Neoadjuvant Selicrelumab, an Agonist CD40 Antibody, Induces Changes in the Tumor Microenvironment in Patients with Resectable Pancreatic Cancer

PURPOSE

CD40 activation is a novel clinical opportunity for cancer immunotherapy. Despite numerous active clinical trials with agonistic CD40 monoclonal antibodies (mAb), biological effects and treatment-related modulation of the tumor microenvironment (TME) remain poorly understood.

PATIENTS AND METHODS

Here, we performed a neoadjuvant clinical trial of agonistic CD40 mAb (selicrelumab) administered intravenously with or without chemotherapy to 16 patients with resectable pancreatic ductal adenocarcinoma (PDAC) before surgery followed by adjuvant chemotherapy and CD40 mAb.

RESULTS

The toxicity profile was acceptable, and overall survival was 23.4 months (95% confidence interval, 18.0-28.8 months). Based on a novel multiplexed immunohistochemistry platform, we report evidence that neoadjuvant selicrelumab leads to major differences in the TME compared with resection specimens from treatment-naïve PDAC patients or patients given neoadjuvant chemotherapy/chemoradiotherapy only. For selicrelumab-treated tumors, 82% were T-cell enriched, compared with 37% of untreated tumors (P = 0.004) and 23% of chemotherapy/chemoradiation-treated tumors (P = 0.012). T cells in both the TME and circulation were more active and proliferative after selicrelumab. Tumor fibrosis was reduced, M2-like tumor-associated macrophages were fewer, and intratumoral dendritic cells were more mature. Inflammatory cytokines/sec CXCL10 and CCL22 increased systemically after selicrelumab.

CONCLUSIONS

This unparalleled examination of CD40 mAb therapeutic mechanisms in patients provides insights for design of subsequent clinical trials targeting CD40 in cancer.

Abstract CT005: T cell inflammation in the tumor microenvironment after agonist CD40 antibody: Clinical and translational results of a neoadjuvant clinical trial

Deploying CD40 activation to stimulate T cell responses upstream of immune checkpoint molecules is a novel clinical opportunity for cancer immunotherapy. Despite numerous active clinical trials with agonistic CD40 monoclonal antibodies (mAb), biological treatment effects especially treatment-related modulation of the tumor microenvironment (TME), remain poorly understood. Here, we performed a neoadjuvant clinical trial of agonistic CD40 mAb (selicrelumab) administered intravenously with or without chemotherapy (gemcitabine and nab-paclitaxel) to 16 resectable patients with pancreatic ductal adenocarcinoma (PDAC) prior to surgery followed by adjuvant chemotherapy and CD40 mAb. The toxicity profile was acceptable, including only grade 1 or 2 cytokine release syndrome and expected toxicities from chemotherapy. Disease-free survival was 13.8 months (95% CI 2.9 - 24.8 months) and median overall survival was 23.4 months (95% CI 18.0 - 28.8), with 8 patients alive at a median of 20.0 months after surgery (follow-up range 12.2 to 34.8 months). Neoadjuvant selicrelumab induced major pharmacodynamic differences in the TME, as revealed by a multiplex imaging platform auditing the immune ecosystem, compared to resection specimens from PDAC patient previously untreated or given neoadjuvant chemotherapy/chemoradiotherapy only. For tumors resected after selicrelumab, 82% (9/11) were T-cell enriched, compared to 37% (38/104) (p=0.004) of untreated tumors and 23% (93/13) of chemotherapy/chemoradiation-treated tumors (p=0.012). Moreover, for selicrelumab tumors, tumor-associated fibrosis was less, “M2” macrophages were fewer, dendritic cells were more mature, and T cells were activated and proliferative, compared to the non-selicrelumab groups. In the periphery, CD8+ and CD4+ T cells were more activated and proliferative, and serum inflammatory cytokines CXCL10 and CCL22 increased after treatment. This study provides proof-of-concept in patients that agonistic CD40 mAb alters the TME, enhances T-cell infiltration, and modulates systemic inflammatory responses. These findings inform design of next-generation CD40 clinical trials.

Citation Format: Katelyn T. Byrne, Courtney B. Betts, Rosemarie Mick, Shamilene Sivagnanam, David L. Bajor, Daniel A. Laheru, E. Gabriela Chiorean, Mark H. O'Hara, Shannon M. Liudahl, Craig Newcomb, Cécile Alanio, Ana P. Ferreira, Byung S. Park, Takuya Ohtani, Austin P. Huffman, Sara A. Väyrynen, Andressa Dias Costa, Judith C. Kaiser, Andreanne M. Lacroix, Colleen Redlinger, Martin Stern, Jonathan A. Nowak, E. John Wherry, Martin A. Cheever, Brian M. Wolpin, Emma E. Furth, Elizabeth M. Jaffee, Lisa M. Coussens, Robert H. Vonderheide. T cell inflammation in the tumor microenvironment after agonist CD40 antibody: Clinical and translational results of a neoadjuvant clinical trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT005.

Pancreatic Cancer Clinical Treatment Trials Accrual: A Closer Look at Participation Rates

OBJECTIVES

Low rates of participation in cancer clinical trials are commonly reported, raising concerns about missed opportunities to engage patients in treatment trials. We reviewed eligibility for and enrollment in pancreatic cancer clinical trials for patients seen at a National Cancer Institute (NCI)-designated cancer center during 1 year, to calculate participation rates with detailed information to determine the best-case participation rate.

MATERIALS AND METHODS

This retrospective cohort study used the Abramson Cancer Center Cancer Registry, clinical trial protocols, and electronic medical records (EMRs) to determine eligibility for all available pancreatic cancer clinical trials. Patient characteristics and reasons for ineligibility were abstracted from EMRs. We then computed participation rates based on enrollment in trials using EMR and clinical trials monitoring data.

RESULTS

Of 233 new pancreatic cancer patients in 2014, 47 or 20% enrolled in a clinical trial (enrollment fraction). According to the EMR, of the 66 patients who were eligible for a trial, 54 (82% of eligible) accepted and 47 (71% of eligible) ultimately enrolled in a trial, 8 (12% of eligible) declined, and 4 (6% of eligible) had no record of patient decision. Enrollment in a trial by both the EMR and clinical trials database was confirmed for 71% of eligible patients.

CONCLUSIONS

This study reveals that 71% of newly diagnosed pancreatic cancer patients who were eligible for a trial were enrolled in a treatment trial. We contend that in-depth analysis, rather than enrollment fraction, should be used to inform the gap between actual participation and optimal clinical trial participation for cancer patients.

Effect of Gemcitabine and nab-Paclitaxel With or Without Hydroxychloroquine on Patients With Advanced Pancreatic Cancer: A Phase 2 Randomized Clinical Trial

Importance

Autophagy is a mechanism of treatment resistance to chemotherapy that has a role in the maintenance of pancreatic cancer. Hydroxychloroquine sulfate (HCQ) is an inhibitor of autophagy that inhibits the fusion of the autophagosome to the lysosome.

Objective

To determine whether HCQ improves overall survival at 1 year in combination with gemcitabine hydrochloride and nab-paclitaxel (GA) among patients with metastatic pancreatic cancer.

Design, Setting, and Participants

Open-label, phase 2 randomized clinical trial conducted between March 18, 2013, and November 16, 2017, at the University of Pennsylvania, HonorHealth, and The Johns Hopkins University among 112 patients with previously untreated metastatic or advanced pancreatic ductal adenocarcinoma, Eastern Cooperative Oncology Group performance status of 0 or 1, and adequate marrow and organ function. All efficacy analyses were performed for the intention-to-treat population.

Interventions

Patients were randomized in a 1:1 ratio to receive GA with or without HCQ. All patients received standard doses of GA, and those randomized to receive HCQ were treated continuously with 600 mg orally twice daily.

Main Outcome and Measure

Overall survival at 1 year.

Results

A total of 112 patients (45 women and 67 men; median age, 65 years; range, 43-86 years) were enrolled; 55 were randomized to receive GA plus HCQ, and 57 to receive GA. Overall survival at 12 months was 41% (95% CI, 27%-53%) in the HCQ group and 49% (95% CI, 35%-61%) in the non-HCQ group. Median progression-free survival was 5.7 months (95% CI, 4.0-9.3 months) in the HCQ group and 6.4 months (95% CI, 4.5-7.6 months) in the non-HCQ group. Median overall survival was 11.1 months (95% CI, 9.0-14.2 months) in the HCQ group and 12.1 months (95% CI, 9.3-15.5 months) in the non-HCQ group. Overall response rate was 38.2% (n = 21) in the HCQ group and 21.1% (n = 12) in the non-HCQ group (P = .047). Treatment-related grade 3 or 4 adverse events that differed between the HCQ and non-HCQ groups were neutropenia (23 of 54 [42.6%] vs 12 of 53 [22.6%]), anemia (2 of 54 [3.7%] vs 9 of 53 [17.0%]), fatigue (4 of 54 [7.4%] vs 0), nausea (5 of 54 [9.3%] vs 0), peripheral neuropathy (7 of 54 [13.0%] vs 3 of 53 [5.7%]), visual changes (3 of 54 [5.6%] vs 0), and neuropsychiatric symptoms (3 of 54 [5.6%] vs 0).

Conclusions and Relevance

The addition of HCQ to block autophagy did not improve the primary end point of overall survival at 12 months. These data do not support the routine use of GA plus HCQ for metastatic pancreatic cancer in the absence of a biomarker. However, improvement seen in the overall response rate with HCQ may indicate a role for HCQ in the locally advanced setting, where tumor response may permit resection.

Trial Registration

ClinicalTrials.gov identifier: NCT01506973.

Combination Paclitaxel and Palbociclib: Results of a Phase I Trial in Advanced Breast Cancer

PURPOSE

The CDK 4/6 inhibitor palbociclib rapidly and reversibly inhibits the cell cycle. The goal of this study was to exploit the cell cycle through intermittent, alternating dosing with palbociclib/paclitaxel to enhance efficacy. We determined the combination dose-limiting toxicity (DLT) in patients with Rb protein-expressing, advanced breast cancer.

PATIENTS AND METHODS

This open-label, phase I trial (NCT01320592) enrolled patients to sequential cohorts of palbociclib orally dosed intermittently between days 1 and 19 of a 28-day cycle alternating with weekly paclitaxel. Dose escalation proceeded in a standard 3 + 3 design. Ten additional patients received the combination at the recommended phase II dose (RP2D). Those who reached response plateau ≥6 cycles could continue on palbociclib alone on a 3 week on/1 week off schedule at one dose level above their combination dose.

RESULTS

Twenty-seven patients enrolled. Although there was only 1 DLT (grade 3 alanine aminotransferase/aspartate aminotransferase at 125 mg), neutropenia (NTP) requiring dose modification in cycle 1 (C1) resulted in an RP2D of 75 mg palbociclib/80 mg/m² paclitaxel. During C1, the most common adverse event was NTP, occurring in 15 patients (55.6%); grade 1 or 2 nausea and peripheral neuropathy were also observed in 8 patients each (29.6%). The clinical benefit rate was 55% at the RP2D; benefit was observed across all receptor subtypes.

CONCLUSIONS

Alternating sequential palbociclib/paclitaxel in patients with Rb⁺ advanced breast cancer is feasible and safe, without evidence of additive toxicity. This represents a new application for CDK 4/6 inhibitors in Rb⁺ breast cancer regardless of subtype; efficacy trials are warranted.

Abstract CT085: Randomized phase II trial of hydroxychloroquine in combination with gemcitabine/nab-paclitaxel to inhibit autophagy in pancreatic cancer: A SU2C-funded trial

Autophagy, a regulated metabolic process that enables energy conservation in adverse environmental circumstances, has been shown in animal models to confer resistance to chemotherapy, which can be reversed by hydroxychloroquine (HCQ). After establishing safety in a Phase I run-in, 112 patients were randomized to receive standard gemcitabine (1000mg/m2) and nab-paclitaxel (125 mg/m2) weekly x 3 every 4 weeks, with (n=55 evaluable) or without (n=55 evaluable) HCQ 600mg bid. Median age was 65 (range 43-86) of whom 47% were aged > 65, 40% were female, 93% Caucasian, ECOG PS 0/1 51%/49%, and did not differ between the arms. Treatment-related side-effects were consistent with prior studies, and were balanced by arm, except for Grade 3/4 neutropenia (42 vs 23%), nausea (9 vs 0%), and fatigue (7 vs 0%), all higher with HCQ. Partial responses were observed in 21/46 (46%) with HCQ, and 8/48 (17%) without HCQ. The primary endpoint, overall survival at 12 months, was 41% (95% CI 27-53%) in the HCQ arm and 51% (95% CI 36-63%) in the non-HCQ arm. Median progression-free survival was 5.7 months (95% CI 4.0-9.3) in the HCQ arm and 6.4 months in the non-HCQ arm (95% CI 4.5-7.6). Median overall survival was 11.1 months (95% CI 9.0-14.2) in the HCQ arm and 14.4 months (95% CI 9.5-15.6) in the non-HCQ arm. Genomic testing was performed on a subset of the patients (41%), in whom outcomes did not differ by p53 mutational status. We conclude that based on the primary endpoint, the addition of the autophagy reversal agent HCQ did not improve the survival of patients with metastatic pancreatic cancer. Response rates in patients who received HCQ were higher, and toxicity was tolerable. Autophagy reversal might be explored in the management of locally-advanced disease.

Citation Format: Thomas B. Karasic, Mark H. O'Hara, Arturo Loaiza-Bonilla, Kim A. Reiss-Binder, Ursina R. Teitelbaum, Erkut Borazanci, Ana M. De Jesus-Acosta, Colleen Redlinger, Jessica A. Burrell, Daniel D. Von Hoff, Daniel A. Laheru, Ravi K. Amaravadi, Jeffrey A. Drebin, Peter J. O'Dwyer. Randomized phase II trial of hydroxychloroquine in combination with gemcitabine/nab-paclitaxel to inhibit autophagy in pancreatic cancer: A SU2C-funded trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr CT085.

Combining Machine Learning and Nanofluidic Technology To Diagnose Pancreatic Cancer Using Exosomes

Circulating exosomes contain a wealth of proteomic and genetic information, presenting an enormous opportunity in cancer diagnostics. While microfluidic approaches have been used to successfully isolate cells from complex samples, scaling these approaches for exosome isolation has been limited by the low throughput and susceptibility to clogging of nanofluidics. Moreover, the analysis of exosomal biomarkers is confounded by substantial heterogeneity between patients and within a tumor itself. To address these challenges, we developed a multichannel nanofluidic system to analyze crude clinical samples. Using this platform, we isolated exosomes from healthy and diseased murine and clinical cohorts, profiled the RNA cargo inside of these exosomes, and applied a machine learning algorithm to generate predictive panels that could identify samples derived from heterogeneous cancer-bearing individuals. Using this approach, we classified cancer and precancer mice from healthy controls, as well as pancreatic cancer patients from healthy controls, in blinded studies.

A magnetic micropore chip for rapid (<1 hour) unbiased circulating tumor cell isolation and in situ RNA analysis

The use of microtechnology for the highly selective isolation and sensitive detection of circulating tumor cells has shown enormous promise. One challenge for this technology is that the small feature sizes - which are the key to this technology's performance - can result in low sample throughput and susceptibility to clogging. Additionally, conventional molecular analysis of CTCs often requires cells to be taken off-chip for sample preparation and purification before analysis, leading to the loss of rare cells. To address these challenges, we have developed a microchip platform that combines fast, magnetic micropore based negative immunomagnetic selection (>10 mL h^-1) with rapid on-chip in situ RNA profiling (>100× faster than conventional RNA labeling). This integrated chip can isolate both rare circulating cells and cell clusters directly from whole blood and allow individual cells to be profiled for multiple RNA cancer biomarkers, achieving sample-to-answer in less than 1 hour for 10 mL of whole blood. To demonstrate the power of this approach, we applied our device to the circulating tumor cell based diagnosis of pancreatic cancer. We used a genetically engineered lineage-labeled mouse model of pancreatic cancer (KPCY) to validate the performance of our chip. We show that in a cohort of patient samples (N = 25) that this device can detect and perform in situ RNA analysis on circulating tumor cells in patients with pancreatic cancer, even in those with extremely sparse CTCs (<1 CTC mL^-1 of whole blood).

Toxicity study of gemcitabine, oxaliplatin, and bevacizumab followed by 5-fluorouracil, oxaliplatin, bevacizumab, and radiotherapy in patients with locally advanced pancreatic cancer

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Background: Patients with advanced pancreatic cancer experience higher response rates (though not always improved survival) with combinations of either platinum compounds or bevacizumab in combination with gemcitabine. In patients with locally advanced pancreatic cancer, improved response affects local control and surgical options.

Methods: We piloted a three-drug combination of gemcitabine/oxaliplatin/5-FU/bevacizumab Q2w for four cycles, followed by oxaliplatin (85 mg/m2/q2w) and bevacizumab (5 mg/kg q2w) added to infusional 5-FU and radiation, in patients with pancreatic cancer that was unresectable or borderline resectable.

Results: Nineteen patients have been treated, of whom 17 received the entire treatment. Median age was 60, with 12 women and 7 men. Stages were: one IIA, one IIB, and 17 III. Sixteen were unresectable and 3 borderline resectable by protocol-specified criteria. Major toxicities during chemotherapy were: grade 3 neutropenia (5/19); grade 2 neutropenia (7/19), anemia (2/19), thrombocytopenia (2/19). During chemoradiation major toxicities were: grade 3 nausea (3/19), vomiting (3/19), leukopenia (2/19); grade 2 nausea (5/19), leukopenia (4/19). One patient had grade 3 pulmonary embolism that led to withdrawal from the study. One patient had progressive pain early on; no other disease progression was noted during treatment. Five patients (3 inoperable, 2 borderline) went on to have surgery. Median survival was 14 months (range 3 to 40+). For the 5 patients who had surgery, median survival was 17.1 months (range 9.5 to 40+).

Conclusions: We conclude that this regimen is well-tolerated by patients with locally advanced pancreatic cancer, and that the therapeutic results support further evaluation. Additional correlative studies are underway to identify characteristics associated with a favorable outcome.

Single nucleotide polymorphisms of TSER, ATM, RecQ1 genes association with survival in pancrease cancer

e14590

Background: Pancreatic cancer (PaCa) is the 4th leading cause of cancer-related mortality in the U.S . We tried to determine whether ATM, RecQ1 gene polymorphisms correlate with gemcitabine (G) and TSER gene polymorphism with capecitabine (C) response and over all survival(OS). We also tested the hypothesis that PaCa pts homozygous for the S/S variant of the TSER will have a higher 6-month survival with C compared to historical controls. TS expression is regulated by a polymorphism in the TSER and has been shown that pts with S/S variant have high response rate and increased toxicity in colon cancer pts. ATM and recQ1 genes are involved with DNA damage response and repair and correlate with G response. Methods: DNA isolated from peripheral blood samples in 82 pts with Stage IV pancreatic cancer was tested for the TSER, ATM and RecQ1 gene polymorphisms. All patients were treated with G 1,000mg/m2 wkly for 3/4 wks. Pts homozygous for the S/S variant were treated with C, 2,000 mg/m2/day for 14 /21days. Pts were evaluated for response to therapy according to the RECIST. Results: 16 pts (19.5%) were positive for S/S variant of TSER, but only 4 (4.8%) were treated. The reasons for declining treatment were geographic, logistic or progression issues. Only 1 pt was evaluable, receiving at least 3 cycles of C . All pts needed dose reductions due to toxicities. Grade 3 hand foot syndrome, diarrhea and vomiting were dose limiting toxicities. No complete or partial responses were seen. The pt who received 3 cycles came off study due to progressive disease and the other 3 pts came of the study due to toxicities. TSER polymorphism was correlated to OS and only S/S variant was significant with a trend towards improved OS by log rank test and Kaplan Meier plot. ATM and RecQ1 gene polymorphisms subtypes did not correlate with G response and OS ( not statistically significant). Conclusions: Our study represents an initial effort to apply pharmacogenetics to PaCa therapy. 19.5% of pts had the S/S variant of the TSER polymorphism, but only 4.8% enrolled. C administration was associated with excess toxicity. The toxicities observed in this study appear to outweigh the benefit of using C in this pt population. There is no correlation between ATM and RecQ1 genotypes with OS. However the sample size is too small to draw conclusions.

[Table: see text]

Effect of BRAFV600E on response to sorafenib in advanced thyroid cancer patients

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Background: We are conducting an open-label phase II study of sorafenib in patients with metastatic, iodine-refractory thyroid carcinoma. Methods: 55 Patients were administered sorafenib 400 mg orally BID. Responses were monitored by PET and CT. Primary endpoints were response rate (RR) and progression free survival (PFS) by RECIST criteria. BRAF and RAS mutation status is determined by DNA sequencing. Outcome data is evaluated using the Kaplan-Meier method and log-rank test. Biologic activity in tissue obtained during treatment at response and progression is being explored using immunohistochemistry (IHC) to pERK, pAKT and Ki-67 among others, in pretreatment blocks from virtually all patients, and a subset of 14 patients in whom on-treatment tissue is available. Results: We have completed accrual of the 55 patients planned for enrollment; median time on study is 34 weeks and 25 pts (45%) are male. Histological subtypes include papillary (PTC): 25 pts (47%); follicular/Hürthle Cell (FTC): 19 pts (36%); medullary: 4 pts (8%), and poorly differentiated/anaplastic: 5 pts (9%). 52/55 patients are evaluable for response at this time. Median PFS was 84 wks. Genotyping of BRAF is complete in 16 patients. For patients with PTC/FTC, the PFS for those with BRAFwt was 54 wks compared to 84+ wks for patients with BRAFV600E (p = 0.028). On-treatment tissue at progression demonstrates heterogeneity, with p-ERK and p-AKT suppressed in some areas, but highly expressed in others. Data at 6 months post accrual of the last patient will be presented along with patient thyroglobulin levels, PET and CT scans. IHC and additional genotyping will also be presented. Conclusions: Sorafenib has activity in patients with advanced thyroid cancer with an overall PFS of 84 wks. While most patients with PTC or FTC achieve durable responses, patients whose tumors harbor BRAFV600E have significantly longer PFS than those that are BRAFwt.

[Table: see text]