Innovations in conditioning and post-transplant maintenance in AML: genomically informed revelations on the graft-versus-leukemia effect.

Acute Myeloid Leukemia (AML) is the prototype of cancer genomics as it was the first published cancer genome. Large-scale next generation/massively parallel sequencing efforts have identified recurrent alterations that inform prognosis and have guided the development of targeted therapies. Despite changes in the frontline and relapsed standard of care stemming from the success of small molecules targeting FLT3, IDH1/2, and apoptotic pathways, allogeneic stem cell transplantation (alloHSCT) and the resulting graft-versus-leukemia (GVL) effect remains the only curative path for most patients. Advances in conditioning regimens, graft-vs-host disease prophylaxis, anti-infective agents, and supportive care have made this modality feasible, reducing transplant related mortality even among patients with advanced age or medical comorbidities. As such, relapse has emerged now as the most common cause of transplant failure. Relapse may occur after alloHSCT because residual disease clones persist after transplant, and develop immune escape from GVL, or such clones may proliferate rapidly early after alloHSCT, and outpace donor immune reconstitution, leading to relapse before any GVL effect could set in. To address this issue, genomically informed therapies are increasingly being incorporated into pre-transplant conditioning, or as post-transplant maintenance or pre-emptive therapy in the setting of mixed/falling donor chimerism or persistent detectable measurable residual disease (MRD). There is an urgent need to better understand how these emerging therapies modulate the two sides of the GVHD vs. GVL coin: 1) how molecularly or immunologically targeted therapies affect engraftment, GVHD potential, and function of the donor graft and 2) how these therapies affect the immunogenicity and sensitivity of leukemic clones to the GVL effect. By maximizing the synergistic action of molecularly targeted agents, immunomodulating agents, conventional chemotherapy, and the GVL effect, there is hope for improving outcomes for patients with this often-devastating disease.

Prophylactic maintenance with venetoclax/azacitidine after reduced-intensity conditioning allogeneic transplant for high-risk MDS and AML.

ABSTRACT: We conducted a phase 1 trial assessing safety and efficacy of prophylactic maintenance therapy with venetoclax and azacitidine (Ven/Aza) for patients with high-risk myelodysplastic syndromes (MDS)/acute myeloid leukemia (AML) undergoing reduced intensity allogeneic stem cell transplantation (allo-SCT) after Ven and fludarabine/busulfan conditioning (Ven/FluBu2 allo-SCT) with tacrolimus and methotrexate as graft-versus-host disease (GVHD) prophylaxis. Among 27 patients who underwent Ven/FluBu2 allo-SCT (55.6% with prior Ven exposure, and 96% with positive molecular measurable residual disease), 22 received maintenance therapy with Aza 36 mg/m2 intravenously on days 1 to 5, and Ven 400 mg by mouth on days 1 to 14 per assigned dose schedule/level (42-day cycles × 8, or 28-day cycles × 12). During maintenance, the most common grade 3-4 adverse events were leukopenia, neutropenia, and thrombocytopenia, which were transient and manageable. Infections were uncommon (n = 4, all grade 1-2). The 1-year and 2-year moderate/severe chronic GVHD rates were 4% (95% confidence interval [CI], 0.3%-18%) and 22% (95% CI, 9%-40%), respectively. After a median follow-up of 25 months among survivors, the median overall survival (OS) was not reached. Among the 22 patients who received Ven/Aza maintenance, the 2-year OS, progression-free survival, nonrelapse mortality, and cumulative incidence of relapse rates were 67% (95% CI, 43%-83%), 59% (95% CI, 36%-76%), 0%, and 41% (95% CI, 20%-61%), respectively. Immune monitoring demonstrated no significant impact on T-cell expansion but identified reduced B-cell expansion compared with controls. This study demonstrates prophylactic Ven/Aza maintenance can be safely administered for patients with high-risk MDS/AML, but a randomized study is required to properly assess any potential benefit. This trial was registered at www.clinicaltrials.gov as #NCT03613532.

Operationalizing inclusion: moving from an elusive goal to strategic action.

To mitigate the structural and institutional biases that contribute to inequities in health, we need a diverse cadre of individuals to feel included and advance within our field in order to bring a multicultural set of perspectives to the studies we conduct, the science we generate, the health and academic systems we design, and the medical and scientific knowledge we impart. There has been increasing focus on diversity, inclusion, and equity in recent years; however, often these terms are presented without adequate precision and, therefore, the inability to effectively operationalize inclusion and achieve diversity within organizations. This narrative review details several key studies, with the primary objective of presenting a roadmap to guide defining, measuring, and operationalizing inclusion within work and learning environments.

Development of a student-created internal medicine frameworks website for healthcare trainees.

OBJECTIVES: Describe medical student perspectives on framework learning and develop a free, online, mobile-friendly framework website. METHODS: Internal medicine clerkship students were surveyed at a single U.S. medical school regarding how they learn frameworks. We used Draw.io to create frameworks, which were edited by expert clinicians. Frameworks were hosted online through an academic server, and Google analytics was used to track website activity. RESULTS: Most medical students report learning frameworks from attending clinicians. We developed 87 frameworks on the "Penn Frameworks'' website, which was visited by 9,539 unique users from 124 countries over three years. CONCLUSIONS: Most medical students perceive that they learn frameworks during clinical rotations from attending clinicians. We found that it is feasible to develop a low-cost, expert-curated, mobile-friendly resource to supplement in-person learning.

Allelic complexity of KMT2A partial tandem duplications in acute myeloid leukemia and myelodysplastic syndromes.

KMT2A partial tandem duplication (KMT2A-PTD) is an adverse risk factor in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), a potential therapeutic target, and an attractive marker of measurable residual disease. High initial KMT2A-PTD RNA levels have been linked to poor prognosis, but mechanisms regulating KMT2A-PTD expression are not well understood. Although KMT2A-PTD has been reported to affect only a single allele, it has been theorized but not proven that genomic gains of a monoallelic KMT2A-PTD may occur, thereby potentially driving high expression and disease progression. In this study, we identified 94 patients with KMT2A-PTDs using targeted DNA next-generation sequencing (NGS) and found that 16% (15/94) had complex secondary events, including copy-neutral loss of heterozygosity and selective gain involving the KMT2A-PTD allele. High copy numbers indicating complexity were significantly enriched in AML vs MDS and correlated with higher RNA expression. Moreover, in serial samples, complexity was associated with relapse and secondary transformation. Taken together, we provide approaches to integrate quantitative and allelic assessment of KMT2A-PTDs into targeted DNA NGS and demonstrate that secondary genetic events occur in KMT2A-PTD by multiple mechanisms that may be linked to myeloid disease progression by driving increased expression from the affected allele.

Impact of diagnostic genetics on remission MRD and transplantation outcomes in older patients with AML.

Older patients with acute myeloid leukemia (AML) have high relapse risk and poor survival after allogeneic hematopoietic cell transplantation (HCT). Younger patients may receive myeloablative conditioning to mitigate relapse risk associated with high-risk genetics or measurable residual disease (MRD), but older adults typically receive reduced-intensity conditioning (RIC) to limit toxicity. To identify factors that drive HCT outcomes in older patients, we performed targeted mutational analysis (variant allele fraction ≥2%) on diagnostic samples from 295 patients with AML aged ≥60 years who underwent HCT in first complete remission, 91% of whom received RIC, and targeted duplex sequencing at remission in a subset comprising 192 patients. In a multivariable model for leukemia-free survival (LFS) including baseline genetic and clinical variables, we defined patients with low (3-year LFS, 85%), intermediate (55%), high (35%), and very high (7%) risk. Before HCT, 79.7% of patients had persistent baseline mutations, including 18.3% with only DNMT3A or TET2 (DT) mutations and 61.4% with other mutations (MRD positive). In univariable analysis, MRD positivity was associated with increased relapse and inferior LFS, compared with DT and MRD-negative mutations. However, in a multivariable model accounting for baseline risk, MRD positivity had no independent impact on LFS, most likely because of its significant association with diagnostic genetic characteristics, including MDS-associated gene mutations, TP53 mutations, and high-risk karyotype. In summary, molecular associations with MRD positivity and transplant outcomes in older patients with AML are driven primarily by baseline genetics, not by mutations present in remission. In this group of patients, where high-intensity conditioning carries substantial risk of toxicity, alternative approaches to mitigating MRD-associated relapse risk are needed.

BCOR and BCORL1 Mutations Drive Epigenetic Reprogramming and Oncogenic Signaling by Unlinking PRC1.1 from Target Genes.

Polycomb repressive epigenetic complexes are recurrently dysregulated in cancer. Unlike polycomb repressive complex 2 (PRC2), the role of PRC1 in oncogenesis and therapy resistance is not well-defined. Here, we demonstrate that highly recurrent mutations of the PRC1 subunits BCOR and BCORL1 in leukemia disrupt assembly of a noncanonical PRC1.1 complex, thereby selectively unlinking the RING-PCGF enzymatic core from the chromatin-targeting auxiliary subcomplex. As a result, BCOR-mutated PRC1.1 is localized to chromatin but lacks repressive activity, leading to epigenetic reprogramming and transcriptional activation at target loci. We define a set of functional targets that drive aberrant oncogenic signaling programs in PRC1.1-mutated cells and primary patient samples. Activation of these PRC1.1 targets in BCOR-mutated cells confers acquired resistance to treatment while sensitizing to targeted kinase inhibition. Our study thus reveals a novel epigenetic mechanism that explains PRC1.1 tumor-suppressive activity and identifies a therapeutic strategy in PRC1.1-mutated cancer. SIGNIFICANCE: We demonstrate that BCOR and BCORL1 mutations in leukemia unlink PRC1.1 repressive function from target genes, resulting in epigenetic reprogramming and activation of aberrant cell signaling programs that mediate treatment resistance. Our study provides mechanistic insights into the pathogenesis of PRC1.1-mutated leukemia that inform novel therapeutic approaches. This article is highlighted in the In This Issue feature, p. 85.

Donor Clonal Hematopoiesis and Recipient Outcomes After Transplantation.

PURPOSE: Clonal hematopoiesis (CH) can be transmitted from a donor to a recipient during allogeneic hematopoietic cell transplantation. Exclusion of candidate donors with CH is controversial since its impact on recipient outcomes and graft alloimmune function is uncertain. PATIENTS AND METHODS: We performed targeted error-corrected sequencing on samples from 1,727 donors age 40 years or older and assessed the effect of donor CH on recipient clinical outcomes. We measured long-term engraftment of 102 donor clones and cytokine levels in 256 recipients at 3 and 12 months after transplant. RESULTS: CH was present in 22.5% of donors, with DNMT3A (14.6%) and TET2 (5.2%) mutations being most common; 85% of donor clones showed long-term engraftment in recipients after transplantation, including clones with a variant allele fraction < 0.01. DNMT3A-CH with a variant allele fraction ≥ 0.01, but not smaller clones, was associated with improved recipient overall (hazard ratio [HR], 0.79; P = .042) and progression-free survival (HR, 0.72; P = .003) after adjustment for significant clinical variables. In patients who received calcineurin-based graft-versus-host disease prophylaxis, donor DNMT3A-CH was associated with reduced relapse (subdistribution HR, 0.59; P = .014), increased chronic graft-versus-host disease (subdistribution HR, 1.36; P = .042), and higher interleukin-12p70 levels in recipients. No recipient of sole DNMT3A or TET2-CH developed donor cell leukemia (DCL). In seven of eight cases, DCL evolved from donor CH with rare TP53 or splicing factor mutations or from donors carrying germline DDX41 mutations. CONCLUSION: Donor CH is closely associated with clinical outcomes in transplant recipients, with differential impact on graft alloimmune function and potential for leukemic transformation related to mutated gene and somatic clonal abundance. Donor DNMT3A-CH is associated with improved recipient survival because of reduced relapse risk and with an augmented network of inflammatory cytokines in recipients. Risk of DCL in allogeneic hematopoietic cell transplantation is driven by somatic myelodysplastic syndrome-associated mutations or germline predisposition in donors.

Adding venetoclax to fludarabine/busulfan RIC transplant for high-risk MDS and AML is feasible, safe, and active.

Adding the selective BCL-2 inhibitor venetoclax to reduced-intensity conditioning chemotherapy (fludarabine and busulfan [FluBu2]) may enhance antileukemic cytotoxicity and thereby reduce the risk of posttransplant relapse. This phase 1 study investigated the recommended phase 2 dose (RP2D) of venetoclax, a BCL-2 selective inhibitor, when added to FluBu2 in adult patients with high-risk acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), and MDS/myeloproliferative neoplasms (MPN) undergoing transplant. Patients received dose-escalated venetoclax (200-400 mg daily starting day -8 for 6-7 doses) in combination with fludarabine 30 mg/m2 per day for 4 doses and busulfan 0.8 mg/kg twice daily for 8 doses on day -5 to day -2 (FluBu2). Transplant related-toxicity was evaluated from the first venetoclax dose on day -8 to day 28. Twenty-two patients were treated. At study entry, 5 patients with MDS and MDS/MPN had 5% to 10% marrow blasts, and 18 (82%) of 22 had a persistent detectable mutation. Grade 3 adverse events included mucositis, diarrhea, and liver transaminitis (n = 3 each). Neutrophil/platelet recovery and acute/chronic graft-versus-host-disease rates were similar to those of standard FluBu2. No dose-limiting toxicities were observed. The RP2D of venetoclax was 400 mg daily for 7 doses. With a median follow-up of 14.7 months (range, 8.6-24.8 months), median overall survival was not reached, and progression-free survival was 12.2 months (95% confidence interval, 6.0-not estimable). In patients with high-risk AML, MDS, and MDS/MPN, adding venetoclax to FluBu2 was feasible and safe. To further address relapse risk, assessment of maintenance therapy after venetoclax plus FluBu2 transplant is ongoing. This study was registered at clinicaltrials.gov as #NCT03613532.

Morning report goes virtual: learner experiences in a virtual, case-based diagnostic reasoning conference.

OBJECTIVES: Participation in case-based diagnostic reasoning (DR) conferences has previously been limited to those who can attend in-person. Technological advances have enabled these conferences to migrate to virtual platforms, creating an opportunity to improve access and promote learner participation. We describe the design and evaluation of virtual morning report (VMR), a novel case-based DR conference that aimed to expand access to these conferences, leverage a virtual platform to create new opportunities for learner participation, and improve learner confidence in performing DR. METHODS: VMR took place on a videoconferencing platform. Participants included health professions students, post-graduate trainees, and practitioners. In designing VMR, we adapted concepts from the experience-based model of learning to design opportunities for learner participation. Teaching strategies were informed by information-processing and situativity theories. We evaluated learner experiences in VMR using a survey with open and closed-ended questions. Survey items focused on accessing case-based teaching conferences outside of VMR, participant perceptions of the educational value of VMR, and VMR's impact on participants' confidence in performing DR. We used thematic analysis to manually code open-ended responses and identify themes. RESULTS: 203 participants (30.2%) completed the survey. 141 respondents (69.5%) reported they did not otherwise have access to a DR conference. The majority of participants reported increased confidence performing DR. Respondents highlighted that VMR supplemented their education, created a supportive learning environment, and offered a sense of community. CONCLUSIONS: VMR can expand access to DR education, create new opportunities for learner participation, and improve learner confidence in performing DR.

A New Way of Evaluating Effectiveness of URM Summer Pipeline Programs.

PURPOSE: Many academic medical centers fund educational opportunities (pipeline programs) for students who are underrepresented in medicine (URM). However, there is a sparsity of published literature on pipeline programs and an even smaller body of published literature that investigates program effectiveness. METHODS: In a retrospective cohort study (n=12) of the Provost's Summer Mentorship Program-Medicine (SMPM), we evaluated students' rating of program effectiveness, students' rating of the program's impact on their mindsets, and SAT scores. Several program mindsets, including sense of belonging (inclusiveness) in the health professions and connection to mentors in the medical field, reflect common barriers that prevent URM students from pursuing careers in medicine as outlined in pipeline literature. We describe program effectiveness using mean and median ratings of SMPM effectiveness, ratings of mindsets, and SAT scores. We used Wilcoxon Rank Sum to assess pre and post program differences in ratings of mindsets and SAT scores. RESULTS: SMPM was effective for learners. The overall mean rating for SMPM effectiveness was 4.27. Mindsets for confidence, interest, sense of belonging, college mentorship, and physician mentorship were statistically different from the start to the end of SMPM (p<0.05), with mean improvement of about 34%, 41%, 44%, 180%, and 140% respectively. The mean pre and post SMPM SAT scores as well as 4-month follow-up SAT mean scores were 713 (SD:155), 813 (SD:83), and 1058 (SD:147), respectively. There was a statistically significant difference between all three SAT scores (p<0.05). CONCLUSION: In addition to providing educational support, our pipeline program effectively increased students' sense of belonging in the medical field and their connections to physician mentors, which are two common barriers for URM students who are interested in medicine.

A coach of my own.

This personal view about medical student self-feedback is based on personal experiences as a third-year medical student with insights from a director of undergraduate medical education for a department of medicine. We highlight the importance of adult-learning theory in the clinical arena, and suggest that the application of self-regulated learning theory during clinical clerkships may contribute to increased student engagement and partnership in learning.

Trends in Racial/Ethnic Representation Among US Medical Students.

Importance: With increasing efforts to create a diverse physician workforce that is reflective of the demographic characteristics of the US population, it remains unclear whether progress has been made since 2009, when the Liaison Committee on Medical Education set forth new diversity accreditation guidelines. Objective: To examine demographic trends of medical school applicants and matriculants relative to the overall age-adjusted US population. Design, Setting, and Participants: Repeated cross-sectional study of Association of American Medical Colleges data on self-reported race/ethnicity and sex of medical school applicants and matriculants compared with population distribution of the medical school-aged population (20-34 years). Data from US allopathic medical school applicants and matriculants from 2002 to 2017 were analyzed. Main Outcomes and Measures: Trends were measured using the representation quotient, the ratio of the proportion of a racial/ethnic group in the medical student body to the general age-matched US population. Linear regression estimates were used to evaluate the trend over time for Asian, black, white, Hispanic, American Indian or Alaska Native (AIAN), and Native Hawaiian or Other Pacific Islander medical school matriculants by sex. Results: The number of medical school applicants increased 53%, from 33 625 to 51 658, and the number of matriculants increased 29.3%, from 16 488 to 21 326, between 2002 and 2017. During that time, proportions of black, Hispanic, Asian, and Native Hawaiian or Other Pacific Islander male and female individuals aged 20 to 34 years in the United States increased, while proportions of white male and female individuals decreased and proportions of AIAN male and female individuals were stable. From 2002 to 2017, black, Hispanic, and AIAN applicants and matriculants of both sexes were underrepresented, with a significant trend toward decreased representation for black female applicants from 2002 to 2012 (representation quotient slope, -0.011; 95% CI, -0.015 to -0.007; P < .001). Conclusions and Relevance: Black, Hispanic, and AIAN students remain underrepresented among medical school matriculants compared with the US population. This underrepresentation has not changed significantly since the institution of the Liaison Committee of Medical Education diversity accreditation guidelines in 2009. This study's findings suggest a need for both the development and the evaluation of more robust policies and programs to create a physician workforce that is demographically representative of the US population.