORR of 11% and a DCR of 78%. The median progression-free survival was 2.1 months (95% CI, 1.8-3.5 months), and overall survival was 9.4 months (95% CI, 5.6-11.9 months). No dose-limiting toxicities or grade 3-5 immune-related adverse events were observed. CONCLUSIONS: The findings from this trial highlight that, in heavily pretreated patients with gynecologic cancer, even multidrug regimens targeting multiple immunologic pathways, although safe, did not produce significant responses. A DCR of 78% in patients with cervical cancer who received avelumab and utomilumab indicates that further research on this combination in select patients may be warranted.

T-cell receptor beta variable gene polymorphism predicts immune-related adverse events during checkpoint blockade immunotherapy.

BACKGROUND: Immune checkpoint inhibitors have revolutionized cancer treatment. However, they are associated with a unique spectrum of side effects, called immune-related adverse events (irAEs), which can cause significant morbidity and quickly progress to severe or life-threatening events if not treated promptly. Identifying predictive biomarkers for irAEs before immunotherapy initiation is therefore a critical area of research. Polymorphisms within the T-cell receptor beta (TCRB) variable (TRBV) gene have been implicated in autoimmune disease and may be mechanistically linked to irAEs. However, the repetitive nature of the TCRB locus and incomplete genome assembly has hampered the evaluation of TRBV polymorphisms in the past. PATIENTS AND METHODS: We used a novel method for long-amplicon next generation sequencing of rearranged TCRB chains from peripheral blood total RNA to evaluate the link between TRBV polymorphisms and irAEs in patients treated with immunotherapy for cancer. We employed multiplex PCR to create amplicons spanning the three beta chain complementarity-determining regions (CDR) regions to enable detection of polymorphism within the germline-encoded framework and CDR1 and CDR2 regions in addition to CDR3 profiling. Resultant amplicons were sequenced via the Ion Torrent and TRBV allele profiles constructed for each individual was correlated with irAE annotations to identify haplotypes associated with severe irAEs (≥ grade 3). RESULTS: Our study included 81 patients who had irAEs when treated with immunotherapy for cancer. By using principal component analysis of the 81 TRBV allele profiles followed by k-means clustering, we identified six major TRBV haplotypes. Strikingly, we found that one-third of this cohort possessed a TRBV allele haplotype that appeared to be protective against severe irAEs. CONCLUSION: The data suggest that long-amplicon TCRB repertoire sequencing can potentially identify TRBV haplotype groups that correlate with the risk of severe irAEs. Germline-encoded TRBV polymorphisms may serve as a predictive biomarker of severe irAEs.

Effects of glutamine for prevention of radiation-induced esophagitis: a double-blind placebo-controlled trial.

Purpose Acute radiation-induced esophagitis (ARIE) leads to treatment delays, decreased quality of life (QOL), and secondary adverse events such as weight loss. Grade 3 ARIE occurs in 15%-30% of patients undergoing radiotherapy to the esophagus, leading to disruption or discontinuation of treatment. The purpose of this study was to assess the effects of glutamine, a common nutritional supplement, on ARIE in patients with thoracic malignancies. Patients and methods This double-blind, placebo-controlled trial enrolled patients with advanced thoracic malignancies receiving concurrent chemotherapy/radiotherapy or radiotherapy alone, with radiation doses to the esophagus ≥45 Gy. Patients were randomized (1:1) to receive 4 g of glutamine or glycine placebo twice daily. The primary objective was to determine whether glutamine decreases the severity of ARIE in these patients. Secondary objectives included assessment of the effects of glutamine on other measures of ARIE, weight, symptom burden measure assessed by the MD Anderson Symptom Inventory (MDASI-HN) questionnaire and the toxicity profile of glutamine. Results At the time of interim analysis, 53 patients were enrolled: 27 in the glutamine arm and 26 in the placebo arm. There was no difference in the incidence of esophagitis in the first 6 weeks of radiotherapy between the glutamine and placebo arms (74% versus 68%; P = 1.00). There were no significant differences between the two arms for time to onset of esophagitis. The duration of ARIE was shorter (6.3 versus 7.1 weeks; P = 0.54) and median weight loss was lower (0.9 kg versus 2.8 kg; p = 0.83) in the glutamine arm versus the placebo arm. The groups differ significantly in core symptom severity (2.1 vs 1.5, p < .03) but not in head and neck specific symptom severity (1.2 vs 1.1, p < .60) nor in symptom interference (2.1 vs 1.7, p < .22). There was no grade 3 or higher adverse event at least possibly related to glutamine. The study was terminated for futility following interim analysis. Conclusion Oral glutamine was not associated with significant improvement in severity of ARIE, weight loss, head and neck specific symptoms or symptom interference compared with placebo in patients with advanced thoracic malignancies receiving radiotherapy to the esophagus.Clinical trial information. NCT01952847, and date of registration is September 30, 2013.

Decrease in tumor content assessed in biopsies is associated with improved treatment outcome response to pembrolizumab in patients with rare tumors.

BACKGROUND: Decreased tumor content (TC) in resection specimens after neoadjuvant therapy is used to predict prognosis. We investigated whether TC assessed in biopsy specimens or the shift in TC from baseline to on-treatment can be used accordingly to predict response in patients with rare tumors who were treated with pembrolizumab. METHODS: A total of 57 tumors (represented by 173 baseline and 179 on-treatment biopsies) from 57 patients with rare tumors participating in an ongoing phase II clinical trial of pembrolizumab were evaluated. TC was estimated on H&E-stained slides and tumors were dichotomized into low and high TC according to a cut-off of 10%. Necrosis, proliferative fibrosis (PF) and normal tissue were assessed in on-treatment biopsies. TC at baseline and on-treatment, as well as the shift in TC from baseline to on-treatment, was correlated with clinical response defined according to Response Evaluation Criteria in Solid Tumors. RESULTS: A decrease in TC was seen in 14% (n=8); no change in TC was seen in 75% (n=43); and an increase in TC from baseline to on-treatment was seen in 11% (n=6). Objective response was significantly associated with decrease in TC from baseline to on-treatment (38%, 3/8) compared with no change/increase in TC (6%, 3/49) (p=0.031). Patients with a decrease in TC had a significantly increased time to progression (TTP) (75% probability) compared with patients with an increase (20% probability) or no change in TC (19% probability) (p=0.0042). Low TC was seen in 23% (13/57) of the tumors at baseline and in 26% (15/57) on-treatment. High TC was seen in 77% (44/57) of tumors at baseline and in 74% (42/57) on-treatment. No significant associations with response were seen for necrosis, PF or normal tissue in on-treatment biopsies. CONCLUSION: Patients with a decrease in TC from baseline to on-treatment had a significant improvement in objective response and a longer TTP. Our data suggest that the shift in TC might be used to predict response to pembrolizumab in rare tumors. However, further investigations in larger cohorts are needed to determine the clinical value of TC, the shift in TC and the cut-off of 10% assessed in biopsies. TRIAL REGISTRATION NUMBER: NCT02721732.

Phase 2 study of pembrolizumab in patients with advanced rare cancers.

BACKGROUND: Patients with advanced rare cancers have poor prognosis and few treatment options. As immunotherapy is effective across multiple cancer types, we aimed to assess pembrolizumab (programmed cell death 1 (PD-1) inhibitor) in patients with advanced rare cancers. METHODS: In this open-label, phase 2 trial, patients with advanced rare cancers whose tumors had progressed on standard therapies, if available, within the previous 6 months were enrolled in nine tumor-specific cohorts and a 10th cohort for other rare histologies. Pembrolizumab 200 mg was administered intravenously every 21 days. The primary endpoint was non-progression rate (NPR) at 27 weeks; secondary endpoints were safety and tolerability, objective response rate (ORR), and clinical benefit rate (CBR). RESULTS: A total of 127 patients treated between August 15, 2016 and July 27, 2018 were included in this analysis. At the time of data cut-off, the NPR at 27 weeks was 28% (95% CI, 19% to 37%). A confirmed objective response (OR) was seen in 15 of 110 (14%) evaluable patients (complete response in one and partial response in 14). CBR, defined as the percentage of patients with an OR or stable disease ≥4 months, was 38% (n=42). Treatment was ongoing in 11 of 15 patients with OR at last follow-up. In the cohort with squamous cell carcinoma (SCC) of the skin, the NPR at 27 weeks was 36%, ORR 31%, and CBR 38%. In patients with adrenocortical carcinoma (ACC), NPR at 27 weeks was 31%, ORR 15%, and CBR 54%. In the patients with carcinoma of unknown primary (CUP), NPR at 27 weeks was 33%, ORR 23%, and CBR 54%. In the paraganglioma-pheochromocytoma cohort, NPR at 27 weeks was 43%, ORR 0%, and CBR 75%. Treatment-related adverse events (TRAEs) occurred in 66 of 127 (52%) patients, and 12 (9%) had grade ≥3 TRAEs. The most common TRAEs were fatigue (n=25) and rash (n=17). There were six deaths, all of which were unrelated to the study drug. CONCLUSIONS: The favorable toxicity profile and antitumor activity seen in patients with SCC of skin, ACC, CUP, and paraganglioma-pheochromocytoma supports further evaluation of pembrolizumab in this patient population. TRIAL REGISTRATION NUMBER: NCT02721732.

Efficacy of pembrolizumab in patients with pituitary carcinoma: report of four cases from a phase II study.

Pituitary carcinoma is an aggressive tumor characterized by metastatic spread beyond the sellar region. Symptoms can be debilitating due to hormonal excess and survival is poor. Pituitary carcinomas recur despite conventional multimodality treatments. Given the recent advances in the use of immune checkpoint inhibitors (CPIs) to treat various solid cancers, there has been interest in exploring the role of immunotherapy for treating aggressive, refractory pituitary tumors. We treated 4 patients with pituitary carcinoma with pembrolizumab as part of a phase II clinical trial. Two patients (patients 1 and 2) with functioning corticotroph pituitary carcinomas (refractory to surgery, radiotherapy and chemotherapy) had partial radiographic (60% and 32% per Immune-Related Response Evaluation Criteria In Solid Tumors, respectively) and hormonal responses. Patient 1's response continues 42 months after initiation of pembrolizumab and his tumor tissue obtained after treatment with temozolomide demonstrated a hypermutator phenotype with MSH2 and MSH6 gene mutations. Patient 2's tumor after exposure to temozolomide was not sampled, but prior somatic mutational testing was negative. One patient with a non-functioning corticotroph tumor (patient 3) had a best response of stable disease for 4 months. One patient with a prolactin-secreting carcinoma (patient 4) had progressive disease. The latter 2 patients' tumors did not demonstrate a hypermutator phenotype after treatment with temozolomide. Programmed death-ligand 1 staining was negative in all tumors. We report 2 cases of corticotroph pituitary carcinoma responsive to pembrolizumab after prior exposure to alkylating agents. The role of CPIs in treating patients with pituitary carcinoma, the relationship between tumor subtype and response to immunotherapy and mechanisms of hypermutation in this orphan disease require further study.Trial registration number: NCT02721732.

Incidence of immune-related adverse events and its association with treatment outcomes: the MD Anderson Cancer Center experience.

Background Immunotherapy is emerging as the cornerstone for treatment of patients with advanced cancer, but significant toxicity (immune-related adverse events [irAEs]) associated with unbridled T cell activity remains a concern. Patients and methods A retrospective review of the electronic medical records of 290 patients with advanced cancer treated on an immunotherapy-based clinical trial in the Department of Investigational Cancer Therapeutics at The University of Texas MD Anderson Cancer Center between February 2010 and September 2015 was performed. Clinical and laboratory parameters were collected to determine the incidence of irAEs, risk factors, and their association with treatment outcomes. Results Ninety eight of 290 patients (34%) experienced any grade irAEs. Among the 15 (5.2%) patients with grade ≥ 3 irAEs, the most common irAEs were dermatitis and enterocolitis. Although 80% of the patients with grade ≥ 3 irAEs required systemic corticosteroids, all the 15 patients recovered from the irAEs. On re-challenge, 4 of the 5 patients who had received systemic corticosteroids for irAE continued to respond. There were no irAE-related deaths. Importantly, patients with grade ≥ 3 irAEs had improved overall response rate (25 vs. 6%; p = 0.039) and longer median time to progression (30 weeks vs. 10 weeks; p = 0.0040) when compared to those without grade ≥ 3 irAEs. Conclusion Incidence of irAEs with immunotherapeutic agents indicates an active immune status, suggestive of potential clinical benefit to the patient. Further validation of this association in a large prospective study is warranted.

Radiomics to predict immunotherapy-induced pneumonitis: proof of concept.

We present the first reported work that explores the potential of radiomics to predict patients who are at risk for developing immunotherapy-induced pneumonitis. Despite promising results with immunotherapies, immune-related adverse events (irAEs) are challenging. Although less common, pneumonitis is a potentially fatal irAE. Thus, early detection is critical for improving treatment outcomes; an urgent need to identify biomarkers that predict patients at risk for pneumonitis exists. Radiomics, an emerging field, is the automated extraction of high fidelity, high-dimensional imaging features from standard medical images and allows for comprehensive visualization and characterization of the tissue of interest and corresponding microenvironment. In this pilot study, we sought to determine whether radiomics has the potential to predict development of pneumonitis. We performed radiomic analyses using baseline chest computed tomography images of patients who did (N = 2) and did not (N = 30) develop immunotherapy-induced pneumonitis. We extracted 1860 radiomic features in each patient. Maximum relevance and minimum redundancy feature selection method, anomaly detection algorithm, and leave-one-out cross-validation identified radiomic features that were significantly different and predicted subsequent immunotherapy-induced pneumonitis (accuracy, 100% [p = 0.0033]). This study suggests that radiomic features can classify and predict those patients at baseline who will subsequently develop immunotherapy-induced pneumonitis, further enabling risk-stratification that will ultimately lead to better treatment outcomes.

Adverse Events in Cancer Immunotherapy.

Cancer immunotherapy has resulted in durable responses in patients with metastatic disease, unseen with traditional chemotherapy. Several therapies have been approved by the Food and Drug Administration for the treatment of various cancers, including: immune checkpoint inhibitors, cytokines - interleukin 2 (IL-2) and interferon alpha (IFN), and the cancer vaccine sipuleucel-T. These therapies upregulate the immune system to enhance antitumor responses. As a consequence, they can cause inflammatory and immune-related adverse events that can affect one or more organs, can be serious, and on occasion lifethreatening. The management of these adverse events is complex, and requires a multidisciplinary approach involving not only oncologists, but also other internal medicine specialists, to ensure prompt diagnosis and optimal management of these complications.