Extrapulmonary Neuroendocrine Carcinoma Research Articles

A novel and uniquely designed bispecific antibody (LBL-024) against PD-L1 and 4-1BB in patients with advanced malignant tumors and neuroendocrine carcinoma: A report of safety and robust efficacy of LBL-024 monotherapy in phase I/II, first-in-human, open-label, multicenter, dose escalation/expansion study.

4010 Background: LBL-024 blocks the immunosuppressive pathway of tumor cells by targeting PD-L1 and effectively localizes 4-1BB co-stimulation to the tumor microenvironment, to improve the anti-tumor immune response. Here we report the safety and efficacy of LBL-024 in patients with advanced malignant tumors, particularly the robust clinical benefit in extrapulmonary neuroendocrine carcinoma (EP-NEC). Methods: Patient population: Phase Ⅰ, advanced malignant tumors exhausted standard cares and phase Ⅱ, EP-NEC failed at least one line of chemotherapy. Seven dose levels of LBL-024 were evaluated (0.2, 0.8, 3.2, 6, 10, 15 and 25 mg/kg, i.v. Q3W) and 15 mg/kg was selected for phase Ⅱ. The primary endpoints were tolerability, safety and efficacy (RECIST 1.1) and the second objectives were pharmacokinetics, pharmacodynamics, and other efficacy parameters. Results: By October 31, 2023, 162 patients were enrolled (64 in phase Ⅰ, and 98 in phase Ⅱ). Tumor types include EP-NEC (46, 28.4%), NSCLC (33, 20.4%), biliary tract cancer (31, 19.1%), and other tumors (52, 32.1%). During the dose escalation stage, no DLT was observed, and the MTD was not reached. The median follow-up was 4.2 months (95%CI: 3.9, 4.9). 126 out of 162 patients (77.8%) experienced TRAEs of all grades, with 34 (21.0%) having grade ≥3 TRAEs. The most common TRAEs (≥15%) included anemia (31.5%), AST increased (30.9%), ALT increased (25.3%), and white blood cell count decreased (22.2%). Out of 146 who underwent efficacy evaluation, the ORR and DCR were 15.1% and 46.6%, respectively. Robust efficacy signals were observed in 41 patients with EP-NEC (Table 1). 6 months of DoR will be available for report in ASCO. Conclusions: LBL-024 has showed good safety profile and very promising antitumor effects in patients with advanced malignant tumors, particularly EP-NEC patients who failed at least one line of chemotherapy. The efficacy observed in EP-NEC is significantly higher than the historic reports with immunotherapy (≤10%) and chemotherapy (about 18%). The extremely robust efficacy and good safety profile support a pivotal study for accelerated development of EP-NEC, the highly unmet medical needs and deadly disease. Clinical trial information: NCT05170958 . [Table: see text]

Integrated genomic and transcriptomic characterization of neuroendocrine carcinomas for improved treatment decision-making.

e15138 Background: Neuroendocrine carcinomas (NECs) are poorly characterized due to their innate heterogeneity, thus limiting treatment and clinical trial options for patients. Here, we used whole exome sequencing (WES) and RNA sequencing (RNA-seq) to explore the genetic and microenvironmental landscape of NECs in order to understand the unique features of different NEC types, with the aim of improving treatment modalities. Methods: We analyzed 51 NEC clinical samples morphologically verified by a pathologist: lung NEC (20 small cell NEC and 1 large cell NEC cases), gastroenteropancreatic NEC (GEP, 12 cases), cancer of unknown primary (7 cases), Merkel cell carcinoma (MCC, 5 cases), genitourinary tract NEC (3 cases), and breast NEC (3 cases). Findings on tumor mutational burden (TMB, mut/Mb), microsatellite instability (MSI), gene expression signatures, and tumor microenvironment (TME) profiling were reported. Small cell lung cancer (SCLC) subtyping was performed as reported by Gay et al. on the entire NEC cohort. Results: Half of the patients with lung NEC and 84% of those with extrapulmonary NEC satisfied the molecular inclusion criteria for clinical trials, with the most frequent criterion being KRAS G12X or G13X mutations. Among the extrapulmonary NEC samples, 13.7% were deemed eligible for targeted therapy, specifically for cases with BRAF V600E mutation and/or high TMB (> 10 mut/Mb). We detected varying TMB and distinct gene expression features across the entire cohort. Specifically, we found 2 MCC cases to be Merkel cell polyomavirus-positive with low TMB and devoid of UV-associated mutations. One GEP-NEC case exhibited a high MSI (MSI-high) status. We detected 6 SCLC cases (3 non-smokers, 3 former smokers) with surprisingly low levels of tobacco-associated mutations (<10% of all mutations). Two GEP-NEC cases had high levels of mutations associated with tobacco smoking. While TME profiling showed no significant difference in cell population makeup across all samples, transcriptional SCLC subtyping revealed significant differences among the cases. Inflammatory SCLC (SCLC-I) samples showed statistically significant enrichment of all subpopulations of the immune microenvironment (i.e., B cells, T cells, NK cells), supporting the use of immune checkpoint blockade for treatment. The POU2F3+ SCLC (SCLC-P) samples showed low expression of all neuroendocrine diagnostic markers (i.e., INSM1, NCAM1, SYP, CHGA). Conclusions: Given the heterogeneous molecular features across diverse NEC tumors, a uniform treatment strategy is unlikely to benefit all NEC patients. Hence, our ability to detect these unique molecular features is crucial for matching individual NEC patients with specific clinical trials and targeted therapies that may improve their outcomes. Thus, a concerted effort using in-depth genomic, transcriptomic, and TME profiling for NEC tumors is warranted.

SWOG S2012: Randomized phase II/III trial of first line platinum (P)/etoposide (E) with or without atezolizumab (NSC #783608) in patients with advanced or metastatic poorly differentiated extrapulmonary neuroendocrine carcinomas (NEC).

TPS4201 Background: Poorly differentiated, extrapulmonary NEC are rare cancers with median overall survival (OS) <1 year. Treatment is extrapolated from small cell lung cancer (SCLC) with use of P (cisplatin or carboplatin) + E. More effective treatment regimens and predictive biomarkers are needed to improve outcomes. In SCLC, induction therapy with combination of P/E + PD-L1 checkpoint inhibitor atezolizumab and maintenance atezolizumab improved OS (12.3 months vs 10.3 months; HR 0.70, 95% CI 0.54 – 0.91, P=0.007) vs P/E alone (1). No study to date has compared PD-1/PD-L1 inhibition during induction only vs during induction and maintenance therapy. In SCLC, distinct molecular subtypes can be identified by the presence of specific transcription factors (e.g., ASCL1, NEUROD1, POU2F3) or an inflamed gene signature (SCLC-I), with SCLC-I pts more likely to benefit clinically from the addition of immunotherapy (2). In this study we plan to test the benefit of adding atezolizumab to induction P/E as well as the role of adding maintenance atezolizumab after induction P/E plus atezolizumab. We also plan to correlate tumor- and blood-based subtype biomarkers with response to therapy. Methods: Eligible pts ≥18 years old have evaluable, histologically confirmed extrapulmonary NEC, Zubrod PS ≤2, and are allowed to have up to 1 cycle of P/E prior to enrollment. P (cisplatin 75 mg/m2 or carboplatin AUC 5, iv) on day 1, E 100 mg/m2 iv on days 1-3, and atezolizumab 1200 mg iv on day 1 of q21 day cycles. Pts are randomized to 1 of 3 arms: A) Induction P/E + atezolizumab -> maintenance atezolizumab B) Induction P/E + atezolizumab -> observation C) Induction P/E -> observation. The primary objective is to compare the overall survival (OS, from randomization) between arms in a fixed sequence: A vs C -> B vs C -> A vs B. Secondary objectives include comparing OS (from start of maintenance/observation), progression free survival, response rate, duration of response, and safety/tolerability across arms. Tumor and blood samples will be banked for future biomarker analyses, including immunohistochemistry of transcription factors on tissue and whole exome sequencing on tumor and circulating tumor DNA. With 189 pts (168 eligible), the study has 84% power to detect an improvement in 12-months OS from 35% to 57.5% (HR 0.53). This study was activated December 2021 with 3 pts enrolled over 1 year due to restricting enrollment of NEC of small cell histology only. The protocol was amended in January 2023 to broaden eligibility to all NEC subtypes (small cell, large cell, and undefined histology with Ki-67 ≥55%). As of January 2024, 35 patients have been enrolled. A protocol amendment is planned to remove the need for Ki-67 index for NEC of genitourinary origin to improve accrual. 1. Horn L, et al. N Engl J Med 2018. 2. Gay CM, et al. Cancer Cell 2021. Clinical trial information: NCT05058651 .

The clinical utility of plasma cell-free DNA (cfDNA) in NET-02: Randomised, phase II trial of liposomal irinotecan (nal-IRI)/5-fluorouracil (5-FU)/folinic acid or docetaxel as second-line (2L) therapy in patients (pts) with progressive poorly differentiated extra-pulmonary neuroendocrine carcinoma (PD-EP-NEC).

4130 Background: In NET-02, nal-IRI/5-FU, but not docetaxel, met the primary endpoint of 6-month (mo) progression-free survival (PFS) rate in pts with progressive PD-EP-NEC (1). The prognostic potential of cfDNA in progressive PD-EP-NEC has not been explored in a prospective randomised trial. Methods: NET-02 was a multi-centre, randomised (1:1), phase II trial of IV nal-IRI/5-FU/folinic acid, Q14 days (ARM A), or IV docetaxel, Q21 days (ARM B), as 2L therapy in pts with progressive PD-EP-NEC. Plasma samples were taken at baseline (T0), following 6 weeks of treatment (T1) and at progression (T2). Samples were analysed using a multi-omic next-generation sequencing (NGS) approach (T7-MBD-seq) (measures genome-wide methylation and low pass whole genome copy number alterations (CNA)). The tumour fraction (TF) of cfDNA was determined using ichorCNA and correlated with clinical outcomes using Cox proportional hazards model and Logistic regression. Results: Of 56 pts evaluable for efficacy, there were 54 (96%) T0 samples (48 passed quality control), 31 (55%) at T1 and 20 (36%) at T2. At T0, 36/48 (75%) samples had detectable TF by copy number (using 3% TF cut-off). For the entire cohort, T0 TF was negatively prognostic for overall survival (OS) (Hazard Ratio (HR) 1.17, 95% Confidence interval (CI) 1.00-1.37, P=.044), but not for 6 mo PFS rate (Odds ratio (OR) 1.25, 95% CI 0.91-1.73, P=.17), response rate (RR) (OR 1.11, 95% CI 0.67-1.76, P=.65) or PFS (HR 1.04, 95%CI 0.91-1.20, P=.53). In the entire cohort, median OS split by TF (N=16 each) was 10.2 mo (95% CI 4.1-not available (NA)) for low (TF≤8.6%), 6.9 mo (95% CI 3.4-14.8) for medium (8.6<TF≤24.3%) and 3.7 mo (95% CI 2.8-NA) for high (TF>24.3%). T0 TF was also negatively prognostic for 6 mo PFS rate and OS in ARM A (P=.02, P=.03), but not ARM B (P=.61, P=.48), but was not prognostic for RR or PFS (Table). TF correlated with the presence of liver metastases (Wilcoxon Rank Sum P=.009), but not with ECOG PS (P=.14), sex (P=.10), Ki-67 (P=.39) or age (Spearman rank correlation P=.45). Longitudinal copy number and methylation cfDNA analysis is on-going. Conclusions: These results suggest that it may be possible to stratify prognosis based on amount of baseline TF in patients with progressive PD-EP-NEC, and may also identify patients who would benefit most from the nal-IRI combination. 1. McNamara 2023, EClin Med. Clinical trial information: 03837977. [Table: see text]

Extrapulmonary Neuroendocrine Carcinomas: Current Management and Future Perspectives.

Neuroendocrine carcinomas (NECs) are poorly differentiated and highly aggressive epithelial neuroendocrine neoplasms. The most common primary site is the lung, but they may arise in every organ. Approximately 37% of extrapulmonary NECs (EP-NECs) occur in the gastroenteropancreatic (GEP) tract, followed by the genitourinary (GU) system and gynecological tract. As a result of their rarity, there is scant evidence to guide treatment recommendations, and a multidisciplinary approach is essential for the management of such patients. Platinum-based chemotherapy currently represents the standard of care for EP-NECs of any site, mirroring the management of small-cell lung cancer (SCLC), but further approaches are still under investigation. Indeed, ongoing trials evaluating targeted therapies, immune checkpoint inhibitors (ICIs), and radionuclide therapy could provide potentially breakthrough therapeutic options. Given the relative dearth of evidence-based literature on these orphan diseases, the aim of this review is to provide an overview of the pathology and current treatment options, as well as to shed light on the most pressing unmet needs in the field.

Abstract LB_A16: DareonTM-5: An open-label Phase II trial of BI 764532, a DLL3-targeting T cell engager, in patients with relapsed/refractory small cell lung cancer or other neuroendocrine carcinomas

Abstract Background: Small cell lung cancer (SCLC), extra-pulmonary neuroendocrine carcinomas (epNECs) and large cell NECs (LCNECs) of the lung are difficult-to-treat, aggressive tumors with limited treatment (Tx) options. Standard of care for metastatic disease is platinum-based chemotherapy ± immunotherapy. However, nearly all patients (pts) relapse, and outcomes are poor. Hence, alternative therapies are needed. Delta-like ligand 3 (DLL3), a Notch ligand, is highly expressed on the cell surface of SCLCs, epNECs and LCNECs. BI 764532, a humanized IgG-like T cell engager, binds to DLL3-positive tumor cells and CD3 on T-cells and promotes T cell-mediated cytotoxicity. In an ongoing first-in-human trial, BI 764532 exhibited promising efficacy and manageable tolerability in pts with DLL3-positive SCLC, epNEC and LCNEC of the lung (NCT04429087). Here we describe a planned Phase II dose optimization trial to assess safety/efficacy of two different doses of BI 764532 monotherapy in pts with progressive/recurrent SCLC, epNEC or LCNEC of the lung (NCT05882058). Methods: The trial will recruit adult pts (n = ~120; ~70 sites; ~15 countries) with histologically/cytologically confirmed relapsed/refractory SCLC, epNEC or LCNEC of the lung who have received ≥2 (SCLC) or ≥1 (epNEC/LCNEC) prior lines of therapy, including ≥1 platinum-based regimen. Pts with mixed tumor histology are permitted if the SCLC/NEC component is predominant (≥50% of tumor tissue). Pts will be randomized 1:1 to receive one of two dose levels of intravenous BI 764532 (3-week cycles) stratified by tumor type (n ~ 60/arm). Tx will continue until disease progression, undue toxicity, withdrawal of consent or any other documented criteria for stopping Tx (maximum Tx duration: 36 months). Interim analyses for dose selection are planned after 30 pts have been followed for ≥6 and ≥12 weeks or have stopped Tx. A third interim efficacy analysis will be conducted when 60 pts per dose have been followed for ≥12 weeks or have stopped Tx. Key exclusion criteria: ECOG PS ≥2; untreated/symptomatic brain metastases or leptomeningeal disease; active/previous history of interstitial lung disease/pneumonitis; previous Tx with DLL3-targeting therapies; Tx with other anti-cancer drug <4 weeks prior to first administration of BI 764532; unresolved toxicity from prior anti-tumor Tx; diagnosis of immunodeficiency, or intake of immunosuppressive therapy ≤7 days prior to first administration of BI 764532. Primary endpoints: objective response (RECIST v1.1; investigator assessment); occurrence of Tx-emergent adverse events (TEAEs) during the on-Tx period. Secondary endpoints: duration of objective response; progression-free survival; disease control; overall survival; pt-reported outcomes; TEAEs leading to discontinuation during the on-Tx period. Further endpoints: pharmacokinetics (PK); prespecified and exploratory biomarker analysis (archival tumor tissue is required). The comparison of the two target doses in this trial will be based on the totality of data, including safety, efficacy, PK and biomarker data. Citation Format: Valentina Gambardella, Alastair Greystoke, Martin Reck, Meiruo Liu, Martha Mueller, Ulrich Duenzinger, Emily B Bergsland, Taofeek Owonikoko. DareonTM-5: An open-label Phase II trial of BI 764532, a DLL3-targeting T cell engager, in patients with relapsed/refractory small cell lung cancer or other neuroendocrine carcinomas [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr LB_A16.

CTIM-30. A PHASE 1B, OPEN-LABEL, DOSE-ESCALATION TRIAL OF THE DELTA-LIKE LIGAND 3 (DLL3)/CD3 IGG-LIKE T CELL ENGAGER, BI 764532, IN PATIENTS WITH DLL3-POSITIVE GLIOMA

Abstract BACKGROUND Patients with progressive diffuse gliomas have limited treatment options. DLL3, a Notch ligand, is expressed on most diffuse gliomas. BI 764532, a humanized IgG-like T cell engager, binds selectively to DLL3-positive cells and promotes T cell-mediated cytotoxicity. Preclinical data showed activity of BI 764532 against intracranial tumors. In an ongoing first-in-human trial in patients with DLL3-positive small-cell lung carcinoma and other neuroendocrine carcinomas (NECs) including extrapulmonary NECs and large-cell NECs of the lung (NCT04429087), BI 764532 exhibited promising efficacy and manageable tolerability. Here we describe a planned Phase Ib dose-escalation/expansion trial of BI 764532 monotherapy in patients with DLL3-positive refractory/relapsed diffuse glioma. METHODS The dose-escalation part will include ~12–20 patients (≥3 patients per dose level) from 12 sites across Europe/USA. Dose escalation will be guided by Bayesian logistic regression model with overdose control. BI 764532 will be administered intravenously. Treatment will continue until disease progression, undue toxicity, informed consent withdrawn, or other reasons requiring treatment discontinuation. Once a recommended dose for expansion is established, ~15 patients from Europe will be treated in a dose-expansion phase. Key inclusion criteria: ≥18 years old; histologically confirmed primary progressive diffuse glioma who have failed on standard-of-care therapies; DLL3-positivity by IHC on archived tumor tissue by central pathology review. Key exclusion criteria: extracranial metastatic or leptomeningeal disease; previous treatment with DLL3-targeting therapies; prior treatment with bevacizumab/other anti-VEGF/anti-angiogenic treatment ≤6 months prior to first administration of BI 764532; persistent toxicity from previous treatments that has not resolved to ≤CTCAE Grade 1; diagnosis of immunodeficiency, or intake of immunosuppressive therapy ≤7 days prior to first administration of BI 764532. Primary endpoints: dose-limiting toxicities (DLTs) during the maximum tolerated dose evaluation period (escalation phase); DLTs during the entire treatment period (expansion phase). Other objectives include pharmacokinetics, pharmacodynamics, preliminary efficacy and evaluation of DLL3 as a potential biomarker.

Selection of Chemotherapy in Advanced Poorly Differentiated Extra-Pulmonary Neuroendocrine Carcinoma.

Extra-pulmonary poorly differentiated neuroendocrine carcinoma is rare, and evidence for treatment has been limited. In this article, the evidence behind the cytotoxic chemotherapy choices used for metastatic or unresectable EP-PD-NEC is reviewed. In the first-line setting, etoposide and platinum chemotherapy or irinotecan and platinum have been demonstrated to be equivalent in a large phase III trial. Questions remain regarding the optimal number of cycles, mode of delivery, and the precise definition of platinum resistance in this setting. In the second-line setting, FOLFIRI has emerged as an option, with randomized phase 2 trials demonstrating modest, but significant, response rates. Beyond this, data are extremely limited, and several regimens have been used. Heterogeneity in biological behaviour is a major barrier to optimal EP-PD-NEC management. Available data support the potential role of the Ki-67 index as a predictive biomarker for chemotherapy response. A more personalised approach to management in future studies will be essential, and comprehensive multi-omic approaches are required to understand tumour somatic genetic changes in relation to their effects on the surrounding microenvironment.

1205TiP Camrelizumab combined with EP/EC chemotherapy followed by camrelizumab plus apatinib for first-line therapy of advanced extrapulmonary neuroendocrine carcinoma: A prospective, single-arm, multicenter clinical study

1205TiP Camrelizumab combined with EP/EC chemotherapy followed by camrelizumab plus apatinib for first-line therapy of advanced extrapulmonary neuroendocrine carcinoma: A prospective, single-arm, multicenter clinical study

Managing Metastatic Extrapulmonary Neuroendocrine Carcinoma After First-Line Treatment.

Extrapulmonary neuroendocrine carcinoma (EP-NEC) is a rare, aggressive malignancy that can arise from any organ and frequently presents with distant metastases. Advanced disease has a poor prognosis with median overall survival (OS) rarely exceeding 1 year even with systemic therapy. The management paradigm of advanced/metastatic EP-NEC has been extrapolated from small cell lung cancer (SCLC) and commonly consists of 1st line therapy with etoposide and platinum (cisplatin or carboplatin), followed by alternative cytotoxic regimens at the time of progression. Only a minority of patients are able to receive 2nd line therapy, and cytotoxics derived from the SCLC paradigm such as topotecan or lurbinectedin have very limited activity. We aimed to evaluate emerging therapeutic options in the 2nd and later lines and survey potential future developments in this space. After a long period of stagnation in treatment options and outcomes, more promising regimens are gradually being utilized in the 2nd line setting including systemic therapy combinations such as FOLFIRI, FOLFOX, modified FOLFIRINOX, CAPTEM, and, more recently, novel checkpoint inhibitors such as nivolumab and ipilimumab. Simultaneously, advances in the understanding of disease biology are helping to refine patient selection and identify commonalities between NEC and their sites of origin which may eventually lead to additional targeted therapy options. While many questions remain, contemporary developments give grounds for optimism that improved outcomes for EP-NEC will soon be within reach.

Clinical features and prognosis of advanced intra- and extra-pulmonary neuroendocrine carcinomas.

We examined the clinical features and prognosis of advanced intra- and extra-pulmonary neuroendocrine carcinomas (NECs) to offer additional guidance for the clinical treatment of small-cell lung cancer (SCLC), which is a type of advanced intrapulmonary NEC (IPNECs). The clinical data and survival of 123 patients with advanced IPNECs and extrapulmonary NECs (EPNECs) were obtained. We retrospectively examined the corresponding clinical diagnosis and treatment and investigated the significant factors influencing the survival prognosis of patients with NECs. There were 90 cases of IPNECs (including 81 cases of SCLC), and 33 cases of EPNECs. The median overall survival (OS) of IPNECs was significantly longer than that of the EPNECs in the gastrointestinal tract and in the other regions (P < 0.05). The median OS of patients with other IPNECs was longer than that of patients with SCLC (P > 0.05). Multivariate analysis demonstrated that age, liver metastasis, number of cycles of first-line chemotherapy, and chest radiotherapy were risk factors influencing OS in patients with NECs (P < 0.05). The survival of IPNECs was significantly longer than that of EPNECs in the gastrointestinal tract and other regions. Nevertheless, patients with advanced NECs who were older and had liver metastases had a poorer prognosis. Multidisciplinary treatments including multicycle chemotherapy and a combination of chemotherapy and radiotherapy should function significantly in extending the survival of NECs.

Outcomes for immuno-chemotherapy based treatment in patients with poorly differentiated extrapulmonary neuroendocrine carcinoma.

e14619 Background: Extrapulmonary neuroendocrine carcinoma (EP-NEC) represents a rare collection of neuroendocrine cancers characterized with a poor prognosis and modest treatment benefit similar to small cell lung carcinoma (SCLC). Platinum-based chemotherapy (cisplatin or carboplatin) and etoposide is the preferred 1st line therapy for patients (pts) with metastatic EP-NEC who are not eligible for curative surgery (Frizziero et al. 2019). Studies in pts with advanced SCLC have shown improved progression free survival (PFS) and overall survival (OS) with the addition of atezolizumab, an anti-PD-L1 monoclonal antibody, to induction chemotherapy (4 cycles) versus chemotherapy alone (Horn et al. 2018). Prospective trials investigating immune checkpoint inhibitors such as atezolizumab plus chemotherapy have yet to be published in EP-NEC. Methods: We retrospectively reviewed all registered pts at the Gastrointestinal Medical Oncology Clinic at Banner-University of Arizona Cancer Center who received at least 1 dose of atezolizumab from 1/2017 through 3/2022 (UAIRB00001593). Criteria for pt selection for analysis was based on the following: pts diagnosed with grade III, Ki 67&gt;20%, poorly differentiated, metastatic EP-NEC and treated with ≥ 1 dose of atezolizumab plus chemotherapy as 1st line treatment. Results: Ten pts received atezolizumab based therapy during this timeframe. 6 pts met criteria for analysis and 4 pts were excluded for alternative diagnoses. 4 pts were female, 2 pts were male, and the average age at diagnosis was 63.8 years. The median number of chemotherapy cycles was 7.0 [4-17]. The median number of atezolizumab doses was 7.5 [6-28]. The median PFS was 7 months (95% CI 5-*). The median overall survival (mOS) was 13 months (95% CI 8-*). The mOS since starting atezolizumab was 12 months (95% CI 8-*). [*Upper bound of 95% CI cannot be determined.] Five pts (83%) demonstrated a partial response per RECISTv1.1. All pt tumors were MMR-proficient/MSI-stable and PD-L1 expression was negative in 3 pts (PD-L1 status unavailable for 3 pts). No hospitalizations related to immunotherapy or chemotherapy were observed. The most common adverse events included nausea, diarrhea and fatigue. One immune-mediated adverse event of thyroid dysfunction was observed and successfully medically managed. Conclusions: Our experience with atezolizumab plus chemotherapy for 1st line EP-NEC pts demonstrated efficacy via high response rate and survival rates above historical experience. Continuing chemotherapy beyond the induction phase until maximum clinical response demonstrated tolerability with manageable side effects. Although the scope is limited due to sample size, this data supports further investigation of this combination. There is an ongoing large, randomized, prospective trial investigating this regimen in frontline, metastatic EP-NEC pts ( NCT05058651 ).

NET-02: a randomised, non-comparative, phase II trial of nal-IRI/5-FU or docetaxel as second-line therapy in patients with progressive poorly differentiated extra-pulmonary neuroendocrine carcinoma.

The prognosis for patients with poorly-differentiated extra-pulmonary neuroendocrine carcinoma (PD-EP-NEC) is poor. A recognised first-line (1L) treatment for advanced disease is etoposide/platinum-based chemotherapy with no standard second-line (2L) treatment. Patients with histologically-confirmed PD-EP-NEC (Ki-67>20%; Grade 3) received IV liposomal irinotecan (nal-IRI) (70mg/m2 free base)/5-FU (2400mg/m2)/folinic acid, Q14 days (ARM A), or IV docetaxel (75mg/m2), Q21 days (ARM B), as 2L therapy. Primary endpoint was 6-month progression-free survival (PFS) rate (80% power to demonstrate one-sided 95% lower confidence interval excluded 15% (target level of efficacy: 30%)). Secondary endpoints: objective response rate (ORR), median PFS, overall survival (OS), toxicity and patient-reported quality-of-life (QoL) (ClinicalTrials.gov: NCT03837977). Of 58 patients (29 each arm); 57% male, 90% ECOG PS 0/1, 10% PS 2, 89.7% Ki-67≥55%, primary site: 70.7%-gastrointestinal, 18.9%-other, 10.3%-unknown, 91.4%/6.9%/1.7% were resistant/sensitive/intolerant to 1L platinum-based treatment, respectively. The primary end-point of 6-month PFS rate was met by ARM A: 29.6% (lower 95% Confidence-Limit (CL) 15.7), but not by ARM B: 13.8% (lower 95%CL:4.9). ORR, median PFS and OS were 11.1% (95%CI:2.4-29.2) and 10.3% (95%CI:2.2-27.4%); 3 months (95%CI:2-6) and 2 months (95%CI:2-2); and 6 months (95%CI:3-10) and 6 months (95%CI:3-9) in ARMS A and B, respectively. Adverse events≥grade 3 occurred in 51.7% and 55.2% (1 and 6 discontinuations due to toxicity in ARMS A and B), respectively. QoL was maintained in ARM A, but not ARM B. nal-IRI/5-FU/folinic acid, but not docetaxel, met the primary endpoint, with manageable toxicity and maintained QoL, with no difference in OS. ORR and median PFS were similar in both arms. This study provides prospective efficacy, toxicity and QoL data in the 2L setting in a disease group of unmet need, and represents some of the strongest evidence available to recommend systemic treatment to these patients. Servier.

Efficacy of first-line checkpoint inhibitors in combination with chemotherapy in high-grade extrapulmonary metastatic neuroendocrine carcinomas.

Poorly differentiated extrapulmonary neuroendocrine carcinomas (EP NECs) are aggressive cancers characterized by a high Ki-67 index, rapid tumor growth and poor survival, and are subdivided into small and large cell carcinoma. For small cell carcinoma of the lung, a pulmonary NEC, the combination of cytotoxic chemotherapy (CTX) and a checkpoint inhibitor (CPI) is considered standard therapy and superior to CTX alone. EP NECs are typically treated with platinum-based regimens, some clinicians have adopted the addition of a CPI to CTX based on data from trials in patients with small cell carcinoma of the lung. In this retrospective study of EP NECs, we report 38 patients treated with standard first-line CTX and 19 patients treated with CTX plus CPI. We did not observe any additional benefit of adding CPI to CTX in this cohort.

NET-02 final results: A randomised, phase II trial of liposomal irinotecan (nal-IRI)/5-fluorouracil (5-FU)/folinic acid or docetaxel as second-line (2L) therapy in patients (pts) with progressive poorly differentiated extrapulmonary neuroendocrine carcinoma (PD-EP-NEC).

646 Background: As demonstrated in the primary analysis of NET-02, nal-IRI/5-FU/folinic acid, but not docetaxel, met the primary endpoint of 6 month (mo) progression-free survival (PFS) rate in pts with progressive PD-EP-NEC. Here, the final results are presented. Methods: This was a multi-centre, randomised (1:1), phase II trial of IV nal-IRI (70mg/m2 free base)/5-FU (2400 mg/m2)/folinic acid, Q14 days (ARM A), or IV docetaxel (75mg/m2), Q21 days (ARM B), as 2L therapy in pts with progressive PD-EP-NEC, aimed at selecting a treatment for continuation to a phase III trial. On disease progression, pts in both arms could receive further systemic treatment as recommended by their physicians. Primary endpoint was 6 mo PFS rate; 80% power to demonstrate the one-sided 95% confidence interval (CI) of the 6 mo PFS rate excluded 15%, if the true rate was ≥30% (required level of efficacy); a rate of &lt;15% would give grounds for rejection (additional selection criteria: toxicity and quality of life (QoL)). Intention was to show that regimens were sufficiently active, but not to assess superiority of one regimen over the other. Secondary endpoints included objective response rate (ORR), PFS, overall survival (OS), toxicity, QoL (European Organisation for Research and Treatment of Cancer QLQ C30 and GINET21) and translational end-points. Results: Of 58 pts in 15 UK centres (Nov 18-Dec 21), 29 in ARM A (2 pts excluded for efficacy analysis: well-differentiated grade 3 (G3) neuroendocrine tumour and goblet cell adenocarcinoma), 29 in ARM B. Eight pts in both arms (27.6% each) received subsequent chemotherapy. Fifty-four pts (93%) have died; the primary end-point of 6-mo PFS rate was met in ARM A; ORR, median PFS and OS are also presented. Adverse events ≥ G3 occurred in 51.7% and 55.2% in ARM A and B with 1 and 6 discontinuations due to toxicity in ARM A and B, respectively. Health-related QoL was maintained (C30 functional scales &amp; global health status remained stable pre-progression) and potentially improved (sustained improvement in role functioning) with nal-IRI/5-FU/folinic acid, but not docetaxel (all C30 functional scales &amp; global health status worsened between baseline and week 18, and treatment-related symptoms also worsened in GINET21). Translational analysis is on-going. Conclusions: nal-IRI/5-FU warrants further evaluation in pts with PD-EP-NEC, with the results highlighting that conduct of randomised trials in this disease group of unmet need is possible and safe. Clinical trial information: NCT03837977 . [Table: see text]

Impact of prognostic factors on platinum response in extrapulmonary neuroendocrine carcinoma

Impact of prognostic factors on platinum response in extrapulmonary neuroendocrine carcinoma

Clinical Analysis of Extrapulmonary Neuroendocrine Carcinoma: A Retrospective and Single Institution Experience

Introduction: Extrapulmonary neuroendocrine carcinoma (EPNEC) is a clinicopathological entity distinct from neuroendocrine carcinoma of the lung. Here, we reviewed the clinical features, treatment modalities, and prognosis of EPNEC patients in a single-institution series. Methods: We retrospectively reviewed the medical records of EPNEC patients and examined the clinical profiles and treatment outcomes at our hospital between 2013 and 2021. Results: Thirty-one EPNEC patients (21 men and 10 women) with a median age of 65 years were included. The primary sites were as follows: stomach (n = 7); rectum and bladder (n = 3 each); prostate, esophagus, cervix, and pancreas (n = 2 each); maxillary sinus, parotid gland, gallbladder, anal canal, larynx, uterine body, ovary, appendix, anterior mediastinum, and unknown primary lesion (n = 1 each). Thirteen patients had locally advanced stage and 18 cases had distant metastases. Chemotherapy using platinum-combined CPT-11 or VP-16 was mainly performed. Various therapeutic modalities were used, especially in locally advanced cases. Ten patients underwent surgery, including initial surgery in 5 and conversion in 5 after chemotherapy. The response rate to initial chemotherapy was 56.5%, and the median overall survival in all patients was 12.8 (95% CI: 9.6–34.5) months. Survival was significantly longer in patients with locally advanced stage (80.3 months) and receiving surgery (not reached) than in those with metastatic disease (9.9 months) and without surgery (9.6 months). Conclusion: EPNEC occurs in various organs and has poor prognosis. Long-term survival may be possible with surgical resection in cases with early-stage disease or tumor shrinkage due to chemotherapy.

The efficacy of oxaliplatin, surufatinib, and camrelizumab on neuroendocrine carcinoma: a case report and literature review

Extra-pulmonary neuroendocrine carcinomas (EP-NECs) are rare, accounting for ~1/100,000 of NECs, aggressive neoplasms and poor prognosis. Sometimes, a non-neuroendocrine component is also accompanying these EP-NECs. Curative surgery is suggested for early stage patients while system chemotherapy and locoregional radiotherapy are considered for advanced inoperable disease. Nonetheless, there was lack of standard second-line treatment strategy. Herein, we report a case of NEC involving a large cell neuroendocrine carcinoma (LCNEC) and adenocarcinoma of the gallbladder treated with a surufatinib-containing regimen in the second-line treatment setting and establish the efficacy of this regimen in the treatment of EP-NECs. A 58-year-old male presented with symptoms such as distension in the upper right abdomen and a palpable mass. The abdominal magnetic resonance imaging (MRI) scan showed a giant soft tissue mass in the left lobe of the liver, and liver biopsy suggested LCNEC with a non-neuroendocrine (NNE) component. Based on the available literature, a first-line therapy of oxaliplatin + gemcitabine + camrelizumab + apatinib was started initially; however, there was rapid tumor progression. Thus, a second line of treatment was started, where apatinib was replaced with surufatinib, which was given along with oxaliplatin and camrelizumab and continued for seven complete cycles. The patient was re-examined with MRI, which showed a significant decrease in tumor size. And a partial response was achieved. Main adverse events included hand and foot numbness, hypertension, proteinuria, hematuria, and hyperthyroidism. The patient underwent surgery after the second line of treatment and the post-operative pathology report revealed the presence of LCNEC and adenocarcinoma of the gallbladder. Two months later, re-examination result showed no tumor recurrence. As yet, the criteria strategy for unresectable EP-NECs to improve survival outcomes is scarce. EP-NECs are badly in need of effective second-line therapy to carry out survival benefits after resistance to first-line regimen. The case report demonstrated that a surufatinib-containing regimen including oxaliplatin and camrelizumab could be an effective treatment strategy for the second-line treatment of EP-NECs. Furthermore, this strategy is well tolerated and treatment-related toxicity are manageable. More clinical trials are warranted to further confirm the efficacy.

Molecular Classification of Extrapulmonary Neuroendocrine Carcinomas With Emphasis on POU2F3-positive Tuft Cell Carcinoma.

Extrapulmonary neuroendocrine carcinomas (EP-NECs) are associated with a poor clinical outcome, and limited information is available on the biology and treatment of EP-NECs. We studied EP-NECs by applying the recent novel findings from studies of pulmonary neuroendocrine carcinomas, including POU2F3, the master regulator of tuft cell variant of small cell lung carcinomas. A cohort of 190 patients with surgically resected EP-NECs or poorly differentiated carcinomas (PDCs) were established. Immunohistochemistry (IHC) for POU2F3 along with ASCL1, NEUROD1, YAP1, and conventional neuroendocrine markers was performed on tissue microarrays. Selected cases with or without POU2F3 expression were subjected to targeted gene expression profiling using nCounter PanCancer Pathway panel. POU2F3-positive tuft cell carcinomas were present in 12.6% of EP-NEC/PDCs, with variable proportions according to organ systems. POU2F3 expression was negatively correlated with the expression levels of ASCL1, NEUROD1, and conventional neuroendocrine markers ( P <0.001), enabling IHC-based molecular classification into ASCL1-dominant, NEUROD1-dominant, POU2F3-dominant, YAP1-dominant, and not otherwise specified subtypes. Compared wih POU2F3-negative cases, POU2F3-positive tuft cell carcinomas showed markedly higher expression levels of PLCG2 and BCL2 , which was also validated in the entire cohort by IHC. In addition to POU2F3, YAP1-positive tumors were a distinct subtype among EP-NEC/PDCs, characterized by unique T-cell inflamed microenvironment. We found rare extrapulmonary POU2F3-positive tumors arising from previously unappreciated cells of origin. Our data show novel molecular pathologic features of EP-NEC/PDCs including potential therapeutic vulnerabilities, thereby emphasizing the need for focusing on unique features of EP-NEC/PDCs.

Health-related quality of life (HRQoL) in patients (pts) with progressive, poorly differentiated, extra-pulmonary neuroendocrine carcinoma (PD-EP-NEC) enrolled in NET-02: A phase II trial of liposomal irinotecan (nal-IRI)/5-fluorouracil (5-FU)/folinic acid or docetaxel as second-line therapy.

293 Background: NET-02 was a multi-centre, randomised (1:1), non-comparative phase II trial of nal-IRI/5-FU/folinic acid (ARM A) or docetaxel (ARM B) in pts with progressive PD-EP-NEC, aimed at selecting a treatment for evaluation in a phase III trial. Primary analysis (N = 58) showed ARM A, but not ARM B, achieved the target 6-month progression-free survival rate primary endpoint (McNamara et al. ASCO 2022). HRQoL was a secondary endpoint in NET-02. Methods: HRQoL was assessed using the EORTC QLQ-C30 and GINET21 (at baseline (BL), 6-weekly intervals and at disease progression). The mean change from BL was estimated for each scale by timepoint and treatment arm. Results are presented where there were ≥4 responses per time point. Scores were considered stable if they did not change by &gt; 10 points from BL. The mean BL C30 scores for all pts were compared to United Kingdom (UK) population normative C30 data using a 2-sample t-test. Results: Fifty-four of 58 pts (93%) completed a BL questionnaire; of these, 39 (72%) completed ≥1 post-BL questionnaire, with 21 (51%) completing questionnaires at progression. Global health status (GHS) and all functional scales in ARM A remained stable from BL to intervals pre-progression, with a sustained improvement in role functioning observed post-BL. In ARM B, GHS and all C30 functional scales decreased by &gt; 10 points between BL and week 18 (worsening of QoL). Both arms had a &gt; 10-point increase from BL in constipation and diarrhoea in ≥1 post-BL time point. In ARM A, pain, insomnia and financial problems decreased from BL. No C30 symptom scales in ARM B were consistently lower post-BL. Patterns of change in GINET21 mean score were similar in both arms: body image, disease-related worries, information/communication, sexual function and social function all had a &gt; 10-point reduction in score from BL (indicating improvement in symptoms/problems); endocrine and gastrointestinal symptoms remained stable; muscle/bone pain varied across time points, initially showing a reduction in pain followed by an increase, compared to BL. In comparison to the UK C30 norms (BL all pts), 11 of 15 C30 scales did not significantly differ (P &gt; 0.05). Mean scores for fatigue and appetite loss were significantly higher than UK C30 norms (worse symptoms in pts from NET-02) (P = 0.03, P = 0.0003 respectively). However, emotional functioning and GHS were significantly better in pts from NET-02 (P = 0.001, P = 0.03 respectively). Role and social functioning were lower in pts from NET-02 (both P = 0.06) (poorer level of functioning). Conclusions: HRQoL was maintained and potentially improved with nal-IRI/5-FU/folinic acid, but not docetaxel. Compared to the UK general population, BL QoL did not substantially differ in pts from NET-02. Clinical trial information: NCT03837977.