ABSTRACT Objectives To characterize practice patterns and outcomes in the management of low‐ and intermediate‐grade salivary gland carcinoma prior to the existence of treatment guidelines. Methods Analysis of a registry of patients who underwent parotid and submandibular gland resections for low‐and intermediate‐grade carcinomas between 2010 and 2019. Results Of all 786 patients included in the study, 726 (92%) had preoperative imaging and 653 (83%) had preoperative biopsy. Of the 729 patients with parotid gland cancer, the majority underwent superficial ( n = 384, 53%) or total ( n = 254, 35%) parotidectomy. In patients with facial nerve preservation, total parotidectomy was associated with a significant increase in transient facial weakness (72/177 (41%) vs. 82/311 (26%), RR 0.65, 95% CI 0.50–0.84, p < 0.05) and permanent facial nerve weakness (23/176 (13%) vs. 16/301 (5%), RR 0.41, 95% CI 0.22–0.75, p < 0.05) compared to superficial parotidectomy. Adjuvant radiation therapy ( RT ) was delivered to 285 (36%) patients. The proportion of patients receiving adjuvant RT declined significantly over the time period from 2015 to 2019 compared to 2010 to 2014 at 162/504 (32%) and 123/282 (44%), respectively ( RR 0.74, 95% CI 0.61–0.89, p < 0.05). When comparing the time periods from 2015 to 2019 and 2010 to 2014, there was no significant difference in local control rates ( RR 0.52, 95% CI 0.26–1.04, p = 0.06) or regional control rates ( RR 0.75, 95% CI 0.26–2.13, p = 0.58). Conclusions Management of low‐ and intermediate‐grade salivary cancer from 2010 to 2019 was variable, which is expected given the rarity and heterogeneity of the disease and the lack of treatment guidelines prior to 2021. Most patients with parotid malignancies underwent superficial or total parotidectomy. The extent of parotidectomy had an impact on facial nerve function outcomes. Delivery of adjuvant radiation trended down with time. The data presented here will support dissemination of the guidelines and provide data that could inform future trials. Level of Evidence 2b.
Everolimus and Low-Dose Tacrolimus After Heart Transplant in Children
ImportanceStudies suggest that everolimus may reduce the risk of rejection, cardiac allograft vasculopathy (CAV), chronic kidney disease (CKD), and cytomegalovirus (CMV) after heart transplant. Everolimus use is controversial because of data demonstrating higher infection deaths when everolimus is introduced de novo after transplant. It is unclear whether everolimus is safe and effective when initiated at 6 months posttransplant in children, a population in which median graft survival is limited to 15 years and randomized clinical trials are lacking.ObjectiveTo evaluate the safety and efficacy of everolimus combined with low-dose tacrolimus to prevent major adverse transplant events (MATEs) in children after heart transplant.Design, Setting, and ParticipantsMulticenter, randomized, open-label, clinical trial enrolling 211 patients who were alive 6 months after pediatric heart transplant at 25 US sites from February 2018 to August 2020. The last date of follow-up was April 17, 2023.InterventionsParticipants were randomized to receive everolimus and low-dose tacrolimus (n = 107) or standard-dose tacrolimus and mycophenolate mofetil (n = 104) for 30 months.Main Outcomes and MeasuresThe primary efficacy end point was the MATE-3 score at 30 months, a validated composite ordinal end point including acute cellular rejection, CAV, and CKD. The primary safety end point was the MATE-6 score, encompassing the MATE-3 score plus antibody-mediated rejection, infection, and posttransplant lymphoproliferative disorder.ResultsAmong 211 children randomized, the mean age was 8.2 (SD, 6.3) years, 97 (46%) underwent transplant for congenital heart disease, and 49 (23%) were treated for rejection before 6 months. At 30 months, the mean MATE-3 score did not differ between the 2 treatment groups (mean difference, −0.32; 95% CI, −0.90 to 0.20; P = .16). The mean MATE-6 score was no higher in the everolimus group than in the mycophenolate group (baseline-adjusted mean difference, −0.40; 95% CI, −1.81 to 0.93), meeting the success criterion for safety (noninferiority margin &lt;3). There were no differences in graft survival, MATE-free survival, or freedom from any individual MATE. Everolimus was associated with greater improvement in estimated glomerular filtration rate at 12 months (mean difference, 10.5 mL/min/1.73 m2; 95% CI, 1.09-19.91 mL/min/1.73 m2) and a lower incidence of CMV infection (hazard ratio, 0.50; 95% CI, 0.26-0.93).Conclusions and RelevanceAmong 6-month pediatric heart transplant survivors, everolimus and low-dose tacrolimus did not differ from tacrolimus and mycophenolate in preventing the composite of cellular rejection, CAV, and CKD at 30 months. However, everolimus and low-dose tacrolimus appear to be safe based on the total burden of 6 MATEs and may be associated with improved kidney function and less CMV infection.Trial RegistrationClinicalTrials.gov Identifier: NCT03386539
Association of Platelet Trajectory Patterns with In-Hospital Mortality in Critically Ill Adults with Acute Kidney Injury Receiving Continuous Renal Replacement Therapy
Abstract Background: Thrombocytopenia commonly occurs in critically ill patients with acute kidney injury (AKI) receiving continuous renal replacement therapy (CRRT) and is associated with poor outcomes. While previous studies have examined static platelet counts and relative declines, the prognostic significance of platelet trajectory patterns before and after CRRT initiation remains unclear. This study investigates the association between platelet count trajectories and in-hospital mortality in critically ill adult patients with AKI receiving CRRT. Methods: This study is a single-center retrospective cohort study utilizing electronic health record (EHR) data from critically ill adults (≥18 years) with AKI who received CRRT at the University of Alabama at Birmingham between January 2012 and December 2023. Platelet trajectories were assessed using mixed-effects models incorporating all platelet measurements within seven days before and after CRRT initiation. The slopes of platelet count change were categorized as descending (≤ -10 × 10³/μL/day), stable (-10 to 10), or ascending (≥ 10), creating a total of nine trajectory patterns by combining the three pre-CRRT and three during-CRRT categories. The primary outcome was in-hospital mortality, which was analyzed in relation to these trajectory patterns using logistic regression models adjusted for demographics, comorbidities, Sequential Organ Failure Assessment (SOFA) score, medications, and use of other organ support devices as covariates. Results: The study included 2,226 critically ill adults with AKI on CRRT, encompassing 8,569 patient-days before and 11,699 patient-days after CRRT initiation for platelet slope calculation. The median age was 59 years (IQR 48–69) and the median SOFA score at CRRT initiation was 12 (9–14). The in-hospital mortality rate was 57.8%. Before CRRT initiation, the most common trajectory was descending (46.2%), while after CRRT initiation, the stable pattern was most prevalent (58.3%). All patterns with a descending platelet trajectory during-CRRT were significantly associated with higher in-hospital mortality (aOR 1.92 [95% CI: 1.16–3.21] for ascending-descending; 1.49 [1.07–2.08] for stable-descending; 1.52 [1.04–2.23] for descending-descending). In contrast, all patterns with stable or increasing platelet counts during-CRRT tended to have lower mortality. Conclusions: A descending platelet trajectory after CRRT initiation was independently associated with increased in-hospital mortality.
Abstract 7237: Rapid-onset squamous cell carcinoma and spontaneous regression following papillomavirus infection
Abstract Squamous cell carcinoma (SCC) development in mammals is thought to require months or years from the time that initial changes occur. We show that SCCs induced by the mouse papillomavirus MmuPV1, which are generally diagnosed 4-6 months post infection, can be found as soon as 2 weeks post infection. SCCs developed within 2 weeks in immune-competent, adult FVB (FVB/NTac) mice at sites prone to human papillomavirus (HPV)-induced tumors and cancers in human patients: the base of the tongue, the anus, and the skin. The anterior tongue, less susceptible than the base of the tongue to HPV-induced cancer in humans, was resistant to rapid-onset cancer. The presence of invasive cancer in histological tissue sections was verified by multiple pathologists. These diagnoses were corroborated by the results of a classic test of malignancy: skin tumors obtained two weeks post infection grew ectopically as subcutaneous grafts in immune-deficient hosts. Preventative treatment with a novel BRD4 inhibitor dramatically reduced the frequency of ear skin SCCs present 2 weeks post infection and significantly reduced overall disease severity. Like many human papillomaviruses, MmuPV1 lacks an E5 gene. Expression of HPV16 E5 driven by the Keratin 14 promoter in FVB mice (FVB/NTac-Tg(KRT14-HPV16E5*)33Plam/Plam) significantly increased the frequency of rapid-onset invasive cancers caused by MmuPV1 at the base of the tongue and in the anus. In an E5-transgenic mouse with a persistent MmuPV1-induced ear skin lesion, we detected a lymph node metastasis at 38 weeks - further demonstrating a cancer phenotype. Cancers and less severe dysplasia induced by infection at the base of the tongue or the anus spontaneously regressed within 4 to 8 weeks of infection; however, ear lesions persisted. When CD4+ and CD8+ T cells were depleted, lesions at the base of the tongue and anus also persisted, indicating that spontaneous regression involves a T cell-mediated immune response. These results indicate that papillomavirus infection alone is sufficient to induce rapid onset of invasive cancer, and that persistence of disease depends on the tissue-specific immune microenvironment. Citation Format: Andrea Bilger, Ella T. Ward-Shaw, Denis L. Lee, Renee E. King, Shwu-Yuan Wu, Michael A. Newton, Cheng-Ming Chiang, Darya Buehler, Kristina Matkowskyj, John P. Sundberg, Rong Hu, Paul F. Lambert. Rapid-onset squamous cell carcinoma and spontaneous regression following papillomavirus infection [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 7237.
Mucopolysaccharidosis Type IIIA Presenting as Hypertrophic Cardiomyopathy
SUMMARY In 13 Smooth Fox Terriers with a congenital form of myasthenia gravis, clinical signs included intermittent, progressive muscle weakness that became more pronounced with exercise; muscle wasting; megaesophagus; and aspiration pneumonia. Neurologic abnormalities were apparent only during periods of weakness and included inability to retract the fore- and hindlimbs from painful stimuli. A decrement of the compound muscle action potential was evident during repetitive supramaximal nerve stimulation. Intravenous injection of a short-acting cholinesterase inhibitor evoked immediate improvement of clinical and electromyographic signs. Intracellular microelectrode studies of a biopsied external intercostal muscle revealed reduced amplitude of miniature end-plate potentials, as occurs in acquired myasthenia gravis. However, in contrast to acquired myasthenia gravis, antibodies directed against acetylcholine receptors were not demonstrable in serum and were not bound to acetylcholine receptors in muscle. Despite lack of complexing with immunoglobulin, the amount of acetylcholine receptor protein in biopsied external intercostal muscles from 9 affected pups was less than 25% of the amount in 5 unaffected littermates. The latter finding accounted for the reduction in amplitude of miniature end-plate potential and the failure of neuromuscular transmission. Treatment with a long-acting cholinesterase inhibitor in 6 cases resulted in temporary improvement in muscle strength.
SUMMARY A case of the autoimmune form of myasthenia gravis and a case of what is probably a congenital form of myasthenia gravis were diagnosed in 2 unrelated cats. Neuromuscular weakness exacerbated by exercise was a prominent feature in both cats. Weakness was eliminated temporarily by administration of anticholinesterase drugs. Serum autoantibodies to acetylcholine receptors of skeletal muscle were present in the 1st cat and were not detected in the 2nd cat. A characteristic decrement in the amplitude of the compound muscle action potential during repetitive stimulation of the motor nerve was elicited in the 2nd cat. There was marked electromyographic improvement in response to anticholinesterase drugs. Electromyography was not performed in the 1st cat.
Altered Calcium Signaling Via STIM1 Drives Aberrant Megakaryopoiesis and Myelofibrosis
Activating mutations in the calcium sensor STIM1 underlie Stormorken Syndrome (SS), a rare congenital disorder that causes thrombocytopenia and tubular aggregate myopathy. We recently identified two patients with SS and confirmed mutations in STIM1 (R304W and S88G), who were found to have features consistent with myelofibrosis (MF), as indicated by bone marrow biopsies demonstrating megakaryocyte hyperplasia and atypia in conjunction with marked reticulin fibrosis. The unusual MF findings in these two patients raised the hypothesis that altered calcium signaling represents a shared hallmark of congenital platelet disorders such as Stormorken Syndrome and myeloproliferative neoplasms (MPNs) including MF. Analyzing gene expression data from public datasets, we found increased expression of STIM1 in megakaryocyte progenitors and platelets, as well as CD34+ hematopoietic stem/progenitor cells (HSPCs), from MPN patients (including those with CALR or JAK2 mutations) vs healthy controls. These findings led us to hypothesize that dysregulation of STIM1 and store operated calcium entry (SOCE) signaling may contribute to altered megakaryopoiesis and development of fibrosis in both SS and MPNs. To further delineate these processes, we analyzed samples from our two SS patients, demonstrating constitutive activation of SOCE causing increased calcium flux, as well as decreased aggregation in mature platelets. We also performed transmission electron microscopy (TEM) and identified platelets with abnormal granularity in dense and alpha granules. We also performed single cell RNA-seq on SS patient peripheral blood mononuclear cells, which revealed enhanced NFkB inflammatory signaling, suggesting that altered signaling driven by STIM1 mutations may drive aberrant inflammation to contribute to MF development. To corroborate these initial observations, we identified a separate family cohort of 9 individuals in Italy with SS and confirmed STIM1 mutation (L92V). In ex vivo megakaryocytic differentiation assays, cells derived from these patients demonstrated a defect in thrombopoiesis with significantly decreased pro-platelet formation and adhesion to extracellular matrix. To further characterize the effects of the gain of function STIM1 mutations seen in our patients, we developed a novel, conditional knock-in mouse model of the heterozygous R304W mutation in the coiled coil (CC) domain of Stim1. Induction of hematopoietic-specific expression of mutant Stim1 via Vav-Cre resulted in recapitulation of hematological features of SS, including thrombocytopenia and a mild bleeding tendency, with confirmation of increased SOCE activity and calcium flux. Notably, we confirmed the development of bone marrow fibrosis, as well as findings of severe osteosclerosis, in these mice. TEM imaging confirmed that platelets from Stim1R304W/+Vav-Cre mice exhibit abnormal granularity, similar to what we observed from our SS patients. Noting that we identified increased STIM1 expression in samples from MPN patients harboring either JAK2 or CALR mutations, we further characterized the role of STIM1 in MPN disease development. NSGS mice were engrafted with CALR-mutant CD34+ cells subjected to CRISPR ablation of STIM1. Recipient mice exhibited decreased human CD45+ cell engraftment in conjunction with prolonged survival. In contrast, targeting of STIM1 in JAK2-mutant CD34+ cells led to exacerbated disease phenotypes, as manifested by enhanced human CD45+ cell engraftment, worsened splenomegaly, and early lethality. Taken together, these findings suggest a striking, differential relationship between mutant JAK2 and CALR and STIM1 activity and their relationship to MF development. Altogether, this study represents the first demonstration of MF development in patients with Stormorken Syndrome, and reveals a previously unrecognized hallmark of altered calcium signaling via aberrant STIM1 activation underlying SS and MPNs. We further demonstrate recapitulation of these hematologic features in a novel knock-in Stim1R304W/+Vav-Cre mouse model. These findings implicate an important role for STIM1and SOCE activity in MF development, and further uncover important distinctions between JAK2 vs CALR mutations and their interaction with altered STIM1 activity. These studies may contribute to the development of novel therapeutic approaches for these disorders.
Apex Part 2 Trial in Progress: A Phase 2 Open-Label Clinical Study of Bezuclastinib in Adult Patients with Advanced Systemic Mastocytosis
Background and Significance: Systemic mastocytosis (SM) is a rare heterogeneous disease characterized by the aberrant accumulation of neoplastic mast cells (MC). In about 95% of adult patients, SM is driven by a gain-of-function mutation (D816V) in exon 17 of KIT. Advanced SM (AdvSM) is a life-threatening form of SM and includes three subtypes: aggressive SM (ASM), SM with an associated hematologic neoplasm (SM-AHN), and mast cell leukemia (MCL). Despite improvement in disease control with approval of tyrosine kinase inhibitors (TKIs), there is still unmet need for improved tolerability and efficacy in AdvSM treatments. Bezuclastinib, an oral and selective type 1 TKI that potently inhibits KIT D816V, is being studied in patients diagnosed with AdvSM in the Apex study (NCT04996875). Results from the Part 1 dose optimization portion of Apex were presented previously. Part 1 randomized 32 patients 1:1:1:1 to receive bezuclastinib at 50, 100, or 200 mg BID or 400 mg QD. Initial results from the Part 1 dose optimization portion of the Apex trial in patients with AdvSM demonstrated encouraging safety profile and signs of clinical activity, as well as deep reductions across biomarkers of MC burden including bone marrow MC burden, serum tryptase levels, and KIT D816V variant allele fraction (VAF). In addition, 94%, 93%, and 100% of patients demonstrated ≥50% reduction in serum tryptase, KIT D816V VAF, and bone marrow MC burden, respectively. Exposure achieved with 100 mg BID of bezuclastinib original formulation resulted in optimal efficacy and safety outcomes. 150 mg QD of an optimized formulation is expected to deliver bezuclastinib exposures consistent with the 100 mg BID of the original formulation. Part 2 is further evaluating the efficacy and safety of bezuclastinib in patients with AdvSM at the selected Part 2 dose of 150mg QD of the optimized formulation. Study Design and Methods: Apex is a multicenter, Phase 2 open-label study of bezuclastinib in patients with AdvSM as defined per the WHO criteria. Enrollment includes previously treated and treatment-naïve patients. Part 2 is enrolling approximately 65 patients including up to 15 patients without measurable mIWG C-findings. The Part 2 expansion portion of the Apex study is designed to evaluate the efficacy and safety of bezuclastinib in patients with AdvSM, including ASM, SM-AHN, or MCL. Key eligibility criteria include measurable disease (centrally adjudicated) according to modified IWG-MRT-ECNM criteria and clinically acceptable laboratory values including platelet count ≥50,000/µL. The primary efficacy endpoint of Part 2 is overall response rate (ORR = complete response [CR] + complete remission with partial hematologic recovery [CRh] + partial response [PR] + clinical improvement [CI]) per mIWG-MRT-ECNM criteria according to mIWG-MRT-ECNM response criteria and will be confirmed by a Central Response Review Committee. Secondary endpoints include further characterization of safety and tolerability, pure pathologic response, biomarker response (including changes in bone marrow MC burden, serum tryptase level, and KIT D816V mutational burden), duration of response, time to response, progression-free survival, and overall survival (OS). Apex Part 2 is actively enrolling. Study sites are enrolling in North America, Asia-Pacific, and Europe. In addition, a high-risk SM-AHN sub-study assessing the safety and feasibility of the combination of bezuclastinib 150 mg QD and azacitidine may enroll up to 20 patients who are currently receiving or indicated for azacitidine and have biopsy-proven SM with an associated high- or very high-risk myeloid neoplasm. Patients with SM-AHN from Part 1 or Part 2 who have demonstrated AHN progression may enroll in an additional rollover cohort to receive bezuclastinib with concomitant azacitidine or hydroxyurea.