Price, Katharine A.

Introduction Immune-mediated hematologic disorders are relatively rare but potentially life-threatening immune-related adverse events (irAE) with immune checkpoint inhibitor (ICI) therapy (Shiuan, Beckermann et al 2017). The management strategy often relies on systemic corticosteroids and other immunosuppressant agents in steroid-refractory cases (Brahmer, Lacchetti et al 2018). We hereby describe our institution's experience in diagnosing and managing immune-related hematologic adverse events (ir-h-AE). Methods We retrospectively searched the electronic health record for all ir-h-AE diagnosed by treating providers and confirmed by study authors between 2015 and 2020. The search included patients on ICI and the following conditions: immune-related neutropenia (IRN), autoimmune hemolytic anemia (AIHA), cold agglutinin disease (CAD), immune thrombocytopenia (ITP), immune-related pancytopenia, aplastic anemia (AA), and pure red cell aplasia (PRCA). For AIHA, PRCA, and CAD, partial response (PR) was defined as hemoglobin greater than 10 g/dL but < 12 g/dL and 2 g/dL above the nadir without blood product transfusion. Complete response (CR) was defined as hemoglobin of ≥ 12 g/dL and 2 g/dL above the nadir without blood product transfusion (Peñalver, Alvarez-Larrán et al. 2010). For ITP, CR was defined as platelet count ≥ 100 × 109/L and absence of bleeding. PR was defined as platelet count ≥ 30 × 109/L and ≥ two-fold increase from the baseline count and absence of bleeding (Gómez-Almaguer, Tarín-Arzaga et al. 2013). For IRN, CR was defined as absolute neutrophil count (ANC) ≥ 1500/ mm3 on 2 consecutive measurements separated by 7 days; PR was defined as ANC ≥ 500/ mm3 sustained over 7 days. JMP® 14.1 was used for data analysis. Results Seventeen patients were identified, 9 (52.9%) of whom were female (table 1). Median age was 68 years (range 26-78). The most common pre-existing malignancies were melanoma (6 patients, 35.3%), non-small cell lung cancer (4 patients, 23.5%), and gastrointestinal cancer (3 patients, 17.6%). The ir-h-AE included 7 patients (41.2%) with warm AIHA, 4 (23.5%) with ITP (1 had immune-related pancytopenia that resolved with ITP persisting), 3 (17.6%) with IRN, 1 with AA, 1 with CAD, and 1 with PRCA and mild ITP. All patients had received an ICI dose within 60 days of diagnosis (range 3-52 days, median 18 days). Only 1 patient had a concomitant chronic autoimmune disorder (antinuclear antibody-positive arthritis). Four patients (23.5%) were receiving chemotherapy. Sixteen patients (94.1%) required treatment and received corticosteroids. Eight out of 15 evaluable patients (53.3%) responded to corticosteroids only. Another 4 responders (26.7%) required additional therapies including intravenous immunoglobulins (IVIG) (4, 23.5%) and/or rituximab (4, 23.5%). Overall response rate was 71.4% for AIHA and 100% for IRN. ITP was likely underrepresented in our cohort, and the response rate of 66.7% is likely lower than the response rate in clinical practice. This could be related to the fact that many mild thrombocytopenia cases are not further evaluated in clinical practice. None of our patients died from the sequelae of an ir-h-AE. Two patients (11.8%) died within 30 days of ir-h-AE diagnosis (disseminated intravascular coagulation likely due to the underlying malignancy and sepsis from bacterial pneumonia). At the time of ir-h-AE diagnosis, the malignancy was showing evidence of response in 9 patients (52.9%), progression in 6 patients (35.3%), and stability in 2 patients (11.8%). ICI therapy was permanently discontinued in 9 patients (52.9%) and temporarily held in 6 patients (35.3%). Three of the 5 patients (60%), who were rechallenged with ICI therapy, had recurrence of the same ir-h-AE (AIHA) with adequate response to therapy. Non-hematologic irAE (7 patients, 41.2%) included 3 patients with hepatitis, 2 with thyroiditis, 2 with pneumonitis, 1 with colitis, and 1 with dermatitis. Conclusion Our clinical experience with ir-h-AE highlights the importance of exercising vigilance in assessing the hematologic parameters of patients receiving ICI therapy. While relatively rare, ir-h-AE may impact the clinical course of patients with cancer and their eligibility for therapies that have the potential of offering durable control of the underlying malignancy. ir-h-AE respond to classical therapies including corticosteroids, IVIG, and rituximab. Disclosures Block: Merck: Research Funding; Bristol-Myers Squibb: Research Funding; Genentech: Research Funding; Pharmacyclics: Research Funding; Marker Therapeutics: Research Funding; Transgene: Research Funding; Immune Design: Research Funding. Kottschade:Bristol-Myers Squibb: Consultancy, Research Funding.

Abstract Background Patients with human papillomavirus–related oropharyngeal cancers have excellent outcomes but experience clinically significant toxicities when treated with standard chemoradiotherapy (70 Gy). We hypothesized that functional imaging could identify patients who could be safely deescalated to 30 Gy of radiotherapy. Methods In 19 patients, pre- and intratreatment dynamic fluorine-18-labeled fluoromisonidazole positron emission tomography (PET) was used to assess tumor hypoxia. Patients without hypoxia at baseline or intratreatment received 30 Gy; patients with persistent hypoxia received 70 Gy. Neck dissection was performed at 4 months in deescalated patients to assess pathologic response. Magnetic resonance imaging (weekly), circulating plasma cell-free DNA, RNA-sequencing, and whole-genome sequencing (WGS) were performed to identify potential molecular determinants of response. Samples from an independent prospective study were obtained to reproduce molecular findings. All statistical tests were 2-sided. Results Fifteen of 19 patients had no hypoxia on baseline PET or resolution on intratreatment PET and were deescalated to 30 Gy. Of these 15 patients, 11 had a pathologic complete response. Two-year locoregional control and overall survival were 94.4% (95% confidence interval = 84.4% to 100%) and 94.7% (95% confidence interval = 85.2% to 100%), respectively. No acute grade 3 radiation–related toxicities were observed. Microenvironmental features on serial imaging correlated better with pathologic response than tumor burden metrics or circulating plasma cell-free DNA. A WGS-based DNA repair defect was associated with response (P = .02) and was reproduced in an independent cohort (P = .03). Conclusions Deescalation of radiotherapy to 30 Gy on the basis of intratreatment hypoxia imaging was feasible, safe, and associated with minimal toxicity. A DNA repair defect identified by WGS was predictive of response. Intratherapy personalization of chemoradiotherapy may facilitate marked deescalation of radiotherapy.

AbstractBackgroundAggressive dose de‐escalated adjuvant radiation therapy (RT) in patients with human papillomavirus–associated oropharyngeal squamous cell carcinoma (HPV(+)OPSCC).MethodsPatients with HPV(+)OPSCC on a phase II clinical trial of primary surgery and neck dissection followed by dose de‐escalated RT (N = 79) were compared with a cohort of patients who received standard adjuvant therapy (N = 115). Local recurrence‐free, regional recurrence‐free, distant metastases‐free survival, and progression‐free survival (PFS) were assessed.ResultsOf 194 patients, 23 experienced progression at a median of 1.1 years following surgery (interquartile range [IQR] 0.7‐2.0; range 0.3‐5.4); 10 patients in the de‐escalated cohort and 13 patients in the standard cohort. The 3‐year PFS rate for the de‐escalated cohort was 87%, and in the standard cohort was 90% (hazard ratio [HR] 1.18, 95% confidence interval (CI) [0.50‐2.75]).ConclusionPatients with HPV(+)OPSCC who undergo surgical resection and neck dissection and meet criteria for adjuvant therapy can undergo aggressive dose de‐escalation of RT without increasing risk of progression locally, regionally or at distant sites.

We sought to determine the incidence and location of human papillomavirus (HPV)–associated anogenital disease in women with HPV‐positive oropharyngeal squamous cell carcinoma (OPSCC) via a retrospective cohort study with prospective contact to update history at Mayo Clinic in Rochester, Minnesota. Females undergoing treatment for nonmetastatic HPV‐positive OPSCC from 2011 to 2019 were identified. Clinical history and outcomes were abstracted from medical records. Patients without documented anogenital history were contacted, consented, and administered a survey, and external records were requested and reviewed. Seventeen of 46 patients (37.0%) had a history of anogenital HPV‐associated disease, and 16 of 17 (94.1%) required procedures to diagnose or treat HPV lesions. The cervix was the most common site (16/17, 94.1%). Procedures included colposcopy (n = 6), cervical excision (n = 3), cryotherapy (n = 4), and hysterectomy (n = 3). One case of fatal cervical carcinoma was noted, diagnosed 1 year following OPSCC. Three of 17 (17.6%) had HPV‐related vulvovaginal disease, and 1 of 17 had anal disease. Patients with a history of HPV‐positive OPSCC may be at elevated risk for HPV‐associated anogenital disease.

The treatment of patients with HPV-associated oropharyngeal cancer (HPV-OPC) is rapidly evolving and challenging the standard of care of definitive radiotherapy with concurrent cisplatin. There are numerous promising de-escalation strategies under investigation, including deintensified definitive chemoradiotherapy, transoral surgery followed by de-escalated adjuvant therapy, and induction chemotherapy followed by de-escalated locoregional therapy. Definitive radiotherapy alone or with cetuximab is not recommended for curative-intent treatment of patients with locally advanced HPV-OPC. The results of ongoing phase III studies are awaited to help answer key questions and address ongoing controversies to transform the treatment of patients with HPV-OPC. Strategies for de-escalation under investigation include the incorporation of immunotherapy and the use of novel biomarkers for patient selection for de-escalation.

10530 Background: Learner wellbeing may be adversely affected by the experience of discrimination. Eliciting details from this vulnerable population about these experiences is a challenge. This study characterizes trainee experiences of discrimination and inclusion to inform graduate medical education (GME) policies and practice. Methods: Anonymous semi-structured, private phone interviews were conducted with fellows after informed consent. No identifying information was exchanged and the interviewer had no supervisory role over learners. Demographic information was obtained via anonymous online survey. Results: Of 29 fellows approached, 20 consented; 17 interviewed (10 men; median age 32 years). Racial & ethnic distribution: 6 Asian, 2 Black, 2 Multi-racial, 4 White, 3 Hispanic/Latino. All fellows reported discriminatory behavior that they either experienced or witnessed. Incidents of discriminatory behavior towards trainees were more common from patients (pts) (n = 41) than staff (n = 12). Discrimination from pts included requesting a different physician based on accent (n = 13), race (n = 11), perceived avoidance of a trainee considered “different” (n = 11), sex (n = 5), & ethnicity (n = 4). Six trainees were aware of policies against pt discrimination but only 1 trainee reported an incident. Trainees did not report because of the nature of incidents (micro aggressions that are difficult to characterize) and sense of futility of reporting. Discriminatory behavior from staff was based on perceived micro aggressions (n = 4), sex (n = 3), ethnicity (n = 3), ageism (n = 1), and sexual orientation (n = 1). Impact on trainees ranged from negative (personal anguish) to positive (motivation to improve communication). Coping mechanisms included debriefing with family/trainees and focusing on good pt experiences. Trainees felt that having diverse co-fellows, involvement on committees, and supportive program leadership promoted inclusivity. Conclusions: Our study found that discriminatory behavior towards trainees is common. Our methodology allows for honest & safe discussions. GME programs must assess their learning climate with respect to bias/inclusivity & develop appropriate processes.

6095 Background: Prognosis for patients (pts) with locally-advanced, HPV-positive oropharynx squamous cell carcinoma (HPV+OPSCC) is significantly better than for pts with HPV-negative head and neck squamous cell carcinoma (HNSCC). Historic survival of pts with metastatic HNSCC is 6-9 months with palliative therapy. However, the prognosis and survival of pts with HPV+OPSCC with distant metastases is not known. Methods: Pts with HPV+OPSCC with distant metastatic disease were identified from databases from the departments of surgery, radiation, and medical oncology. Demographic and clinical data was abstracted from the medical record. All pts had confirmed HPV/p16+ disease. Results: Fifteen pts with metastatic HPV+ OPSCC were identified. The median age was 57 years (range 42-78, 15 male). The median pack-year smoking was 0 (range 0-120). Primary site included 10 tonsil and 5 tongue base. At diagnosis, one pt had stage III and 14 had stage IV disease (IVA: 9, IVB: 2, IVC: 3). T- and N-stage included T1 (1), T2 (10), T3 (3), T4 (1) and N1 (1), N2a (1), N2b (9), N2c (3), N3 (1). Extracapsular extension was seen in 8 pts, absent in 2, and unknown in 5. Seven pts had lymph node (LN) involvement at level IV/V. Initial therapy for locally-advanced disease included surgery followed by adjuvant radiation (RT) in 1 pt and chemoRT in 8, and definitive chemoRT in 3 pts. Three pts were metastatic at initial diagnosis. Of 6 pts with an isolated metastatic site, 3 pts are alive > 2 years from diagnosis of metastasis (median 1.97 years, range 0.49-2.29). Palliative therapy included surgery (3), RT (9), platinum chemo +/- cetuximab (8), cetuximab alone (2) or with a taxane (2). The most common sites of metastasis included bone (6), lung (5), and LNs (5). The 1-year survival rate after diagnosis of metastatic disease was 92%. The median time to diagnosis of metastatic disease after definitive therapy was 0.47 years (95% CI 0.19-1.29); 75% of pts who developed metastatic disease did so within 1 year of definitive therapy. Of note, 2 of the 15 pts developed a secondary immune-mediated malignancy (melanoma and non-HIV associated Kaposi’s sarcoma). Conclusions: The survival of pts with metastatic HPV+OPSCC is significantly better than that of historic controls.

On June 10, 2019, the US Food and Drug Administration approved pembrolizumab for first-line treatment of metastatic or unresectable human papillomavirus (HPV)–positive and HPV-negative recurrent head and neck squamous cell carcinoma (HNSCC) based on the KEYNOTE-048 phase III study. Pembrolizumab is now the first anti–programmed cell death protein 1 (PD-1) therapy approved in the first-line HNSCC setting. Pembrolizumab is approved as first-line monotherapy for tumors that express programmed death-ligand 1 (PD-L1) or in combination with chemotherapy regardless of PD-L1 expression. As the indications for immunotherapy for HNSCC broaden, practitioners will need to know how to recognize and manage more immunotherapy-related toxicities. The following case study provides insight into the assessment and management of the specific immune-related toxicities of dermatitis and mucositis associated with pembrolizumab-chemotherapy combination therapy using Immuno-Oncology Essentials guidance. Assessment and early management of immunotherapy toxicity is critical, as is a multidisciplinary approach.

Background: Anaplastic thyroid cancer (ATC) has poor prognosis with median overall survival (OS) of ∼6 months. We previously reported high PD-1/PDL-1 staining in ATC, raising the possibility of the productive application of the immunotherapeutic pembrolizumab. However, having found pembrolizumab to anecdotally have limited single-agent activity in ATC, we sought to alternatively define whether pembrolizumab might synergistically combine with chemoradiotherapy as initial ATC therapy. Methods: An investigator-initiated therapeutic phase 2 trial of pembrolizumab, 200 mg intravenously (IV) every 3 weeks, combined with chemoradiotherapy (docetaxel/doxorubicin, 20 mg/m 2 each IV weekly plus volumetric modulated arc therapy) was initiated as frontline therapy (with or without surgery) in ATC to assess efficacy and toxicities. Six-month OS was selected as the primary endpoint using a Simon's optimal design with interim analysis (targeting accrual of 25 patients; Cohort A: prior resection, Cohort B: no resection). Based on a prior patient cohort-treated similarly, but without pembrolizumab, the design was such that, if 6-month true survival is 75%, the probability of declaring the approach worthy of further pursuit would be 91%. Results: Three patients were enrolled, two with rapidly enlarging unresectable neck masses. Early tumor responses were favorable in all three, and all three satisfactorily completed: intended radiotherapy, preceding and radiotherapy-concurrent pembrolizumab, and concurrent chemoradiotherapy. However, all three patients died <6 months following therapy initiation—one from pulmonary metastases and two from otherwise unexpected fatal pulmonary complications occurring subsequent to chemoradiotherapy completion—prompting study closure. Conclusions: Although initially tolerated and effective in terms of locoregional disease control, disappointing survival outcomes compared with historical controls raise uncertainty that the piloted approach merits further pursuit in ATC.

PURPOSE The purpose of this study was to determine if dose de-escalation from 60 to 66 Gy to 30 to 36 Gy of adjuvant radiotherapy (RT) for selected patients with human papillomavirus–associated oropharyngeal squamous cell carcinoma could maintain historical rates for disease control while reducing toxicity and preserving swallow function and quality of life (QOL). PATIENTS AND METHODS MC1273 was a single-arm phase II trial testing an aggressive course of RT de-escalation after surgery. Eligibility criteria included patients with p16-positive oropharyngeal squamous cell carcinoma, smoking history of 10 pack-years or less, and negative margins. Cohort A (intermediate risk) received 30 Gy delivered in 1.5-Gy fractions twice per day over 2 weeks along with 15 mg/m 2 docetaxel once per week. Cohort B included patients with extranodal extension who received the same treatment plus a simultaneous integrated boost to nodal levels with extranodal extension to 36 Gy in 1.8-Gy fractions twice per day. The primary end point was locoregional tumor control at 2 years. Secondary end points included 2-year progression-free survival, overall survival, toxicity, swallow function, and patient-reported QOL. RESULTS Accrual was from September 2013 to June 2016 (N = 80; cohort A, n = 37; cohort B, n = 43). Median follow-up was 36 months, with a minimum follow-up of 25 months. The 2-year locoregional tumor control rate was 96.2%, with progression-free survival of 91.1% and overall survival of 98.7%. Rates of grade 3 or worse toxicity at pre-RT and 1 and 2 years post-RT were 2.5%, 0%, and 0%. Swallowing function improved slightly between pre-RT and 12 months post-RT, with one patient requiring temporary feeding tube placement. CONCLUSION Aggressive RT de-escalation resulted in locoregional tumor control rates comparable to historical controls, low toxicity, and little decrement in swallowing function or QOL.