High CD34-positive cell dose in matched unrelated donor allogeneic hematopoietic stem cell transplant is not associated with graft-versus-host disease or mortality

BACKGROUND

CD34+ stem cells serve as the primary graft source for allogeneic transplants, with a minimum of 2-4 × 106 cells/kg needed for engraftment. There are conflicting data on outcomes at high stem cell doses, with studies limited by few patients receiving doses far above the minimum target.

STUDY DESIGN AND METHODS

In this retrospective, single-center study of patients with hematologic malignancies who underwent matched unrelated donor transplants, we assessed outcomes for engraftment, survival, relapse, and graft-versus-host disease (GVHD) for the highest CD34+ dose quintile (>13 × 106 cells/kg, n = 36) compared to the remaining patients (n = 139). Similar analysis was performed correlating T cell dose and outcomes.

RESULTS

There was no difference between the groups in neutrophil engraftment, with a trend toward faster platelet engraftment. There was no significant difference in mortality (adjusted risk ratio [aRR] = 1.02, 95% confidence interval [CI] = 0.85-1.22), relapse (aRR = 1.10, 95% CI = 0.85-1.42), or overall survival by Kaplan-Meier analysis (p = .44). High CD34+ dose was not associated with higher incidence of acute GVHD (aRR = 0.99 grades II-IV, aRR = 1.18 grades III-IV) or chronic GVHD (aRR = 0.87 overall, RR = 1.21 severe). There was limited correlation between CD34+ and T cell dose (R2 = .073), and there was no significant difference in survival, relapse, or GVHD in the highest T cell dose quintile (n = 33) compared to the remaining quintiles (n = 132).

DISCUSSION

We found no difference in survival, relapse, or GVHD incidence or severity in patients receiving CD34+ doses above prior cutoffs reported in the literature. These data do not support the routine use of graft CD34+ dose reduction.

Management of isocitrate dehydrogenase 1/2 mutated acute myeloid leukemia

The emergence of next generation sequencing and widespread use of mutational profiling in acute myeloid leukemia (AML) has broadened our understanding of the heterogeneous molecular basis of the disease. Since genetic sequencing has become a standard practice, several driver mutations have been identified. Accordingly, novel targeted therapeutic agents have been developed and are now approved for the treatment of subsets of patients that carry mutations in FLT3, IDH1, and IDH2 [1, 2]. The emergence of these novel agents in AML offers patients a new modality of therapy, and shifts treatment paradigms toward individualized medicine. In this review, we outline the role of IDH mutations in malignant transformation, focus in on a novel group of targeted therapeutic agents directed toward IDH1- and IDH2-mutant AML, and explore their impact on prognosis in patients with AML.

Updated COVID-19 clearance time among patients with cancer in the Delta and Omicron waves

BACKGROUND

COVID-19 infection delays therapy and in-person evaluation for oncology patients, but clinic clearance criteria are not clearly defined.

METHODS

We conducted a retrospective review of oncology patients with COVID-19 at a tertiary care center during the Delta and Omicron waves and compared clearance strategies.

RESULTS

Median clearance by two consecutive negative tests was 32.0 days (Interquartile Range [IQR] 22.0-42.5, n = 153) and was prolonged in hematologic malignancy versus solid tumors (35.0 days for hematologic malignancy, 27.5 days for solid tumors, p = 0.01) and in patients receiving B-cell depletion versus other therapies. Median clearance by single negative test was reduced to 23.0 days (IQR 16.0-33.0), with recurrent positive rate 25.4% in hematologic malignancy versus 10.6% in solid tumors (p = 0.02). Clearance by a predefined waiting period required 41 days until an 80% negative rate.

CONCLUSIONS

COVID-19 clearance remains prolonged in oncology patients. Single-negative test clearance can balance delays in care with risk of infection in patients with solid tumors.

Phase 2 clinical trial evaluating abatacept in patients with steroid-refractory chronic graft-versus-host disease

Steroid-refractory chronic graft-versus-host disease (cGVHD) after allogeneic transplant remains a significant cause of morbidity and mortality. Abatacept is a selective costimulation modulator, used for the treatment of rheumatologic diseases, and was recently the first drug to be approved by the US Food and Drug Administration for the prophylaxis of acute graft-versus-host disease. We conducted a phase 2 study to evaluate the efficacy of abatacept in steroid-refractory cGVHD. The overall response rate was 58%, seen in 21 out of 36 patients, with all responders achieving a partial response. Abatacept was well tolerated with few serious infectious complications. Immune correlative studies showed a decrease in interleukin -1α (IL-1α), IL-21, and tumor necrosis factor α as well as decreased programmed cell death protein 1 expression by CD4+ T cells in all patients after treatment with abatacept, demonstrating the effect of this drug on the immune microenvironment. The results demonstrate that abatacept is a promising therapeutic strategy for the treatment of cGVHD. This trial was registered at www.clinicaltrials.gov as #NCT01954979.

Immunotherapy for the treatment of multiple myeloma

Despite advances in treatment for multiple myeloma, the majority of patients ultimately develop relapsed disease marked by immune evasion and resistance to standard therapy. Immunotherapy has emerged as a powerful tool for tumor-directed cytotoxicity with the unique potential to induce immune memory to reduce the risk of relapse. Understanding the specific mechanisms of immune dysregulation and dysfunction in advanced myeloma is critical to the development of further therapies that produce a durable response. Adoptive cellular therapy, most strikingly CAR T cell therapy, has demonstrated dramatic responses in the setting of refractory disease. Understanding the factors that contribute to immune evasion and the mechanisms of response and resistance to therapy will be critical to developing the next generation of adoptive cellular therapies, informing novel combination therapy, and determining the optimal time to incorporate immune therapy in the treatment of myeloma.

COVID-19 clearance among patients with cancer during the Delta and Omicron waves

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Background: COVID-19 presents a particular challenge in oncology, as in-person visits and treatments can be delayed during infection and patients are at risk for prolonged viral shedding. Our center uses two consecutive negative PCR tests for patients to return to clinic. As vaccination rates increase, we questioned the need for this strategy vs a time-based clearance approach. Methods: We identified cancer patients who tested positive for COVID-19 from 10/1/2021 to 3/31/2022 at a single tertiary care center and performed chart review under an IRB-approved protocol. Subgroups were compared using the Welch’s t-test and Welch’s ANOVA for 2 or > 2 groups, respectively. Results: 169 patients were identified. 153 had documented clearance defined as two consecutive negative PCR tests. The mean clearance time was 35.7 days (95% CI 32.3-39.0). There was a trend toward longer clearance time in patients with hematologic vs solid tumors (39.6 vs 33.2, p =.06) and a significant increase in patients treated with B cell depletion (58.0) vs chemo/targeted therapy (35.7, p =.01) or immunotherapy (29.0, p =.004). No significant difference was found by vaccination status or between the Delta and Omicron waves. If defined as one negative test, mean clearance time was 25.9 days (95% CI 23.6-28.1), and there was a significant difference in patients with hematologic vs solid tumors and in those treated with B cell depletion vs other therapies. However, 16.0% (27/169) of patients had a subsequent positive test after a first negative result, with increased incidence in patients with hematologic malignancy (26.2%, 16/61) and stem cell/adoptive cell transplant (46.2%, 6/13). Conclusions: COVID-19 is a significant barrier to oncologic care, and clearance times remain longer than reported for the general population. In this single center study, clearance time was > 1 month and further increased in patients with hematologic malignancy or on B cell depleting therapy. While adjusting clearance criteria to a single negative test or specific timeframe may be an attractive option to reduce delays, a large proportion of patients may have further positive PCR testing.[Table: see text]

Smoking cessation counseling in patients with active malignancy

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Background: Tobacco smoking increases risk of multiple malignancies, most notably lung cancer, and is a leading cause of premature morbidity and mortality. Tobacco cessation counseling is effective in assisting patients to quit smoking and improving health outcomes, but over one third of smokers report receiving no counseling by healthcare providers. In this study, we investigated rates of tobacco cessation education at ambulatory visits among patients with active malignancy. Methods: We identified ambulatory visits among current smokers with a diagnosis of malignancy using the National Ambulatory Medical Care Survey (NAMCS), a nationally representative sample of ambulatory visits in the US, from 2008 to 2018. We first determined weighted rates of documented smoking cessation counseling. We next evaluated sociodemographic characteristics, provider and visit type, and chronic conditions as determinants of counseling in this population using logistic regression. Results: We identified 2,437 total visits during the study period, representing an estimated 48.9 million such visits in the US. In this cohort, smoking cessation counseling was provided at 14.2% (95% confidence interval [CI] 12.1-16.7%) of visits. Patients were significantly less likely to receive counseling with older age (adjusted OR 0.97 per year of age; 95% CI 0.96-0.98) and less likely in surgical (OR 0.49; 95% CI 0.32-0.75) or medical subspecialties (OR 0.60; 95% CI 0.36-0.99) compared to primary care visits. Sex, race, year of visit, insurance type, and previous visit to the same provider were not significantly related to receipt of counseling. Patients with concomitant COPD were substantially more likely to receive counseling (OR 3.50; 95% CI 2.21-5.53), with 28.4% (95% CI 21.5-36.4%) of such visits including tobacco cessation education. Conclusions: Tobacco smoking is a modifiable risk factor associated with multiple malignancies and substantial non-neoplastic morbidity and mortality. Nonetheless, smokers with current malignancy receive smoking cessation counseling at only about one in seven outpatient visits, with lower frequency with advanced age and at subspecialty visits. As more effective treatments improve survival for cancer patients, further work is needed to improve tobacco cessation efforts that could improve survival and quality of life.[Table: see text]

Development of a 2-dimensional atlas of the human kidney with imaging mass cytometry

An incomplete understanding of the biology of the human kidney, including the relative abundances of and interactions between intrinsic and immune cells, has long constrained the development of therapies for kidney disease. The small amount of tissue obtained by renal biopsy has previously limited the ability to use patient samples for discovery purposes. Imaging mass cytometry (IMC) is an ideal technology for quantitative interrogation of scarce samples, permitting concurrent analysis of more than 40 markers on a single tissue section. Using a validated panel of metal-conjugated antibodies designed to confer unique signatures on the structural and infiltrating cells comprising the human kidney, we performed simultaneous multiplexed imaging with IMC in 23 channels on 16 histopathologically normal human samples. We devised a machine-learning pipeline (Kidney-MAPPS) to perform single-cell segmentation, phenotyping, and quantification, thus creating a spatially preserved quantitative atlas of the normal human kidney. These data define selected baseline renal cell types, respective numbers, organization, and variability. We demonstrate the utility of IMC coupled to Kidney-MAPPS to qualitatively and quantitatively distinguish individual cell types and reveal expected as well as potentially novel abnormalities in diseased versus normal tissue. Our studies define a critical baseline data set for future quantitative analysis of human kidney disease.