Anti-programmed Cell Death-1 Therapy Research Articles

A phase 2 open-label study of cemiplimab in patients with advanced cutaneous squamous cell carcinoma (EMPOWER-CSCC-1): Final long-term analysis of groups 1, 2, and 3, and primary analysis of fixed-dose treatment group 6

BackgroundIn the phase 2 EMPOWER-CSCC-1 study (NCT02760498), cemiplimab demonstrated antitumor activity against metastatic (mCSCC) and locally advanced cutaneous squamous cell carcinoma (laCSCC). ObjectivesTo report final analysis of weight-based cemiplimab in mCSCC and laCSCC (Groups 1 and 2), fixed-dose cemiplimab in mCSCC (Group 3), and primary analysis of fixed-dose cemiplimab in mCSCC/laCSCC (Group 6). MethodsPatients received cemiplimab (3 mg/kg intravenously [IV] every 2 weeks [Groups 1 and 2]) or cemiplimab (350 mg IV [Groups 3 and 6]) every 3 weeks. The primary endpoint was objective response rate (ORR). Duration of response (DOR) and progression-free survival (PFS) are presented per protocol, according to post-hoc sensitivity analyses that only include the period of protocol-mandated imaging assessments. ResultsAt 42.5 months, ORR for Groups 1–3 (n=193) was 47.2%, estimated 12-month DOR was 88.3%, and median PFS was 26.0 months. At 8.7 months, ORR for Group 6 (n=165 patients) was 44.8%; median DOR and median PFS were not reached. Serious treatment-emergent adverse event rates (grade ≥3) were Groups 1–3: 31.1% and Group 6: 34.5%. LimitationsNon-randomized study, non-survival primary endpoint. ConclusionEMPOWER-CSCC-1 provides the largest prospective data on long-term efficacy and safety for anti-programmed cell death-1 therapy in advanced CSCC.

JAAD Game Changers: “Cutaneous adverse events of anti–programmed cell death-1 therapy in patients with metastatic melanoma: A single-institution cohort”

JAAD Game Changers: “Cutaneous adverse events of anti–programmed cell death-1 therapy in patients with metastatic melanoma: A single-institution cohort”

A novel liver-function-indicators-based prognosis signature for patients with hepatocellular carcinoma treated with anti-programmed cell death-1 therapy

BackgroundThe liver function reserve has a significant impact on the therapeutic effects of anti-programmed cell death-1 (PD-1) for hepatocellular carcinoma (HCC). This study aimed to comprehensively evaluate the ability of liver-function-based indicators to predict prognosis and construct a novel prognostic score for HCC patients with anti-PD-1 immunotherapy.MethodsBetween July 2018 and January 2020, patients diagnosed with HCC who received anti-PD-1 treatment were screened for inclusion in the study. The valuable prognostic liver-function-based indicators were selected using Cox proportional hazards regression analysis to build a novel liver-function-indicators-based signature (LFIS). Concordance index (C-index), the area under the receiver operating characteristic (ROC) curve (AUC), and Kaplan–Meier survival curves were utilized to access the predictive performance of LFIS.ResultsA total of 434 HCC patients who received anti-PD-1 treatment were included in the study. The LFIS, based on alkaline phosphatase-to-albumin ratio index, Child–Pugh score, platelet-albumin score, aspartate aminotransferase-to-lymphocyte ratio index, and gamma-glutamyl transpeptidase-to-lymphocyte ratio index, was constructed and identified as an independent risk factor for patient survival. The C-index of LFIS for overall survival (OS) was 0.692, which was higher than the other single liver-function-based indicator. The AUC of LFIS at 6-, 12-, 18-, and 24-month were 0.74, 0.714, 0.747, and 0.865 for OS, respectively. Patients in the higher-risk LFIS group were associated with both worse OS and PFS. An online and easy-to-use calculator was further constructed for better application of the LFIS signature.ConclusionThe LFIS score had an excellent prognosis prediction ability superior to every single liver-function-based indicator for anti-PD-1 treatment in HCC patients. It is a reliable, easy-to-use tool to stratify risk for OS and PFS in HCC patients who received anti-PD-1 treatment.

A phase 1/2 study of ubamatamab (REGN4018), a MUC16×CD3 bispecific antibody, administered alone or in combination with cemiplimab (anti–PD-1) in patients with recurrent ovarian cancer or MUC16+ endometrial cancer.

TPS5632 Background: Mucin 16 (MUC16) is a cell surface glycoprotein that is overexpressed in ovarian cancer (OC) and endometrial cancer (EC). Ubamatamab is a MUC16 × cluster of differentiation 3 (MUC16×CD3) bispecific antibody that bridges MUC16 on tumor cells and CD3 on T cells to promote T-cell–mediated cytotoxicity. Cemiplimab, a monoclonal antibody targeting the programmed cell death-1 (PD-1) receptor, enhanced MUC16×CD3 activity in preclinical models. In Phase 1 of this first-in-human study (NCT03564340), ubamatamab alone and in combination with cemiplimab demonstrated an acceptable safety profile, durable clinical activity across a range of doses, and linear pharmacokinetics (PK) in patients (pts) with recurrent OC (Liu et al. IGCS 2023. Plenary 03). Phase 2 will assess the efficacy of ubamatamab alone and in combination with cemiplimab in pts with recurrent OC. Ubamatamab will also be evaluated for recurrent advanced or metastatic EC that is MUC16+. Methods: For individuals with recurrent OC, elevated serum cancer antigen (CA)-125 ≥2× the upper limit of normal, and up to four prior lines of cytotoxic therapy, weekly dosing of ubamatamab alone or in combination with cemiplimab will be evaluated in monotherapy and combination therapy expansion cohorts. A Phase 2 cohort will also be randomized 1:1:1 to receive ubamatamab 250 mg IV Q3W or 800 mg IV Q3W or ubamatamab 250 mg IV Q3W + cemiplimab 350 mg IV Q3W. For the EC cohort (≥25% of tumor cells MUC16+, as assessed by immunohistochemistry [IHC]) pts with advanced or metastatic EC that has progressed or is recurrent after prior anti–PD-1 therapy and prior platinum-based chemotherapy will be enrolled. The initial EC cohort will receive ubamatamab 250 mg IV Q3W. Based upon observed safety and activity, additional cohorts may be enrolled to receive ubamatamab 800 mg IV Q3W and/or ubamatamab 250 mg IV Q3W + cemiplimab 350 mg IV Q3W. To limit the risk of cytokine release syndrome, all pts will receive ubamatamab once-weekly step-up dosing prior to addition of cemiplimab and/or Q3W dosing. Expansion cohorts will use a Simon 2-stage study design, with an interim analysis after the first 20 pts. Any treatment arm with ≥3 objective responses may be expanded to 50 pts. In Phase 2, the primary endpoint will be the objective response rate for each arm (RECIST v1.1). Secondary endpoints include duration of response and progression-free survival, safety, PK, and change from baseline in quality of life. Exploratory objectives include clinical correlation with serum CA-125, MUC16 IHC, and immune markers. The study is currently enrolling to these OC and EC expansion cohorts. Clinical trial information: NCT03564340 .

Real-world relapse-free survival data on adjuvant anti-PD-1 therapy for patients with newly diagnosed and recurrent stage III melanoma.

We aimed to compare the relapse-free survival (RFS) in patients treated with adjuvant anti-programmed cell death-1 (anti-PD-1) therapy for a first diagnosis of stage III melanoma to patients treated after resection of the recurrences. Patients treated with adjuvant anti-PD-1 therapy after complete resection of stage III melanoma between September 2018 and January 2021, were included. Depending on when adjuvant anti-PD-1 treatment was initiated, patients were divided over 2 cohorts: for the first diagnosis (cohort A) or for a second or subsequent diagnosis (cohort B) of stage III melanoma. Clinical data and RFS were compared between cohorts. 66 patients were included: 37 in cohort A, 29 in cohort B. Median follow-up time from the start of adjuvant therapy was 21 months and 17 months in cohorts A and B, respectively. Significant differences in ulceration of the primary tumor ( P = 0.032), stage according to the 7th AJCC (American Joint Committee on Cancer , P = 0.026) and type of metastatic involvement ( P = 0.005) were found between cohorts. In cohorts A and B, 18 (49%) and 8 (28%) patients developed a recurrence and the 1-year RFS was 51% and 72%, respectively. In cohort B, RFS remained longer in the patients of which the interval between first diagnosis of stage III melanoma and start of adjuvant therapy was >48 months compared to ≤48 months (83% vs. 65%, P = 0.253). This study demonstrates that patients with recurrent stage III disease, not previously treated with adjuvant systemic therapy, may derive similar benefit to a first diagnosis of stage III patients if access to adjuvant therapy changes.

Blockage of CacyBP inhibits macrophage recruitment and improves anti-PD-1 therapy in hepatocellular carcinoma

BackgroundDespite remarkable advancements in cancer immunotherapy, the overall response rate to anti-programmed cell death-1 (anti-PD-1) therapy in hepatocellular carcinoma (HCC) patients remains low. Our previous study has demonstrated the critical role of CacyBP/SIP (Calcyclin-Binding Protein and Siah-1 Interacting Protein) as a regulator of HCC development and progression. However, the possible impact of CacyBP on the tumor immune microenvironment has not yet been clarified.MethodsThe expressions of CacyBP and Myd88 in HCC cell lines and tissues was detected by bioinformatics analysis, real-time quantitative PCR, western blotting and immunohistochemistry. The interaction between CacyBP and Myd88 was measured using co-immunoprecipitation and immunofluorescence. In vitro and in vivo assays were used to investigate the regulation of CacyBP on tumor-associated macrophages (TAMs).ResultsWe identified that CacyBP was positively correlated with Myd88, a master regulator of innate immunity, and Myd88 was a novel binding substrate downstream of CacyBP in HCC. Additionally, CacyBP protected Myd88 from Siah-1-mediated proteasome-dependent degradation by competitively binding to its Toll/interleukin-1 receptor (TIR) domain. Inhibition of CacyBP-Myd88 signaling subsequently diminished HDAC1-mediated H3K9ac and H3K27ac modifications on the CX3CL1 promoter and reduced its transcription and secretion in HCC cells. Moreover, by using in vitro and in vivo strategies, we demonstrated that depletion of CacyBP impaired the infiltration of TAMs and the immunosuppressive state of the tumor microenvironment, further sensitizing HCC-bearing anti-PD-1 therapy.ConclusionsOur findings suggest that targeting CacyBP may be a novel treatment strategy for improving the efficacy of anti-PD-1 immunotherapy in HCC.

Long-term survival benefit of anti-PD-1 therapy in patients with relapsed or refractory classical Hodgkin lymphoma

Anti-programmed cell death-1 (anti-PD-1) therapies have shown a favorable efficacy and good tolerance for relapsed or refractory (r/r) classical Hodgkin lymphoma (cHL). However, there are limited data on long-term outcomes among patients with r/r cHL who achieve an objective response to anti-PD-1 therapies. A total of 260 responders from four, phase 2 clinical trials were included in this study. The median age was 32 years with a male/female ratio of 1.3:1. After a median follow-up period of 31.1 months, 116 (44.6%) responders experienced disease progression and 18 (6.9%) died. The 3-year progression-free survival (PFS) and overall survival (OS) rates were 55.1% and 89.7% overall. Patients with partial remission (PR) had inferior outcomes compared with those who achieved complete remission (3-year PFS, 29.5% vs. 72.3%, P < 0.001; 3-year OS, 81.5% vs. 94.4%, P = 0.017). Moreover, the survival outcome was inferior for patients with refractory disease compared with those with relapsed disease. Multivariate Cox regression analysis showed PR and refractory disease were independent risk factors for PFS. In conclusion, PR and refractory disease have a negative impact on the survival benefit of anti-PD-1 therapeutics in patients with r/r cHL, which highlights the need for multimodal treatment strategies.

A Subungual Nevoid Melanoma of the Right Hallux from a 65-Year-Old Man: A Case Report.

Nevoid melanoma (NeM) is a rare variant of malignant melanoma characterized by slight cellular atypia, polymorphism, and incomplete maturation. It most frequently occurs on the trunk and arms but rarely on the foot. Here, we report a subungual NeM of the right hallux. A 65-year-old man presented with severe pain of 6 months' duration to his right great toe following self-treatment for an ingrown nail. He was evaluated and treated with debridement of the toenail at an urgent medical center 3 months prior. However, this had not relieved his pain. The patient also noticed discoloration of his distal great toe over the past 3 months. Removal of part of the ingrown nail revealed a pigmented mass extending distally from the matrix. Surgical excision of the mass was performed because of the concern for malignancy. The diagnosis of NeM was based on histologic analysis along with enhanced diagnostic modalities. The patient was further treated with surgical amputation of the great toe and anti-programmed cell death-1 therapy. The patient had no relapse at 1-year follow-up. Nevoid melanoma is a rare variant of malignant melanoma on the toes, which needs to be differentiated from a nevus with atypia, with a variety of modalities including cellular and molecular profiling. The optimal treatment is amputation.

Clinical and pathological characteristics of immune-mediated liver injury caused by immune checkpoint inhibitors

Objective: Cancer immunotherapy can lead to various side effects, termed immune-related adverse events (irAE). This study summarized and analyzed the clinical and pathological characteristics of immune-mediated liver injury caused by immune checkpoint inhibitors (ILICI). Methods: This is a retrospective case series study involving 11 patients diagnosed with ILICI at the Peking Union Medical College Hospital from November 2019 to November 2021. Patient demographic information and clinical data, including gender, age, ILICI onset, clinical and radiological manifestations, pathological features, treatment, and resumption of ICI were retrospectively collected and analyzed. Results: The patients were primarily males (9/11) with a median age of 65 (range: 32-73) years. ICI mainly resulted in either partial remission (4/11) or stable disease (3/11). ILICI occurred after a median of two cycles of anti-programmed cell death-1 (PD-1) therapy, with a median time from the initial and last anti-PD-1 therapy to ILICI onset of 57 days and 17 days, respectively. ILICI was mostly severe (3/11) or very severe (6/11). While the clinical and radiological manifestations were non-specific, the pathological features were active lobular hepatitis and portal inflammation, with prominent CD8+T lymphocyte infiltration. The basic treatment was hepatoprotective drugs (10/11). Glucocorticoids were used as the primary therapy (9/11) but were ineffective in 4 of 9 cases. Of these, 3 of 9 cases received combined treatment with mycophenolate mofetil (MMF), only one of whom achieved remission. By the end of the study, 2 of 11 cases had resumed ICI and neither had experienced an ILICI relapse. Conclusion: The ILICI patients in this study had a corresponding history of ICI treatment and pathological features. The main treatment included hepatoprotective drugs and glucocorticoids. Immunosuppressive drugs were added for some cases but had poor efficacy.

Are more courses of immunochemotherapy beneficial for the short-term outcome of locally advanced esophageal squamous cell carcinoma?

Immune checkpoint inhibitor (ICI) monotherapy and neoadjuvant immunochemotherapy have shown promising results in esophageal carcinoma. However, it is still unclear whether more courses of immunochemotherapy are therapeutically better. We aimed to investigate the safety and efficacy of three courses of neoadjuvant treatment for patients with locally advanced esophageal squamous cell carcinoma (ESCC). Patients with locally advanced ESCC received three courses of camrelizumab plus nab-paclitaxel and capecitabine before undergoing surgery. Additionally, patients received safety, computed tomography (CT), and endoscopy (with endoscopic ultrasonography and mucosal biopsy) assessments before and in the second and third courses of treatment. We used the CT and endoscopic assessment results from the second and third courses for comparison. From May 2020 to December 2021, 47 patients were enrolled at Sun Yat-sen University Cancer Center. In our study, 43 patients completed three courses of preoperative chemotherapy combined with anti-Programmed cell death-1 (PD-1) therapy and radical surgical resection. The toxicity of the third course of immunochemotherapy was mild and well tolerated without increased treatment-related adverse events (TRAEs) and mortality compared with that of the second course of treatment. In terms of efficacy, an additional course of treatment after the second course of treatment was effective, with increased CT and endoscopy T (clinical T stage) downstaging rates by 16.3% and 25.9%, N (clincial N stage) downstaging rates by 7.0% and 11.1%, and objective response rates (ORRs) by 13.6% and 22.0%, respectively. Regardless of downstaging or ORR, three courses of immunochemotherapy appear to be superior to two courses of treatment without increasing TRAEs.

Prognostic value of esophageal cancer immune prognostic index in advanced esophageal squamous cell carcinoma patients with anti-programmed cell death-1 therapy.

This study aimed to determine whether the immune prognostic index (ECIPI), based on hemoglobin (Hb) and neutrophil-to-lymphocyte ratio (NLR), could predict the prognosis in patients with advanced esophageal squamous cell carcinoma (ESCC) receiving programmed cell death-1 (PD-1) inhibitor treatment. Advanced ESCC patients who had been treated with PD-1 inhibitors from Jan 2016 to Oct 2021 were included. Kaplan-Meier method and Cox proportional hazards regression were used to analyze progression-free survival (PFS) and overall survival (OS). The overall response rate (ORR) was the percentage of complete and partial responses. Univariate and multivariate analyses were used for estimating hazard ratio (HR) and 95% confidence interval (CI). Patients were grouped by ECIPI (good: Hb > 105 g/L and NLR ≤ 4.3; intermediate: Hb ≤ 105 g/L and NLR ≤ 4.3, or Hb > 105 g/L and NLR < 4.3; poor: Hb ≤ 105 g/L and NLR > 4.3). Variables for the multivariate model were selected if the p-value was below 0.05 in the univariate analysis. All statistical comparisons were two-way, and a p-value below 0.05 was set as statistical significance. Totally, of 123 ESCC patients with stage III or IV were included in the study. Efficacy evaluation showed that patients with pretreatment ECIPI good had the best ORR compared with those with ECIPI intermediate and ECIPI poor (53% vs. 22% vs. 8%, p< 0.01). Multivariate analysis showed that ECIPI was an independent influential factor for PFS (p= 0.004) and OS (p< 0.001). Kaplan-Meier curves demonstrated that patients with ECIPI good had the longest PFS (median: 11.6 vs. 3.5 vs. 1.7months, p< 0.0001) and OS (median: 23.6 vs. 16.7 vs. 4.0months, p< 0.0001) compared with those with ECIPI intermediate and ECIPI poor. Subgroup analysis indicated that ECIPI good was associated with improved PFS and OS in patients with ECOG 0-1, PD-1 inhibitor plus chemotherapy, first-line treatment, and smoke (all p< 0.05). Pretreatment ECIPI was associated with the prognosis in advanced ESCC patients with anti-PD-1 therapy, suggesting that ECIPI may be a useful tool to identify patients likely sensitive to PD-1 inhibitors.

Discontinuation of anti-PD1 in advanced melanoma: an observational retrospective study from the Italian Melanoma Intergroup

BackgroundImmunotherapy has improved the survival of patients with stage IV melanoma. In responders, clinical benefits may be long-lasting and persist even after treatment discontinuation. The optimal duration of anti-PD1 (anti-Programmed cell death-1) therapy in metastatic melanoma patients remains to be elucidated. Moreover, limited data are available on clinical outcomes of patients that discontinued anti-PD1 immunotherapy in a real-life setting. The aim of this study was to evaluate the progression-free survival (PFS) in patients with metastatic melanoma who interrupted anti-PD-1 treatment in the in the absence of disease progression. MethodsWe retrospectively reviewed patients with advanced/metastatic melanoma treated with anti-PD1 immunotherapy at 23 Italian Melanoma Intergroup (IMI) centres. The study investigated the risk of relapse in patients who stopped anti-PD1 therapy due to CR (Complete response), treatment-related toxicity, or by their own choice after a long period of treatment. Clinical and biological factors associated with or without recurrence were evaluated. ResultsThe study population included 237 patients. The median age of patients was 68.9 years (standard deviation: 13; range 33–95). The median time on treatment was 33 months (standard deviation: 18, 7; range 1–98). Among the 237 patients, 128 (54%) interrupted the anti-PD1 for CR, 74 patients (31.2%) for adverse events (37 patients in CR, 27 patients in partial response (PR), ten patients in stable disease (SD), and 35 patients (14.8%) by their own choice (12 patients in CR, 17 patients in PR, and 6 patients in SD). After a mean follow-up of 21 months (range 1–81), PFS after anti-PD1 discontinuation was 85.7%. Thirty-four patients (14.3%) developed disease progression after a median of 12 months (range 1–35): ten patients (29.4%) after discontinuation in CR, 17 patients (50%) after discontinuation for treatment-related toxicity (seven in CR, five in PR, five in SD), and seven (20.6%) after discontinuation due to the patient’s decision (two in CR, four in PR, one in SD). Only 7.8% of patients who interrupted in CR (10/128), along with 23% of patients who interrupted for limiting toxicity (17/74) and 20% of patients who interrupted by their own choice (7/35), developed recurrence. Regarding patients who discontinued therapy because of CR, we observed a negative association between recurrence and site of primary melanoma, especially mucosal sites (p = <0.05, HR (Hazard ratio) 15.57 IC (confidence interval) 95% 2.64–91.73). Moreover, M1b patients who achieved a CR showed a lower number of relapses (p = <0.05, HR 3.84 IC 95% 1.40–8.48). ConclusionsThis study shows in a real-life setting that, with anti-PD-1 therapy, long-lasting responses, can be maintained after anti-PD1 interruption. In 70.6% of cases, recurrences were observed among patients who did not obtain a CR at treatment discontinuation.

150P Phase I study of fianlimab: A human lymphocyte activation gene-3 (LAG-3) monoclonal antibody, in combination with cemiplimab in advanced melanoma (mel) - Subgroup analysis

Concurrent blockade of LAG-3 may enhance efficacy of anti-programmed cell death-1 (PD-1) therapies. We previously presented safety and efficacy data from the phase 1 study in patients (pts) with advanced mel treated with anti-LAG-3 (fianlimab) in combination with anti-PD-1 (cemiplimab). We demonstrated high clinical activity among pts with anti–PD-1/PD-ligand (L)1-naive (expansion cohort [EC] 6 and 15) advanced mel. Among pts in EC6+EC15 (N=80), the objective response rate (ORR) was 63.8%, the disease control rate (DCR) was 80.0%, and the median duration of response (mDOR) was not reached (NR).

400P Phase I study of fianlimab, a human lymphocyte activation gene-3 (LAG-3) monoclonal antibody, in combination with cemiplimab in advanced melanoma (mel)

Concurrent blockade of LAG-3 may enhance efficacy of anti-programmed cell death-1 (PD-1) therapies. We present updated safety and clinical activity data from patients (pts) with advanced mel treated with concurrent anti-LAG-3 (fianlimab) and anti-PD-1 (cemiplimab).

Multiplexed imaging mass cytometry reveals distinct tumor-immune microenvironments linked to immunotherapy responses in melanoma

BackgroundSingle-cell technologies have enabled extensive analysis of complex immune composition, phenotype and interactions within tumor, which is crucial in understanding the mechanisms behind cancer progression and treatment resistance. Unfortunately, knowledge on cell phenotypes and their spatial interactions has only had limited impact on the pathological stratification of patients in the clinic so far. We explore the relationship between different tumor environments (TMEs) and response to immunotherapy by deciphering the composition and spatial relationships of different cell types.MethodsHere we used imaging mass cytometry to simultaneously quantify 35 proteins in a spatially resolved manner on tumor tissues from 26 melanoma patients receiving anti-programmed cell death-1 (anti-PD-1) therapy. Using unsupervised clustering, we profiled 662,266 single cells to identify lymphocytes, myeloid derived monocytes, stromal and tumor cells, and characterized TME of different melanomas.ResultsCombined single-cell and spatial analysis reveals highly dynamic TMEs that are characterized with variable tumor and immune cell phenotypes and their spatial organizations in melanomas, and many of these multicellular features are associated with response to anti-PD-1 therapy. We further identify six distinct TME archetypes based on their multicellular compositions, and find that patients with different TME archetypes responded differently to anti-PD-1 therapy. Finally, we find that classifying patients based on the gene expression signature derived from TME archetypes predicts anti-PD-1 therapy response across multiple validation cohorts.ConclusionsOur results demonstrate the utility of multiplex proteomic imaging technologies in studying complex molecular events in a spatially resolved manner for the development of new strategies for patient stratification and treatment outcome prediction.

Peripheral T cell cytotoxicity predicts the efficacy of anti-PD-1 therapy for advanced non-small cell lung cancer patients

Anti-programmed cell death-1 (PD-1) therapy exerts beneficial effects in a limited population of cancer patients. Therefore, more accurate diagnostics to predict the efficacy of anti-PD-1 therapy are desired. The present study investigated whether peripheral T cell cytotoxicity predicts the efficacy of anti-PD-1 therapy for advanced non-small cell lung cancer (NSCLC) patients. Advanced NSCLC patients treated with anti-PD-1 monotherapy (nivolumab or pembrolizumab) were consecutively enrolled in the present study. Peripheral blood samples were subjected to an analysis of peripheral T cell cytotoxicity and flow cytometry prior to the initiation of anti-PD-1 therapy. Peripheral T cell cytotoxicity was assessed using bispecific T-cell engager (BiTE) technology. We found that progression-free survival was significantly longer in patients with high peripheral T cell cytotoxicity (p = 0.0094). In the multivariate analysis, treatment line and peripheral T cell cytotoxicity were independent prognostic factors for progression-free survival. The analysis of T cell profiles revealed that peripheral T cell cytotoxicity correlated with the ratio of the effector memory population in CD4+ or CD8+ T cells. Furthermore, the results of flow cytometry showed that the peripheral CD45RA+CD25+/CD4+ T cell ratio was higher in patients with than in those without severe adverse events (p = 0.0076). These results indicated that the peripheral T cell cytotoxicity predicted the efficacy of anti-PD-1 therapy for advanced NSCLC patients.

790MO Phase I study of fianlimab, a human lymphocyte activation gene-3 (LAG-3) monoclonal antibody, in combination with cemiplimab in advanced melanoma (mel)

Concurrent blockade of LAG-3 may enhance efficacy of anti-programmed cell death-1 (PD-1) therapies. We present updated safety and clinical activity data from patients (pts) with advanced mel treated with concurrent anti-LAG-3 (fianlimab) and anti-PD-1 (cemiplimab).

Combination high-dose interleukin-2 and nivolumab for programmed cell death-1 refractory metastatic melanoma: a case series

BackgroundTherapeutic options are needed for metastatic melanoma refractory to therapies directed against programmed cell death-1. High-dose interleukin-2 has the potential to overcome programmed cell death-1 resistance.Case presentationWe report three consecutive Caucasian patients, two female (60 and 55 years old) and one male (56 years old), refractory to anti-programmed cell death-1 therapy who were treated with concurrent nivolumab and standard-dosing bolus high-dose interleukin-2. We did not see any unexpected toxicities with overlapping treatments as compared with either high-dose interleukin-2 or nivolumab alone.ConclusionsThe tolerance and disease control observed among the three patients in this limited series support formal exploration of this combination.

B Cells in Tumor Microenvironment Associated With The Clinical Benefit to Programmed Cell Death Protein-1 Blockade Therapy in Patients With Advanced Esophageal Squamous Cell Carcinoma.

BackgroundB cells and B cell-related gene signatures in the tumor microenvironment (TME) are associated with the efficacy of anti-programmed cell death-1 (anti-PD-1) therapy in several cancer types, but not known for esophageal squamous cell carcinoma (ESCC).Patients and MethodsPatients with advanced ESCC receiving anti-PD-1/PD-L1-based therapy were retrospectively included. A targeted RNA profiling of 770 immune-related genes from archival ESCC tissues was performed. Differential immune-related pathways and the levels of infiltrating immune cells were estimated through Gene Set Enrichment Analysis and CIBERSORT, respectively. CD19 and CD138 expression were evaluated through immunohistochemistry (IHC). The markers evaluated were correlated with clinical benefit (CB; defined as either objective response or stable disease for ≥6 months) and survival.ResultsA total of 64 patients were enrolled. The transcriptome analysis based on 25 patients revealed that B cell signature was significantly increased in patients with CB (P <.05) and correlated with a longer PFS (P = .032) and OS (P = .013). Multiple genes representative of B cells, B cell functions, and plasma cells were upregulated in patients with CB. On further analysis of B cell subtypes in patients with CB, increase of naïve B cells (P = .057) and plasma cells (P <.01) was found but not memory B cells (P = .27). The CD19 expression in tumor stroma, detected by IHC, was higher in patients with CB (P = .033).ConclusionB cells in the TME were associated with CB in patients with advanced ESCC receiving anti-PD-1/PD-L1-based therapy.

P1351: CHARACTERIZING ALLOGENEIC STEM CELL TRANSPLANTATION SAFETY IN PATIENTS WITH HEMATOLOGIC MALIGNANCIES AFTER PEMBROLIZUMAB THERAPY

Background: Although allogeneic stem cell transplantation (allo-SCT) and programmed cell death 1 (PD-1) blockade have separately shown efficacy in some lymphoid malignancies, the safety of allo-SCT after anti–PD-1 therapy in these patients remains a high clinical interest. Aims: We present data from an analysis from 4 KEYNOTE phase 1-3 studies to describe predetermined complications in patients who received allo-SCT following pembrolizumab therapy. Methods: The analysis included patients from the KEYNOTE-013 (NCT01953692, n=20), KEYNOTE-087 (NCT02453594, n=31), KEYNOTE-170 (NCT02576990, n=5), and KEYNOTE-204 (NCT02684292, n=14) trials who have a known allo-SCT transplantation date received within 2 years of the last dose of study pembrolizumab. Descriptive statistics were used for predefined post–allo-SCT complications of interest. The cumulative incidence of acute grade 2-4 graft-versus-host disease (GVHD), acute grade 3-4 GVHD, and chronic GVHD was estimated. The corresponding competing risk events were death without acute grade 2-4 GVHD, death without acute grade 3-4 GVHD, and death without chronic GVHD, respectively. The cumulative incidence of post–allo-SCT transplant-related mortality (TRM) was estimated with relapse as a competing risk. Progression-free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method. Results: Seventy patients were included in the analysis. Median age was 30 y (range, 18-65), 57 (81.4%) had classical Hodgkin lymphoma (cHL), and the rest had non-Hodgkin lymphoma. 69 of 70 (98.6%) patients received pembrolizumab monotherapy; 1 patient received pembrolizumab + lenalidomide. Median duration on study treatment was 5.3 months (range, 0.7-29.6) and median time from last pembrolizumab dose to first allo-SCT was 4.6 months (range, 1-20). Before transplantation, 49 patients (70.0%) had intervening anticancer regimen; 34 (48.6%) had active disease, 31 patients (44.3%) were in remission at time of transplant, and 5 patients (7.1%) had unknown disease status. Overall, 55 patients (78.6%) developed GVHD (acute, 38; chronic, 17). The estimated 6-month post–allo-SCT cumulative incidence was 0.41 (95% CI, 0.30-0.53) for grade II-IV acute GVHD and 0.20 (95% CI, 0.12-0.30) for grade III-IV acute GVHD; 1 year post–allo-SCT was 0.21 (95% CI, 0.12-0.31) for chronic GVHD. Other predetermined complications, including critical illness, immune-mediated adverse events, pulmonary complications, and veno-occlusive liver disease, occurred in 32 patients (45.7%). After a median follow-up (defined as the time from allo-SCT to data cutoff) of 40.1 months (range, 5.1-71.2), the post–allo-SCT median PFS was not reached (NR) (95% CI, 14.5-NR) and the 30-month post–allo-SCT PFS rate was 56.8% (95% CI, 42.9-68.5) (Figure A); median OS was NR (95% CI, NR-NR) and the OS rate at 12 months was 82.2% (Figure B). The estimated post–allo-SCT cumulative incidence for TRM at 6 months was 0.09 (95% CI, 0.03-0.17) and for relapse at 26 months was 0.27 (95% CI, 0.16-0.38). PFS and OS outcomes were comparable in the subgroup of patients with cHL. Image:Summary/Conclusion: The incidence of GVHD in this population is comparable to historical data (40%-80% and 30%-70%, respectively). The incidence of severe acute GVHD may be higher than a typical modern allo-SCT series, although TRM was low. The observed PFS and OS outcomes compare favorably to historical benchmarks (2-year PFS ranging from 45%-48%; 1-year OS >80%). Altogether, this analysis lends confidence that allo-SCT is feasible for patients with lymphoid malignancies after PD-1 blockade.