Clonal Hematopoiesis in Patients With Neuroendocrine Tumor Treated With Lutetium-177 and the Risk of Thrombocytopenia: A Prospective Study.

PURPOSE: Thrombocytopenia is a relatively common dose-limiting toxicity during peptide receptor radionuclide therapy (PRRT) in patients with NET. Although uncommon, some patients develop persistent cytopenia and eventually therapy-related myeloid neoplasm (t-MN), which has a dismal prognosis. As the indications for PRRT are expanding, it is important to investigate factors that may predict cytopenias during/after PRRT. We prospectively evaluated the prevalence of clonal hematopoiesis (CH) and cytopenia in patients with NET undergoing PRRT. MATERIALS AND METHODS: Patients with metastatic NET with plan to receive four cycles of lutetium-177 were enrolled. CH was evaluated before PRRT using a panel of 220 genes with a targeted depth of ≥1,000×. Patients were followed during PRRT and every 3 months thereafter. RESULTS: Of 37 patients enrolled, the median age was 68 years and 51.4% were male. Previous treatment exposures included alkylating agents in 30%, platinum agents in 8%, and external radiation in 13%. CH was detected in 35.1% using a variant allele frequency (VAF) cutoff of ≥2% and 45.9% with a VAF of ≥1%. The most common mutations were in age-related genes (DNMT3A, TET2). CH was not associated with anemia or neutropenia; however, it was associated with lower platelet count at baseline and more time spent in a thrombocytopenic state during/after PRRT. Five patients had bone marrow biopsies (BMBs) because of sustained hematologic dysfunction post-PRRT, and of those, diagnoses included clonal cytopenia of undetermined significance (CCUS) in three and idiopathic cytopenia of undetermined significance (ICUS) in two. CONCLUSION: CH is present in 35.1% of patients with NET and is associated with thrombocytopenia risk during PRRT. Future studies with long-term follow-up will delineate whether CH might be a predictor for higher risk of t-MN after PRRT.

Combination Targeted Therapy with Lenvatinib and Pembrolizumab in Progressive, Radioiodine-Refractory Differentiated Thyroid Cancers.

PURPOSE: Lenvatinib, a potent multi-kinase inhibitor, improves progression-free survival (PFS) in patients with radioiodine (RAI)-refractory differentiated thyroid cancer (DTC); however, most patients experience disease progression, warranting further therapy. We evaluated the efficacy and safety of combination lenvatinib plus pembrolizumab (LP) in these patients. PATIENTS AND METHODS: We enrolled patients with progressive, RAI-refractory DTC that were either naïve to multi-kinase inhibitors (cohort 1) or who had progressed on lenvatinib (cohort 2). Patients received oral lenvatinib daily (cohort 1, 20 mg; cohort 2, dose at progression ) and intravenous pembrolizumab (200 mg) every 21 days. RESULTS: 30 and 27 patients were enrolled in cohort 1 and 2, respectively. Adverse events were consistent with those observed in other cancers. In cohort 1, the confirmed overall response rate (ORR) was 65.5%. There were no complete responses (CR, primary endpoint). The 12 and 18-month PFS were 72.0% and 58.0%, respectively, and median PFS was 26.8 months. In cohort 2, the confirmed ORR was 16% (primary endpoint), and median PFS was 10.0 months (95% CI; 7.0-17.9 months). Tumor histology, driver mutations, and immune-related biomarkers, including PD-L1 expression, thyroid-specific antibody levels, and CD8+ T cell tumor infiltrate, did not correlate with response to therapy. Increased baseline peripheral blood monocytes and neutrophil to lymphocyte ratio were associated with a worse PFS in cohort 1. CONCLUSIONS: Combination lenvatinib plus pembrolizumab may enhance the durability of lenvatinib monotherapy in lenvatinib-naïve patients. Furthermore, the addition of pembrolizumab may be a viable salvage therapy for patients who have progressed on lenvatinib.

Extending venous thromboembolism secondary prevention with apixaban in cancer patients. The EVE trial.

BACKGROUND: Cancer-associated venous thromboembolism (VTE) management guideline recommendations include continued therapeutic anticoagulation while active cancer persists. The Federal Drug Administration label for apixaban for secondary VTE prevention includes a dose reduction to 2.5 mg twice daily after 6 months of treatment. OBJECTIVES: The study's purpose was to determine whether this dose reduction is advisable for cancer-associated VTE. METHODS: A randomized, double-blind trial compared apixaban 2.5 mg with 5 mg twice daily for 12 months among cancer patients with VTE who had completed 6 to 12 months of anticoagulation therapy. The primary outcome was combined major bleeding plus clinically relevant nonmajor bleeding. RESULTS: Of 370 patients recruited, 360 were included in the intention-to-treat analyses. Major plus clinically relevant nonmajor bleeding occurred in 16 of 179 patients (8.9%) in the apixaban 2.5 mg group compared with 22 of 181 patients (12.2%) in the 5 mg group (hazard ratio [HR], 0.72; 95% CI, 0.38-1.37; P = .39). Major bleeding occurred in 2.8% of the apixaban 2.5 mg group and in 2.2% of the 5 mg group (HR, 1.26; 95% CI, 0.34-4.66; P = .73). Recurrent VTE or arterial thrombosis occurred in 9 of 179 patients (5.0%) in the apixaban 2.5 mg group and 9 of 181 patients (5.0%) in the 5 mg group (HR, 1.0; 95% CI, 0.40-2.53; P = 1.00). All-cause mortality rates were similar between groups, 13% vs 12% (HR, 1.14; 95% CI, 0.63-2.04; P = .67). CONCLUSION: For secondary prevention of cancer-associated VTE, apixaban 2.5 mg compared with 5 mg twice daily did not lower combined bleeding events (EVE trial NCT03080883).

Alliance A151945: Accrual and characteristics of adolescent and young adult patients in Alliance trials from 2000 to 2017.

BACKGROUND: Identifying patient- and disease-specific characteristics associated with clinical trial enrollment of adolescents and young adults (AYAs) with cancer may target efforts to improve accrual. METHODS: Alliance for Clinical Trials in Oncology (Alliance) trials opened from January 1, 2000, and closed before January 1, 2018, for common AYA cancers were identified. Proportions of AYAs (aged 18-39 years old) versus non-AYAs (aged ≥40 years old) enrolled by cancer type were summarized by descriptive statistics. Among studies with ≥20 AYAs enrolled, demographic and disease characteristics of AYAs versus non-AYAs were compared with χ2 and Kruskal-Wallis tests. A qualitative review was also conducted of therapeutic trials included in analysis in PubMed through December 31, 2021, that reported AYA-specific survival. RESULTS: Among 188 trials enrolling 40,396 patients, AYAs represented 11% (4468 of 40,396) of accrual. AYA accrual varied by cancer type (leukemia, 23.6%; breast, 9.9%; lymphoma, 14.8%; colorectal, 6.2%; central nervous system, 8.1%; melanoma, 11.8%; sarcoma, 12%). Across ages, the proportion of Black and Hispanic patients enrolled was 1%-10%. Compared to non-AYAs, AYAs in breast and colorectal cancer trials were less likely to be White and more likely to be Hispanic. Disease characteristics differed by age for selected trials. Two trials reported AYA-specific survival, with no significant differences observed by age. CONCLUSIONS: AYA accrual to Alliance trials was comparable to or exceeded population-based, age-specific prevalence estimates for most cancer types. Greater proportional representation of Hispanic and non-White patients among AYAs reflects US demographic trends. The small number of minority patients enrolled across ages underscores the persistent challenge of ensuring equitable access to trials, including for AYAs.

A five arm natural history study of nasal vestibulitis.

INTRODUCTION: Nasal symptoms are frequently reported by patients undergoing chemotherapy. METHODS: Eligible patients planning to receive paclitaxel, docetaxel, nab-paclitaxel, bevacizumab without a concomitant taxane, or "other" (non-taxane, non-bevacizumab) chemotherapy regimens were invited to participate in this prospective study. Patients reported nasal symptoms prior to each dose of chemotherapy. RESULTS: The percentage of patients (95% CI) who reported nasal symptoms was the same for patients who received bevacizumab or nab-paclitaxel, 82.6% (61.2%, 95.1%). There were no significant differences among the proportions of patients experiencing nasal symptoms within the paclitaxel, nab-paclitaxel, and bevacizumab cohorts. Patients in the nab-paclitaxel cohort were more likely to experience symptoms than those in the non-taxane non-bevacizumab cohort or docetaxel cohort (p = 0.001, p = 0.001). Patients in the bevacizumab cohort were more likely to experience nasal symptoms than those in the non-taxane non-bevacizumab cohort (p = 0.03). CONCLUSION: Nasal vestibulitis symptoms are common in patients receiving chemotherapy, especially those receiving paclitaxel, docetaxel, and bevacizumab. Further investigations into treatments of this symptom complex are warranted.

Successes and lessons learned in database development for national multi-site cancer care delivery research trials: the Alliance for Clinical Trials in Oncology experience.

INTRODUCTION: Alliance for Clinical Trials in Oncology (Alliance) coordinated trials utilize Medidata Rave® (Rave) as the primary clinical data capture system. A growing number of innovative and complex cancer care delivery research (CCDR) trials are being conducted within the Alliance with the aims of studying and improving cancer-related care. Because these trials encompass patients, providers, practices, and their interactions, a defining characteristic of CCDR trials is multilevel data collection in pragmatic settings. Consequently, CCDR trials necessitated innovative strategies for database development, centralized data management, and data monitoring in the presence of these real-world multilevel relationships. Having real trial experience in working with community and academic centers, and having recently implemented five CCDR trials in Rave, we are committed to sharing our strategies and lessons learned in implementing such pragmatic trials in oncology. METHODS: Five Alliance CCDR trials are used to describe our approach to analyzing the database development needs and the novel strategies applied to overcome the unanticipated challenges we encountered. The strategies applied are organized into 3 categories: multilevel (clinic, clinic stakeholder, patient) enrollment, multilevel quantitative and qualitative data capture, including nontraditional data capture mechanisms being applied, and multilevel data monitoring. RESULTS: A notable lesson learned in each category was (1) to seek long-term solutions when developing the functionality to push patient and non-patient enrollments to their respective Rave study database that affords flexibility if new participant types are later added; (2) to be open to different data collection modalities, particularly if such modalities remove barriers to participation, recognizing that additional resources are needed to develop the infrastructure to exchange data between that modality and Rave; and (3) to facilitate multilevel data monitoring, orient site coordinators to the their trial's multiple study databases, each corresponding to a level in the hierarchy, and remind them to establish the link between patient and non-patient participants in the site-facing NCI web-based enrollment system. CONCLUSION: Although the challenges due to multilevel data collection in pragmatic settings were surmountable, our shared experience can inform and foster collaborations to collectively build on our past successes and improve on our past failures to address the gaps.

Impact of Massage Therapy on the Quality of Life of Hospice Patients and Their Caregivers: A Pilot Study.

Evidence for massage therapy (MT) in hospice patients remains limited. We conducted a prospective pilot study on MTs impact on quality of life of hospice patients and caregivers. Patient-caregiver dyads were enrolled if patients scored ≥5 on pain, depression, anxiety, or well-being using the revised Edmonton Symptom Assessment System Revised (ESAS-r). The patient received MT weekly for up to 3 massages with assessments completed at baseline, after each massage, and 1 week after the final massage for patients and at baseline and 1 week after final massage for caregivers. A satisfaction survey was completed at study completion. A pro-rated area under the curve (AUC) was utilized to assess the primary endpoints of change in ESAS-r for patient ratings of pain, depression and anxiety as well as the Linear Analogue Self-Assessment (LASA). Median difference scores (end of study value)-(baseline value) for each participant and caregiver were calculated. Of 27 patients and caregivers enrolled, 25 patients received MT. Fifteen patients completed all 3 MT sessions and were given the final symptom assessment and satisfaction survey and their caregivers completed final assessments. The proportion of patients considered success (AUC > baseline) in the primary endpoints were the following: pain 40.9%, depression 40.9%, anxiety 54.5%, LASA 54.5%. Median difference scores were largely zero indicating no significant temporal change in symptoms. Patients were highly satisfied with MT. This pilot study indicated that MT was a feasible and well-received intervention in our population of patients with inadequately controlled symptoms.

Histone deacetylase 3 represses cholesterol efflux during CD4+ T-cell activation.

After antigenic activation, quiescent naive CD4+ T cells alter their metabolism to proliferate. This metabolic shift increases production of nucleotides, amino acids, fatty acids, and sterols. Here, we show that histone deacetylase 3 (HDAC3) is critical for activation of murine peripheral CD4+ T cells. HDAC3-deficient CD4+ T cells failed to proliferate and blast after in vitro TCR/CD28 stimulation. Upon T-cell activation, genes involved in cholesterol biosynthesis are upregulated while genes that promote cholesterol efflux are repressed. HDAC3-deficient CD4+ T cells had reduced levels of cellular cholesterol both before and after activation. HDAC3-deficient cells upregulate cholesterol synthesis appropriately after activation, but fail to repress cholesterol efflux; notably, they overexpress cholesterol efflux transporters ABCA1 and ABCG1. Repression of these genes is the primary function for HDAC3 in peripheral CD4+ T cells, as addition of exogenous cholesterol restored proliferative capacity. Collectively, these findings demonstrate HDAC3 is essential during CD4+ T-cell activation to repress cholesterol efflux.

The mitochondrial iron transporter ABCB7 is required for B cell development, proliferation, and class switch recombination in mice.

Iron-sulfur (Fe-S) clusters are cofactors essential for the activity of numerous enzymes including DNA polymerases, helicases, and glycosylases. They are synthesized in the mitochondria as Fe-S intermediates and are exported to the cytoplasm for maturation by the mitochondrial transporter ABCB7. Here, we demonstrate that ABCB7 is required for bone marrow B cell development, proliferation, and class switch recombination, but is dispensable for peripheral B cell homeostasis in mice. Conditional deletion of ABCB7 using Mb1-cre resulted in a severe block in bone marrow B cell development at the pro-B cell stage. The loss of ABCB7 did not alter expression of transcription factors required for B cell specification or commitment. While increased intracellular iron was observed in ABCB7-deficient pro-B cells, this did not lead to increased cellular or mitochondrial reactive oxygen species, ferroptosis, or apoptosis. Interestingly, loss of ABCB7 led to replication-induced DNA damage in pro-B cells, independent of VDJ recombination, and these cells had evidence of slowed DNA replication. Stimulated ABCB7-deficient splenic B cells from CD23-cre mice also had a striking loss of proliferation and a defect in class switching. Thus, ABCB7 is essential for early B cell development, proliferation, and class switch recombination.

ST8Sia6 Promotes Tumor Growth in Mice by Inhibiting Immune Responses.

Many tumors exhibit increased incorporation of sialic acids into cell-surface glycans, which impact the tumor microenvironment. Sialic acid immunoglobulin-like lectins (Siglec) are receptors that recognize sialic acids and modulate immune responses, including responses to tumors. However, the roles of individual sialyltransferases in tumorigenesis and tumor growth are not well understood. Here, we examined the sialyltransferase ST8Sia6, which generated α2,8-linked disialic acids that bind to murine Siglec-E and human Siglec-7 and -9. Increased ST8Sia6 expression was found on many human tumors and associated with decreased survival in several cancers, including colon cancer. Because of this, we engineered MC38 and B16-F10 tumor lines to express ST8Sia6. ST8Sia6-expressing MC38 and B16-F10 tumors exhibited faster growth and led to decreased survival, which required host Siglec-E. ST8Sia6 expression on tumors also altered macrophage polarization toward M2, including upregulation of the immune modulator arginase, which also required Siglec-E. ST8Sia6 also accelerated tumorigenesis in a genetically engineered, spontaneous murine model of colon cancer, decreasing survival from approximately 6 months to 67 days. Thus, ST8Sia6 expression on tumors inhibits antitumor immune responses to accelerate tumor growth.

Natural history of nasal vestibulitis associated with paclitaxel, docetaxel, and other chemotherapy agents: a Minnesota Cancer Clinical Trials Network (MNCCTN) study.

PURPOSE: To describe the natural history of nasal vestibulitis in patients receiving taxane chemotherapy, including incidence, severity, and associated symptoms. METHODS: Eligible patients with minimal or no baseline nasal symptoms were enrolled in this natural history study at initiation of a new chemotherapy regimen. Patients completed nasal symptom logs each time they received a chemotherapy dose. This manuscript reports upon the patients who received paclitaxel, docetaxel, or non-taxane non-bevacizumab chemotherapy. The proportions of patients within each cohort reporting any treatment-emergent nasal symptoms were estimated, with corresponding exact 95% confidence intervals. A cumulative incidence function was estimated within the chemotherapy cohorts to calculate the cumulative incidence rate of treatment-emergent nasal vestibulitis, treating death and disease progression as competing risks. RESULTS: Of the 81 evaluable patients, nasal symptoms were reported by 76.5% (58.8%, 89.3%) receiving paclitaxel, 54.2% (32.8%, 74.5%) receiving docetaxel, and 47.8% (26.8%, 69.4%) receiving non-taxane and non-bevacizumab chemotherapy. Of the three pairwise chemotherapy group comparisons, both the tests comparing the cumulative incidence function between the paclitaxel and non-taxane non-bevacizumab chemotherapy cohorts and between the paclitaxel and docetaxel cohorts achieved statistical significance at the 5% level with a higher incidence of treatment-emergent nasal vestibulitis in the paclitaxel cohort in both comparisons (P = 0.026 and P = 0.035, respectively). These significant differences were retained in the cumulative incidence function regression analysis controlling for age, smoking history, allergies, and asthma. Most patients in the paclitaxel cohort reported nasal symptoms as moderate or severe (56%). CONCLUSION: Patients receiving paclitaxel chemotherapy experience a high incidence of nasal symptoms.

Cutting Edge: ST8Sia6-Generated α-2,8-Disialic Acids Mitigate Hyperglycemia in Multiple Low-Dose Streptozotocin-Induced Diabetes.

The immune system contains a series of checks and balances that maintain tolerance and prevent autoimmunity. Sialic acid-binding Ig-type lectins (Siglecs) are cell surface receptors found on immune cells and inhibit inflammation by recruiting protein tyrosine phosphatases to ITIMs. Islet-resident macrophages express Siglec-E, and Siglec-E expression decreases on islet-resident macrophages as insulitis progresses in the NOD mouse. The sialyltransferase ST8Sia6 generates α-2,8-disialic acids that are ligands for Siglec-E in vivo. We hypothesized that engaging Siglec-E through ST8Sia6-generated ligands may inhibit the development of immune-mediated diabetes. Constitutive overexpression of ST8Sia6 in pancreatic ß cells mitigated hyperglycemia in the multiple low-dose streptozotocin model of diabetes, demonstrating that engagement of this immune receptor facilitates tolerance in the setting of inflammation and autoimmune disease.

The Interaction between NKAP and HDAC3 Is Critical for T Cell Maturation.

NKAP and HDAC3 are critical for T cell maturation. NKAP and HDAC3 physically associate, and a point mutation in NKAP, NKAP(Y352A), abrogates this interaction. To evaluate the significance of NKAP and HDAC3 association in T cell maturation, transgenic mice were engineered for cre-mediated endogenous NKAP gene deletion coupled to induction of NKAP(Y352A) or a wild type (WT) control transgene, NKAP(WT), in double positive thymocytes or regulatory T cells (Tregs). T cell maturation was normal in mice with endogenous NKAP deletion coupled to NKAP(WT) induction. However, severe defects occurred in T cell and Treg maturation and in iNKT cell development when NKAP(Y352A) was induced, recapitulating NKAP deficiency. Conventional T cells expressing NKAP(Y352A) failed to enter the long-term T cell pool, did not produce cytokines, and remained complement susceptible, whereas Tregs expressing NKAP(Y352A) were eliminated as recent thymic emigrants leading to lethal autoimmunity. Overall, these results demonstrate the significance of NKAP-HDAC3 association in T cells.

Murine T Cell Maturation Entails Protection from MBL2, but Complement Proteins Do Not Drive Clearance of Cells That Fail Maturation in the Absence of NKAP.

Recent thymic emigrants that fail postpositive selection maturation are targeted by complement proteins. T cells likely acquire complement resistance during maturation in the thymus, a complement-privileged organ. To test this, thymocytes and fresh serum were separately obtained and incubated together in vitro to assess complement deposition. Complement binding decreased with development and maturation. Complement binding decreased from the double-positive thymocyte to the single-positive stage, and within single-positive thymocytes, complement binding gradually decreased with increasing intrathymic maturation. Binding of the central complement protein C3 to wild-type immature thymocytes required the lectin but not the classical pathway. Specifically, MBL2 but not MBL1 was required, demonstrating a unique function for MBL2. Previous studies demonstrated that the loss of NKAP, a transcriptional regulator of T cell maturation, caused peripheral T cell lymphopenia and enhanced complement susceptibility. To determine whether complement causes NKAP-deficient T cell disappearance, both the lectin and classical pathways were genetically ablated. This blocked C3 deposition on NKAP-deficient T cells but failed to restore normal cellularity, indicating that complement contributes to clearance but is not the primary cause of peripheral T cell lymphopenia. Rather, the accumulation of lipid peroxides in NKAP-deficient T cells was observed. Lipid peroxidation is a salient feature of ferroptosis, an iron-dependent nonapoptotic cell death. Thus, wild-type thymocytes naturally acquire the ability to protect themselves from complement targeting by MBL2 with maturation. However, NKAP-deficient immature peripheral T cells remain scarce in complement-deficient mice likely due to ferroptosis.

Cutting Edge: HDAC3 Protects Double-Positive Thymocytes from P2X7 Receptor-Induced Cell Death.

Intricate life-versus-death decisions are programmed during T cell development, and the regulatory mechanisms that coordinate their activation and repression are still under investigation. In this study, HDAC3-deficient double-positive (DP) thymocytes exhibit a severe decrease in numbers. The thymic cortex is rich in ATP, which is released by macrophages that clear apoptotic DP thymocytes that fail to undergo positive selection. We demonstrate that HDAC3 is required to repress expression of the purinergic receptor P2X7 to prevent DP cell death. HDAC3-deficient DP thymocytes upregulate the P2X7 receptor, increasing sensitivity to ATP-induced cell death. P2rx7/HDAC3-double knockout mice show a partial rescue in DP cell number. HDAC3 directly binds to the P2rx7 enhancer, which is hyperacetylated in the absence of HDAC3. In addition, RORγt binds to the P2rx7 enhancer and promotes P2X7 receptor expression in the absence of HDAC3. Therefore, HDAC3 is a critical regulator of DP thymocyte survival and is required to suppress P2X7 receptor expression.