Cancer mRNA vaccines: clinical advances and future opportunities.

mRNA vaccines have been revolutionary in terms of their rapid development and prevention of SARS-CoV-2 infections during the COVID-19 pandemic, and this technology has considerable potential for application to the treatment of cancer. Compared with traditional cancer vaccines based on proteins or peptides, mRNA vaccines reconcile the needs for both personalization and commercialization in a manner that is unique to each patient but not beholden to their HLA haplotype. A further advantage of mRNA vaccines is the availability of engineering strategies to improve their stability while retaining immunogenicity, enabling the induction of complementary innate and adaptive immune responses. Thus far, no mRNA-based cancer vaccines have received regulatory approval, although several phase I-II trials have yielded promising results, including in historically poorly immunogenic tumours. Furthermore, many early phase trials testing a wide range of vaccine designs are currently ongoing. In this Review, we describe the advantages of cancer mRNA vaccines and advances in clinical trials using both cell-based and nanoparticle-based delivery methods, with discussions of future combinations and iterations that might optimize the activity of these agents.

Failure of treatment-free remission after a prolonged deep molecular response in patients with chronic myeloid leukemia.

Patients with chronic myeloid leukemia in chronic phase (CML-CP) can have a normal life expectancy when treated with the BCR::ABL1 tyrosine kinase inhibitors. In recent years, treatment discontinuation and treatment-free remission (TFR) emerged as the new goal of therapy in patients with CML-CP. Deep and sustained molecular remissions for more than 3 to 5 years are associated with higher chances of a successful TFR. However, although uncommon, some patients may still experience molecular or hematological relapse after treatment discontinuation, even after a prolonged duration of remission. In this case series, we report the outcome of four patients with CML-CP who were treated with tyrosine kinase inhibitors and achieved a deep molecular response for ≥8 years, but eventually experienced disease relapse after treatment discontinuation. We discuss the importance of regular monitoring after treatment discontinuation as well as future strategies to increase the chances of TFR in patients with CML-CP.

Association of leukemic molecular profile with efficacy of inotuzumab ozogamicin in adults with relapsed/refractory ALL.

The phase 3 INO-VATE trial demonstrated higher rates of remission, measurable residual disease negativity, and improved overall survival for patients with relapsed/refractory (R/R) acute lymphoblastic leukemia (ALL) who received inotuzumab ozogamicin (InO) vs standard of care chemotherapy (SC). Here we examined associations between genomic alterations and the efficacy of InO. Of 326 randomized patients, 91 (InO, n=43; SC, n=48) had samples evaluable for genomic analysis. The spectrum of gene fusions and other genomic alterations observed was comparable with prior studies of adult ALL. Responses to InO were observed in all leukemic subtypes, genomic alterations, and risk groups. Significantly higher rates of complete remission (CR)/CR with incomplete count recovery rates were observed with InO vs SC in patients with BCR::ABL1-like ALL (85.7% [6/7] vs 0% [0/5] P=0.0076), with TP53 alterations (100% [5/5] vs 12.5% [1/8], P=0.0047), and in the high-risk BCR::ABL1- (BCR::ABL1-like, low hypodiploid, KMT2A-rearranged) group (83.3% [10/12] vs 10.5% [2/19]; P<0.0001). This retrospective, exploratory analysis of the INO-VATE trial demonstrated potential for benefit with InO for patients with R/R ALL across leukemic subtypes, including BCR::ABL1-like ALL, and for those bearing diverse genomic alterations. Further confirmation of the efficacy of InO in patients with R/R ALL exhibiting the BCR::ABL1-like subtype or harboring TP53 alterations is warranted. This trial was registered at www.clinicaltrials.gov as no. NCT01564784.

Association Between Diagnosis-to-Limb Revascularization Time and Clinical Outcomes in Outpatients With Chronic Limb-Threatening Ischemia: Insights From the CLIPPER Cohort.

BACKGROUND: The extent and consequences of ischemia in patients with chronic limb-threatening ischemia (CLTI) may change rapidly, and delays from diagnosis to revascularization may worsen outcomes. We sought to describe the association between time from diagnosis to endovascular lower extremity revascularization (diagnosis-to-limb revascularization [D2L] time) and clinical outcomes in outpatients with CLTI. METHODS AND RESULTS: In the CLIPPER cohort, comprising patients between 66 and 86 years old diagnosed with CLTI betweeen 2010 and 2019, we used Medicare claims data to identify patients who underwent outpatient endovascular revascularization within 180 days of diagnosis. We described the risk-adjusted association between D2L time and clinical outcomes. Among 1 130 065 patients aged between 66 and 86 years with CLTI, 99 221 (8.8%) underwent outpatient endovascular lower extremity revascularization within 180 days of their CLTI diagnosis. Among patients with D2L time <30 days, there was no association between D2L time and all-cause death or major lower extremity amputation. However, among patients with D2L time >30 days, each additional 10-day increase in D2L time was associated with a 2.5% greater risk of major amputation (hazard ratio, 1.025 [95% CI, 1.014-1.036]). There was no association between D2L time and all-cause death. CONCLUSIONS: A delay of >30 days from CLTI diagnosis to lower extremity endovascular revascularization was associated with an increased risk of major lower extremity amputation among patients undergoing outpatient endovascular revascularization. Improving systems of care to reduce D2L time could reduce amputations.

Iguratimod, an allosteric inhibitor of macrophage migration inhibitory factor (MIF), prevents mortality and oxidative stress in a murine model of acetaminophen overdose.

BACKGROUND: Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine that has been implicated in multiple inflammatory and non-inflammatory diseases, including liver injury induced by acetaminophen (APAP) overdose. Multiple small molecule inhibitors of MIF have been described, including the clinically available anti-rheumatic drug T-614 (iguratimod); however, this drug's mode of inhibition has not been fully investigated. METHODS: We conducted in vitro testing including kinetic analysis and protein crystallography to elucidate the interactions between MIF and T-614. We also performed in vivo experiments testing the efficacy of T-614 in a murine model of acetaminophen toxicity. We analyzed survival in lethal APAP overdose with and without T-614 and using two different dosing schedules of T-614. We also examined MIF and MIF inhibition effects on hepatic hydrogen peroxide (H2O2) as a surrogate of oxidative stress in non-lethal APAP overdose. RESULTS: Kinetic analysis was consistent with a non-competitive type of inhibition and an inhibition constant (Ki) value of 16 µM. Crystallographic analysis revealed that T-614 binds outside of the tautomerase active site of the MIF trimer, with only the mesyl group of the molecule entering the active site pocket. T-614 improved survival in lethal APAP overdose when given prophylactically, but this protection was not observed when the drug was administered late (6 h after APAP). T-614 also decreased hepatic hydrogen peroxide concentrations during non-lethal APAP overdose in a MIF-dependent fashion. CONCLUSIONS: T-614 is an allosteric inhibitor of MIF that prevented death and decreased hepatic hydrogen peroxide concentrations when given prophylactically in a murine model of acetaminophen overdose. Further studies are needed to elucidate the mechanistic role of MIF in APAP toxicity.

Genomic determinants of response and resistance to inotuzumab ozogamicin in B-cell ALL.

Inotuzumab ozogamicin (InO) is an antibody-drug conjugate that delivers calicheamicin to CD22-expressing cells. In a retrospective cohort of InO-treated patients with B-cell acute lymphoblastic leukemia, we sought to understand the genomic determinants of response and resistance to InO. Pre- and post-InO patient samples were analyzed by whole genome, exome, and/or transcriptome sequencing. Acquired CD22 mutations were observed in 11% (3/27) of post-InO relapsed tumor samples, but not in refractory samples (0/16). There were multiple CD22 mutations per sample and the mechanisms of CD22 escape included epitope loss (protein truncation, protein destabilization) and epitope alteration. Two CD22 mutant cases were post-InO hypermutators resulting from error-prone DNA damage repair (non-homologous/alternative end joining, mismatch repair deficiency), suggesting hypermutation drove escape from CD22-directed therapy. CD22-mutant relapses occurred after InO and subsequent hematopoietic stem cell transplantation (HSCT), suggesting InO eliminated predominant clones, leaving subclones with acquired CD22 mutations that conferred resistance to InO and subsequently expanded. Acquired loss-of-function mutations in TP53, ATM and CDKN2A were observed, consistent with compromise of the G1/S DNA damage checkpoint as a mechanism of evading InO-induced apoptosis. Genome wide CRISPR/Cas9 screening in cell lines identified DNTT (TdT) loss as a marker of InO resistance. In conclusion, genetic alterations modulating CD22 expression and DNA damage response influence InO efficacy. Our findings highlight the importance of defining the basis of CD22 escape, and eradication of residual disease prior to HSCT. The identified mechanisms of escape from CD22-targeted therapy extend beyond antigen loss, and provide opportunities to improve therapeutic approaches and overcome resistance.

Exploring the impact of high-energy diets on cattle: insights into subacute rumen acidosis, insulin resistance and hoof health.

Cattle lameness remains a significant concern, causing economic losses and compromising animal welfare. Claw horn lesions have been identified as a major cause of lameness in dairy cows but its correlation with high-energy diet and ruminal acidosis remains unclear. Hence, the primary objective of this study was to assess the effects of a high starch and a conventional diet on the rumen environment, acute phase proteins, and metabolic alterations, with a particular focus on insulin resistance and the consequent implications for the histology of the hooves in Holstein steers. Sixteen animals were divided into the high-starch (HS; 37% starch) and conventional (CON; 16.8% starch) groups. Glucose tolerance tests (GTT), blood, rumen fluid analysis, and histological evaluations of the hoof tissue were conducted over a 102-d experimental period. The HS group showed a lower ruminal pH than the CON group, and with values indicating subacute ruminal acidosis (SARA). The plasma glucose and IGF-1 concentrations were higher in the HS group, suggesting an anabolic state. Both groups exhibited an increase in the insulin area under the curve (AUC) after the GTT on d 102. Histological analysis of the hooves showed a reduction in the length and width of the epidermal lamella in both groups. There was a significant negative correlation between the insulin AUC and the length and width of the epidermal lamella. Since both groups were similarly affected, the hypothesis that histological alterations were caused by the experimental diets still needs confirmation. Additionally, the development of SARA was not essential for the observed histological changes in the hoof. Further studies are warranted to thoroughly investigate the role of insulin and IGF-1 imbalances in claw health.

Inotuzumab in Older Patients with Newly Diagnosed Acute Lymphoblastic Leukemia-A Podcast.

Older patients with acute lymphoblastic leukemia (ALL) have historically had poor outcomes (5-year survival rate, 20%) with standard intensive and dose-adjusted chemotherapy regimens, due to a high incidence of adverse biologic features including high-risk cytogenetics, presence of TP53 mutations, and poor tolerance to intensive therapy. Thus, there is an unmet medical need in this patient population. Inotuzumab ozogamicin is a humanized antibody-drug conjugate that targets CD22-positive leukemic blasts. It is approved for the treatment of relapsed or refractory ALL and has been shown to be effective and tolerable in older patients. Several ongoing trials in older patients with newly diagnosed ALL have yielded encouraging data with inotuzumab ozogamicin in induction alone and in combination with low-intensity chemotherapy. In this podcast, the authors summarize and highlight some of the recent findings on the use of inotuzumab ozogamicin as induction therapy for older adults with newly diagnosed ALL.

Cytogenetic and Molecular Associations with Outcomes in Higher-Risk Myelodysplastic Syndromes Treated with Hypomethylating Agents plus Venetoclax.

PURPOSE: Hypomethylating agents (HMA) combined with venetoclax are an emerging therapeutic strategy for higher-risk myelodysplastic syndromes (HR-MDS). The cytogenetic and molecular factors associated with outcomes with this combination for HR-MDS are incompletely understood. EXPERIMENTAL DESIGN: We pooled patient data from 3 prospective trials evaluating HMA-venetoclax in HR-MDS to study associations between cytogenetic and molecular factors and overall response rate (ORR), overall survival (OS), and event-free survival (EFS). The Kaplan-Meier method was used to estimate time-to-event endpoints. Univariate and multivariate analyses using logistic regression (for ORR) or the Cox proportional hazards model (for OS and EFS) were used to identify associations between clinical, cytogenetic, and molecular factors and outcomes. RESULTS: A total of 80 patients (52 HMA-naïve, 28 HMA-failure) were included. ORR was 90% in HMA-naïve and 57% in HMA-failure. Median OS was 28.2 and 8.3 months in HMA-naïve and HMA-failure, respectively. Median EFS was 17.9 and 5.5 months in HMA-naïve and HMA-failure, respectively. In addition, 24/52 (46%) of the HMA-naïve and 3/28 (11%) of the HMA-failure patients proceeded to allogeneic stem cell transplantation (SCT). Factors associated with inferior outcomes were prior HMA failure, complex cytogenetics, trisomy 8, TP53 mutations, and RAS pathway mutations. Mutations in RNA splicing, DNA methylation, and ASXL1 appeared favorable. Blast percentage was not predictive of outcomes. CONCLUSIONS: Knowledge of cytogenetic and molecular alterations may help identify which patients with HR-MDS benefit the most from venetoclax.

Safety and long-term survival results of the addition of inotuzumab ozogamicin to the conditioning regimen of allogeneic stem cell transplantation: A single-center phase 1,2 trial.

Here we report on the first prospective study evaluating the safety and long-term survival when an escalating dose of inotuzumab ozogamicin (INO) (0.6, 1.2, or 1.8 mg/m2 on day 13) was added to one alkylator-containing conditioning regimen in patients with relapsed CD22 (+) lymphoid malignancies who were candidates for hematopoietic stem cell transplantation (HSCT). Twenty-six patients were enrolled. Six (23%) of these patients entered the phase 1 study: four were treated at an INO dose of 0.6 mg/m2 and two at dose of 1.2 mg/m2. None of these patients experienced dose-limiting toxicities. The remaining 20 (77%) patients entered the phase 2 part of the study at the maximum dose of 1.8 mg/m2. One patient developed VOD; this patient had received nivolumab immediately before HSCT while simultaneously experiencing hyperacute graft-vs-host disease (GVHD). Treatment-related mortality (TRM) at 5 years was 12%. With a median follow-up of 48.7 months, the 5-year overall survival (OS) and progression-free survival (PFS) rates were 84% and 80%, respectively. Compared with a historical cohort who received same conditioning for HSCT but without INO (n = 56), the INO group showed no significant differences in incidence of liver toxicity, engraftment time, TRM, or risk of acute GVHD. Patients with lymphoma who received INO had a trend for a better 5-year OS (93% versus 68%) and PFS (93% versus 58%) than those in the control group. In conclusion, our results showed that INO is safe with no increased risk of VOD when combined with one alkylator-containing regimen of HSCT.

Expanded specific T cells to hypomutated regions of the SARS-CoV-2 using mRNA electroporated antigen-presenting cells.

The COVID-19 pandemic has caused about seven million deaths worldwide. Preventative vaccines have been developed including Spike gp mRNA-based vaccines that provide protection to immunocompetent patients. However, patients with primary immunodeficiencies, patients with cancer, or hematopoietic stem cell transplant recipients are not able to mount robust immune responses against current vaccine approaches. We propose to target structural SARS-CoV-2 antigens (i.e., Spike gp, Membrane, Nucleocapsid, and Envelope) using circulating human antigen-presenting cells electroporated with full length SARS-CoV-2 structural protein-encoding mRNAs to activate and expand specific T cells. Based on the Th1-type cytokine and cytolytic enzyme secretion upon antigen rechallenge, we were able to generate SARS-CoV-2 specific T cells in up to 70% of unexposed unvaccinated healthy donors (HDs) after 3 subsequent stimulations and in 100% of recovered patients (RPs) after 2 stimulations. By means of SARS-CoV-2 specific TCRß repertoire analysis, T cells specific to Spike gp-derived hypomutated regions were identified in HDs and RPs despite viral genomic evolution. Hence, we demonstrated that SARS-CoV-2 mRNA-loaded antigen-presenting cells are effective activating and expanding COVID19-specific T cells. This approach represents an alternative to patients who are not able to mount adaptive immune responses to current COVID-19 vaccines with potential protection across new variants that have conserved genetic regions.

Targetable genetic abnormalities in patients with acute myeloblastic leukemia across age groups.

Incidence of potential targetable genetic abnormalities by age in AML.

Vaccines: a promising therapy for myelodysplastic syndrome.

Myelodysplastic neoplasms (MDS) define clonal hematopoietic malignancies characterized by heterogeneous mutational and clinical spectra typically seen in the elderly. Curative treatment entails allogeneic hematopoietic stem cell transplant, which is often not a feasible option due to older age and significant comorbidities. Immunotherapy has the cytotoxic capacity to elicit tumor-specific killing with long-term immunological memory. While a number of platforms have emerged, therapeutic vaccination presents as an appealing strategy for MDS given its promising safety profile and amenability for commercialization. Several preclinical and clinical trials have investigated the efficacy of vaccines in MDS; these include peptide vaccines targeting tumor antigens, whole cell-based vaccines and dendritic cell-based vaccines. These therapeutic vaccines have shown acceptable safety profiles, but consistent clinical responses remain elusive despite robust immunological reactions. Combining vaccines with immunotherapeutic agents holds promise and requires further investigation. Herein, we highlight therapeutic vaccine trials while reviewing challenges and future directions of successful vaccination strategies in MDS.

A Review of the Therapeutic Role of Bosutinib in Chronic Myeloid Leukemia.

The development of the BCR::ABL1 tyrosine kinase inhibitors (TKIs) has transformed Philadelphia chromosome (Ph)-positive chronic myeloid leukemia (CML) from a fatal disease to an often-indolent illness that, when managed effectively, can restore a life expectancy close to that of the normal population. Bosutinib is a second-generation TKI approved for adults with Ph-positive CML in chronic phase, accelerated phase, or blast phase that is resistant or intolerant to prior therapy, and for newly diagnosed Ph-positive chronic phase CML. This review details the efficacy of bosutinib for the treatment of CML in the first- and second-line settings, as well as in third- and later-line settings for high-risk patients resistant or intolerant to at least 2 TKIs. It also outlines bosutinib studies that provide evidence for dose-optimization strategies that can be used to improve efficacy and effectively manage adverse events. The studies that provide evidence for specific patient populations benefiting particularly from bosutinib dose-optimization strategies are also discussed. The well-established, long-term side-effect profile and the potential to make dose adjustments with bosutinib make it an appropriate treatment option for patients with CML. Bosutinib has demonstrated a positive impact on health-related quality of life and an important role in the long-term treatment of patients with CML.

Endoscopic treatment of primary obstructive megaureter with high pressure balloon dilation in infants.

INTRODUCTION AND OBJECTIVE: Ureteral reimplantation of the dilated ureter in infants is challenging; however, some patients with primary obstructive megaureter (POM) in this age group require intervention due to clinical or radiological progression. We sought to determine if high pressure balloon dilation (HPBD) can serve as a definitive treatment for POM in children under one year of age, or as a temporizing measure until later reimplantation. MATERIALS AND METHODS: All patients from a single institution who underwent HPBD between October 2009 and May 2022 were retrospectively reviewed. Patients were excluded if older than 12 months or diagnosed with neurogenic bladder, posterior urethral valves, or obstructed refluxing megaureter. Patients with prior surgical intervention at the ureterovesical junction were excluded. Indications for surgery included progressive hydroureteronephrosis or urinary tract infection (UTI). Balloon dilation was performed via cystoscopy with fluoroscopic guidance, followed by placement of two temporary ureteral stents. Primary outcomes were improvement or resolution of megaureter and rates of subsequent reimplantation. Secondary outcomes included total number of anesthetics and postoperative UTIs. RESULTS: Fifteen infants with median age of 7.6 months (IQR 3.8-9.7) underwent HPBD. Twelve (80%) patients were detected prenatally and 3 (20%) after a UTI. Indication for surgery was progressive hydroureteronephrosis in 10 patients (67%) and UTI in five (33%). All had SFU grade 3 or 4 hydronephrosis on preoperative ultrasound and median distal ureteral diameter was 13 mm. Median follow up was 2.9 years. Twelve (80%) succeeded with endoscopic treatment: 7 patients had an undetectable distal ureter on ultrasound at last follow-up, 5 were improved with median distal ureteral diameter of 7 mm. Three patients (20%) required ureteral reimplantation due to progressive dilation, all with grade 4 hydronephrosis and distal ureteral diameters were 11, 15, and 21 mm. Six patients (40%) required two anesthetics to complete endoscopic treatment. Among those, 4 patients required initial stent placement for passive dilation followed by a second anesthetic for HPBD weeks later. Two patients underwent repeat HPBD following postoperative proximal migration of the ureteral stents. All 15 patients had an additional anesthetic for removal of stents. Five patients (33%) were treated for a symptomatic UTI (4 febrile, 1 afebrile) with the stents indwelling but there were no UTIs in the group following stent removal. CONCLUSION: Balloon dilation is a practical option for treatment of POM in infants, and in most cases (80%) avoids subsequent open surgery (over median 2.9 years of follow-up).

Prognostic risk signature in patients with acute myeloid leukemia treated with hypomethylating agents and venetoclax.

ABSTRACT: Hypomethylating agents (HMAs) and venetoclax (Ven) represent the standard of care for patients with acute myeloid leukemia (AML) who are ineligible for intensive chemotherapy. However, the European LeukemiaNet (ELN) risk classifications have been validated for patients treated with intensive therapy. In this study, we validate a recently proposed new molecular prognostic risk signature (mPRS) for patients with AML treated with HMAs and Ven. This classification allocated patients to favorable, intermediate (N/KRAS or FLT3-internal tandem duplication mutations), and lower (TP53 mutations) benefit groups. We retrospectively analyzed 159 patients treated with HMA and Ven. The mPRS classification allocated 74 (47%), 31 (19%), and 54 (34%) patients to the higher, intermediate, and lower-benefit groups, respectively. The overall response rate was 71% (86%, 54%, and 59% in the higher, intermediate, and lower-benefit groups, respectively). The median overall survival (OS) and event-free survival (EFS) times were 30 and 19 months, respectively, in the higher-benefit group; 12 and 8 months in the intermediate-benefit group; and 5 and 4 months in the lower-benefit group (P < .001). The C-index for OS and EFS was higher when stratifying patients according to mPRS classification than with the ELN 2022 classification. The 2-year cumulative incidence of relapse was 35%, 70%, and 60% in the higher, intermediate, and lower-benefit groups, respectively (P = .005). The mPRS classification accurately segregated groups of patients with AML treated with HMA plus Ven. In these patients, N/KRAS and TP53 mutations appear to negatively affect outcomes; therefore, new treatment approaches are warranted.

Genomic determinants of response and resistance to inotuzumab ozogamicin in B-cell ALL.

Inotuzumab ozogamicin (InO) is an antibody-drug conjugate that delivers calicheamicin to CD22-expressing cells. In a retrospective cohort of InO treated patients with B-cell acute lymphoblastic leukemia, we sought to understand the genomic determinants of response to InO. Acquired CD22 mutations were observed in 11% (3/27) of post-InO relapsed tumor samples. There were multiple CD22 mutations per sample and the mechanisms of CD22 escape included protein truncation, protein destabilization, and epitope alteration. Hypermutation by error-prone DNA damage repair (alternative end-joining, mismatch repair deficiency) drove CD22 escape. Acquired loss-of-function mutations in TP53 , ATM and CDKN2A were observed, suggesting compromise of the G1/S DNA damage checkpoint as a mechanism of evading InO-induced apoptosis. In conclusion, genetic alterations modulating CD22 expression and DNA damage response influence InO efficacy. The escape strategies within and beyond antigen loss to CD22-targeted therapy elucidated in this study provide insights into improving therapeutic approaches and overcoming resistance. KEY POINTS: We identified multiple mechanisms of CD22 antigen escape from inotuzumab ozogamicin, including protein truncation, protein destabilization, and epitope alteration.Hypermutation caused by error-prone DNA damage repair was a driver of CD22 mutation and escape.