Biomarkers of pembrolizumab efficacy in advanced anal squamous cell carcinoma: analysis of a phase II clinical trial and a cohort of long-term responders

BACKGROUND

Recent trials suggest that programmed cell death 1 (PD-1)-directed immunotherapy may be beneficial for some patients with anal squamous cell carcinoma and biomarkers predictive of response are greatly needed.

METHODS

This multicenter phase II clinical trial (NCT02919969) enrolled patients with metastatic or locally advanced incurable anal squamous cell carcinoma (n=32). Patients received pembrolizumab 200 mg every 3 weeks. The primary endpoint of the trial was objective response rate (ORR). Exploratory objectives included analysis of potential predictive biomarkers including assessment of tumor-associated immune cell populations with multichannel immunofluorescence and analysis of circulating tumor tissue modified viral-human papillomavirus DNA (TTMV-HPV DNA) using serially collected blood samples. To characterize the clinical features of long-term responders, we combined data from our prospective trial with a retrospective cohort of patients with anal cancer treated with anti-PD-1 immunotherapy (n=18).

RESULTS

In the phase II study, the ORR to pembrolizumab monotherapy was 9.4% and the median progression-free survival was 2.2 months. Despite the high level of HPV positivity observed with circulating TTMV-HPV DNA testing, the majority of patients had low levels of tumor-associated CD8+PD-1+ T cells on pretreatment biopsy. Patients who benefited from pembrolizumab had decreasing TTMV-HPV DNA scores and a complete responder's TTMV-HPV DNA became undetectable. Long-term pembrolizumab responses were observed in one patient from the trial (5.3 years) and three patients (2.5, 6, and 8 years) from the retrospective cohort. Long-term responders had HPV-positive tumors, lacked liver metastases, and achieved a radiological complete response.

CONCLUSIONS

Pembrolizumab has durable efficacy in a rare subset of anal cancers. However, despite persistence of HPV infection, indicated by circulating HPV DNA, most advanced anal cancers have low numbers of tumor-associated CD8+PD-1+ T cells and are resistant to pembrolizumab.

A Phase I Expansion Cohort Study Evaluating the Safety and Efficacy of the CHK1 Inhibitor LY2880070 with Low-dose Gemcitabine in Patients with Metastatic Pancreatic Adenocarcinoma

PURPOSE

Combining gemcitabine with CHK1 inhibition has shown promise in preclinical models of pancreatic ductal adenocarcinoma (PDAC). Here, we report the findings from a phase I expansion cohort study (NCT02632448) investigating low-dose gemcitabine combined with the CHK1 inhibitor LY2880070 in patients with previously treated advanced PDAC.

PATIENTS AND METHODS

Patients with metastatic PDAC were treated with gemcitabine intravenously at 100 mg/m2 on days 1, 8, and 15, and LY2880070 50 mg orally twice daily on days 2-6, 9-13, and 16-20 of each 21-day cycle. Pretreatment tumor biopsies were obtained from each patient for correlative studies and generation of organoid cultures for drug sensitivity testing and biomarker analyses.

RESULTS

Eleven patients with PDAC were enrolled in the expansion cohort between August 27, 2020 and July 30, 2021. Four patients (36%) experienced drug-related grade 3 adverse events. No objective radiologic responses were observed, and all patients discontinued the trial by 3.2 months. In contrast to the lack of efficacy observed in patients, organoid cultures derived from biopsies procured from two patients demonstrated strong sensitivity to the gemcitabine/LY2880070 combination and showed treatment-induced upregulation of replication stress and DNA damage biomarkers, including pKAP1, pRPA32, and γH2AX, as well as induction of replication fork instability.

CONCLUSIONS

No evidence of clinical activity was observed for combined low-dose gemcitabine and LY2880070 in this treatment-refractory PDAC cohort. However, the gemcitabine/LY2880070 combination showed in vitro efficacy, suggesting that drug sensitivity for this combination in organoid cultures may not predict clinical benefit in patients.

Adipose tissue and skeletal muscle wasting precede clinical diagnosis of pancreatic cancer

Patients with pancreatic cancer commonly develop weight loss and muscle wasting. Whether adipose tissue and skeletal muscle losses begin before diagnosis and the potential utility of such losses for earlier cancer detection are not well understood. We quantify skeletal muscle and adipose tissue areas from computed tomography (CT) imaging obtained 2 months to 5 years before cancer diagnosis in 714 pancreatic cancer cases and 1748 matched controls. Adipose tissue loss is identified up to 6 months, and skeletal muscle wasting is identified up to 18 months before the clinical diagnosis of pancreatic cancer and is not present in the matched control population. Tissue losses are of similar magnitude in cases diagnosed with localized compared with metastatic disease and are not correlated with at-diagnosis circulating levels of CA19-9. Skeletal muscle wasting occurs in the 1-2 years before pancreatic cancer diagnosis and may signal an upcoming diagnosis of pancreatic cancer.

G-CSF rescue of FOLFIRINOX-induced neutropenia leads to systemic immune suppression in mice and humans

BACKGROUND

Recombinant granulocyte colony-stimulating factor (G-CSF) is routinely administered for prophylaxis or treatment of chemotherapy-induced neutropenia. Chronic myelopoiesis and granulopoiesis in patients with cancer has been shown to induce immature monocytes and neutrophils that contribute to both systemic and local immunosuppression in the tumor microenvironment. The effect of recombinant G-CSF (pegfilgrastim or filgrastim) on the production of myeloid-derived suppressive cells is unknown. Here we examined patients with pancreatic cancer, a disease known to induce myeloid-derived suppressor cells (MDSCs), and for which pegfilgrastim is routinely administered concurrently with FOLFIRINOX but not with gemcitabine-based chemotherapy regimens.

METHODS

Serial blood was collected from patients with pancreatic ductal adenocarcinoma newly starting on FOLFIRINOX or gemcitabine/n(ab)paclitaxel combination chemotherapy regimens. Neutrophil and monocyte frequencies were determined by flow cytometry from whole blood and peripheral blood mononuclear cell fractions. Serum cytokines were evaluated pretreatment and on-treatment. Patient serum was used in vitro to differentiate healthy donor monocytes to MDSCs as measured by downregulation of major histocompatibility complex II (HLA-DR) and the ability to suppress T-cell proliferation in vitro. C57BL/6 female mice with pancreatic tumors were treated with FOLFIRINOX with or without recombinant G-CSF to directly assess the role of G-CSF on induction of immunosuppressive neutrophils.

RESULTS

Patients receiving FOLFIRINOX with pegfilgrastim had increased serum G-CSF that correlated with an induction of granulocytic MDSCs. This increase was not observed in patients receiving gemcitabine/n(ab)paclitaxel without pegfilgrastim. Interleukin-18 also significantly increased in serum on FOLFIRINOX treatment. Patient serum could induce MDSCs as determined by in vitro functional assays, and this suppressive effect increased with on-treatment serum. Induction of MDSCs in vitro could be recapitulated by addition of recombinant G-CSF to healthy serum, indicating that G-CSF is sufficient for MDSC differentiation. In mice, neutrophils isolated from spleen of G-CSF-treated mice were significantly more capable of suppressing T-cell proliferation.

CONCLUSIONS

Pegfilgrastim use contributes to immune suppression in both humans and mice with pancreatic cancer. These results suggest that use of recombinant G-CSF as supportive care, while critically important for mitigating neutropenia, may complicate efforts to induce antitumor immunity.

Programmatic Precision Oncology Decision Support for Patients With Gastrointestinal Cancer

PURPOSE

With the growing number of available targeted therapeutics and molecular biomarkers, the optimal care of patients with cancer now depends on a comprehensive understanding of the rapidly evolving landscape of precision oncology, which can be challenging for oncologists to navigate alone.

METHODS

We developed and implemented a precision oncology decision support system, GI TARGET, (Gastrointestinal Treatment Assistance Regarding Genomic Evaluation of Tumors) within the Gastrointestinal Cancer Center at the Dana-Farber Cancer Institute. With a multidisciplinary team, we systematically reviewed tumor molecular profiling for GI tumors and provided molecularly informed clinical recommendations, which included identifying appropriate clinical trials aided by the computational matching platform MatchMiner, suggesting targeted therapy options on or off the US Food and Drug Administration-approved label, and consideration of additional or orthogonal molecular testing.

RESULTS

We reviewed genomic data and provided clinical recommendations for 506 patients with GI cancer who underwent tumor molecular profiling between January and June 2019 and determined follow-up using the electronic health record. Summary reports were provided to 19 medical oncologists for patients with colorectal (n = 198, 39%), pancreatic (n = 124, 24%), esophagogastric (n = 67, 13%), biliary (n = 40, 8%), and other GI cancers. We recommended ≥ 1 precision medicine clinical trial for 80% (406 of 506) of patients, leading to 24 enrollments. We recommended on-label and off-label targeted therapies for 6% (28 of 506) and 25% (125 of 506) of patients, respectively. Recommendations for additional or orthogonal testing were made for 42% (211 of 506) of patients.

CONCLUSION

The integration of precision medicine in routine cancer care through a dedicated multidisciplinary molecular tumor board is scalable and sustainable, and implementation of precision oncology recommendations has clinical utility for patients with cancer.

Lynch Syndrome-Associated Cancers Beyond Colorectal Cancer

Lynch syndrome (LS) is a common form of inherited cancer susceptibility, which predisposes to colorectal cancer (CRC) along with a wide array of other extracolonic malignancies, including other gastrointestinal cancers, cancers of the gynecologic and genitourinary tracts, and other organ sites. Recent data have provided novel insights into patient-specific factors that can help clinicians understand an individual LS carrier's risk of extracolonic cancers, including sex, specific LS gene, age, family history of cancer, and other factors. This summary seeks to provide an update on extracolonic cancer risks in LS and provide recommendations for surveillance and risk reduction.

Inherited Pancreatic Cancer Syndromes and High-Risk Screening

Pancreatic cancer is the third leading cause of cancer death in the United States, with a 5-year survival rate of 9%. Individuals with inherited pancreatic cancer syndromes are at an increased risk for developing pancreatic cancer and may benefit from pancreatic cancer surveillance with the goal to detect and intervene on early-stage cancer or high-risk precursor lesions. Given the screening implications for family members and therapeutic implications for probands, all patients diagnosed with pancreatic cancer are recommended to undergo germline genetic testing.

Familial Burden and Other Clinical Factors Associated With Various Types of Cancer in Individuals With Lynch Syndrome

BACKGROUND & AIMS

Lynch syndrome (LS) is associated with increased risks of various gastrointestinal, gynecologic, genitourinary, and other cancers. Many clinical practice guidelines recommend that LS carriers' screening strategies be devised based on their family history of various cancers, in addition to age-, sex-, and gene-specific considerations. The aim of this study was to examine the association between family history and other clinical factors with LS carriers' histories of various cancers.

METHODS

Two cohorts of LS carriers were analyzed: a laboratory-based cohort of consecutively ascertained individuals undergoing germline LS testing and a clinic-based cohort of LS carriers undergoing clinical care at an academic medical center. Multivariable logistic regression was performed to assess clinical factors associated with LS carriers' histories of various cancers/neoplasms. Familial burden was defined as LS carriers' aggregate number of first-/second-degree relatives with a history of a given malignancy.

RESULTS

Multivariable analysis of the laboratory-based cohort (3828 LS carriers) identified familial burden as being incrementally associated with LS carriers' personal history of endometrial (odds ratio [OR], 1.37 per affected first-/second-degree relative; 95% confidence interval [CI], 1.21-1.56), urinary tract (OR, 2.72; 95% CI, 2.02-3.67), small bowel (OR, 3.17; 95% CI, 1.65-6.12), gastric (OR, 1.93; 95% CI, 1.24-3.02), and pancreaticobiliary cancers (OR, 2.10; 95% CI, 1.21-3.65) and sebaceous neoplasms (OR, 7.39; 95% CI, 2.71-20.15). Multivariable analysis of the clinic-based cohort (607 LS carriers) confirmed a significant association of familial burden of endometrial and urinary tract cancers.

CONCLUSIONS

Familial burden - in addition to age, sex, and specific LS gene - should be used to assess LS carriers' risks of specific cancers and guide decision-making about organ-specific surveillance.

Diagnosis and Treatment of Metastatic Colorectal Cancer: A Review

IMPORTANCE

Colorectal cancer (CRC) is the third most common cause of cancer mortality worldwide with more than 1.85 million cases and 850 000 deaths annually. Of new colorectal cancer diagnoses, 20% of patients have metastatic disease at presentation and another 25% who present with localized disease will later develop metastases.

OBSERVATIONS

Colorectal cancer is the third most common cause of cancer mortality for men and women in the United States, with 53 200 deaths projected in 2020. Among people diagnosed with metastatic colorectal cancer, approximately 70% to 75% of patients survive beyond 1 year, 30% to 35% beyond 3 years, and fewer than 20% beyond 5 years from diagnosis. The primary treatment for unresectable metastatic CRC is systemic therapy (cytotoxic chemotherapy, biologic therapy such as antibodies to cellular growth factors, immunotherapy, and their combinations.) Clinical trials completed in the past 5 years have demonstrated that tailoring treatment to the molecular and pathologic features of the tumor improves overall survival. Genomic profiling to detect somatic variants is important because it identifies the treatments that may be effective. For the 50% of patients with metastatic CRC with KRAS/NRAS/BRAF wild-type tumors, cetuximab and panitumumab (monoclonal antibodies to the epithelial growth factor receptor [EGFR]), in combination with chemotherapy, can extend median survival by 2 to 4 months compared with chemotherapy alone. However, for the 35% to 40% of patients with KRAS or NRAS sequence variations (formerly termed mutations), effective targeted therapies are not yet available. For the 5% to 10% with BRAF V600E sequence variations, targeted combination therapy with BRAF and EGFR inhibitors extended overall survival to 9.3 months, compared to 5.9 months for those receiving standard chemotherapy. For the 5% with microsatellite instability (the presence of numerous insertions or deletions at repetitive DNA units) or mismatch repair deficiency, immunotherapy may be used in the first or subsequent line and has improved treatment outcomes with a median overall survival of 31.4 months in previously treated patients.

CONCLUSIONS AND RELEVANCE

Advances in molecular profiling of metastatic CRC facilitate the ability to direct treatments to the biologic features of the tumor for specific patient subsets. Although cures remain uncommon, more patients can anticipate extended survival. Genomic profiling allows treatment selection so that more patients derive benefit and fewer are exposed to toxicity from ineffective therapies.

A Multi-Institutional Cohort of Therapy-Associated Polyposis in Childhood and Young Adulthood Cancer Survivors

Prior small reports have postulated a link between gastrointestinal polyposis and childhood and young adulthood cancer (CYAC) treatment (therapy-associated polyposis; TAP), but this remains a poorly understood phenomenon. The aim of this study was to describe the phenotypic spectrum of TAP in a multi-institutional cohort. TAP cases were identified from eight high-risk cancer centers. Cases were defined as patients with ≥10 gastrointestinal polyps without known causative germline alteration or hereditary colorectal cancer predisposition syndrome who had a history of prior treatment with chemotherapy and/or radiotherapy for CYAC. A total of 34 TAP cases were included (original CYAC: 27 Hodgkin lymphoma, three neuroblastoma, one acute myeloid leukemia, one medulloblastoma, one nephroblastoma, and one non-Hodgkin lymphoma). Gastrointestinal polyposis was first detected at a median of 27 years (interquartile range, 20-33) after CYAC treatment. A total of 12 of 34 (35%) TAP cases had ≥50 colorectal polyps. A total of 32 of 34 (94%) had >1 histologic polyp type. A total of 25 of 34 (74%) had clinical features suggestive of ≥1 colorectal cancer predisposition syndrome [e.g., attenuated familial adenomatous polyposis (FAP), serrated polyposis syndrome, extracolonic manifestations of FAP, mismatch repair-deficient colorectal cancer, or hamartomatous polyposis] including 8 of 34 (24%) with features of multiple such syndromes. TAP is an apparently acquired phenomenon that should be considered in patients who develop significant polyposis without known causative germline alteration but who have had prior treatment for a CYAC. Patients with TAP have features that may mimic various hereditary colorectal cancer syndromes, suggesting multiple concurrent biologic mechanisms, and recognition of this diagnosis may have implications for cancer risk and screening.

Recent advances in Lynch syndrome

Lynch syndrome is one of the most common hereditary cancer predisposition syndromes and is associated with increased risks of colorectal and endometrial cancer, as well as multiple other cancer types. While the mechanism of mismatch repair deficiency and microsatellite instability and its role in Lynch-associated carcinogenesis has been known for some time, there have been significant advances recently in diagnostic testing and the understanding of the molecular pathogenesis of Lynch tumors. There is also an increased awareness that the clinical phenotype and cancer risk varies by specific mismatch repair mutation, which in turn has implications on surveillance strategies for patients. Even the treatment of Lynch-associated cancers has changed with the addition of immunotherapy for advanced disease. This progress report aims to review some of the many advances in epidemiology, molecular pathogenesis, diagnosis, clinical phenotype, cancer surveillance, treatment, and chemo- and immune-prevention strategies in the Lynch syndrome field over the past 5 years.

Association of Thrombolysis in Myocardial Infarction Myocardial Perfusion Grade with cardiovascular magnetic resonance measures of infarct architecture after primary percutaneous coronary intervention for ST-segment elevation myocardial infarction

BACKGROUND

Primary percutaneous coronary intervention (pPCI) routinely restores normal epicardial flow among patients with ST-segment elevation myocardial infarction (STEMI). However, impairment of myocardial perfusion frequently persists. The goal of this analysis was to determine whether impaired myocardial perfusion was associated with cardiovascular magnetic resonance-defined abnormalities in infarct architecture, including infarct size (IS), infarct surface area (ISA), infarct border zone (IBZ), and infarct complexity (IC).

METHODS

Thirty-one patients with STEMI treated with pPCI were included in the analysis. Cardiovascular magnetic resonance was performed within 7 days of presentation and repeated at 3 months. Infarct complexity was defined as the ratio of actual ISA to an idealized smooth ISA and normalized to IS.

RESULTS

Impaired Thrombolysis in Myocardial Infarction Myocardial Perfusion Grade (TMPG) (<3) was associated with larger ISA at baseline (78.2 +/- 25.3 cm(2) vs 40.3 +/- 30.3 cm(2), P = .02) and follow-up (58.8 +/- 27.5 cm(2) vs 26.3 +/- 20.2 cm(2), P = .03) and larger IBZ at follow-up (7.8% +/- 2.7% vs 4.1% +/- 3.3%, P = .02). At follow-up, ISA, when normalized to IS, was significantly higher among patients with impaired myocardial perfusion (TMPG <3) (6.9 +/- 2.5 vs 5.9 +/- 2.4 cm(2)/%, P = .03). Thrombolysis in MI myocardial perfusion grade <3 was also associated with increased IC at follow-up (52% +/- 12% vs 33% +/- 16%, P = .01).

CONCLUSIONS

Impaired TMPG is associated with larger ISA, IBZ, and increased IC. At 3 months, TMPG remained associated with ISA and IC after adjusting for IS, suggesting that impaired TMPG after pPCI is associated with infarct architecture after healing, independent of IS.

Transfusion associated microchimerism: a heretofore little-recognized complication following transfusion

Potent antiplatelet and antithrombotic agents have significantly reduced mortality in the setting of acute coronary syndromes and percutaneous coronary intervention. However these agents are associated with increased bleeding which is in turn associated with adverse clinical outcomes. In many centers, transfusion is often used to correct for blood loss. Blood transfusion in the setting of acute coronary syndrome has been associated with adverse clinical outcomes including increased mortality. Transfusion associated microchimerism (TA-MC) is a newly recognized complication of blood transfusion. There is engraftment of the donor's hematopoietic stem cells in patients who then develop microchimerism. This article discusses the association of bleeding/blood transfusion with adverse outcomes and the potential role of TA-MC in clinical outcomes.

Use of the TIMI frame count in the assessment of coronary artery blood flow and microvascular function over the past 15 years

Since its introduction, the TIMI frame count method has contributed to the understanding of the pathophysiology of coronary artery disease. In this article, the evolution of the TFC method and its applicability in the assessment of various therapeutic modalities are described.