A phase II basket trial of Dual Anti-CTLA-4 and Anti-PD-1 Blockade in Rare Tumors (DART) SWOG S1609: High-grade neuroendocrine neoplasm cohort

BACKGROUND

The authors previously reported the results of the nonpancreatic neuroendocrine neoplasm cohort of the SWOG S1609 DART (Dual Anti-CTLA-4 and Anti-PD-1 Blockade in Rare Tumors) trial, which permitted all histologic grades and had a 44% overall response rate (ORR) among patients with high-grade disease. Here they sought to validate their findings in a dedicated prospective cohort of high-grade neuroendocrine neoplasms within S1609.

METHODS

A prospective, open-label, multicenter, phase 2 clinical trial of ipilimumab plus nivolumab was conducted across multiple rare tumor cohorts. The dedicated, high-grade neuroendocrine neoplasm cohort was examined here. The primary end point was the ORR according to version 1.1 of the Response Evaluation Criteria in Solid Tumors. Secondary end points included progression-free survival (PFS), overall survival (OS), and toxicity.

RESULTS

Nineteen patients with high-grade neuroendocrine neoplasms (defined by local pathology review) were enrolled in this cohort of S1609. The most common primary sites were unknown primaries (21%), which were followed by the rectum, gastroesophageal junction, cervix, and pancreas (11%). The median number of lines of prior therapy was 1 (range, 0-3). All patients were microsatellite-stable. The median Ki-67 value was 80%. The ORR was 26% (95% confidence interval [CI], 11%-45%), and the clinical benefit rate (stable disease for ≥6 months plus partial responses plus complete responses) was 32% (95% CI, 13%-57%). The 6-month PFS rate was 32% (95% CI, 16%-61%) with a median PFS of 2.0 months (95% CI, 1.8 months to ∞) and a median OS of 8.7 months (95% CI, 6.1 months to ∞). The most common toxicities were fatigue (32%) and rash (26%), and the most common grade 3/4 immune-related adverse event was rash (15%); there were no events that required treatment discontinuation and no grade 5 events.

CONCLUSIONS

Ipilimumab plus nivolumab demonstrated a 26% ORR in patients with high-grade neuroendocrine neoplasms, with durable responses seen in patients with refractory disease.

Co-occurrence of multiple endocrine neoplasia type 4 and spinal neurofibromatosis: a case report

Multiple Endocrine Neoplasia (MEN) type 4 is a rare genetic condition that results from variants of the CDKN1B gene and predisposes individuals to develop endocrine tumors. Spinal neurofibromatosis (SNF) is an uncommon subtype of neurofibromatosis type 1 (NF1) characterized by bilateral neurofibromas of all spinal roots. Here we report a case of the co-occurrence of these syndromes, which has not yet been described in the literature. A male in his 60s presented with Gleason 5 + 4 localized prostate adenocarcinoma treated with radical prostatectomy. Two years later, he developed liver and bone metastasis consistent with trans-differentiation into small cell carcinoma. He developed hypercalcemia due to primary hyperparathyroidism from a parathyroid adenoma treated surgically. His family history was significant for a first-degree relative with a clinical diagnosis of NF1 and several second-degree relatives with multiple café-au-lait macules. Spine MRI showed multiple bilateral neurofibromas. Germline genetic testing showed a pathogenic variant in the CDKN1B gene, a variant in the NF1 gene, and a normal MEN1 gene. In this rare case of MEN4 and SNF, the patient was asymptomatic for much of his life. In addition to parathyroid adenoma and spinal neurofibromas, he had prostate adenocarcinoma with trans-differentiation into metastatic small cell cancer. Whether this diagnosis was coincidental or related to an emerging phenotype remains to be elucidated.

KRAS G12V Mutation in Acquired Resistance to Combined BRAF and MEK Inhibition in Papillary Thyroid Cancer

BRAF V600E mutations occur in approximately 40% of all patients with papillary thyroid cancer (PTC) and are associated with a worse prognosis in population studies. Treatment with single-agent BRAF inhibitors can result in nondurable partial responses (PRs) in clinical trials, but resistance inevitably develops. The mechanisms of resistance are not completely understood, but in non-thyroid tumors harboring BRAF V600E mutations, resistance has been ascribed to concurrent or acquired mutations in MEK1/2, RAC1, KRAS, and NRAS. This case report describes a patient with radioactive iodine-refractory metastatic PTC treated in a clinical trial with combination BRAF and MEK inhibition who achieved a durable PR. At time of progression, biopsy revealed an acquired KRAS G12V-activating mutation. The patient subsequently went on to have a PR to cabozantinib therapy in the clinical trial. This is the first reported case of an acquired KRAS-activating mutation that developed during treatment with BRAF and MEK inhibition in a patient with BRAF-mutated PTC. The KRAS mutation was also detected in peripheral blood samples taken as part of the trial, indicating that resistant mutations may be identified through noninvasive means. The identification of resistant mutations in patients at time of progression is necessary to identify possible therapeutic options including potential clinical trials.ClinicalTrials.gov identifier: NCT01723202.

Neuroendocrine liver metastases: a contemporary review of treatment strategies

Well-differentiated neuroendocrine tumors (NETs) are globally increasing in prevalence and the liver is the most common site of metastasis. Neuroendocrine liver metastases (NELM) are heterogeneous in clinical presentation and prognosis. Fortunately, recent advances in diagnostic techniques and therapeutic strategies have improved the multidisciplinary management of this challenging condition. When feasible, surgical resection of NELM offers the best long-term outcomes. General indications for hepatic resection include performance status acceptable for major liver surgery, grade 1 or 2 tumors, absence of extrahepatic disease, adequate size and function of future liver remnant, and feasibility of resecting >90% of metastases. Adjunct therapies including concomitant liver ablation are generally safe when used appropriately and may expand the number of patients eligible for surgery. Among patients with synchronous resectable NELM, resection of the primary either in a staged or combined fashion is recommended. For patients who are not surgical candidates, liver-directed therapies such as transarterial embolization, chemoembolization, and radioembolization can provide locoregional control and improve symptoms of carcinoid syndrome. Multiple systemic therapy options also exist for patients with advanced or progressive disease. Ongoing research efforts are needed to identify novel biomarkers that will define the optimal indications for and sequencing of treatments to be delivered in a personalized fashion.

Direct exposure to SARS-CoV-2 and cigarette smoke increases infection severity and alters the stem cell-derived airway repair response

Most demographic studies are now associating current smoking status with increased risk of severe COVID-19 and mortality from the disease but there remain many questions about how direct cigarette smoke exposure affects SARS-CoV-2 airway cell infection. We directly exposed mucociliary air-liquid interface (ALI) cultures derived from primary human nonsmoker airway basal stem cells (ABSCs) to short term cigarette smoke and infected them with live SARS-CoV-2. We found an increase in the number of infected airway cells after cigarette smoke exposure as well as an increased number of apoptotic cells. Cigarette smoke exposure alone caused airway injury that resulted in an increased number of ABSCs, which proliferate to repair the airway. But we found that acute SARS-CoV-2 infection or the combination of exposure to cigarette smoke and SARS-CoV-2 did not induce ABSC proliferation. We set out to examine the underlying mechanism governing the increased susceptibility of cigarette smoke exposed ALI to SARS-CoV-2 infection. Single cell profiling of the cultures showed that infected airway cells displayed a global reduction in gene expression across all airway cell types. Interestingly, interferon response genes were induced in SARS-CoV-2 infected airway epithelial cells in the ALI cultures but smoking exposure together with SARS-CoV-2 infection reduced the interferon response. Treatment of cigarette smoke-exposed ALI cultures with Interferon β-1 abrogated the viral infection, suggesting that the lack of interferon response in the cigarette smoke-exposed ALI cultures allows for more severe viral infection and cell death. In summary, our data show that acute smoke exposure allows for more severe proximal airway epithelial disease from SARS-CoV-2 by reducing the mucosal innate immune response and ABSC proliferation and has implications for disease spread and severity in people exposed to cigarette smoke.

SARS-CoV-2 infection of primary human lung epithelium for COVID-19 modeling and drug discovery

Coronavirus disease 2019 (COVID-19) is the latest respiratory pandemic resulting from zoonotic transmission of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). Severe symptoms include viral pneumonia secondary to infection and inflammation of the lower respiratory tract, in some cases causing death. We developed primary human lung epithelial infection models to understand responses of proximal and distal lung epithelium to SARS-CoV-2 infection. Differentiated air-liquid interface cultures of proximal airway epithelium and 3D organoid cultures of alveolar epithelium were readily infected by SARS-CoV-2 leading to an epithelial cell-autonomous proinflammatory response. We validated the efficacy of selected candidate COVID-19 drugs confirming that Remdesivir strongly suppressed viral infection/replication. We provide a relevant platform for studying COVID-19 pathobiology and for rapid drug screening against SARS-CoV-2 and future emergent respiratory pathogens.

ONE SENTENCE SUMMARY

A novel infection model of the adult human lung epithelium serves as a platform for COVID-19 studies and drug discovery.

SARS-CoV-2 infection of primary human lung epithelium for COVID-19 modeling and drug discovery

Coronavirus disease 2019 (COVID-19) is the latest respiratory pandemic resulting from zoonotic transmission of severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2). Severe symptoms include viral pneumonia secondary to infection and inflammation of the lower respiratory tract, in some cases causing death. We developed primary human lung epithelial infection models to understand responses of proximal and distal lung epithelium to SARS-CoV-2 infection. Differentiated air-liquid interface cultures of proximal airway epithelium and 3D organoid cultures of alveolar epithelium were readily infected by SARS-CoV-2 leading to an epithelial cell-autonomous proinflammatory response. We validated the efficacy of selected candidate COVID-19 drugs confirming that Remdesivir strongly suppressed viral infection/replication. We provide a relevant platform for studying COVID-19 pathobiology and for rapid drug screening against SARS-CoV-2 and future emergent respiratory pathogens.

One Sentence Summary

A novel infection model of the adult human lung epithelium serves as a platform for COVID-19 studies and drug discovery.

Multicenter phase 2 trial of nintedanib in advanced nonpancreatic neuroendocrine tumors

BACKGROUND

Antiangiogenic-targeting agents have low response rates in patients with nonpancreatic neuroendocrine tumors (NETs). Nintedanib is an oral antiangiogenic agent that has inhibitory effects on the fibroblast growth factor receptor, which is highly expressed in NETs. The authors hypothesized that nintedanib would be active in patients with nonpancreatic NETs.

METHODS

Patients with advanced, grade 1 or 2, nonpancreatic NETs who were receiving a stable dose of somatostatin analogue were enrolled. Nintedanib was administered at a dose of 200 mg twice daily in 28-day cycles. The primary endpoint was progression-free survival (PFS) at 16 weeks.

RESULTS

Thirty-two patients were enrolled, and 30 were evaluable for the primary outcome. Most had radiographic disease progression within 12 months before enrollment. The 16-week PFS rate was 83%, and the median PFS and overall survival were 11.0 months and 32.7 months, respectively. Nintedanib was well tolerated and delayed deterioration in quality of life. The baseline serotonin level had a strong, positive correlation with activated but exhausted T cells.

CONCLUSIONS

Nintedanib is active in nonpancreatic NETs. The immunosuppressive effect of serotonin should be targeted in future clinical trials.

A pilot study of Bruton’s tyrosine kinase inhibitor ibrutinib alone and in combination with PD-1 inhibitor nivolumab in patients with metastatic solid tumors

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Background: Myeloid-derived suppressor cells (MDSC) are expanded in cancer and promote immune suppression. We have shown that ibrutinib inhibits migration and immunosuppressive function of MDSC. Moreover, the combination of ibrutinib and a PD-L1 inhibitor has been found to have synergistic anti-tumor effects in a multiple solid tumor mouse models. Therefore, we conducted a pilot study testing the combination of ibrutinib and nivolumab in patients with metastatic solid tumors. Methods: Sixteen patients with advanced solid tumors were recruited to this trial. Ibrutinib was dosed as an oral single agent, starting 7 days prior to cycle 1 of nivolumab and given until cycle 1, day 8 of nivolumab. Nivolumab was administered intravenously on days 1 and 15 on 28-day cycles. Patients had blood samples collected prior to initiation of ibrutinib, day 1 of cycle 1, day 8 of cycle 1, day 1 of cycle 2, and at the time of disease progression. From these specimens, we measured circulating MDSC levels, other circulating immune subsets, T cell proliferation, and cytokines/chemokines levels. Circulating MDSC levels were measured by mass spectrometry. T cell function was evaluated by CFSE to monitor proliferating cells by dye dilution and cytokine/chemokine levels were measured with a U-PLEX assay. Data were analyzed using two-tailed, paired Student's t-tests to assess statistical significance. Results: An increase in circulating MDSC (22% to 28%; SD 9.158) levels was observed following 7 days of single-agent ibrutinib compared to baseline. However, in combination therapy, MDSC levels decreased (19%; SD 13.17) prior to cycle 2. Despite increasing levels of circulating MDSC, T cell function improved throughout the study. Furthermore, plasma levels of chemokines associated with MDSC recruitment and migration significantly decreased with ibrutinib treatment (IL-12, CCL2, CCL3, and CCL4). Of the 16 patients, four achieved a partial response and four achieved stable disease. Median progression free survival was 3.5 months and median overall survival was 11.5 months. Conclusions: The combination of ibrutinib and nivolumab was well tolerated, demonstrated early signs of immune modulation, and showed preliminary signs of promising clinical activity in patients with metastatic solid tumors. Clinical trial information: NCT03525925 .

Lenvatinib plus pembrolizumab combination therapy in patients with radioiodine-refractory (RAIR), progressive differentiated thyroid cancer (DTC): Results of a multicenter phase II international thyroid oncology group trial

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Background: Lenvatinib is an approved therapy for patients with RAIR DTC. While the overall response rate (ORR) is high, few patients achieve a complete response (CR) and most patients eventually have progressive disease (PD). Combination lenvatinib and pembrolizumab is being explored in many different cancers, and this combination has been approved for advanced endometrial carcinoma. Methods: Patients with RAIR DTC with Response Evaluation Criteria in Solid Tumor (RECIST v1.1) measurable PD (<14 months (mo) prior to registration) were enrolled in this single-arm multicenter phase II study. Patients were excluded if they had received previous VEGFR-directed multikinase therapy. The lenvatinib starting dose was 20 mg/day orally and pembrolizumab was 200mg IV every 3 weeks. The primary endpoint was CR. ORR, progression-free survival (PFS) and safety graded by Common Terminology Criteria for Adverse Events v4.0 were secondary endpoints. Results: Thirty patients were enrolled. The median age was 62.5 years, and 53% of the patients were women. Seventy percent of patients had grade 3 adverse events (AEs) and 10 percent had grade 4 AEs. There were no treatment-related deaths. The most common > grade 3 AEs were hypertension (47%), weight loss (13%), maculopapular rash (13%), leukopenia (7%), diarrhea (7%) and oral mucositis (7%). Twenty-one patients (70%) required lenvatinib dose reduction. Of 29 evaluable patients, 18 (62%) had a partial response (PR) and 10 (35%) had stable disease (SD). The clinical benefit rate (ORR +SD) was 97%. Median time to tumor nadir was 7.4 mo (1.6-17.8 mo). Median PFS was not yet reached. The PFS at 12 months was 74%. Median time on therapy was 9.9 mo (3.2-18.9 mo). Fourteen patients are continuing therapy (7.6-18.9 mo). Six of these patients (43%) have not yet reached tumor size nadir. Three patients (10%) had > 80% target tumor shrinkage. Conclusions: Lenvatinib plus pembrolizumab is reasonably tolerated in patients with RAIR DTC. To date, there have been no documented complete responses. Combination lenvatinib plus pembrolizumab therapy has a high ORR in patients with RAIR DTC. Continuation of this study will help determine the depth and length of the responses. Clinical trial information: NCT02973997 .

TTF-1 Positive Primary Small Cell Carcinoma of the Breast: A Case Report and Review of the Literature

Primary small cell carcinoma of the breast (SCCB) is a rare tumor subtype comprising <0.1% of all breast carcinomas. Here we present a case of thyroid transcription factor-1 (TTF-1) positive SCCB that recurred within 3 years of diagnosis in the lung and lymph nodes. Given the small number of cases, no clear guidelines exist on the appropriate management of patients with these aggressive tumors. We present a case study and review the current literature to highlight the knowledge gaps and needs of patients with these rare tumors. A 50-year-old premenopausal woman with no family history, presented with a palpable right breast mass. Biopsy was consistent with primary SCCB that was poorly differentiated, positive for synaptophysin and chromogranin and TTF-1 and presence of ductal carcinoma in situ component showing neuroendocrine differentiation. Imaging with PET, CT, and MRI brain excluded any other sites of primary disease. She underwent a right lumpectomy with axillary lymph node dissection and was treated with adjuvant cisplatin-based chemotherapy and concurrent radiation therapy. Thirty-four months later, routine scans showed a new right lower-lobe lung nodule and an enlarged sub-carinal node that was proven to be poorly differentiated neuroendocrine cancer. This case report sheds light on a rarely described disease and provides a comprehensive approach to diagnosis and management. Primary SCCB is an extremely rare, aggressive form of breast cancer that is molecularly and histologically similar to SCLC. However, a review of the literature highlights recent mutational analyses that show important differences between these two cancer types, including an increase in PIK3CA mutations in primary SCCB. Further studies, including genomic analyses are needed to better define this malignancy and to develop a standard treatment.

Transarterial Chemoembolization vs Radioembolization for Neuroendocrine Liver Metastases: A Multi-Institutional Analysis

BACKGROUND

Liver-directed hepatic arterial therapies are associated with improved survival and effective symptom control for patients with unresectable neuroendocrine liver metastases (NELM). Whether transarterial chemoembolization (TACE) or transarterial radioembolization (TARE) with yttrium-90 (y-90) are associated with improved short- or long-term outcomes is unknown.

STUDY DESIGN

A retrospective review was performed of all patients with NELM undergoing transarterial therapies, from 2000 to 2018, at 2 academic medical centers. Postoperative morbidity, radiographic response according to response evaluation criteria in solid tumors (RECIST) criteria, and long-term outcomes were compared between patients who underwent TACE vs TARE.

RESULTS

Among 248 patients with NELM, 197 (79%) received TACE and 51 (21%) received TARE. While patients who underwent TACE were more likely to have carcinoid syndrome, larger tumors, and higher chromogranin A levels, there was no difference in tumor differentiation, primary site, bilobar disease, or synchronous presentation. Nearly all TARE treatments (92%) were performed as outpatient procedures, while 99% of TACE patients spent at least 1 night in the hospital. There were no differences in overall morbidity (TARE 13.7% vs TACE 22.6%, p = 0.17), grade III/IV complication (5.9% vs 9.2%, p = 0.58), or 90-day mortality. The disease control rate (DCR) on first post-treatment imaging (RECIST partial/complete response or stable disease) was greater for TACE compared with TARE (96% vs 83%, p < 0.01). However, there was no difference in median overall survival (OS, 35.9 months vs 50.1 months, p = 0.3) or progression-free survival (PFS, 15.9 months vs 19.9 months, p = 0.37).

CONCLUSIONS

In this retrospective multi-institutional analysis, both TACE and TARE with Y-90 were safe and effective liver-directed therapies for unresectable NELM. Although TARE was associated with a shorter length of hospital stay, TACE demonstrated improved short-term DCR, and both resulted in comparable long term outcomes.

Radiographic characteristics of neuroendocrine liver metastases do not predict clinical outcomes following liver resection

Background

Previous research has demonstrated that specific radiographic criteria, including the presence of calcifications and the enhancement pattern on computed tomography (CT) imaging, correlates with clinicopathologic features and outcomes of patients with gastroenteropancreatic neuroendocrine tumors (NET). We sought to investigate whether these radiographic characteristics were prognostic among patients with neuroendocrine liver metastases (NELM) undergoing surgical resection.

Methods

The preoperative contrast-enhanced CT scans of all patients who underwent resection of NELM at a single institution between 2000-2015 were retrospectively reviewed. The presence of calcifications was determined on non-contrast phase imaging. Enhancement on the arterial phase scan was categorized as hyperenhancing, hypoenhancing, or mixed. Relevant clinicopathologic characteristics as well as recurrence-free survival (RFS) and overall survival (OS) were compared between groups.

Results

Among 82 patients who underwent resection of NELM, 57 had available data on calcifications while 51 had data available on arterial enhancement patterns. Among all patients, median age was 58 (IQR: 47-63) and the majority were female (N=48, 59.5%). The most common primary tumor locations were pancreas (N=25, 30.5%) and small bowel (N=27, 32.9%). The most commonly performed operations were right hepatectomy (N=29, 35.4%), bisegmentectomy (N=15, 18.3%), and segmentectomy (N=14, 17.1%). Median tumor number was 4 (IQR: 2-9), median Ki-67 was 5% (IQR: 2-10%), and median size of the largest liver metastasis was 4.5 (IQR: 2.8-7.7) cm. Twelve (21%) patients had tumor calcifications. Among patients with and without calcifications there were no differences in demographics, clinicopathologic characteristics, RFS (P=0.772) or OS (P=0.095). Arterial enhancement was hypoenhancing in 23 (45.1%), hyperenhancing in 10 (19.6%), and mixed in 18 (35.3%). Similarly, there were no differences between arterial enhancement groups in demographics, clinicopathologic characteristics, RFS (P=0.618) or OS (P=0.268).

Conclusions

Radiographic characteristics on contrast-enhanced CT are not associated with the outcomes of patients undergoing resection of NELM. Future investigations should evaluate the prognostic impact of functional neuroendocrine imaging.

Nivolumab in Metastatic Adrenocortical Carcinoma: Results of a Phase 2 Trial

CONTEXT

Systemic treatment of metastatic adrenocortical carcinoma (ACC) remains limited to chemotherapy and mitotane. Preliminary evidence suggesting that antitumor immune responses can be elicited in ACC has fostered interest in checkpoint inhibitors such as anti-PD-1 nivolumab.

OBJECTIVE

The primary endpoint was objective response rate according to the response evaluation criteria in solid tumors. Secondary endpoints were progression-free survival (PFS), overall survival, and safety.

DESIGN

Single-arm, multicenter, phase 2 clinical trial with two-stage design.

SETTING

Comprehensive cancer center.

PATIENTS

Ten adult patients with metastatic ACC previously treated with platinum-based chemotherapy and/or mitotane as well as patients who declined front-line chemotherapy.

INTERVENTION

Nivolumab (240 mg) IV every 2 weeks.

RESULTS

Ten patients with metastatic ACC were enrolled between March and December 2016. The median number of doses of nivolumab administered was two. Three patients only received one treatment [one died of disease progression, one discontinued due to adverse events (AEs), one withdrew after beginning treatment]. The median PFS was 1.8 months. The median follow-up was 4.5 months (range, 0.1 to 25.6 months). Two patients had stable disease for a duration of 48 and 11 weeks, respectively. One patient had an unconfirmed partial response but discontinued the study due to an AE. Most AEs were grade 1/2. The most common grade 3/4 treatment-related AEs were aspartate aminotransferase and alanine aminotransferase elevations, mucositis, and odynophagia.

CONCLUSION

Nivolumab demonstrated modest antitumor activity in patients with advanced ACC. The nivolumab safety profile was consistent with previous clinical experience without any unexpected AEs in this population.

Targeting BRAF Mutations in High-Grade Neuroendocrine Carcinoma of the Colon

Mutations in the RAS/RAF/MEK/ERK pathway leading to constitutive activation and uncontrolled cellular growth have been identified in various human malignancies, making this pathway a target for potential therapeutics. The activating BRAF^V600E mutation is one well-characterized oncogenic mutation that has been described and targeted with clinical success in various malignancies, including melanoma and hairy cell leukemia. Although BRAF-directed treatments have yielded clinical benefit in a subset of tumor types, such as melanoma, thyroid cancer, and lung cancer, BRAF inhibition fails to confer a clinical benefit in colon cancer. Identification of patients for whom BRAF inhibition may produce clinically meaningful outcomes is imperative. The incidence of BRAF mutations in neuroendocrine carcinoma (NEC) is estimated to be 5% to 10%. A recent case series demonstrated benefit in targeting the BRAF^V600E mutation in metastatic high-grade rectal NECs. Combination BRAF and MEK inhibition is known to yield improved outcomes compared with BRAF inhibition alone in melanoma. This report presents 2 patients with high-grade colorectal NECs who had different responses to treatment with combined BRAF/MEK inhibition after experiencing disease progression through first-line platinum-based chemotherapy. One patient experienced an excellent initial response to therapy before ultimately experiencing progression, and in the other patient initially had stable disease before eventually experiencing progression. These cases highlight the complicated role BRAF mutations play in gastrointestinal NECs, and the need for further research to identify not only patients who may benefit from BRAF-directed therapies but also strategies to avoid development of resistance.

Vandetanib-induced Phototoxic Drug Eruption Treated with Polypodium Leucotomos Extract: A Case Report and Review of the Literature

Vandetanib is a tyrosine kinase inhibitor approved by the United States Food and Drug Administration for the treatment of metastatic medullary thyroid cancer. It has been linked to a variety of dermatologic reactions, including photosensitivity. We describe the case of a 55-year-old man who developed a severe, painful, erythematous, bullous eruption in sun-exposed areas one month after the initiation of vandetanib. The eruption was initially refractory to treatment with steroids and did not resolve with strict sun avoidance, but finally cleared after a few weeks of oral supplementation with Polypodium leucotomos (P. leucotomos) extract. P. leucotomos is an extract derived from a tropical fern, with antioxidant effects that mitigate ultraviolet-induced cutaneous erythema via inflammatory interference and the promotion of other cytotoxic responses. This case illustrates the potential for P. leucotomos to be used as a safe and effective photoprotective agent for refractory phototoxic reactions. Further randomized, controlled trials are needed to better understand the mechanism of action and photoprotective properties of P. leucotomos in the treatment of tyrosine kinase-induced phototoxicity and other dermatoses.

Abstract CT169: Pilot study testing the effects of BTK inhibitor ibrutinib and nivolumab on levels and function of myeloid-derived suppressor cells and other immune subsets in patients with metastatic solid tumors (NCT03525925)

Background: Myeloid-derived suppressor cells (MDSC) are a naturally occurring population of immature myeloid cells with immune suppressive function that curtail inflammatory processes. In cancer, these cells abnormally expand and migrate to tumor/lymphoid regions where they negatively impact antigen specific and innate immune effector cells. Circulating MDSC levels have also been associated with the higher tumor burden and decreased survival of patients with solid tumors. Preclinical studies performed by our group demonstrated that ibrutinib (PCI-32765), an irreversible inhibitor of Bruton’s tyrosine kinase, is capable of inhibiting MDSC generation and their immunosuppressive function (A. Stiff, CA Res, 2016). We also found that the combination of ibrutinib and a PD-L1 inhibitor worked synergistically in a mouse model of mammary carcinoma. Based on these results, targeting MDSC with ibrutinib has the potential to enhance the efficacy of immune checkpoint inhibitors such as nivolumab in patients with advanced solid tumors.

Materials and Methods: This pilot study will assess the effect of single agent ibrutinib and ibrutinib in combination with nivolumab on levels and function of circulating myeloid-derived suppressor cells in 15 patients with advanced solid tumors. Eligible patients are required to have metastatic malignancy and be eligible for treatment with nivolumab as determined by the treating physician. Study subjects will be treated with ibrutinib at 420 mg given orally once daily. Nivolumab will be given at a standard dose of 240 mg IV over 30 minutes on days 1 and 15 on 28-day cycles. Ibrutinib dosing will be started 7 (+/-2) days prior to cycle 1 of nivolumab therapy and will be given until cycle 1, day 8 of nivolumab or total of 15 days (whichever comes first). Peripheral blood will be collected just prior to initiation of ibrutinib (at day -7), prior to day 1 of cycle 1, prior to day 8 of cycle 1, prior to day 1 of cycle 2 and at the time of disease progression. The primary objective is to evaluate the effect of the ibrutinib therapy on circulating levels of myeloid-derived suppressor cells (MDSC). The safety of the study combination, effect of ibrutinib/nivolumab on immune cell subsets and the length of progression-free survival will also be assessed.

Conclusion: The study opened to accrual on August 10, 2018 and is currently enrolling the target 15 patients. To date 9 patients are on study.

Citation Format: Brooke Benner, Megan Duggan, Andrew Stiff, Bhavana Konda, Robert D. Rupert, Paul Monk, Claire Verschraegen, Hiral Shah, Anne Noonan, William E. Carson, Robert Wesolowski. Pilot study testing the effects of BTK inhibitor ibrutinib and nivolumab on levels and function of myeloid-derived suppressor cells and other immune subsets in patients with metastatic solid tumors (NCT03525925) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT169.

First real-world experience of peptide receptor radionuclide therapy (PRRT) in neuroendocrine tumors (NET) since US FDA approval

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Background: PRRT using 177Lu-DOTATATE was US FDA approved in Jan 2018, and real world data in the US is lacking. Methods: We retrospectively reviewed medical records of patients who began PRRT 03/14/18 - 10/01/18 at our institution. 177Lu-DOTATATE was administered at a dose of 200mCi over 20-30 min every 8 weeks for 4 doses. Infusion of arginine-lysine 25gm/25gm in 1-liter normal saline was given over 4 hours starting 30 min prior to treatment, in addition to intravenous palonosetron 0.25mg. Results: 51 patients received at least 1 of 4 doses and 40/51 were no longer on active therapy. 28/40 received all 4 doses and 12/40 discontinued treatment after < 4 doses. 25/40 were evaluable for response per RECIST v1.1. 16/25 (64%) had GI NET, 3/25 (12%) pancreatic NET, 4/25 (16%) atypical lung carcinoid, 1/25 (4%) multifocal NET, and 1/25 (4%) had paraganglioma. 28% had grade 1, 56% grade 2, and 8% (2/25) had grade 3 (Ki 67: 25% and 40%) NET. 12/25 (48%) had received ≥2 prior systemic therapies not including somatostatin analogs, and 10/25 (40%) had ≥1 prior liver-directed therapy. Median follow-up from date of last PRRT was 61.5 days. Objective response (partial response) rate was 16% (4/25; table). 18/25 (72%) had stable disease and 3/25 (12%) had progressive disease. Most adverse events (AEs) were grade 1-2 and included fatigue, nausea, abdominal pain, and cytopenias. ≥Grade 3 AEs requiring treatment discontinuation included symptomatic gastric outlet obstruction (2/51), small bowel obstruction (1/51), ischemic enteritis (1/51), confusion/bone pains (1/51), liver failure (1/51), and severe neutropenia (1/51). All patients with ≥grade 3 AEs had a high tumor burden at baseline. Conclusions: 177Lu-DOTATATE is an effective and safe treatment in advanced NET, and our results are consistent with NETTER 1 data.[Table: see text]