Use of Endpoints in Phase III Randomized Controlled Trials for Hematopoietic Stem Cell Transplantation Over the Last 15 Years: A Systematic Review.

This systematic review aimed to evaluate the proportion of primary and secondary endpoints in hematopoietic stem cell transplant (HSCT) phase III randomized clinical trials (RCTs) and analyze their trends in time and study sponsorship status. The Chi-square test and logistic regression analyses were performed using SPSS version 28. A total of 147 HSCT phase III RCTs from 2006 to 2021 reported 197 primary and 600 secondary endpoints. Overall survival (OS, 17 %), progression-free survival (PFS, 15 %), graft versus host disease (GVHD, 8 %), event-free survival (EFS, 8 %), and organ function (8 %) were the most common primary endpoints. GVHD (12.3 %, n = 74), safety/toxicity/adverse events (11.8 %, n = 71), OS (11.5 %, n = 69), PFS (9.3 %, n = 56), and relapse rate (RR; 7.5 %, n = 45) were the most common secondary endpoints during 2006-2021. After 2013, an increase was noted in the use of PFS as a primary endpoint (12 %-18 %, p = 0.196), while the use of OS as a primary endpoint declined (20 %-13 %, p = 0.170). An increase was observed in using the secondary endpoints RR (5 %-10 %, p = 0.047) and NRM (3 %-6 %, p = 0.047). EFS was used more (14 % vs. 4 %, p = 0.012) than ORR (11 % vs. 2 %, p = 0.003) as a primary endpoint in pharmaceutical-compared to non-pharmaceutical-sponsored studies. As secondary endpoints, the use of EFS (4 % vs. 1 %, p = 0.013) and ORR (4 % vs. 1 %, p = 0.028) was higher, whereas that of organ systems/functions (1.5 % vs. 5.5 %, p = 0.022) and GVHD (6.5 % vs. 15 %, p = 0.002) was lower in pharmaceutical-compared to non-pharmaceutical sponsored studies. GVHD-free relapse-free survival was reported as a primary endpoint in 2 % of studies, while only 5 % reported quality of life as a secondary endpoint. We described commonly used endpoints in HSCT phase III RCTs and patterns in their use over time by funding source and study intervention category.

Outcomes with allogeneic hematopoietic stem cell transplantation in TP53-mutated myelodysplastic syndrome: A systematic review and meta-analysis.

We conducted a systematic review and meta-analysis to evaluate outcomes after allogeneic hematopoietic stem cell transplantation (Allo-HSCT) in TP53-mutated myelodysplastic syndromes (MDS). A literature search was performed on PubMed, Cochrane, Embase, and Clinicaltrials.gov. After screening 626 articles, eight studies were included. Data were extracted following the PRISMA guidelines and analyzed using the meta-package by Schwarzer et al. We analyzed 540 patients. The pooled median 3 (1-5) year overall survival was 21% (95% CI 0.08-0.37, I2=91%, n=540). The pooled relapse rate was 58.9% (95% CI 0.38-0.77, I2=93%, n=487) at a median of 1.75 (1-3) years. The pooled 4-year progression- free survival was 34.8% (95% CI 0.15-0.57, I2=72%, n=105). Outcomes of Allo-HSCT for TP53-mutated MDS patients remain poor, with 21% OS at three years; however, Allo-HSCT confers a survival advantage as compared to non-transplant palliative therapies. Our findings suggest the need to explore novel therapeutic agents in prospective clinical trials.

Lessons learned from COVID-19 pandemic: outcomes after SARS-CoV-2 infection in hematopoietic cell transplant and cell therapy recipients.

We investigated the outcomes after Coronavirus disease 2019 (COVID) in hematopoietic cell transplant (HCT) or chimeric antigen receptor-T cell (CART) therapy recipients in a single-centre study including all (n = 261)HCT/CART recipients (allogeneic-HCT 49%, autologous-HCT 40%, CART 11%). The median age was 60 (22-80) years. COVID severity was mild (74%), moderate (11%), and severe/critical (16%) with a mortality rate of 7% and a median duration of infection of 5.7 weeks. Significant predictors of COVID severe disease or mortality included concurrent infection (HR 14.9, 95% CI 2.2-5.6) and immunosuppressive therapy (OR 4.8, 95% CI 1.2-3.4).HCT/CART recipients have a higher risk of mortality with COVID and warrant vigilant interventions.

Outcomes with chimeric antigen receptor t-cell therapy in relapsed or refractory acute myeloid leukemia: a systematic review and meta-analysis.

Background: We conducted a systematic review and meta-analysis to evaluate outcomes following chimeric antigen receptor T cell (CAR-T) therapy in relapsed/refractory acute myeloid leukemia (RR-AML). Methods: We performed a literature search on PubMed, Cochrane Library, and Clinicaltrials.gov. After screening 677 manuscripts, 13 studies were included. Data was extracted following PRISMA guidelines. Pooled analysis was done using the meta-package by Schwarzer et al. Proportions with 95% confidence intervals (CI) were computed. Results: We analyzed 57 patients from 10 clinical trials and 3 case reports. The pooled complete and overall response rates were 49.5% (95% CI 0.18-0.81, I2 =65%) and 65.2% (95% CI 0.36-0.91, I2 =57%). The pooled incidence of cytokine release syndrome, immune-effector cell associated neurotoxicity syndrome, and graft-versus-host disease was estimated as 54.4% (95% CI 0.17-0.90, I2 =77%), 3.9% (95% CI 0.00-0.19, I2 =22%), and 1.6% (95%CI 0.00-0.21, I2 =33%), respectively. Conclusion: CAR-T therapy has demonstrated modest efficacy in RR-AML. Major challenges include heterogeneous disease biology, lack of a unique targetable antigen, and immune exhaustion.

Outcomes of Tyrosine Kinase Inhibitors Maintenance Therapy with or without Allogeneic Hematopoietic Stem Cell Transplantation in Philadelphia Chromosome Positive Acute Lymphoblastic Leukemia in First Complete Remission: A Systematic Review and Meta-Analysis.

We conducted a systematic review and meta-analysis to compare outcomes of tyrosine kinase inhibitor (TKI) maintenance therapy with or without allogeneic hematopoietic stem cell transplantation (HSCT) in Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukemia (ALL) in first remission (CR1). A literature search was performed on PubMed, Cochrane, and Clinical trials.gov. After screening 1720 articles, 12 studies were included. Proportions and odds ratios (OR) with 95% confidence intervals (CI) were computed. I2 provides an estimate of the percentage of variability in results across studies that is due to real differences and not due to chance. Of 1039 patients, 635 (61%) had TKI alone and 404 (39%) patients had HSCT followed by TKI. At 3 years, a trend towards poor overall survival (OS; OR 0.67, 95% CI 0.39-1.15, I2 = 68%), (disease-free survival; OR 0.58, 95% CI 0.26-1.29, I2 = 76%), and higher relapse rate (RR; OR = 2.52, 95% CI = 1.66-3.83, I2 = 26%) was seen with TKI alone compared to HSCT-TKI. Although HSCT followed by TKI maintenance in Ph+ ALL has long been considered standard of care, the introduction of potent third-generation TKIs and bispecific T-cell engagers such as Blinatumomab has significantly improved outcomes while sparing the need for HSCT in newly diagnosed patients.

Use of endpoints in phase III randomized controlled trials for acute myeloid leukemia over the last 15 years: a systematic review.

We systematically evaluated the primary and secondary endpoints used in acute myeloid leukemia (AML) phase III randomized controlled trials (RCTs). We included 238 phase III AML RCTs in the past 15 years that reported 279 primary endpoints and 657 secondary endpoints. Overall survival (OS), progression-free survival (PFS), event-free survival (EFS), and complete remission (CR) were primary endpoints in 120 (43%), 34 (12%), 30 (11%), and 41 (15%) studies, respectively. OS (12.5%), PFS (13.2%), CR (14%), safety (11%), and EFS (9%) were commonly reported secondary endpoints. Among primary endpoints, a higher use of OS (OR 2.03, 95%CI 1.10-3.75, p = 0.023) and lower use of PFS (OR 0.25, 95%CI 0.12-0.52, p < 0.001) was observed from 2014 to 2021 compared to 2006-2013; CR was frequently used in relapsed/refractory compared to frontline RCTs (OR 2.20, 95%CI 1.11-4.38, p = 0.025); EFS was frequently used in frontline compared to relapsed/refractory AML RCTs (OR 10.11, 95%CI 1.34-76.34, p = 0.025). A higher trend in the use of clinically meaningful and objective endpoint of OS over the last 15 years.

Impact of natural killer cells on outcomes after allogeneic hematopoietic stem cell transplantation: A systematic review and meta-analysis.

Background: Natural killer (NK) cells play a vital role in early immune reconstitution following allogeneic hematopoietic stem cell transplantation (HSCT). Methods: A literature search was performed on PubMed, Cochrane, and Clinical trials.gov through April 20, 2022. We included 21 studies reporting data on the impact of NK cells on outcomes after HSCT. Data was extracted following the PRISMA guidelines. Pooled analysis was done using the meta-package (Schwarzer et al.). Proportions with 95% confidence intervals (CI) were computed. Results: We included 1785 patients from 21 studies investigating the impact of NK cell reconstitution post-HSCT (8 studies/1455 patients), stem cell graft NK cell content (4 studies/185 patients), therapeutic NK cell infusions post-HSCT (5 studies/74 patients), and pre-emptive/prophylactic NK cell infusions post-HSCT (4 studies/77 patients). Higher NK cell reconstitution was associated with a better 2-year overall survival (OS) (high: 77%, 95%CI 0.73-0.82 vs low: 55%, 95%CI 0.37-0.72; n=899), however, pooled analysis for relapse rate (RR) or graft versus host disease (GVHD) could not be performed due to insufficient data. Higher graft NK cell content demonstrated a trend towards a better pooled OS (high: 65.2%, 95%CI 0.47-0.81 vs low: 46.5%, 95%CI 0.24-0.70; n=157), lower RR (high: 16.9%, 95%CI 0.10-0.25 vs low: 33%, 95%CI 0.04-0.72; n=157), and lower acute GVHD incidence (high: 27.6%, 95%CI 0.20-0.36 vs low: 49.7%, 95%CI 0.26-0.74; n=157). Therapeutic NK or cytokine-induced killer (CIK) cell infusions for hematologic relapse post-HSCT reported an overall response rate (ORR) and complete response (CR) of 48.9% and 11% with CIK cell infusions and 82.8% and 44.8% with NK cell infusions, respectively. RR, acute GVHD, and chronic GVHD were observed in 55.6% and 51.7%, 34.5% and 20%, and 20.7% and 11.1% of patients with CIK and NK cell infusions, respectively. Pre-emptive donor-derived NK cell infusions to prevent relapse post-HSCT had promising outcomes with 1-year OS of 69%, CR rate of 42%, ORR of 77%, RR of 28%, and acute and chronic GVHD rates of 24.9% and 3.7%, respectively. Conclusion: NK cells have a favorable impact on outcomes after HSCT. The optimal use of NK cell infusions post-HSCT may be in a pre-emptive fashion to prevent disease relapse.

Outcomes with mismatched unrelated donor allogeneic hematopoietic stem cell transplantation in adults: A systematic review and meta-analysis.

Background: Allogeneic hematopoietic stem cell transplantation (HSCT) is a potentially curative therapy for various hematologic disorders. Alternative donor strategies such as mismatched unrelated donors (MMUD) offer the option of HSCT to patients lacking a human leukocyte antigen (HLA)-matched donor. We conducted a systematic review and meta-analysis to evaluate outcomes after MMUD-HSCT. Methods: A literature search was performed on PubMed, Cochrane Library, and ClinicalTrials.gov from the inception date through April 6, 2022. After screening 2477 manuscripts, 19 studies were included. Data was extracted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Pooled analysis was done using the meta-package by Schwarzer et al. Proportions with 95% confidence intervals (CI) were computed. Results: A total of 3336 patients from 19 studies were included. The median age was 52.1 years, and 53% of recipients were males. The graft source was bone marrow in 19% and peripheral blood stem cells in 81% of recipients. The median time to transplant from hematologic diagnosis was 10 (1-247) months. Hematologic diagnoses included myeloid (82.9%), lymphoid (41.1%), and other disorders (3%). The reduced intensity and myeloablative conditioning were used in 65.6% and 32% of recipients, respectively. In-vivo T-cell depletion was performed in 56.7% of the patients. Most patients had one (87.9%) or two (11.4%) antigen HLA-mismatch. The pooled 1-year overall survival (OS) was 63.9% (95% CI 0.57-0.71, n=1426/2706), and the pooled 3-year OS was 42.1% (95% CI 0.34.2-0.50, n=907/2355). The pooled progression-free survival was 46.6% (95% CI 0.39-0.55, n=1295/3253) after a median follow-up of 1.8 (range 1-6) years. The pooled relapse rate was 26.8% (95% CI 0.22-0.32, n=972/3253) after a median follow-up of 2.25 (1-3) years. The pooled incidence of acute (grade II-IV) graft-versus-host disease (GVHD) and chronic GVHD was 36.4% (95% CI 0.31-0.42, n=1131/3030) and 41.2% (95% CI 0.35-0.48, n=1337/3228), respectively. The pooled non-relapse mortality was 22.6% (95% CI 0.17-0.29, n=888/3196) after a median follow-up of 2.6 (1-5) years. Conclusion: MMUD-HSCT has demonstrated favorable outcomes with an acceptable toxicity profile. It represents a promising option in patients lacking an HLA-matched or haploidentical donor and may expand HSCT access to underrepresented racial and ethnic populations.

Outcomes with allogeneic hematopoietic stem cell transplantation in TP53-mutated acute myeloid leukemia: a systematic review and meta-analysis.

We conducted a systematic review and meta-analysis to evaluate outcomes after allogeneic hematopoietic stem cell transplantation (HSCT) in TP53-mutated acute myeloid leukemia (AML). We performed a literature search on PubMed, Embase, Cochrane Library, and ClinicalTrials.gov. After screening 592 manuscripts, eight studies were included. Data were extracted following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Pooled analysis was done using the meta-package by Schwarzer et al. Proportions with 95% confidence intervals (CIs) were computed. We analyzed 297 patients. The median follow-up was 45 (0.9-407.3) months. The pooled 2-year overall survival was 29.7% (95% CI 0.17-0.43, n = 82/248). The pooled relapse rate was 61.4% (95% CI 0.41-0.79, n = 139/247) at a median follow-up time of 2 (0.26-3) years. Three-year progression-free survival and non-relapse mortality were reported by one study as 7.5% and 32.5%, respectively. Outcomes of HSCT for TP53-mutated AML are poor; however, HSCT confers a survival advantage as compared to non-transplant palliative therapies.

Top 100 Cited Articles on Clinical Hematopoietic Stem Cell Transplantation: A Bibliometric Analysis.

We conducted a bibliometric analysis to identify scholarly impact and factors associated with the top 100 cited articles on clinical hematopoietic stem cell transplantation (HSCT). In January 2021, a title-specific search was conducted. Non-HSCT and pre-clinical (in-vitro and animal) studies were excluded. A total of 39,406 records were identified and a list of the top 100 articles was made. Articles included in our study were characterized by the citations received, publication year, topic, study design, authors, h-index, and institutions. Linear regression analyses were performed. The 100 most cited articles were published over 52 years from 1968 to 2020, with a maximum number of articles (n = 40) published in the 1990s decade. Top-100 articles were cited 62,002 times with a median citation count of 465 (range 336-2240). The top-cited articles originated from 12 countries. United States contributed 69 articles. The University of Washington Fred Hutchinson Cancer Center (n = 15) was the leading institution. Blood (n = 32) and New England Journal of Medicine (n = 31) made the greatest contribution, and 52 manuscripts were clinical trials. The first author's H-index significantly correlated with citation count while journal impact factor, years since publication, first author's gender, and the number of authors did not have a significant association with the number of citations. In a multivariate regression model, the first author's h-index (regression coefficient 5.46, 95% confidence interval 2.99 to 7.93, p < 0.001) independently correlated with the citation count. Our study highlights the most influential articles on clinical HSCT and provides valuable insight for future research needs of the specialty.

Outcomes after venetoclax with hypomethylating agents in myelodysplastic syndromes: a systematic review and meta-analysis.

We present a systematic review and meta-analysis to evaluate outcomes after venetoclax (VEN) with hypomethylating agents (HMA) in myelodysplastic syndromes (MDS). We performed a literature search on PubMed, Cochrane Library, EMBASE, and Clinicaltrials.gov. After screening 2004 manuscripts, 16 studies were included. Data was extracted following PRISMA guidelines. Pooled analysis was done using the meta-package by Schwarzer et al. Proportions with 95% confidence intervals (CI) were computed. We analyzed the outcomes of 373 patients from 11 retrospective studies and five phase 1 b clinical trials. Pooled complete response with or without hematological recovery was 60% (95% CI 0.49-0.7, I2= 67%, n = 373). Hematopoietic cell transplantation was performed in 32% of patients (95% CI 0.2-0.46, I2= 62%, n = 187). Overall mortality was 45% (95% CI 0.31-0.59, I2=54%, n = 140). VEN-HMA combination therapy demonstrated promising outcomes in MDS. Prospective randomized data is needed to ascertain the benefit of VEN and its impact in MDS patients.

Gender disparities in the National Institutes of Health funding for hematologic malignancies and cellular therapies.

We investigated gender inequality in the National Institutes of Health (NIH) funding for hematologic malignancies and cellular therapies (HMCT). The data were retrieved from the NIH Research Portfolio Online Reporting Tools (RePORT). In 2018-2019, 1834 grants totaling $799 million were awarded (men 71% vs. women 29%) to 975 principal investigators (PIs), including 680 (70%) male PIs and 295 (30%) female PIs. There was no significant gender difference in the mean grant amount per PI. Male PIs as compared to female PIs had a higher h-index (44 vs 31, p < 0.001), a higher number of publications (159.5 vs 94, p < 0.001), and higher years of active research (26 vs 21, p < 0.001). In multivariate analyses, a higher h-index independently predicted a higher mean grant amount per PI (p = 0.010), and female PIs were independently less likely to have a higher h-index (p < 0.001). Our study shows significant gender disparity in the NIH funding for HMCT research.

Impact of COVID-19 in hematopoietic stem cell transplant recipients: A systematic review and meta-analysis.

BACKGROUND: Hematopoietic stem cell transplant (HSCT) recipients are at increased risk of mortality and morbidity with coronavirus disease 2019 (COVID-19) due to severe immune dysfunction. METHODS: A literature search was performed on PubMed, Cochrane, and Clinical trials.gov from the date of inception to 12/08/2021. We identified 19 original studies reporting data on COVID-19 in HSCT recipients after screening 292 articles. Data were extracted following preferred reporting items for systematic reviews and meta-analysis guidelines. Quality evaluation was done using the National Institutes of Health (NIH) quality assessment tool. Inter-study variance was calculated using Der Simonian-Laird Estimator. Pooled analysis was conducted using MetaXL. A random-effects model was used to estimate the proportions with 95% confidence intervals (CI). RESULTS: Of 6711 patients in 19 studies, 2031 HSCT patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were analyzed. The median age of patients was 56.9 (range 1-81.6) years, and 63% patients were men according to 14 studies. The median time from transplant to SARS-CoV-2 infection for autologous (auto) and allogeneic (allo) HSCT patients was 23.2 (0.33-350.5) months and 16.4 (0.2-292.7) months, respectively. The median follow-up time after COVID-19 diagnosis was 28 (0-262) days. The COVID-19 mortality rate was 19% (95% CI 0.15-0.24, I2  = 76%, n = 373/2031). The pooled mortality rate was 17% (95% CI 0.12-0.24, I2  = 78%, n = 147/904) in auto-HSCT patients and 21% (95% CI 0.16-0.25, I2  = 60%, n = 231/1103) in allo-HSCT patients. CONCLUSIONS: HSCT recipients have a high risk of mortality and clinical complications due to COVID-19. There is a need for ongoing vigilance, masks, and social distancing, vaccination, and aggressive management of SARS-CoV-2 infection in HSCT recipients.

Chronic graft-versus-host disease presenting as acute polymyositis: A case series and systematic review.

Chronic graft-versus-host disease (cGvHD) remains a significant complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Commonly targeted organs are skin, eyes, mouth, gastrointestinal tract, and liver. Muscular involvement and presentation as acute polymyositis (APM) remain a rare manifestation of cGvHD. We present a case series of three patients who presented with APM as a sole presentation of cGvHD and were treated successfully with corticosteroids and ruxolitinib. We also conducted a systematic review including 72 patients to summarize current literature regarding APM associated with cGvHD after allo-HSCT. The estimated incidence of cGvHD-associated APM is up to 3.4%, with a median time to onset of 1.6 years post-allo-HSCT. Most cases (85%) presented with myalgia and progressive bilateral proximal muscle weakness with elevated creatine kinase and/or aldolase. Over half of the patients had a prior history of acute GvHD. Isolated APM presenting without other clinical manifestations of cGvHD was rare. Biopsy of affected muscles usually shows characteristic myonecrosis, which remains the gold standard for diagnosis. Most cases respond to systemic steroids and immunosuppressive therapy. However, refractory cases remain challenging to treat and can cause significant morbidity and mortality. Ruxolitinib appears to be an effective therapy in this setting.

Impact of SARS-CoV-2 in Hematopoietic Stem Cell Transplantation and Chimeric Antigen Receptor T Cell Therapy Recipients.

Coronavirus disease 2019 (COVID-19), a respiratory illness caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic in March 2020, and has caused more than 600,000 deaths in the United States at the time of this report. Hematopoietic stem cell transplantation (HCT) or chimeric antigen receptor T cell (CAR-T) therapy recipients have a higher risk of mortality with COVID-19 owing to profound immune dysregulation. In this study, we investigated the impact of SARS-CoV-2 in HCT/CAR-T therapy recipients. This single-center prospective study included all (n = 58) adult HCT/CAR-T recipients who were diagnosed with COVID-19 at the University of Kansas Medical Center between March 2020 and May 2021. Baseline and disease-related characteristics were ascertained from medical records. Data were analyzed using SPSS version 21 (IBM, Armonk, NY). Bivariate analyses, using the chi-square and t-test, and logistic regression analyses were conducted. The study included 58 HCT/CAR-T patients who acquired SARS-CoV-2 infection, including recipients of allogeneic HCT (n = 32), autologous HCT (n = 23), and CAR-T therapy (n = 3). The median patient age was 58 years (range, 24 to 77 years), and 64% were males. The median time from HCT/CAR-T therapy to SARS-CoV-2 infection was 17.7 months (range, 0.2 to 201.9 months), and 22% of the patients acquired SARS-CoV-2 within the first 100 days post-HCT/CAR-T therapy. The primary hematologic disorders were plasma cell (36%), myeloid (38%), and lymphoid (26%) malignancies. Myeloablative conditioning was performed in 62% of patients. Donors were autologous (45%), matched sibling (15%), matched unrelated (21%), and haploidentical (19%). Prior history of grade II-IV acute graft-versus-host disease (GVHD), active GVHD, and current immunosuppressive therapy (IST) was noted in 22%, 31%, and 36% of patients, respectively. Concurrent infections were observed in 19%. Lymphopenia (P = .049) and high serum ferritin concentration (P = .020) were associated with mortality. COVID-19 severity was mild in 50% of the patients, moderate in 22%, and severe in 28%. Clinical findings included pneumonia or abnormal chest imaging (in 50%), hypoxia (28%), intensive care unit admission (19%), and mechanical ventilation (10%). Therapies included remdesivir (in 41%), convalescent plasma (35%), dexamethasone (22%), monoclonal antibodies (19%), and tocilizumab (3%). The median duration of viral shedding (positive SARS-CoV-2 PCR) was 7.7 weeks (range, 2 to 18.7 weeks), and 2 patients had a persistent infection for >5 months post-CAR-T therapy. After a median follow-up of 6.1 months (range, 0.5-13.6 months), the mortality rate was 16% in all patients and 28% in allogeneic HCT recipients. Among 9 patients who died, the median survival after SARS-CoV-2 infection was 23 days (range, 14 to 140 days). In survivors with moderate-severe COVID-19, the median time to recovery was 4.2 weeks (range, 1.1 to 24.7 weeks). Among allogeneic HCT recipients, 5 (16%) developed subsequent pulmonary chronic GVHD necessitating systemic steroids and additional IST. Significant predictors of COVID-19 severity included allogeneic HCT (odds ratio [OR], 3.6, 95% confidence interval [CI], 1.2 to 10.8; P = .020), history of grade II-IV acute GVHD (OR, 4.6; 95% CI, 1.10 to 18.86; P = .036) and concurrent IST (OR, 5.9; 95% CI, 1.8 to 19.8; P = .004). HCT and CAR-T cell therapy recipients are at an increased risk of moderate-severe COVID-19 pneumonia and higher mortality with SARS-CoV-2 infection. Our findings confirm the need for continuing vigilance with social distancing and masks, vaccination prioritization, close monitoring, and aggressive treatment of HCT/CAR-T therapy recipients.

Outcomes with CD34-Selected Stem Cell Boost for Poor Graft Function after Allogeneic Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis.

Poor graft function (PGF) is a life-threatening complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT) characterized by multilineage cytopenia in the absence of mixed donor chimerism (<95% donor), relapse, or severe graft-versus-host disease (GVHD). We present a systemic review and meta-analysis aimed at assessing the outcomes with CD34-selected stem cell boost (SCB) for PGF in adult allo-HSCT recipients. We screened a total of 1753 records identified from 4 databases (PubMed, Embase, Cochrane, and ClinicalTrials.gov) following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, using the search terms "hematological malignancies," "hematopoietic stem cell transplantation," "CD34 antigen(s)," "graft failure," and "poor graft function," from the date of inception to January 2021. After excluding review, duplicate, and nonrelevant articles, we included 7 studies reporting outcomes following administration of CD34-selected SCB for PGF after allo-HSCT, including hematologic complete response (CR) and overall response rate (ORR), GVHD, and overall survival (OS). Quality evaluation was done using the National Institutes of Health quality assessment tool. Pooled analysis was done using the R 'meta' package, and proportions with 95% confidence intervals (CIs) were computed. The inter-study variance was calculated using the Der Simonian-Laird estimator. We identified 209 patients who received CD34-selected SCB for PGF after allo-HSCT. The median age was 49 years (range, 18 to 69 years), and 61% were men. Primary graft sources included peripheral blood stem cells (72%) and bone marrow (28%). Donor types were matched sibling (37%), matched unrelated (36%), mismatched unrelated (22%), and haploidentical donors (5%). The median time from allo-HSCT to SCB was 138 days (range, 113 to 450 days). The median SCB dose was 3.45 × 106 CD34 cells/kg (range, 3.1 to 4.9 × 106 cells/kg). CR and ORR were 72% (95% CI, 63% to 79%; I2 = 26%) and 80% (95% CI, 74% to 85%; I2 = 0%), respectively. After a median follow-up of 42 months (range, 30 to 77 months), the actuarial survival rate was 54% (95% CI, 47% to 61%; I2 = 0%). OS ranged from 80% at 1 year to 40% at 9 years. The incidences of acute and chronic GVHD after SCB were 17% (95% CI, 13% to 23%; I2 = 0%) and 18% (95% CI, 8% to 34%; I2 = 76%), respectively. Nonrelapse mortality was reported in 42 patients, with a pooled rate of 27% (95% CI, 17% to 40; I2 = 59%), and death due to relapse was reported in 25 patients, with a pooled rate of 17% (95% CI, 11% to 23%; I2 = 0%). Our data show that CD34-selected SCB improves outcomes after PGF post allo-HSCT with an acceptable toxicity profile. The literature lacks high-quality randomized evidence, and there remains an unmet need for prospective studies to address the optimal dosing and manipulation of SCB. © 2021 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Comparison of salvage chemotherapy regimens and prognostic significance of minimal residual disease in relapsed/refractory acute myeloid leukemia.

We compared the outcomes of salvage chemotherapy in 146 patients with relapsed (57.5%) or refractory (42.5%) AML who received CLAG-M (51%), MEC (39%) or CLAG (10%). Minimal residual disease (MRD) was assessed by flow cytometry. Bivariate, Kaplan-Meier, and Cox regression analyses were conducted. Complete remission (CR) rate of 46% (CLAG-M 54% versus MEC/CLAG 40%, p = .045) was observed with MRD-negative CR of 33% (CLAG-M 39% versus MEC/CLAG 22%, p = .042). Median overall survival (OS) was 9.7 months; the longest OS occurred with CLAG-M (13.3, 95%CI 2.4-24.3) versus MEC (6.9, 95%CI 2.9-10.9) or CLAG (6.2, 95%CI 2.4-12.6) (p = .025). When adjusted for age, gender, relapsed/refractory AML, poor risk AML, MRD, chemotherapy and transplant, CLAG-M (HR 0.63, 95% CI 0.40-0.98, p = .042), MRD-negativity (HR 0.15, 95% CI 0.07-0.30, p < .001) and transplant (HR 0.22, 95% CI 0.13-0.39, p < .001) were associated with higher OS. Our findings confirm that CLAG-M is a reasonable salvage regimen for RR-AML followed by transplant.

Tumor matrix remodeling and novel immunotherapies: the promise of matrix-derived immune biomarkers.

Recent advances in our understanding of the dynamics of cellular cross-talk have highlighted the significance of host-versus-tumor effect that can be harnessed with immune therapies. Tumors exploit immune checkpoints to evade adaptive immune responses. Cancer immunotherapy has witnessed a revolution in the past decade with the development of immune checkpoint inhibitors (ICIs), monoclonal antibodies against cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed cell death protein 1 (PD-1) or their ligands, such as PD1 ligand 1 (PD-L1). ICIs have been reported to have activity against a broad range of tumor types, in both solid organ and hematologic malignancy contexts. However, less than one-third of the patients achieve a durable and meaningful treatment response. Expression of immune checkpoint ligands (e.g., PD-L1), mutational burden and tumor-infiltrating lymphocytes are currently used as biomarkers for predicting response to ICIs. However, they do not reliably predict which patients will benefit from these therapies. There is dire need to discover novel biomarkers to predict treatment efficacy and to identify areas for development of combination strategies to improve response rates. Emerging evidence suggests key roles of tumor extracellular matrix (ECM) components and their proteolytic remodeling products in regulating each step of the cancer-immunity cycle. Here we review tumor matrix dynamics and matrix remodeling in context of anti-tumor immune responses and immunotherapy and propose the exploration of matrix-based biomarkers to identify candidates for immune therapy.