One CD4+TCR and One CD8+TCR Targeting Autochthonous Neoantigens Are Essential and Sufficient for Tumor Eradication.

PURPOSE: To achieve eradication of solid tumors, we examined how many neoantigens need to be targeted with how many T-cell receptors (TCR) by which type of T cells. EXPERIMENTAL DESIGN: Unmanipulated, naturally expressed (autochthonous) neoantigens were targeted with adoptively transferred TCR-engineered autologous T cells (TCR-therapy). TCR-therapy used CD8+ T-cell subsets engineered with TCRs isolated from CD8+ T cells (CD8+TCR-therapy), CD4+ T-cell subsets engineered with TCRs isolated from CD4+ T cells (CD4+TCR-therapy), or combinations of both. The targeted tumors were established for at least 3 weeks and derived from primary autochthonous cancer cell cultures, resembling natural solid tumors and their heterogeneity as found in humans. RESULTS: Relapse was common with CD8+TCR-therapy even when targeting multiple different autochthonous neoantigens on heterogeneous solid tumors. CD8+TCR-therapy was only effective against homogenous tumors artificially derived from a cancer cell clone. In contrast, a combination of CD8+TCR-therapy with CD4+TCR-therapy, each targeting one neoantigen, eradicated large and established solid tumors of natural heterogeneity. CD4+TCR-therapy targeted a mutant neoantigen on tumor stroma while direct cancer cell recognition by CD8+TCR-therapy was essential for cure. In vitro data were consistent with elimination of cancer cells requiring a four-cell cluster composed of TCR-engineered CD4+ and CD8+ T cells together with antigen-presenting cells and cancer cells. CONCLUSIONS: Two cancer-specific TCRs can be essential and sufficient to eradicate heterogeneous solid tumors expressing unmanipulated, autochthonous targets. We demonstrate that simplifications to adoptive TCR-therapy are possible without compromising efficacy.

Single CAR-T cell treatment controls disseminated ovarian cancer in a syngeneic mouse model.

BACKGROUND: Treatment of some blood cancers with T cells that express a chimeric antigen receptor (CAR) against CD19 have shown remarkable results. In contrast, CAR-T cell efficacy against solid tumors has been difficult to achieve. METHODS: To examine the potential of CAR-T cell treatments against ovarian cancers, we used the mouse ovarian cancer cell line ID8 in an intraperitoneal model that exhibits disseminated solid tumors in female C57BL/6J mice. The CAR contained a single-chain Fv from antibody 237 which recognizes a Tn-glycopeptide-antigen expressed by ID8 due to aberrant O-linked glycosylation in the absence of the transferase-dependent chaperone Cosmc. The efficacy of four Tn-dependent CARs with varying affinity to Tn antigen, and each containing CD28/CD3ζ cytoplasmic domains, were compared in vitro and in vivo in this study. RESULTS: In line with many observations about the impact of aberrant O-linked glycosylation, the ID8Cosmc knock-out (ID8Cosmc-KO) exhibited more rapid tumor progression compared with wild-type ID8. Despite the enhanced tumor growth in vivo, 237 CAR and a mutant with 30-fold higher affinity, but not CARs with lower affinity, controlled advanced ID8Cosmc-KO tumors. Tumor regression could be achieved with a single intravenous dose of the CARs, but intraperitoneal administration was even more effective. The CAR-T cells persisted over a period of months, allowing CAR-treated mice to delay tumor growth in a re-challenge setting. The most effective CARs exhibited the highest affinity for antigen. Antitumor effects observed in vivo were associated with increased numbers of T cells and macrophages, and higher levels of cleaved caspase-3, in the tumor microenvironment. Notably, the least therapeutically effective CAR mediated tonic signaling leading to antigen-independent cytokine expression and it had higher levels of the immunosuppressive cytokine interleukin10. CONCLUSION: The findings support the development of affinity-optimized CAR-T cells as a potential treatment for established ovarian cancer, with the most effective CARs mediating a distinct pattern of inflammatory cytokine release in vitro. Importantly, the most potent Tn-dependent CAR-T cells showed no evidence of toxicity in tumor-bearing mice in a syngeneic, immunocompetent system.

Criteria to make animal studies more relevant to treating human cancer.

Certain aspects of experimental tumor models in mice most accurately reflect the biology and immunology of cancer in patients. A survey of experimental cancer immunotherapy papers published in 2020 shows most do not achieve cancer shrinkage although treatment is initiated at an early time point after cancer cell injection, which does not reflect cancer immunotherapy in patients. Even then, few current experimental approaches eradicate the injected malignant cells, most only delay outgrowth. The value of targeting mutation-encoded tumor-specific antigens becomes increasingly evident while problems of finding normal gene-encoded tumor-associated antigens as safe, effective targets persist. It might be time to refocus on realistic experimental settings and truly cancer-specific targets. These antigens are associated with the least risk of side effects.

The relationship between emotional well-being and understanding of prognosis in patients with acute myeloid leukemia (AML).

PURPOSE: Adults with acute myeloid leukemia (AML) face considerable distress and often have a poor prognosis. However, little is known about these patients' perceptions of prognosis and how this relates to emotional well-being (EWB). METHODS: We conducted a prospective, observational study of 50 adult patients with AML initiating chemotherapy, and surveyed them longitudinally for 6 months about their prognosis, treatment goals, quality of life, and EWB (by FACT-G). We derived a prognostic estimate for each patient based on data from published trials summarized in National Comprehensive Care Network Guidelines. We used descriptive statistics and longitudinal modeling to test the hypothesis that more accurate prognostic awareness is associated with worse EWB. RESULTS: Most patients (n = 43; 86%) had an objectively poor prognosis attributable to relapsed disease, complex karyotype, or FLT3 mutation. Yet, 74% of patients reported expecting a 50% or greater chance of cure. Patients with a poor prognosis more often had discordant prognostic estimates, compared to those with favorable risk AML (OR = 7.25, 95% CI 1.21, 43.37). Patient-reported prognostic estimates did not vary significantly over time. At baseline, patients who better understood their prognosis had worse EWB and overall quality-of-life scores (EWB 12 vs. 19.5; p = 0.01; FACT-G 65 vs. 75.5; p = 0.01). CONCLUSION: Patients with AML overestimate their prognosis, and awareness of a poor prognosis is associated with worse emotional well-being. Efforts are needed to improve patients' understanding of their prognosis, and to provide more psychosocial support and attention to well-being as part of high-quality leukemia care.

Characteristics of Advance Care Planning in Patients With Cancer Referred to Palliative Care.

PURPOSE: Advance care planning (ACP) is a process in which patients share their values, goals, and preferences regarding future medical care. ACP can improve care quality, yet may be challenging to address for patients with cancer. We sought to characterize key components of ACP in patients with cancer as compared with patients with noncancer serious illness referred to palliative care (PC). METHODS: We performed a retrospective cross-sectional analysis of initial outpatient PC visits from the Quality Data Collection Tool for PC database from 2015 to 2019. Quality Data Collection Tool is a web-based point-of-care specialty PC registry to track quality metrics. RESULTS: We analyzed 1,604 patients with cancer and 1,094 patients without cancer: 44% of patients were female, 87% were White, and 98% were non-Hispanic. The average age was 72.2 years (standard deviation [SD] 15.4). Patients with cancer were on average younger than patients without cancer (66.5 [SD: 13.9] v 80.5 [SD: 13.8]) and had a higher Palliative Performance Scale (PPS) (59.5 [SD: 22.4] v 33.4 [SD: 25.1]). In our unadjusted comparison, patients with cancer were less likely to be DNR/DNI (37% v 53%; P < .0001) and less likely to have an advance directive (53% v 73%; < .0001); rates of healthcare proxy identification were similar (92.8% v 94.5%; P = .10). These differences did not persist when we accounted for age, race, sex, and PPS, with age being the primary explanatory factor. CONCLUSION: Despite having serious illness meriting PC referral, many patients with cancer in our study lacked advance directives. This highlights both the important role of oncologists in facilitating ACP and the utility of PC playing a complementary role.

Differences between patients with cardiovascular disease and cancer referred for palliative care.

Our analysis from a national registry shows that compared to cancer, cardiovascular disease patients referred to palliative care are a decade older, have worse functional status and clinician-estimated prognosis. Both groups have very high symptom burden, with cardiovascular disease patients experiencing more dyspnea while pain, nausea, and fatigue are more common in cancer.

Structure-guided engineering of the affinity and specificity of CARs against Tn-glycopeptides.

The potency of adoptive T cell therapies targeting the cell surface antigen CD19 has been demonstrated in hematopoietic cancers. It has been difficult to identify appropriate targets in nonhematopoietic tumors, but one class of antigens that have shown promise is aberrant O-glycoprotein epitopes. It has long been known that dysregulated synthesis of O-linked (threonine or serine) sugars occurs in many cancers, and that this can lead to the expression of cell surface proteins containing O-glycans comprised of a single N-acetylgalactosamine (GalNAc, known as Tn antigen) rather than the normally extended carbohydrate. Previously, we used the scFv fragment of antibody 237 as a chimeric antigen receptor (CAR) to mediate recognition of mouse tumor cells that bear its cognate Tn-glycopeptide epitope in podoplanin, also called OTS8. Guided by the structure of the 237 Fab:Tn-OTS8-glycopeptide complex, here we conducted a deep mutational scan showing that residues flanking the Tn-glycan contributed significant binding energy to the interaction. Design of 237-scFv libraries in the yeast display system allowed us to isolate scFv variants with higher affinity for Tn-OTS8. Selection with a noncognate human antigen, Tn-MUC1, yielded scFv variants that were broadly reactive with multiple Tn-glycoproteins. When configured as CARs, engineered T cells expressing these scFv variants showed improved activity against mouse and human cancer cell lines defective in O-linked glycosylation. This strategy provides CARs with Tn-peptide specificities, all based on a single scFv scaffold, that allows the same CAR to be tested for toxicity in mice and efficacy against mouse and human tumors.

Automated cell cluster analysis provides insight into multi-cell-type interactions between immune cells and their targets.

Understanding interactions between immune cells and their targets is an important step on the path to fully characterizing the immune system, and in doing so, learning how it combats disease. Many studies of these interactions have a narrow focus, often looking only at a binary result of whether or not a specific treatment was successful or only focusing on the interactions between two individual cells. Therefore, in an effort to more comprehensively study multicellular interactions among immune cells and their targets, we used in vitro longitudinal time-lapse imaging and developed an automated cell cluster analysis tool, or macro, to investigate the formation of cell clusters. In particular, we investigated the behavior of cancer-specific CD8+ and CD4+ T cells on how they interact around their targets: cancer cells and antigen-presenting cells. The macro that we established allowed us to examine these large-scale clustering behaviors taking place between those four cell types. Thus, we were able to distinguish directed immune cell clustering from random cell movement. Furthermore, this macro can be generalized to be applicable to systems consisting of any number of differently labeled species and can be used to track clustering behaviors and compare them to randomized simulations.

Cooperation of genes in HPV16 E6/E7-dependent cervicovaginal carcinogenesis trackable by endoscopy and independent of exogenous estrogens or carcinogens.

Human papillomavirus (HPV) infection is necessary but insufficient for progression of epithelial cells from dysplasia to carcinoma-in situ (CIS) to invasive cancer. The combination of mutant cellular and viral oncogenes that regulate progression of cervical cancer (CC) remains unclear. Using combinations of HPV16 E6/E7 (E+), mutant Kras (mKras) (K+) and/or loss of Pten (P-/-), we generated autochthonous models of CC without exogenous estrogen, carcinogen or promoters. Furthermore, intravaginal instillation of adenoCre virus enabled focal activation of the oncogenes/inactivation of the tumor suppressor gene. In P+/+ mice, E6/E7 alone (P+/+E+K-) failed to cause premalignant changes, while mKras alone (P+/+E-K+) caused persistent mucosal abnormalities in about one-third of mice, but no cancers. To develop cancer, P+/+ mice needed both E6/E7 and mKras expression. Longitudinal endoscopies of P+/+E+K+ mice predicted carcinoma development by detection of mucosal lesions, found on an average of 23 weeks prior to death, unlike longitudinal quantitative PCRs of vaginal lavage samples from the same mice. Endoscopy revealed that individual mice differed widely in the time required for mucosal lesions to appear after adenoCre and in the time required for these lesions to progress to cancer. These cancers developed in the transition zone that extends, unlike in women, from the murine cervix to the distal vagina. The P-/-E+K+ genotype led to precipitous cancer development within a few weeks and E6/E7-independent cancer development occurred in the P-/-E-K+ genotype. In the P-/-E+K- genotype, mice only developed CIS. Thus, distinct combinations of viral and cellular oncogenes are involved in distinct steps in cervical carcinogenesis.

An analysis of missing items in real-world electronic patient reported outcomes data: implications for clinical care.

PURPOSE: Utilization of electronic patient-reported outcomes (ePROs) in the clinic can improve quality of life and prolong survival in cancer care. However, there remain unanswered questions regarding trends in missing data and the potential effect on real-time patient care. METHODS: This study utilized a prospectively collected dataset of ePROs from oncology clinics that administered the Patient Care Monitor 2.0 (PCM), a validated symptoms survey assessing 78 items for men, and 86 for women. We tabulated the frequency of missing items, by item and domain (emotional, functional and physical symptom-related), and examined these by age, gender, education, race and marital status. RESULTS: Within 20,986 encounters, there were responses to at least 1 PCM item from 6933 unique patients. The highest frequency of missing answers occurred for: "attend a paid job" (10.7%), "reduced sexual enjoyment" (3.8%), and "run" (3.7%). By domain, 12.3% of functional, 8.4% of physical symptom-related, and 1.6% of emotional constructs contained at least one missing item. For functional and physical symptom-related items, missingness was most common in patients >60 years old. CONCLUSION: The frequency of missingness was highest for functional items, like attending a paid job, suggesting that some respondents (e.g., retirees without a paid job) skipped questions that were less applicable to them. More universal issues for cancer patients, such as emotional well-being, had much lower frequencies of missingness. This suggests differential item completion that warrants further study to understand the inherent drivers. Identifying causes of missingness could improve the clinical utility of ePROs and highlight opportunities to personalize care.

Impact of TCR Diversity on the Development of Transplanted or Chemically Induced Tumors.

Burnet postulated that the diversity of T-cell receptors (TCR) allows T cells to protect against the development of cancers that display antigens with a similar, seemingly endless diversity. To test this hypothesis, we developed a strategy in which a single breeding pair of mice gives rise to four groups of sibling mice. Three of the four groups had a similar number of CD8+ T cells, but TCR diversity was either broad, significantly reduced, or absent when expressing only one type of TCR. The fourth group had no T cells. All mice shared the same housing, and, therefore, their microbial environment was similar. Only slight differences in the intestinal flora were observed under these conditions. An undisturbed broad TCR repertoire was required for the rejection of inoculated cancers displaying the natural antigenic heterogeneity of primary tumors, whereas even one type of TCR was sufficient to protect against artificial cancers stably expressing cognate antigens. The three groups of mice with limited or no TCR repertoire showed an increased risk of developing primary tumors after chemical induction. However, the risk of early death or morbidity in these cohorts of mice was significantly higher than in mice with a diverse TCR repertoire, and it remains unknown whether mice with reduced TCR diversity, who died early without cancer, would have developed tumors with higher, lower, or equal probability after induction. Together, TCR diversity seems crucial to overcome the natural genetic instability of cancers and their antigenic heterogeneity, which impacts the design of cellular therapies.

Prevalence and Predictors of Burnout Among Hospice and Palliative Care Clinicians in the U.S.

CONTEXT: Many clinical disciplines report high rates of burnout, which leads to low quality of care. Palliative care clinicians routinely manage patients with significant suffering, aiming to improve quality of life. As a major role of palliative care clinicians involves educating patients and caregivers regarding identifying priorities and balancing stress, we wondered how clinician self-management of burnout matches against the emotionally exhaustive nature of the work. OBJECTIVES: We sought to understand the prevalence and predictors of burnout using a discipline-wide survey. METHODS: We asked American Academy of Hospice and Palliative Medicine clinician members to complete an electronic survey querying demographic factors, job responsibilities, and the Maslach Burnout Inventory. We performed univariate and multivariable regression analyses to identify predictors of high rates of burnout. RESULTS: We received 1357 responses (response rate 30%). Overall, we observed a burnout rate of 38.7%, with higher rates reported by nonphysician clinicians. Most burnout stemmed from emotional exhaustion, with depersonalization comprising a minor portion. Factors associated with higher odds of burnout include nonphysician clinical roles, working in smaller organizations, working longer hours, being younger than 50 years of age, and working weekends. We did not observe different rates between palliative care clinicians and hospice clinicians. Higher rated self-management activities to mitigate burnout include participating in interpersonal relationships and taking vacations. CONCLUSION: Burnout is a major issue facing the palliative care clinician workforce. Strategies at the discipline-wide and individual levels are needed to sustain the delivery of responsive, available, high-quality palliative care for all patients with serious illness.

Multiple cancer-specific antigens are targeted by a chimeric antigen receptor on a single cancer cell.

Human cancer cells were eradicated by adoptive transfer of T cells transduced with a chimeric antigen receptor (CAR) made from an antibody (237Ab) that is highly specific for the murine Tn-glycosylated podoplanin (Tn-PDPN). The objectives were to determine the specificity of these CAR-transduced T (CART) cells and the mechanism for the absence of relapse. We show that although the 237Ab bound only to cell lines expressing murine Tn-PDPN, the 237Ab-derived 237CART cells lysed multiple different human and murine cancers not predicted by the 237Ab binding. Nevertheless, the 237CART cell reactivities remained cancer specific because all recognitions were dependent on the Tn glycosylation that resulted from COSMC mutations that were not present in normal tissues. While Tn was required for the recognition by 237CART, Tn alone was not sufficient for 237CART cell activation. Activation of 237CART cells required peptide backbone recognition but tolerated substitutions of up to 5 of the 7 amino acid residues in the motif recognized by 237Ab. Together, these findings demonstrate what we believe is a new principle whereby simultaneous recognition of multiple independent Tn-glycopeptide antigens on a cancer cell makes tumor escape due to antigen loss unlikely.

Policy Changes Key To Promoting Sustainability And Growth Of The Specialty Palliative Care Workforce.

Specialized palliative care teams improve outcomes for the steadily growing population of people living with serious illness. However, few studies have examined whether the specialty palliative care workforce can meet the growing demand for its services. We used 2018 clinician survey data to model risk factors associated with palliative care clinicians leaving the field early, and we then projected physician numbers from 2019 to 2059 under four scenarios. Our modeling revealed an impending "workforce valley," with declining physician numbers that will not recover to the current level until 2045, absent policy change. However, sustained growth in the number of fellowship positions over ten years could reverse the worsening workforce shortage. There is an immediate need for policies that support high-value, team-based palliative care through expansion in all segments of the specialty palliative care workforce, combined with payment reform to encourage the deployment of sustainable teams.

Characteristics and Trends Among Patients With Cardiovascular Disease Referred to Palliative Care.

Importance: Use of palliative care (PC) for patients with cardiovascular disease (CVD) has increased recently. However, it is unknown if patients are receiving earlier referrals to PC. Objective: To assess characteristics and trends of patients with CVD referred to PC. Design, Setting, and Participants: Cohort study in which analysis of data from the multicenter Quality Data Collection Tool for Palliative Care registry from January 2, 2015, through December 29, 2017, included patients with CVD 18 years or older referred to initial PC consultation who had a documented palliative performance score (PPS) . Exposures: Patients with CVD who presented for an initial PC visit. Main Outcomes and Measures: The primary outcome was PPS. Secondary outcomes included symptoms and end-of-life documentation. Results: Among 1801 patients (mean [SD] age, 77.7 [13.7] years) from 16 sites in the analysis, 875 (48.6%) were women and 1339 (74.3%) were white. A low PPS score (0%-30%), consistent with bedbound status, was recorded for 521 patients (28.9%), with no change through time. The most common moderate to severe symptoms were poor well-being, tiredness, anorexia, and dyspnea. Year of encounter was associated with improved symptoms of pain (odds ratio, 1.25; 95% CI, 1.05-1.50) and with constipation (odds ratio, 1.32; 95% CI, 1.03-1.69). No change through time was noted in other symptoms or end-of-life documentation. Although the proportion of referrals from general medicine increased from 43.2% (167 of 387) in 2015 to 52.9% (410 of 775) in 2017, the proportion of referrals from cardiologists decreased from 16.5% (64 of 387) in 2015 to 10.5% (81 of 775) in 2017. The proportion of patients referred to PC who were black decreased from 11.9% (46 of 387) in 2015 to 6.3% (49 of 775) in 2017. While 69.5% of all patients with CVD (1252 of 1801) had a primary diagnosis of heart failure, the proportion of non-heart failure CVD diagnoses, such as coronary artery disease and valvular heart disease, increased from 25.6% (99 of 387) in 2015 to 30.1% (233 of 775) in 2017. Conclusions and Relevance: Patients with CVD demonstrated significant symptom burden, and there was no evidence in the registry of change in the PPSs of patients with CVD referred to PC through time. Cardiologists provided comparatively fewer referrals to PC for patients with CVD, and this proportion decreased through time. The proportion of racial and ethnic minorities referred to PC was small and decreased through time. These findings reinforce the need for cardiologists to be more engaged with PC and consider referring appropriate patients with CVD sooner.

Pruritus in patients with solid tumors: an overlooked supportive care need.

PURPOSE: Pruritus is a common symptom in cutaneous malignancies, but its impact on patients with solid tumors is unclear. We explored the impact and management of pruritus in patients with solid tumors, using patient-reported outcomes (PRO) data from a real-world registry. METHODS: From 2006 to 2011, patients seen in the Duke Cancer Institute reported their symptoms via the Patient Care Monitor v2.0, a validated PRO tool that includes a 0-10-point question about pruritus severity. From > 25,000 encounters, 203 patients reported severe pruritus (> 6/10) on at least one visit and 506 total visits were abstracted where patients reported either moderate or severe pruritus (> 3/10). From this cohort, we abstracted demographics, diagnosis, stage, cancer therapy, anti-pruritic therapy, and clinicians' responses. RESULTS: Mean age was 59.8 (SD 13.3), 134 (66%) were female, 125 (62%) were Caucasian, and 65 (32%) were African American. Breast cancer was the most common tumor (36.5%), followed by lung cancer (23.2%). Mean pruritus severity score was 6.8 (SD 1.8) for patients on chemotherapy, 6.9 (SD 1.8) for patients on targeted therapy alone or in combination, and 7.1(SD 1.8) for patients off treatment. Overall, 67% of patients reported at least two episodes of moderate-severe pruritus (mean # of visits 4.2 (SD 2.7)). Despite frequent report of severe and persistent pruritus, this was mentioned in just 28% of clinician notes and an intervention was recommended/prescribed in only 7% of visits. CONCLUSIONS: Pruritus is an under-addressed symptom in patients with solid tumors. Additional research is needed to understand the burden of pruritus in affected populations.

Comparing the Palliative Care Needs of Patients With Hematologic and Solid Malignancies.

CONTEXT: Hematologic cancer patients use palliative care services less frequently than their solid tumor counterparts. Prior work suggests that these patients have a sizable symptom burden, but comparisons between hematologic and solid tumor patients near the end of life are limited. OBJECTIVES: To compare unmet symptom needs in a cohort of hematologic and solid tumor patients referred to specialty palliative care services. METHODS: Using a novel data registry of initial palliative care encounters, we performed a cross-sectional analysis of cancer patients receiving care across 17 sites within the Global Palliative Care Quality Alliance. We compared clinically-significant symptoms (rated as four or greater in severity) between hematologic and solid tumor patients and performed multivariate logistic regression analyses examining the relationship between symptom burden and tumor type. RESULTS: We identified 1235 cancer patients, 108 of which had hematologic malignancies. Pain, dyspnea, nausea, and anorexia burden were as high among patients with hematologic as those with solid malignancies. Blood cancer patients had higher rates of clinically-significant tiredness (51% vs. 42%; P = 0.03) than solid tumor patients. Finally, blood cancer patients had greater odds of being tired (odds ratio 2.19; CI 1.22-3.91) and drowsy (odds ratio 1.81; CI 1.07-3.07) than solid tumor patients independent of age, gender, race, and performance status. CONCLUSIONS: Hematologic and solid tumor patients have significant symptom burden at time of referral to palliative care services. Blood cancer patients may have unique concerns warranting targeted attention, including substantial drowsiness and tiredness. Our findings suggest a need to optimize palliative care usage in the hematologic cancer population.