A phase II study of guadecitabine combined with irinotecan vs regorafenib or TAS-102 in irinotecan-refractory metastatic colorectal cancer patients

DNA methyltransferase inhibitors (DNMTi) have demonstrated benefit in reversing resistance to systemic therapies for several cancer types. In a phase II trial of guadecitabine and irinotecan compared to regorafenib or TAS-102 in pts with advanced mCRC refractory to irinotecan. Patients with mCRC refractory to irinotecan were randomized 2:1 to guadecitabine and irinotecan (Arm A) vs standard of care regorafenib or TAS-102 (Arm B) on a 28-day cycle. Between January 15, 2016 and October 24, 2018, 104 pts were randomized at four international sites, with 96 pts undergoing treatment, 62 in Arm A and 34 in Arm B. Median overall survival was 7.15 months for Arm A and 7.66 months for Arm B (HR 0.93, 95% CI: 0.58-1.47, P = .75). The Kaplan-Meier rates of progression free survival at 4 months were 32% in Arm A and 26% in Arm B. Common ≥Grade 3 treatment related adverse events in Arm A were neutropenia (42%), anemia (18%), diarrhea (11%), compared to Arm B pts with neutropenia (12%), anemia (12%). Guadecitabine and irinotecan had similar OS compared to standard of care TAS-102 or regorafenib, with evidence of target modulation. Clinical trial information: NCT01896856.

Immunotherapy for the treatment of biliary tract cancer: an evolving landscape

Biliary tract cancers (BTCs), consisting of intrahepatic and extrahepatic cholangiocarcinoma and gallbladder cancer, are an aggressive, heterogeneous malignancy. They are most often diagnosed in the locally advanced or metastatic setting, at which point treatment consists of systemic therapy or best supportive care. Our understanding of the tumor microenvironment and the molecular classification has led to the identification of targetable mutations, such as isocitrate dehydrogenase 1 and fibroblast growth factor receptor 2. Despite the identification of these genomic alterations, until recently, little advancement had been made in the first-line setting for advanced BTC. While immunotherapy (IO) has revolutionized the treatment of many malignancies, the use of IO in BTC had yielded limited results prior to TOPAZ-1. In this review, we discuss the systemic therapeutic advances for BTC over the past decade, the rationale for immunotherapy in BTC, prior trials utilizing IO in BTC, and current and emerging immune-based therapeutic options. We further analyze the culmination of these advances, which resulted in the approval of durvalumab with gemcitabine and cisplatin for the first-line treatment of BTC per TOPAZ-1. We also discuss the results of KEYNOTE-966, which similarly reported improved clinical outcomes with the use of pembrolizumab in combination with gemcitabine and cisplatin.

Surgical and local control outcomes after sequential short-course radiation therapy and chemotherapy for rectal cancer

Background

Total neoadjuvant therapy (TNT) is an accepted approach for the management of locally advanced rectal cancer (LARC) and is associated with a decreased risk of development of metastatic disease compared to standard neoadjuvant therapy. However, questions remain regarding surgical outcomes and local control in patients who proceed to surgery, particularly when radiation is given first in the neoadjuvant sequence. We report on our institution's experience with patients who underwent short-course radiation therapy, consolidation chemotherapy, and surgery.

Methods

We retrospectively reviewed surgical specimen outcomes, postoperative complications, and local/pelvic control in a large cohort of patients with LARC who underwent neoadjuvant therapy incorporating upfront short-course radiation therapy followed by consolidation chemotherapy.

Results

In our cohort of 83 patients who proceeded to surgery, a complete/near-complete mesorectal specimen was achieved in 90 % of patients. This outcome was not associated with the time interval from completion of radiation to surgery. Postoperative complications were acceptably low. Local control at two years was 93.4 % for all patients- 97.6 % for those with low-risk disease and 90.4 % for high-risk disease.

Conclusion

Upfront short-course radiation therapy and consolidation chemotherapy is an effective treatment course. Extended interval from completion of short-course radiation therapy did not impact surgical specimen quality.

Neoadjuvant and adjuvant therapy for biliary tract cancer: Advances and limitations

Biliary tract cancers (BTC) are a rare and aggressive consortium of malignancies, consisting of intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, and gallbladder carcinoma. While most patients present with metastatic disease, a minority of patients with BTC are eligible for curative surgical resection at the time of presentation. However, these patients have poor 5-year overall survival rates and high rates of recurrence, necessitating the improvement of the neoadjuvant and adjuvant treatment of BTC. In this review, we assess the neoadjuvant and adjuvant clinical trials for the treatment of BTC and discuss the challenges and limitations of clinical trials, as well as future directions for the treatment of BTC.

CD4 T cell-activating neoantigens enhance personalized cancer vaccine efficacy

Personalized cancer vaccines aim to activate and expand cytotoxic antitumor CD8+ T cells to recognize and kill tumor cells. However, the role of CD4+ T cell activation in the clinical benefit of these vaccines is not well defined. We previously established a personalized neoantigen vaccine (PancVAX) for the pancreatic cancer cell line Panc02, which activates tumor-specific CD8+ T cells but required combinatorial checkpoint modulators to achieve therapeutic efficacy. To determine the effects of neoantigen-specific CD4+ T cell activation, we generated a vaccine (PancVAX2) targeting both major histocompatibility complex class I- (MHCI-) and MHCII-specific neoantigens. Tumor-bearing mice vaccinated with PancVAX2 had significantly improved control of tumor growth and long-term survival benefit without concurrent administration of checkpoint inhibitors. PancVAX2 significantly enhanced priming and recruitment of neoantigen-specific CD8+ T cells into the tumor with lower PD-1 expression after reactivation compared with the CD8+ vaccine alone. Vaccine-induced neoantigen-specific Th1 CD4+ T cells in the tumor were associated with decreased Tregs. Consistent with this, PancVAX2 was associated with more proimmune myeloid-derived suppressor cells and M1-like macrophages in the tumor, demonstrating a less immunosuppressive tumor microenvironment. This study demonstrates the biological importance of prioritizing and including CD4+ T cell-specific neoantigens for personalized cancer vaccine modalities.

Gemcitabine, Docetaxel, Capecitabine, Cisplatin, Irinotecan as First-line Treatment for Metastatic Pancreatic Cancer

Purpose

Treatment of advanced pancreatic cancer with a single therapeutic at a maximal dose has been largely ineffective at increasing survival. Combination therapies are commonly studied but often limited by toxicity. We previously showed that low-dose multiagent therapy with gemcitabine, docetaxel (taxotere), capecitabine (xeloda), and cisplatin (GTX-C) was safe, well tolerated, and effective (NCT01459614). Here, we hypothesize that adding irinotecan to GTX-C may improve survival with minimal toxicity.

Experimental Design

Patients with treatment-naïve metastatic pancreatic adenocarcinoma were treated with gemcitabine, docetaxel (taxotere), capecitabine (xeloda), cisplatin, and irinotecan (GTX-CI). Treatment consisted of capecitabine 500 mg twice daily on days 1-14 and gemcitabine 300 to 500 mg/m2, docetaxel 20 mg/m2, cisplatin 15 to 20 mg/m2, and irinotecan 20 to 60 mg/m2 on days 4 and 11 of a 21-day cycle. The primary objective was 9-month overall survival (OS). Secondary objectives included response rate (RR), disease control rate (DCR), progression-free survival (PFS), and OS.

Results

The regimen was well tolerated. The recommended phase II dose was gemcitabine 500 mg/m2, docetaxel 20 mg/m2, capecitabine 500 mg po bid, cisplatin 20 mg/m2, and irinotecan 20 mg/m2. Median follow-up in phase II was 11.02 months (2.37-45.17). Nine-month OS rate was 57% [95% confidence interval (CI): (41-77)]. RR was 57% [95% CI: (37-75) 50% PR and 7% CR]. DCR was 87% [95% CI: (69-96)]. Median OS and PFS were 11.02 [95% CI: (8.54-21.09)] and 8.34 [95% CI: (6.34-NA)] months, respectively.

Conclusions

The addition of irinotecan to GTX-C was safe and well tolerated. While the study did not meet its primary objective, the responses were clinically meaningful using a well-tolerated regimen.

Significance

We aimed to optimize the previously reported efficacious regimen of low-dose multiagent therapy with GTX-C for the treatment of metastatic pancreatic ductal adenocarcinoma by adding irinotecan. The primary objective was not met, but GTX-CI was well tolerated. The RR of 57%, median PFS of 8.3 months, median OS of 11 months, and 36-month OS rate of 19% suggest clinical benefit. Further optimization of this regimen is warranted.

ME3BP-7 is a targeted cytotoxic agent that rapidly kills pancreatic cancer cells expressing high levels of monocarboxylate transporter MCT1

Nearly 30% of Pancreatic ductal adenocarcinoma (PDAC)s exhibit a marked overexpression of Monocarboxylate Transporter 1 (MCT1) offering a unique opportunity for therapy. However, biochemical inhibitors of MCT1 have proven unsuccessful in clinical trials. In this study we present an alternative approach using 3-Bromopyruvate (3BP) to target MCT1 overexpressing PDACs. 3BP is a cytotoxic agent that is known to be transported into cells via MCT1, but its clinical usefulness has been hampered by difficulties in delivering the drug systemically. We describe here a novel microencapsulated formulation of 3BP (ME3BP-7), that is effective against a variety of PDAC cells in vitro and remains stable in serum. Furthermore, systemically administered ME3BP-7 significantly reduces pancreatic cancer growth and metastatic spread in multiple orthotopic models of pancreatic cancer with manageable toxicity. ME3BP-7 is, therefore, a prototype of a promising new drug, in which the targeting moiety and the cytotoxic moiety are both contained within the same single small molecule.

One Sentence Summary

ME3BP-7 is a novel formulation of 3BP that resists serum degradation and rapidly kills pancreatic cancer cells expressing high levels of MCT1 with tolerable toxicity in mice.

A study of using epigenetic modulators to enhance response to pembrolizumab (MK-3475) in microsatellite stable advanced colorectal cancer

BACKGROUND

Approximately 95% of advanced colorectal cancer patients (CRC) have mismatch repair MMR-proficient (MMRp) tumors, which do not respond to PD1 blockade alone. Preclinical studies have shown that combined histone deacetylases (HDAC) and/or DNA methyltransferases (DNMT) inhibition can induce susceptibility to immune checkpoint therapy and inhibit tumor growth. We conducted a pilot trial evaluating PD-1 immune checkpoint inhibitor therapy in combination with DNMT and HDAC inhibitors in MMRp CRC. The study was designed with a biological endpoint of change in immune cell infiltration, to determine the optimal epigenetic combination that optimizes the tumor microenvironment. This trial was designed to test that hypothesis.

RESULTS

From January 2016 to November 2018, 27 patients were enrolled with median age of 57 (range 40-69) years. Median progression-free survival and overall survival were 2.79 months and 9.17, respectively. One patient in Arm C achieved a durable partial response by RECIST criteria, lasting for approximately 19 months. The most common treatment-related hematological adverse events in all arms were anemia (62%), lymphopenia (54%) and thrombocytopenia (35%), and non-hematological AEs were anorexia (65%), nausea (77%), and vomiting (73%).

CONCLUSIONS

The combination of 5-azacitidine and romidepsin with pembrolizumab was safe and tolerable in patients with advanced MMRp CRC, but with a minimal activity. Further mechanistic investigations are needed to understand epigenetic-induced immunologic shift and to expand the potential applicability of checkpoint inhibitors in this setting.

Phase I Trial of Intravenous Mistletoe Extract in Advanced Cancer

Purpose

Mistletoe extract (ME) is widely used for patients with cancer to support therapy and to improve quality of life (QoL). However, its use is controversial due to suboptimal trials and a lack of data supporting its intravenous administration.

Materials and Methods

This phase I trial of intravenous mistletoe (Helixor M) aimed to determine the recommended phase II dosing and to evaluate safety. Patients with solid tumor progressing on at least one line of chemotherapy received escalating doses of Helixor M three times a week. Assessments were also made of tumor marker kinetics and QoL.

Results

Twenty-one patients were recruited. The median follow-up duration was 15.3 weeks. The MTD was 600 mg. Treatment-related adverse events (AE) occurred in 13 patients (61.9%), with the most common being fatigue (28.6%), nausea (9.5%), and chills (9.5%). Grade 3+ treatment-related AEs were noted in 3 patients (14.8%). Stable disease was observed in 5 patients who had one to six prior therapies. Reductions in baseline target lesions were observed in 3 patients who had two to six prior therapies. Objective responses were not observed. The disease control rate (percentage of complete/partial response and stable disease) was 23.8%. The median stable disease was 15 weeks. Serum cancer antigen-125 or carcinoembryonic antigen showed a slower rate of increase at higher dose levels. The median QoL by Functional Assessment of Cancer Therapy-General increased from 79.7 at week 1 to 93 at week 4.

Conclusions

Intravenous mistletoe demonstrated manageable toxicities with disease control and improved QoL in a heavily pretreated solid tumor population. Future phase II trials are warranted.

Significance

Although ME is widely used for cancers, its efficacy and safety are uncertain. This first phase I trial of intravenous mistletoe (Helixor M) aimed to determine phase II dosing and to evaluate safety. We recruited 21 patients with relapsed/refractory metastatic solid tumor. Intravenous mistletoe (600 mg, 3/week) demonstrated manageable toxicities (fatigue, nausea, and chills) with disease control and improved QoL. Future research can examine ME's effect on survival and chemotherapy tolerability.

A randomized, phase II trial of oral azacitidine (CC-486) in patients with resected pancreatic adenocarcinoma at high risk for recurrence

BACKGROUND

Of the only 20% of patients with resectable pancreatic ductal adenocarcinoma (rPDA), cancer recurs in 80% of cases. Epigenetic dysregulation is an early hallmark of cancer cells acquiring metastatic potential, and epigenetic modulators may reactivate tumor suppressor genes, delay recurrence, and sensitize PDA to future chemotherapy.

METHODS

This was a randomized phase II study (NCT01845805) of CC-486 (oral DNA methyltransferase inhibitor azacitidine) vs. observation (OBS) in rPDA patients harboring high-risk features (stage pN1-2, R1 margins, or elevated CA 19-9 level) with no evidence of disease following standard adjuvant therapy. Patients were randomized to oral CC-486 treatment (300 mg daily on days 1-21 on a 28-day cycle) or OBS for up to 12 cycles or until disease relapse/unacceptable toxicities. Following recurrence, records of next-line therapies, imaging, and survival were obtained. The primary endpoint was progression-free survival (PFS)-time from randomization to recurrence (imaging/biopsy confirmed or death). Secondary endpoints included OS and PFS and ORR and metastatic PFS with subsequent next-line systemic therapy in metastatic setting.

RESULTS

Forty-nine patients (24 in CC-486 arm, 25 in OBS arm) were randomized: median age 66 (range 36-81), 53% male, 73% node positive, 49% elevated CA 19-9, 20% R1 resection, 63% and 100% received perioperative concurrent chemoradiation and chemotherapy, respectively. Median time from surgery to randomization was 9.6 mo (range 2.9-36.8). For the CC-486 arm, median treatment duration was 5.6 mo (range 1.3 to 12.8) with 14 treatment-related grade 3 or 4 AEs among 5 patients (22%) resulting in dose-reduction. Four patients (17%) discontinued therapy due to AEs. With median follow-up of 20.3mo (IQR 12.8, 41.4), 38 (79%) of evaluable patients recurred (34 imaging-confirmed, 4 clinically). Median PFS in imagining-confirmed cases was 9.2 and 8.9mo (HR 0.94, 95% CI 0.46-1.87, p = 0.85) for CC-486 and OBS patients, respectively. Median OS (2-yr OS%) was 33.8 (50%) and 26.4 mo (61%) in CC-486 and OBS patients, respectively. (HR 0.98, 95% CI 0.46-2.05, p = 0.96). ORR with subsequent chemotherapy in the metastatic setting was minimal in both arms.

CONCLUSIONS

Treatment with CC-486 following adjuvant therapy did not prolong time-to-relapse in patients with high-risk rPDA or improve disease response on 1st-line metastatic therapy.

Impact of the COVID-19 Pandemic on Liver Cancer Staging at a Multidisciplinary Liver Cancer Clinic

To compare liver cancer resectability rates before and during the COVID-19 pandemic.

Background

Liver cancers usually present with nonspecific symptoms or are diagnosed through screening programs for at-risk patients, and early detection can improve patient outcomes. In 2020, the COVID-19 pandemic upended medical care across all specialties, but whether the pandemic was associated with delays in liver cancer diagnosis is not known.

Methods

We performed a retrospective review of all patients evaluated at the Johns Hopkins Multidisciplinary Liver Cancer Clinic from January 2019 to June 2021 with a new diagnosis of suspected or confirmed hepatocellular carcinoma (HCC) or biliary tract cancer (BTC).

Results

There were 456 liver cancer patients (258 HCC and 198 BTC). From January 2019 to March 2020 (pre-pandemic), the surgical resectability rate was 20%. The subsequent 6 months (early pandemic), the resectability rate decreased to 11%. Afterward from October 2020 to June 2021 (late pandemic), the resectability rate increased to 27%. The resectability rate early pandemic was significantly lower than that for pre-pandemic and later pandemic combined (11% lower; 95% confidence interval [CI], 2%-20%). There was no significant difference in resectability rates pre-pandemic and later pandemic (7% difference; 95% CI, -3% to 16%). In subgroup analyses, the early pandemic was associated with a larger impact in BTC resectability rates than HCC resectability rates. Time from BTC symptom onset until Multidisciplinary Liver Clinic evaluation increased by over 6 weeks early pandemic versus pre-pandemic (Hazard Ratio, 0.63; 95% CI, 0.44-0.91).

Conclusions

During the early COVID-19 pandemic, we observed a drop in the percentage of patients presenting with curable liver cancers. This may reflect delays in liver cancer diagnosis and contribute to excess mortality related to the COVID-19 pandemic.

Combined MEK/PD-L1 Inhibition Alters Peripheral Cytokines and Lymphocyte Populations Correlating with Improved Clinical Outcomes in Advanced Biliary Tract Cancer

PURPOSE

Biliary tract cancers (BTC) are aggressive malignancies refractory to chemotherapy and immunotherapy. MEK inhibition (MEKi)-based regimens may have utility in this disease when combined with PD-L1 blockade. We hypothesize that dual MEK/PD-L1 inhibition alters circulating soluble and cellular immune mediators to improve clinical outcomes in patients with advanced BTC.

EXPERIMENTAL DESIGN

We examined immune features in peripheral blood from 77 patients with advanced BTC enrolled in a phase II clinical trial investigating atezolizumab with or without cobimetinib. Plasma and peripheral blood mononuclear cells (PBMC) were isolated from whole blood to evaluate soluble factors and immune cell populations. Baseline blood samples were additionally compared with healthy donors to identify immune signatures unique to BTC.

RESULTS

At baseline, the soluble factors platelet-derived growth factor B (PDGF)-BB, placental growth factor (PlGF)-1, IL5, and IL17A were elevated in patients with BTC compared with healthy adult donors, and higher baseline frequencies of CD8+BTLA+ T cells correlated with better overall survival (OS) in this trial. There were also significant treatment-related alterations in several factors, including decreased PDGF-BB following combination treatment, that correlated with improved OS and progression-free survival (PFS). Higher baseline levels of IL23 and RANTES corresponded to improved clinical outcomes following combination treatment. Dual MEK/PD-L1 inhibition increased populations of CD4+TIM3+ and decreased CD8+VISTA+ T cells, correlating with worse OS and better PFS, respectively.

CONCLUSIONS

This work represents a comprehensive analysis of peripheral immune features in patients with BTC and systemic responses to dual MEK/PD-L1 inhibition. These data support further investigation to understand how MEKi combines with immunotherapeutic approaches to improve clinical outcomes for patients with advanced BTC.

Temporal Changes in Cholangiocarcinoma Incidence and Mortality in the United States from 2001 to 2017

Background

Previous studies report increasing cholangiocarcinoma (CCA) incidence up to 2015. This contemporary retrospective analysis of CCA incidence and mortality in the US from 2001-2017 assessed whether CCA incidence continued to increase beyond 2015.

Patients and Methods

Patients (≥18 years) with CCA were identified in the National Cancer Institute Surveillance, Epidemiology, and End Results 18 cancer registry (International Classification of Disease for Oncology [ICD-O]-3 codes: intrahepatic [iCCA], C221; extrahepatic [eCCA], C240, C241, C249). Cancer of unknown primary (CUP) cases were identified (ICD-O-3: C809; 8140/2, 8140/3, 8141/3, 8143/3, 8147/3) because of potential misclassification as iCCA.

Results

Forty-thousand-and-thirty CCA cases (iCCA, n=13,174; eCCA, n=26,821; iCCA and eCCA, n=35) and 32,980 CUP cases were analyzed. From 2001-2017, CCA, iCCA, and eCCA incidence (per 100 000 person-years) increased 43.8% (3.08 to 4.43), 148.8% (0.80 to 1.99), and 7.5% (2.28 to 2.45), respectively. In contrast, CUP incidence decreased 54.4% (4.65 to 2.12). CCA incidence increased with age, with greatest increase among younger patients (18-44 years, 81.0%). Median overall survival from diagnosis was 8, 6, 9, and 2 months for CCA, iCCA, eCCA, and CUP. From 2001-2016, annual mortality rate declined for iCCA (57.1% to 41.2%) and generally remained stable for eCCA (40.9% to 37.0%) and for CUP (64.3% to 68.6%).

Conclusions

CCA incidence continued to increase from 2001-2017, with greater increase in iCCA versus eCCA, whereas CUP incidence decreased. The divergent CUP versus iCCA incidence trends, with overall greater absolute change in iCCA incidence, provide evidence for a true increase in iCCA incidence that may not be wholly attributable to CUP reclassification.

Chemoradiation-induced alteration of programmed death-ligand 1, CD8+ tumor-infiltrating lymphocytes and mucin expression in rectal cancer

Introduction: DNA damage and resulting neoantigen formation is considered a mechanism for synergy between radiotherapy and PD-1/PD-L1 pathway inhibition to induce antitumor immune response. We investigated neoadjuvant chemoradiotherapy (nCRT)-induced changes in CD8+ tumor infiltrating lymphocyte, PD-L1 and mucin expression in rectal cancer patients.

Materials and Methods: Tumor samples of rectal adenocarcinoma patients undergoing resection between 2008-2014 with (n = 62) or without (n = 17) nCRT treatment were collected. Sections were stained with CD8 and PD-L1 antibodies for immunohistochemistry. The prevalence of CD8+ cells was recorded in the tumor, interface tumor and background rectal side. Image analysis was used to determine the density of CD8+ lymphocytes. The percentage of PD-L1 expression was manually counted in tumor cells (TC), tumor stroma (TS) and the invasive front (IF). Mucin expression was determined as the percentage of the mucin area in the whole tumor area.

Results: PD-L1 expression on TCs was identified in 7.6% (6/79) of nCRT specimens (p = 0.33) and in none of the non-nCRT patients. Median densities of CD8+ infiltrating T lymphocytes did not differ significantly between the two groups. Mucin expression was significantly higher in the nCRT cohort (p = 0.02). Higher neutrophil to lymphocytes ratio (NLR) after nCRT was associated with worse outcome (HR = 1.04, 95% CI = 1.00–1.08).

Conclusions: nCRT exposure was associated with a non-significant difference in PD-L1 expression in rectal adenocarcinoma patients, possibly due to sample size limitations. Further mechanistic investigations and comprehensive immune analysis are needed to understand nCRT-induced immunologic shift in rectal cancer and to expand the applicability of checkpoint inhibitors in this setting.

Clinical, Genomic, and Transcriptomic Data Profiling of Biliary Tract Cancer Reveals Subtype-Specific Immune Signatures

PURPOSE

Biliary tract cancers (BTCs) are aggressive cancers that carry a poor prognosis. An enhanced understanding of the immune landscape of anatomically and molecularly defined subsets of BTC may improve patient selection for immunotherapy and inform immune-based combination treatment strategies.

METHODS

We analyzed deidentified clinical, genomic, and transcriptomic data from the Tempus database to determine the mutational frequency and mutational clustering across the three major BTC subtypes (intrahepatic cholangiocarcinoma [IHC], extrahepatic cholangiocarcinoma, and gallbladder cancer). We subsequently determined the relationship between specific molecular alterations and anatomical subsets and features of the BTC immune microenvironment.

RESULTS

We analyzed 454 samples of BTC, of which the most commonly detected alterations were TP53 (42.5%), CDKN2A (23.4%), ARID1A (19.6%), BAP1 (15.5%), KRAS (15%), CDKN2B (14.2%), PBRM1 (11.7%), IDH1 (11.7%), TERT (8.4%), KMT2C (10.4%) and LRP1B (8.4%), and FGFR2 fusions (8.7%). Potentially actionable molecular alterations were identified in 30.5% of BTCs including 39.1% of IHC. Integrative cluster analysis revealed four distinct molecular clusters, with cluster 4 predominately associated with FGFR2 rearrangements and BAP1 mutations in IHC. Immune-related biomarkers indicative of an inflamed tumor-immune microenvironment were elevated in gallbladder cancers and in cluster 1, which was enriched for TP53, KRAS, and ATM mutations. Multiple common driver genes, including TP53, FGFR2, IDH1, TERT, BRAF, and BAP1, were individually associated with unique BTC immune microenvironments.

CONCLUSION

BTC subtypes exhibit diverse DNA alterations, RNA inflammatory signatures, and immune biomarkers. The association between specific BTC anatomical subsets, molecular alterations, and immunophenotypes highlights new opportunities for therapeutic development.

Real-World Analysis of Treatment Patterns, Healthcare Utilization, Costs, and Mortality Among People with Biliary Tract Cancers in the USA

INTRODUCTION

People with advanced biliary tract cancers (BTCs) have a 5-year survival of approximately 2% in the USA. Most cases are inoperable or require systemic treatment following surgery. This study adds to current literature by describing treatment patterns, healthcare resource utilization (HCRU), costs, and mortality among people with BTCs.

METHODS

Adults diagnosed with BTCs were identified in the Merative MarketScan administrative claims databases from 1 January 2016 to 30 June 2020. Descriptive analysis was used to measure treatment patterns (i.e., regimen types, therapy duration) during three lines of therapy (LOT). All-cause and disease-related HCRU and costs were measured per-patient-per-month (PPPM) during the entire follow-up and in each LOT. Mortality was reported among the subset linked to the National Death Index (NDI).

RESULTS

There were 2648 eligible people with BTCs [mean age 64.0 (standard deviation [SD] 12.4) years, 51.5% female, average follow-up 11.9 (SD 11.1) months]. Treatment was received by 56.3% (n = 1490), and 20.9% (n = 5534) and 7.1% (n = 187) moved on to a second and third LOT, respectively. The average treatment duration decreased across LOTs, from 3.8 (SD 3.1) months in LOT1 to 2.6 (SD 2.4) months in LOT3. Gemcitabine + cisplatin was the most common regimen in LOT1 (44.6%). Total all-cause mean healthcare costs PPPM increased after LOT1 (mean $21,517, $29,721, and $28,557, for LOT1, LOT2, and LOT3, respectively) and the majority (71.2%) were related to BTCs. Of people with BTCs linked to the NDI (n = 2168), 66.1% died and average time to death was 11.3 (SD 11.2) months.

CONCLUSIONS

These findings, showing a high rate of mortality, a decrease in treatment duration, and an increase in costs as people progress after LOT1, add recent data to current literature highlighting the unmet need for more effective treatment options for people with BTCs.

Multicenter randomized phase II trial of atezolizumab with or without cobimetinib in biliary tract cancers

BACKGROUNDMEK inhibitors have limited activity in biliary tract cancers (BTCs) as monotherapy but are hypothesized to enhance responses to programmed death ligand 1 (PD-L1) inhibition.METHODSThis open-label phase II study randomized patients with BTC to atezolizumab (anti-PD-L1) as monotherapy or in combination with cobimetinib (MEK inhibitor). Eligible patients had unresectable BTC with 1 to 2 lines of prior therapy in the metastatic setting, measurable disease, and Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 1. The primary endpoint was progression-free survival (PFS).RESULTSSeventy-seven patients were randomized and received study therapy. The trial met its primary endpoint, with a median PFS of 3.65 months in the combination arm versus 1.87 months in the monotherapy arm (HR 0.58, 90% CI 0.35-0.93, 1-tail P = 0.027). One patient in the combination arm (3.3%) and 1 patient in the monotherapy arm (2.8%) had a partial response. Combination therapy was associated with more rash, gastrointestinal events, CPK elevations, and thrombocytopenia. Exploratory analysis of tumor biopsies revealed enhanced expression of antigen processing and presentation genes and an increase in CD8/FoxP3 ratios with combination treatment. Patients with higher baseline or lower fold changes in expression of certain inhibitory ligands (LAG3, BTLA, VISTA) on circulating T cells had evidence of greater clinical benefit from the combination.CONCLUSIONThe combination of atezolizumab plus cobimetinib prolonged PFS as compared with atezolizumab monotherapy, but the low response rate in both arms highlights the immune-resistant nature of BTCs.TRIAL REGISTRATIONClinicalTrials.gov NCT03201458.FUNDINGNational Cancer Institute (NCI) Experimental Therapeutics Clinical Trials Network (ETCTN); F. Hoffmann-La Roche, Ltd.; NCI, NIH (R01 CA228414-01 and UM1CA186691); NCI's Specialized Program of Research Excellence (SPORE) in Gastrointestinal Cancers (P50 CA062924); NIH Center Core Grant (P30 CA006973); and the Passano Foundation.

Implantation of a neoantigen-targeted hydrogel vaccine prevents recurrence of pancreatic adenocarcinoma after incomplete resection

Tumor involvement of major vascular structures limits surgical options in pancreatic adenocarcinoma (PDAC), which in turn limits opportunities for cure. Despite advances in locoregional approaches, there is currently no role for incomplete resection. This study evaluated a gelatinized neoantigen-targeted vaccine applied to a grossly positive resection margin in preventing local recurrence. Incomplete surgical resection was performed in mice bearing syngeneic flank Panc02 tumors, leaving a 1 mm rim adherent to the muscle bed. A previously validated vaccine consisting of neoantigen peptides, a stimulator of interferon genes (STING) agonist and AddaVax^TM (termed PancVax) was embedded in a hyaluronic acid hydrogel and applied to the tumor bed. Tumor remnants, regional lymph nodes, and spleens were analyzed using histology, flow cytometry, gene expression profiling, and ELISPOT assays. The immune microenvironment at the tumor margin after surgery alone was characterized by a transient influx of myeloid-derived suppressor cells (MDSCs), prolonged neutrophil influx, and near complete loss of cytotoxic T cells. Application of PancVax gel was associated with enhanced T cell activation in the draining lymph node and expansion of neoantigen-specific T cells in the spleen. Mice implanted with PancVax gel demonstrated no evidence of residual tumor at two weeks postoperatively and healed incisions at two months postoperatively without local recurrence. In summary, application of PancVax gel at a grossly positive tumor margin led to systemic expansion of neoantigen-specific T cells and effectively prevented local recurrence. These findings support further work into locoregional adjuncts to immune modulation in PDAC.

Pertuzumab and trastuzumab for HER2-positive, metastatic biliary tract cancer (MyPathway): a multicentre, open-label, phase 2a, multiple basket study

BACKGROUND

Systemic therapies for metastatic biliary tract cancers are few, and patients have a median overall survival of less than 1 year. MyPathway evaluates the activity of US Food and Drug Administration-approved therapies in non-indicated tumours with potentially actionable molecular alterations. In this study, we present an analysis of patients with metastatic biliary tract cancers with HER2 amplification, overexpression, or both treated with a dual anti-HER2 regimen, pertuzumab plus trastuzumab, from MyPathway.

METHODS

MyPathway is a non-randomised, multicentre, open-label, phase 2a, multiple basket study. Patients aged 18 years and older with previously treated metastatic biliary tract cancers with HER2 amplification, HER2 overexpression, or both and an Eastern Cooperative Oncology Group performance status of 0-2 were enrolled from 23 study sites in the USA and received intravenous pertuzumab (840 mg loading dose, then 420 mg every 3 weeks) plus trastuzumab (8 mg/kg loading dose, then 6 mg/kg every 3 weeks). The primary endpoint was investigator-assessed objective response rate according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. The primary outcome and adverse events were analysed in all patients who received at least one dose of pertuzumab and trastuzumab. This trial is registered with ClinicalTrials.gov, NCT02091141, and is ongoing.

FINDINGS

39 patients enrolled in the MyPathway HER2 biliary tract cancer cohort between Oct 28, 2014, and May 29, 2019, were evaluable for anti-tumour activity by the March 10, 2020, data cutoff date. Median follow-up was 8·1 months (IQR 2·7-15·7). Nine of 39 patients achieved a partial response (objective response rate 23% [95% CI 11-39]). Grade 3-4 treatment-emergent adverse events were reported in 18 (46%) of 39 patients, most commonly increased alanine aminotransferase and increased aspartate aminotransferase (each five [13%] of 39). Treatment-related grade 3 adverse events were reported in three (8%) of 39 patients, including increased alanine aminotransferase, aspartate aminotransferase, blood alkaline phosphatase, and blood bilirubin. Serious treatment-emergent adverse events were observed in ten (26%) of 39 patients, of which only abdominal pain occurred in more than one patient (two [5%] of 39). There were no treatment-related serious adverse events, treatment-related grade 4 events, or deaths.

INTERPRETATION

Treatment was well tolerated in patients with previously treated HER2-positive metastatic biliary tract cancer. The response rate is promising for the initiation of randomised, controlled trials of pertuzumab plus trastuzumab in this patient population.

FUNDING

F Hoffmann-La Roche-Genentech.

Protein synthesis inhibitor omacetaxine is effective against hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the sixth most common and the fourth most deadly cancer worldwide. The development cost of new therapeutics is a major limitation in patient outcomes. Importantly, there is a paucity of preclinical HCC models in which to test new small molecules. Herein, we implemented potentially novel patient-derived organoid (PDO) and patient-derived xenografts (PDX) strategies for high-throughput drug screening. Omacetaxine, an FDA-approved drug for chronic myelogenous leukemia (CML), was found to be a top effective small molecule in HCC PDOs. Next, omacetaxine was tested against a larger cohort of 40 human HCC PDOs. Serial dilution experiments demonstrated that omacetaxine is effective at low (nanomolar) concentrations. Mechanistic studies established that omacetaxine inhibits global protein synthesis, with a disproportionate effect on short–half-life proteins. High-throughput expression screening identified molecular targets for omacetaxine, including key oncogenes, such as PLK1. In conclusion, by using an innovative strategy, we report — for the first time to our knowledge — the effectiveness of omacetaxine in HCC. In addition, we elucidate key mechanisms of omacetaxine action. Finally, we provide a proof-of-principle basis for future studies applying drug screening PDOs sequenced with candidate validation in PDX models. Clinical trials could be considered to evaluate omacetaxine in patients with HCC.

Development, Practice Patterns, and Early Clinical Outcomes of a Multidisciplinary Liver Cancer Clinic

Multidisciplinary care has been associated with improved survival in patients with primary liver cancers. We report the practice patterns and real world clinical outcomes for patients presenting to the Johns Hopkins Hospital (JHH) multidisciplinary liver clinic (MDLC). We analyzed hepatocellular carcinoma (HCC, n = 100) and biliary tract cancer (BTC, n = 76) patients evaluated at the JHH MDLC in 2019. We describe the conduct of the clinic, consensus decisions for patient management based on stage categories, and describe treatment approaches and outcomes based on these categories. We describe subclassification of BCLC stage C into 2 parts, and subclassification of cholangiocarcinoma into 4 stages. A treatment consensus was finalized on the day of MDLC for the majority of patients (89% in HCC, 87% in BTC), with high adherence to MDLC recommendations (91% in HCC, 100% in BTC). Among patients presenting for a second opinion regarding management, 28% of HCC and 31% of BTC patients were given new therapeutic recommendations. For HCC patients, at a median follow up of 11.7 months (0.7-19.4 months), median OS was not reached in BCLC A and B patients. In BTC patients, at a median follow up of 14.2 months (0.9-21.1 months) the median OS was not reached in patients with resectable or borderline resectable disease, and was 11.9 months in patients with unresectable or metastatic disease. Coordinated expert multidisciplinary care is feasible for primary liver cancers with high adherence to recommendations and a change in treatment for a sizeable minority of patients.

A phase 2 trial of gemcitabine and docetaxel in patients with metastatic colorectal adenocarcinoma with methylated checkpoint with forkhead and ring finger domain promoter and/or microsatellite instability phenotype

Abstract

We previously reported CHFR methylation in a subset of colorectal cancer (CRC; ∼30%) with high concordance with microsatellite instability (MSI). We also showed that CHFR methylation predicted for sensitivity to docetaxel, whereas the MSI‐high phenotypes were sensitive to gemcitabine. We hypothesized that this subset of patients with CRC would be selectively sensitive to gemcitabine and docetaxel. We enrolled a Phase 2 trial of gemcitabine and docetaxel in patients with MSI‐high and/or CHFR methylated CRC. The primary objective was Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 response rate. Enrolled patients were treated with gemcitabine 800 mg/m² on days 1 and 8 and docetaxel 70 mg/m² on day 8 of each 21‐day cycle. A total of 6 patients with CHFR‐methylated, MSI‐high CRC were enrolled from September 2012 to August 2016. The study was closed in September of 2017 due to poor accrual prior to reaching the first interim assessment of response rate, which would have occurred at 10 patients. No RECIST criteria tumor responses were observed, with 3 patients (50%) having stable disease as best response, 1 lasting more than 9 months. Median progression‐free survival (PFS) was 1.79 months (95% confidence interval [CI] = 1.28, not available [NA]) and median overall survival (OS) was 15.67 months (95% CI = 4.24, NA). Common grade 3 toxicities were lymphopenia (67%), leukopenia (33%), and anemia (33%). Although negative, this study establishes a proof‐of‐concept for the implementation of epigenetic biomarkers (CHFR methylation/MSI) as inclusion criteria in a prospective clinical trial to optimize combinatorial strategies in the era of personalized medicine.

A feasibility study of combined epigenetic and vaccine therapy in advanced colorectal cancer with pharmacodynamic endpoint

Epigenetic therapies may modulate the tumor microenvironment. We evaluated the safety and optimal sequence of combination DNA methyltransferase inhibitor guadecitabine with a granulocyte macrophage-colony-stimulating-factor (GM-CSF) secreting colon cancer (CRC) vaccine (GVAX) using a primary endpoint of change in CD45RO + T cells. 18 patients with advanced CRC enrolled, 11 underwent paired biopsies and were evaluable for the primary endpoint. No significant increase in CD45RO + cells was noted. Grade 3-4 toxicities were expected and manageable. Guadecitabine + GVAX was tolerable but demonstrated no significant immunologic activity in CRC. We report a novel trial design to efficiently evaluate investigational therapies with a primary pharmacodynamic endpoint.Trial registry Clinicaltrials.gov: NCT01966289. Registered 21 October, 2013.

Vaccine-Induced Intratumoral Lymphoid Aggregates Correlate with Survival Following Treatment with a Neoadjuvant and Adjuvant Vaccine in Patients with Resectable Pancreatic Adenocarcinoma

PURPOSE

Immunotherapy is currently ineffective for nearly all pancreatic ductal adenocarcinomas (PDAC), largely due to its tumor microenvironment (TME) that lacks antigen-experienced T effector cells (Teff). Vaccine-based immunotherapies are known to activate antigen-specific Teffs in the peripheral blood. To evaluate the effect of vaccine therapy on the PDAC TME, we designed a neoadjuvant and adjuvant clinical trial of an irradiated, GM-CSF-secreting, allogeneic PDAC vaccine (GVAX).

PATIENTS AND METHODS

Eighty-seven eligible patients with resectable PDAC were randomly assigned (1:1:1) to receive GVAX alone or in combination with two forms of low-dose cyclophosphamide. Resected tumors following neoadjuvant immunotherapy were assessed for the formation of tertiary lymphoid aggregates (TLA) in response to treatment. The clinical endpoints are disease-free survival (DFS) and overall survival (OS).

RESULTS

The neoadjuvant treatment with GVAX either alone or with two forms of low-dose cyclophosphamide is safe and feasible without adversely increasing the surgical complication rate. Patients in Arm A who received neoadjuvant and adjuvant GVAX alone had a trend toward longer median OS (35.0 months) than that (24.8 months) in the historical controls who received adjuvant GVAX alone. However, Arm C, who received low-dose oral cyclophosphamide in addition to GVAX, had a significantly shorter DFS than Arm A. When comparing patients with OS > 24 months to those with OS < 15 months, longer OS was found to be associated with higher density of intratumoral TLA.

CONCLUSIONS

It is safe and feasible to use a neoadjuvant immunotherapy approach for PDACs to evaluate early biologic responses. In-depth analysis of TLAs is warranted in future neoadjuvant immunotherapy clinical trials.

Tumor Mutational Burden, Toxicity, and Response of Immune Checkpoint Inhibitors Targeting PD(L)1, CTLA-4, and Combination: A Meta-regression Analysis

PURPOSE

Tumor mutational burden (TMB) has emerged as a potential predictive biomarker for clinical response to ICI therapy, but whether TMB also predicts toxicity remains unknown. We investigated the relationship between TMB, objective response rate (ORR), overall survival (OS), and toxicity for ICI therapy across multiple cancer types.

EXPERIMENTAL DESIGN

We searched MEDLINE, PubMed, and ASCO/ESMO/AACR meetings for clinical trials of anti-PD(L)1, CTLA-4, or combination in 29 cancer types. We assessed ICI administered, responses (complete or partial response), median OS, OS HR, and grade 3/4 toxicity. We conducted a systematic review, meta-analysis and meta-regression using tumor level TMB data from Foundation Medicine.

RESULTS

One hundred seventeen clinical trials, which included 12,450 patients treated with ICI therapy were analyzed. Meta-regression analysis revealed that TMB was significantly associated with ORR for anti-PD(L)1, anti-CTLA-4, and combination (P < 0.0001 for all), but not associated with toxicity in all treatment groups. OS data were unavailable for most studies included in our meta-analysis, and the relationship between TMB and OS in this subset was not significant (P = 0.26). In high TMB tumor types (≥10 mut/megabase) the improvement of ORR and increase in grade 3/4 toxicity with combination ICI therapy as compared with PD(L)1 monotherapy were 21.13% and 25.41%, respectively, as compared with 3.73% and 18.78% in low TMB tumor types (<10 mut/megabase).

CONCLUSIONS

There is a positive association between TMB and clinical response with anti-PD(L)1, anti-CTLA-4, and combination ICIs, but no association between TMB and toxicity. These results imply a favorable risk/benefit ratio for ICIs in tumors with a higher TMB.

A Phase I Study of Dinaciclib in Combination With MK-2206 in Patients With Advanced Pancreatic Cancer

The combination of drugs targeting Ral and PI3K/AKT signaling has antitumor efficacy in preclinical models of pancreatic cancer. We combined dinaciclib (small molecule cyclin dependent kinase inhibitor with MK-2206 (Akt inhibitor) in patients with previously treated/metastatic pancreatic cancer. Patients were treated with dinaciclib (6-12 mg/m² i.v.) and MK-2206 (60-135 mg p.o.) weekly. Tumor biopsies were performed to measure pAKT, pERK, and Ki67 at baseline and after one completed cycle (dose level 2 and beyond). Thirty-nine patients participated in the study. The maximum tolerated doses were dinaciclib 9 mg/m² and MK-2206 135 mg. Treatment-related grade 3 and 4 toxicities included neutropenia, lymphopenia, anemia, hyperglycemia, hyponatremia, and leukopenia. No objectives responses were observed. Four patients (10%) had stable disease as their best response. At the recommended dose, median survival was 2.2 months. Survival rates at 6 and 12 months were 11% and 5%, respectively. There was a nonsignificant reduction in pAKT composite scores between pretreatment and post-treatment biopsies (mean 0.76 vs. 0.63; P = 0.635). The combination of dinaciclib and MK-2206 was a safe regimen in patients with metastatic pancreatic cancer, although without clinical benefit, possibly due to not attaining biologically effective doses. Given the strong preclinical evidence of Ral and AKT inhibition, further studies with better tolerated agents should be considered.

Current and emerging therapies for patients with advanced pancreatic ductal adenocarcinoma: a bright future

Pancreatic ductal adenocarcinoma is the seventh leading cause of cancer death worldwide with an estimated 432 242 deaths occurring in 2018. This estimate, in conjunction with the findings that pancreatic ductal adenocarcinoma incidence is rising and that pancreatic ductal adenocarcinoma has the highest case-fatality rate of any solid tumour, highlights the urgency for designing novel therapeutic strategies to combat this deadly disease. Through the efforts of the global research community, our knowledge of the factors that lead to the development of pancreatic ductal adenocarcinoma, its progression, and the interplay between tumour cells and their surrounding microenvironment have improved substantially. Although these scientific advances have not yet translated into targeted or immunotherapy strategies that are effective for most patients with pancreatic ductal adenocarcinoma, important incremental progress has been made particularly for the treatment of specific molecular subgroups of tumours. Although PD-1 inhibitors for mismatch-repair-deficient tumours and NTRK inhibitors for tumours containing NTRK gene fusions are the most recent targeted agents approved by the US Food and Drug Administration, olaparib for germline BRCA-mutated pancreatic ductal adenocarcinoma is expected to be approved soon in the maintenance setting. These recent advances show the accelerated pace at which pancreatic ductal adenocarcinoma drugs are achieving successful clinical outcomes. Here we review the current understanding of the pathophysiology of pancreatic ductal adenocarcinoma, recent advances in the understanding of the stromal microenvironment, current standard-of-care treatment, and novel therapeutic targets and strategies that hold promise for improving patient outcomes. We predict that there will be major breakthroughs in the treatment of pancreatic ductal adenocarcinoma in the next 5-10 years. These breakthroughs will result from the increased understanding of the treatment barriers imposed by the tumour-associated stroma, and from the development of novel approaches to re-engineer the tumour microenvironment in favour of effective anticancer responses.

Neoantigen-based EpiGVAX vaccine initiates antitumor immunity in colorectal cancer

Metastatic colorectal cancer (CRC) is poorly immunogenic, with limited neoantigens that can be targeted by cancer vaccine. Previous approaches to upregulate neoantigen have had limited success. In this study, we investigated the role of a DNA methyltransferase inhibitor (DNMTi), 5-aza-2'-deoxycytidine (DAC), in inducing cancer testis antigen (CTA) expression and evaluated the antitumor efficacy of a combinatorial approach with an epigenetically regulated cancer vaccine EpiGVAX and DAC. A murine model of metastatic CRC treated with combination therapy with an irradiated whole-cell CRC vaccine (GVAX) and DAC was used to assess the antitumor efficacy. DAC significantly induced expression of CTAs in CRC, including a new CTA Tra-P1A with a known neoepitope, P1A. Epigenetically modified EpiGVAX with DAC improved survival outcomes of GVAX. Using the epigenetically regulated antigen Tra-P1A as an example, our study suggests that the improved efficacy of EpiGVAX with DAC may due in part to the enhanced antigen-specific antitumor immune responses. This study shows that epigenetic therapy with DNMTi can not only induce new CTA expression but may also sensitize tumor cells for immunotherapy. Neoantigen-based EpiGVAX combined with DAC can improve the antitumor efficacy of GVAX by inducing antigen-specific antitumor T cell responses to epigenetically regulated proteins.

Phase II Study of Ensituximab, a Novel Chimeric Monoclonal Antibody, in Adults with Unresectable, Metastatic Colorectal Cancer

PURPOSE

Patients with metastatic colorectal cancer refractory to chemotherapy have limited treatment options. Ensituximab (NEO-102) is a novel chimeric mAb targeting a variant of MUC5AC with specificity to colorectal cancer.

PATIENTS AND METHODS

Single-arm, phase II trial assessed the efficacy and safety of ensituximab in patients with advanced, refractory cancer who expressed MUC5AC antigen in tumor tissue. Ensituximab was administered intravenously every 2 weeks with 3 mg/kg as recommended phase II dose (RP2D). A minimum sample size of 43 patients was required on the basis of the assumption that ensituximab would improve median overall survival (OS) by 7 months using a one-sided significance level of 10% and 80% power. Written informed consent was obtained from all patients.

RESULTS

Sixty-three patients with advanced, refractory colorectal cancer were enrolled and 53 subjects were treated in phase II arm. Median age was 58 years and 46% of the patients were female. Among 57 evaluable patients, median OS was 6.8 months. No responses were observed, and stable disease was achieved in 21% of the patients. The most common treatment-related adverse events (AE) at RP2D included fatigue (38%), anemia (30%), nausea (15%), vomiting (11%), increased bilirubin (9%), constipation (8%), decreased appetite (6%), and diarrhea (6%). Serious AEs at least possibly related to ensituximab occurred in 4 patients and included anemia, nausea, increased bilirubin, and hypoxia. No patients discontinued treatment due to drug-related AEs.

CONCLUSIONS

Ensituximab was well tolerated and demonstrated modest antitumor activity in patients with heavily pretreated refractory colorectal cancer.

Spirituality in cancer patients on phase 1 clinical trials

OBJECTIVES

Patients with cancer who are at a transition to Phase I investigational treatments have been identified as an underserved population with regard to palliative care. This disease transition is often accompanied by spiritual and existential concerns. The study objective was to conduct a secondary analysis of data from a larger study testing a palliative care intervention. This paper reports the findings of this secondary focus on the spiritual needs of this population.

METHODS

Patients (n = 479) were accrued to this study prior to initiating a Phase I clinical trial with data collected at baseline, and 4, 12, and 24 week follow-up.

RESULTS

Qualitative data revealed that the transition to Phase 1 trial participation is a time of balancing hope for extended life with the reality of advancing disease. Quantitative results demonstrated increased spirituality over time in both religious- and non-religious-affiliated patients.

CONCLUSIONS

Patients entering Phase I trials have important spiritual needs as they face treatment decisions, advancing disease, and often mortality. Spiritual care should be provided to seriously ill patients as a component of quality care.

Colorectal Cancer in the Young: Epidemiology, Prevention, Management

Colorectal cancer (CRC) incidence rates in the United States overall have declined since the mid-1980s because of changing patterns in risk factors (e.g., decreased smoking) and increases in screening. However, this progress is increasingly confined to older adults. CRC occurrence has been on the rise in patients younger than age 50, often referred to as early-onset disease, since the mid-1990s. Young patients are more often diagnosed at an advanced stage and with rectal disease than their older counterparts, and they have numerous other unique challenges across the cancer management continuum. For example, young patients are less likely than older patients to have a usual source of health care; often need a more complex treatment protocol to preserve fertility and sexual function; are at higher risk of long-term and late effects, including subsequent primary malignancies; and more often suffer medical financial hardship. Diagnosis is often delayed because of provider- and patient-related factors, and clinicians must have a high index of suspicion if young patients present with rectal bleeding or changes in bowel habits. Educating primary care providers and the larger population on the increasing incidence and characteristic symptoms is paramount. Morbidity can further be averted by increasing awareness of the criteria for early screening, which include a family history of CRC or polyps and a genetic predisposition.

Cost-utility of colorectal cancer screening at 40 years old for average-risk patients

The incidence of colorectal cancer (CRC) is increasing in patients under the age of 50. The purpose of this study was to assess the cost-utility of available screening modalities starting at 40 years in the general population compared to standard screening at 50 years old. A decision tree modeling average-risk of CRC in the United States population was constructed for the cost per quality-adjusted life year (QALY) of the five most common and effective CRC screening modalities in average-risk 40-year olds versus deferring screening until 50 years old (standard of care) under a limited societal perspective. All parameters were derived from existing literature. We evaluated the incremental cost-utility ratio of each comparator at a willingness-to-pay threshold of $50,000/QALY and included multivariable probabilistic sensitivity analysis. All screening modalities assessed were more cost-effective with increased QALYs than current standard care (no screening until 50). The most favorable intervention by net monetary benefit was flexible sigmoidoscopy ($3284 per person). Flexible sigmoidoscopy, FOBT, and FIT all dominated the current standard of care. Colonoscopy and FIT-DNA were both cost-effective (respectively, $4777 and $11,532 per QALY). The cost-effective favorability of flexible sigmoidoscopy diminished relative to colonoscopy with increasing willingness-to-pay. Regardless of screening modality, CRC screening at 40 years old is cost-effective with increased QALYs compared to current screening initiation at 50 years old, with flexible sigmoidoscopy most preferred. Consideration should be given for a general recommendation to start screening at age 40 for average risk individuals.

Nivolumab Is Effective in Mismatch Repair-Deficient Noncolorectal Cancers: Results From Arm Z1D-A Subprotocol of the NCI-MATCH (EAY131) Study

PURPOSE

The National Cancer Institute Molecular Analysis for Therapy Choice (NCI-MATCH) trial, the largest national precision oncology study to date (> 1,100 sites) of patients with relapsed or refractory malignancies, assigned patients to targeted therapy in parallel phase II studies based on tumor molecular alterations. The anti-programmed death receptor 1 inhibitor nivolumab previously showed activity in mismatch repair (MMR)-deficient colon cancer. We hypothesized that nivolumab would have activity in patients with MMR-deficient, noncolorectal tumors.

PATIENTS AND METHODS

Eligible patients with relapsed or refractory tumors, good end-organ function, and Eastern Cooperative Oncology Group performance status of ≤ 1 underwent tumor biopsy for centralized screening of molecular alterations. MMR deficiency was defined by complete loss of nuclear expression of MLH1 or MSH2 MMR gene products by immunohistochemistry (IHC). Patients with MMR-deficient colorectal cancer were excluded. Nivolumab, 3 mg/kg every 2 weeks (28-day cycles) and 480 mg every 4 weeks after cycle 4, was administered intravenously. Disease reassessment was performed every 2 cycles. The primary end point was RECIST 1.1 objective response rate (ORR).

RESULTS

Two percent of 4,902 screened patients had an MMR-deficient cancer by IHC. Forty-two evaluable patients were enrolled, with a median age of 60 years and a median of 3 prior therapies. The most common histologies were endometrioid endometrial adenocarcinoma (n = 13), prostate adenocarcinoma (n = 5), and uterine carcinosarcoma (n = 4). ORR was 36% (15 of 42 patients). An additional 21% of patients had stable disease. The estimated 6-, 12-, and 18-month progression-free survival rates were 51.3% (90% CI, 38.2% to 64.5%), 46.2% (90% CI, 33.1% to 59.3%), and 31.4% (90% CI, 18.7% to 44.2%), respectively. Median overall survival was 17.3 months. Toxicity was predominantly low grade.

CONCLUSION

A variety of refractory cancers (2.0% of those screened) had MMR deficiency as defined in NCI-MATCH. Nivolumab has promising activity in MMR-deficient noncolorectal cancers of a wide variety of histopathologic types.

A phase 2 study of GVAX colon vaccine with cyclophosphamide and pembrolizumab in patients with mismatch repair proficient advanced colorectal cancer

Background

Mismatch repair proficient (MMRp) colorectal cancer (CRC) has been refractory to single‐agent programmed cell death protein 1 (PD1) inhibitor therapy. Colon GVAX is an allogeneic, whole‐cell, granulocyte‐macrophage colony‐stimulating factor ‐secreting cellular immunotherapy that induces T‐cell immunity against tumor‐associated antigens and has previously been studied in combination with low‐dose cyclophosphamide (Cy) to inhibit regulatory T cells.

Methods

We conducted a single‐arm study of GVAX/Cy in combination with the PD1 inhibitor pembrolizumab in patients with advanced MMRp CRC. Patients received pembrolizumab plus Cy on day 1, GVAX on day 2, of a 21‐day cycle. The primary endpoint was the objective response rate by Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Secondary objectives included safety, overall survival, progression‐free survival, changes in carcinoembryonic antigen (CEA) levels, and immune‐related correlates.

Results

Seventeen patients were enrolled. There were no objective responses, and the disease control rate was 18% by RECIST 1.1. The median progression‐free survival was 82 days (95% confidence interval [CI], 48‐97 days) and the median overall survival was 213 days (95% CI 179‐441 days). Biochemical responses (≥30% decline in CEA) were observed in 7/17 (41%) of patients. Grade ≥ 3 treatment‐related adverse events were observed in two patients (hemolytic anemia and corneal transplant rejection). Paired pre‐ and on‐treatment biopsy specimens showed increases in programmed death‐ligand 1 expression and tumor necrosis in a subset of patients.

Conclusions

GVAX/Cy plus pembrolizumab failed to meet its primary objective in MMRp CRC. Biochemical responses were observed in a subset of patients and have not previously been observed with pembrolizumab monotherapy in MMRp CRC, indicating that GVAX may modulate the antitumor immune response.

Abstract I13: Modulating the immune response with epigenetic agents

Epigenetic modulation offers the potential of altering key tumor-immune interactions to allow for more effective therapeutic targeting. Epigenetic abnormalities in cancer in the tumor-immune response will be discussed, as well as data that support the reversibility of these lesions with epigenetic modulators. Preclinical and emerging clinical data in solid tumors will be surveyed, with an eye towards how these data support the rationale of epigenetic-immunotherapy combinations in pancreatic cancer.

Citation Format: Nilofer S. Azad. Modulating the immune response with epigenetic agents [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr I13.

An analysis of genetic heterogeneity in untreated cancers

Genetic intratumoural heterogeneity is a natural consequence of imperfect DNA replication. Any two randomly selected cells, whether normal or cancerous, are therefore genetically different. Here, we review the different forms of genetic heterogeneity in cancer and re-analyse the extent of genetic heterogeneity within seven types of untreated epithelial cancers, with particular regard to its clinical relevance. We find that the homogeneity of predicted functional mutations in driver genes is the rule rather than the exception. In primary tumours with multiple samples, 97% of driver-gene mutations in 38 patients were homogeneous. Moreover, among metastases from the same primary tumour, 100% of the driver mutations in 17 patients were homogeneous. With a single biopsy of a primary tumour in 14 patients, the likelihood of missing a functional driver-gene mutation that was present in all metastases was 2.6%. Furthermore, all functional driver-gene mutations detected in these 14 primary tumours were present among all their metastases. Finally, we found that individual metastatic lesions responded concordantly to targeted therapies in 91% of 44 patients. These analyses indicate that the cells within the primary tumours that gave rise to metastases are genetically homogeneous with respect to functional driver-gene mutations, and we suggest that future efforts to develop combination therapies have the potential to be curative.

Readmission Adversely Affects Survival in Surgical Rectal Cancer Patients

BACKGROUND

Readmission has received attention as a potential healthcare quality metric. No studies have investigated the relationship between readmission and survival in patients undergoing rectal cancer surgery. The aims of this study were to identify factors associated with 30-day readmission after rectal cancer surgery and to determine the impact of readmission on overall survival (OS).

METHODS

Patients who underwent surgical treatment for rectal/rectosigmoid adenocarcinoma stages I-IV were identified using the National Cancer Database (2004-2014). Multivariable logistic regression was used to identify factors for readmission. 2:1 nearest neighbor caliper matching without replacement was used to ensure similarity of patients being compared. Survival analyses were performed using Kaplan-Meier method along with log-rank test and Cox proportional hazards model.

RESULTS

Of 110,167 patients, 7045 (6.39%) were readmitted. Factors associated with readmission included higher Charlson comorbidity score, non-private or no insurance, procedure type, hospitals in the Northeast, South, and Midwest regions, and prolonged length of stay. Within the matched cohort (13,756 non-readmitted and 6878 readmitted), readmitted patients had worse 5- and 10-year OS regardless of cancer stage (p < 0.001) and procedure type. Five- and 10-year OS were 58.98% and 41.01% for readmitted patients, 64.96% and 43.50% for non-readmitted patients. Readmitted patients had shorter OS by 13.14 months and increased risk of mortality (HR 1.20, 95% CI 1.15-1.25, p < 0.001).

CONCLUSIONS

Thirty-day readmission after rectal cancer surgery is associated with decreased OS. Efforts to reduce readmissions should be considered to advance cancer care and enhance the potential for improved patient survival.

Sequential short-course radiation therapy and chemotherapy in the neoadjuvant treatment of rectal adenocarcinoma

Background

There is continued debate regarding the optimal combinations of radiation therapy and chemotherapy in the preoperative treatment of locally advanced rectal adenocarcinomas. We report our single-institution experience of feasibility and early oncologic outcomes of short-course preoperative radiation therapy (5 Gy X 5 fractions) followed by consolidation neoadjuvant chemotherapy.

Methods

We reviewed the records of 26 patients with locally advanced rectal adenocarcinoma. All patients underwent short course radiotherapy (5 Gy X 5 fractions) followed by chemotherapy [either modified infusional and bolus 5-fluorouracail and oxalipatin (mFOLFOX6) or capecitabine and oxaliplatin] prior to consideration for surgery. A full course of chemotherapy was defined as at least 8 weeks of chemotherapy.

Results

There were five clinical (c) T2, 16 cT3, and five cT4 rectal tumors, with 88% cN+. Twenty-five patients received a median of 4 cycles (range 3 to 8) of mFOLFOX6 (with one cycle defined as a two-week period); one patient received 3 cycles of capecitabine and oxaliplatin. All patients completed SCRT; 81% completed the full course of neoadjuvant chemotherapy with 19% requiring dose reductions in chemotherapy, most commonly due to neuropathy. Nineteen patients underwent post-treatment endoscopic evaluation, and nine patients were noted to achieve a complete clinical response (CCR). Six of the nine patients who achieved CCR opted for a non-operative approach of watch-and-wait. Twenty patients underwent surgical resection; pathologic complete response was observed in seven (35%) of these twenty. The main radiation-associated toxicity was proctitis with CTCAE Grade 2 proctitis observed in seven patients (27%). Post-operative Clavien-Dindo Grade 3 complications within 30 days of surgery were identified in six patients (30%), with no Grade 4 or 5 adverse events. Median length of hospital stay was 4.5 days (range 2–16 days); three patients were readmitted within a 30 day period.

Conclusions

Short course preoperative radiotherapy followed by neoadjuvant chemotherapy was well-tolerated and achieved oncologic outcomes that compare favorably with short-course radiation therapy alone or long-course chemoradiotherapy. This regimen is associated with high rates of clinical and pathologic complete response.

Abstract 3971: MEK inhibitors limit inflammatory cytokine production and modulate the immune response in the setting of Cholangiocarcinoma

Cholangiocarcinoma (CC) is a rare but aggressive cancer of the bile ducts with a five-year survival rate of only 2% in patients with metastatic disease. MAP kinase signaling is important in the pathogenesis of CC and serves as a key regulator of cell proliferation and survival. Our data indicate this pathway is constitutively active in several CC cell lines and accompanied by production of immunomodulatory cytokines including IL-6, MCP-1 and GM-CSF. Cobimetinib is a potent and selective inhibitor of MEK that has been utilized clinically in patients with advanced CC. Although MEK inhibitors (MEKi) have been studied in a variety of solid tumors, the mechanisms by which they act upon CC cells are not completely defined. These agents have modest single agent activity in CC, and their impact in combination with immunotherapy is under active investigation. We hypothesized that MEKi can modulate cytokine and chemokine expression from CC tumors, thereby complementing immunotherapy in this aggressive disease. Using a novel panel of human CC cell lines, we demonstrated a variable impact of cobimetinib on in vitro cell proliferation, with a reduction in viability no greater than 35%. However, MEKi reproducibly limited cytokine (GM-CSF and IL-1β) and chemokine (MIP-1α) production from human CC cell lines in vitro. The ability of cobimetinib to limit MAPK signal transduction in these cells was confirmed via immunoblot. These data complement prior published observations by Ebert et al.in 2016 indicating that single agent MEKi is sufficient to elicit T cell infiltration into tumors. We have completed enrollment of a Phase II clinical trial (NCT03201458) evaluating the efficacy of cobimetinib in combination with the PD-L1 inhibitor, atezolizumab. An extensive series of correlative studies are underway in peripheral blood and tumor biopsies to examine the impact of cobimetinib on modulating cytokine and chemokine signatures in the context of PD-L1 targeted therapy. These data will provide new insight into the impact of MEK inhibitors as a complement to immunotherapy in a disease that is refractory to most conventional therapies.

Citation Format: Amanda N. Ruggieri, Matthew R. Farren, Mark Yarchoan, Nilofer S. Azad, Lauren Dennison, Bassel El-Reyes, Gregory B. Lesinski. MEK inhibitors limit inflammatory cytokine production and modulate the immune response in the setting of Cholangiocarcinoma. [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 3971.

A Phase I Trial of the VEGF Receptor Tyrosine Kinase Inhibitor Pazopanib in Combination with the MEK Inhibitor Trametinib in Advanced Solid Tumors and Differentiated Thyroid Cancers

PURPOSE

Differentiated thyroid cancer (DTC) responds to VEGF receptor inhibitors. VEGF signals through RAS/RAF/MEK signaling. We evaluated the safety and efficacy of the VEGF receptor inhibitor pazopanib and MEK inhibitor trametinib in advanced solid tumors and DTC.

PATIENTS AND METHODS

Patients with advanced solid tumors were enrolled in a phase I, multicenter trial with a DTC expansion cohort. Patients received pazopanib 400-800 mg and trametinib 1-2 mg daily. Efficacy in the expansion cohort was assessed with objective response (OR) at 6 months of treatment.

RESULTS

Twenty-six patients were enrolled in five dose levels. MTD was not reached; the recommended phase II dose was pazopanib 800 mg orally and trametinib 2 mg orally every day. There was one dose-limiting toxicity on dose level 1 with grade 3 fatigue and muscle weakness. Common grade 3 adverse events were elevated transaminases (19%), diarrhea (15%), hypertension (12%), and fatigue (8%). Thirteen patients were enrolled in the DTC cohort; OR was 33% (95% confidence interval, 9.9, 65.1%) and median progression-free survival was 10.7 months. The cohort was terminated after planned interim analysis suggested insufficiently increased activity against the historical control of pazopanib alone. Reduction in tumor diameter negatively correlated with p-ERK change in tumor (Spearman ρ = -0.71; P = 0.05). NRAS mutation was associated with response (Fisher exact P = 0.008).

CONCLUSIONS

Pazopanib + trametinib was tolerable at full single-agent doses with clinical activity in DTC but did not achieve the prespecified response rate target.

The DNA Damaging Revolution: PARP Inhibitors and Beyond

Cancer-specific DNA repair defects are abundant in malignant tissue and present an opportunity to capitalize on these aberrations for therapeutic benefit. Early preclinical data demonstrated the concept of synthetic lethality between BRCA genetic defects and pharmacologic PARP inhibition, suggesting that there may be monotherapy activity with this class of agents and supporting the early trial testing of this molecularly driven approach. Although the first foray into the clinic for PARP inhibitors was in combination with DNA-damaging cytotoxic agents, clinical development was limited by the more-than-additive toxicity, in particular dose-limiting myelosuppression. As more tolerable single agents, PARP inhibitors are now approved for the treatment of ovarian cancer in different settings and BRCA-mutant breast cancers. Beyond PARP inhibitors, there is now a large armamentarium of potent and relatively selective inhibitors in clinical trial testing against key targets involved in the DNA damage response (DDR), including ATR, ATM, CHK1/2, WEE1, and DNA-PK. These agents are being developed for patients with molecularly selected tumors and in rational combinations with other molecularly targeted agents and immune checkpoint inhibitors. We detail the clinical progress made in the development of PARP inhibitors, review rational combinations, and discuss the development of emerging inhibitors against novel DDR targets, including DNA repair proteins, DNA damage signaling, and DNA metabolism.

Programmed Cell Death Ligand-1 (PD-L1) and CD8 Expression Profiling Identify an Immunologic Subtype of Pancreatic Ductal Adenocarcinomas with Favorable Survival

Immune-checkpoint therapy has failed to demonstrate meaningful clinical benefit in unselected cases of pancreatic adenocarcinoma (PDAC), but a subset of PDACs are known to upregulate pathways involved in acquired immune suppression. Further delineation of immunologic subtypes of PDAC is necessary to improve clinical trial designs and identify patients who might benefit from immune-checkpoint therapy. We used clinical survival and RNA expression data from The Cancer Genome Atlas (TCGA) to investigate the relationship between immune-modulating pathways and immune subset markers and their impact on survival in PDAC patients. Of the adaptive immune-resistance pathways, expression of PD-L1 and IDO1 was individually associated with poor survival. Although CD8 expression alone was not correlated with survival, the combination of PD-L1^- and high CD8 expression identified a subtype with favorable survival. We further extended these observations using an independent PDAC cohort from our institution via IHC, again observing that the PD-L1^-/CD8^high subtype was associated with positive prognosis. Although PDAC is regarded as a poorly immunogenic cancer type, these findings infer that T-cell infiltration in the absence of adaptive immune-resistance pathways is a feature of long-term survival in PDAC and imply the importance of developing future immunotherapeutic strategies based on data-supported biomarkers to refine patient selection.

PD-L1 expression and tumor mutational burden are independent biomarkers in most cancers

BACKGROUND

PD-L1 expression and tumor mutational burden (TMB) have emerged as important biomarkers of response to immune checkpoint inhibitor (ICI) therapy. These biomarkers have each succeeded and failed in predicting responders for different cancer types. We sought to describe the PD-L1 expression landscape across the spectrum of ICI-responsive human cancers, and to determine the relationship between PD-L1 expression, TMB, and response rates to ICIs.

METHODS

We assessed 9887 clinical samples for PD-L1 expression and TMB.

RESULTS

PD-L1 expression and TMB are not significantly correlated within most cancer subtypes, and they show only a marginal association at the tumor sample level (Pearson's correlation 0.084). Across distinct tumor types, PD-L1 expression and TMB have nonoverlapping effects on the response rate to PD-1/PD-L1 inhibitors and can broadly be used to categorize the immunologic subtypes of cancer.

CONCLUSION

Our results indicate that PD-L1 expression and TMB may each inform the use of ICIs, point to different mechanisms by which PD-L1 expression regulates ICI responsiveness, and identify new opportunities for therapeutic development.

FUNDING

Funding was provided by Foundation Medicine Inc., the Johns Hopkins Bloomberg-Kimmel Institute for Cancer Immunotherapy, the Viragh Foundation, the National Cancer Institute Specialized Program of Research Excellence (SPORE) in Gastrointestinal Cancers (P50 CA062924), the NIH Center Core Grant (P30 CA006973), the Norman & Ruth Rales Foundation, and the Conquer Cancer Foundation.

Phase I study combining the aurora kinase a inhibitor alisertib with mFOLFOX in gastrointestinal cancer

Overexpression and cellular mis-localization of aurora kinase A (AURKA) in gastrointestinal cancers results in chromosomal instability, activation of multiple oncogenic pathways, and inhibition of pro-apoptotic signaling. Inhibition of AURKA causes mitotic delays, severe chromosome congression, and activation of p53/p73 leading to cell death. Our preclinical data showed cooperative activity with the AURKA inhibitor alisertib and platinum agents in cell lines and xenografts, and suggested an optimal treatment window. Therefore, this study was designed to determine the maximum-tolerated dose (MTD) of alisertib in combination with modified FOLFOX (mFOLFOX), as this is a standard platinum-based therapy for gastrointestinal cancers. Standard 3 + 3 dose escalation was used, where the starting dose of alisertib was 10 mg twice daily (Days 1-3), with leucovorin (400 mg/m²) and oxaliplatin (85 mg/m²) on Day 2 followed by continuous 46-h 5-FU (2400 mg/m²) infusion on Days 2-4 in 14-day cycles. Fourteen patients with advanced gastrointestinal cancers were enrolled and two doses explored; two patients were not evaluable for dose-limiting toxicity (DLT) and replaced. Two patients experienced DLTs at 20 mg of alisertib (Grade 3 fatigue (n = 2); Grade 3 nausea, vomiting, dehydration with hospitalization (n = 1)). MTD was 10 mg alisertib with 85 mg/m² oxaliplatin and 2400 mg/m² 5-FU. Most frequent toxicities were nausea (57%), diarrhea, fatigue, neuropathy, and vomiting (43%), and anorexia and anemia (36%); most were Grade 1-2. One patient with colorectal cancer had a partial response of 12 evaluable patients, and four patients had stable disease. Alisertib in combination with mFOLFOX did not demonstrate unexpected side effects, but the regimen was only tolerable at the lowest dose investigated.

Significance and implications of FDA approval of pembrolizumab for biomarker-defined disease

The U.S. Food and Drug Administration (FDA) recently approved pembrolizumab, an anti- programmed cell death protein 1 cancer immunotherapeutic, for use in advanced solid tumors in patients with the microsatellite-high/DNA mismatch repair-deficient biomarker. This is the first example of a tissue-agnostic FDA approval of a treatment based on a patient’s tumor biomarker status, rather than on tumor histology. Here we discuss key issues and implications arising from the biomarker-based disease classification implied by this historic approval.