Bone Marrow Disorder

This is a randomized, double-blind, placebo-controlled, Phase 2/3 study comparing the efficacy and safety of elenestinib (BLU-263) + symptom directed therapy (SDT) with placebo + SDT in participants with indolent systemic mastocytosis (ISM) whose symptoms are not adequately controlled by SDT. Parts 1 and 2 will enroll participants with ISM. Participants enrolled in Part 2 will roll over onto Part 3 to receive treatment with elenestinib in an open-label fashion following completion of the earlier Part. Part K will enroll participants with ISM who have previously received an approved selective KIT inhibitor. The study also includes pharmacokinetic (PK) groups that will enroll participants with ISM.

Myelofibrosis (MF) is a pathological process characterized by dysplasia of bone marrow fibrous tissue, clonal proliferation of potential stem cells, inflammatory changes in the bone marrow microenvironment, and extramedullary hematopoiesis. Bone marrow histopathology is the gold standard for diagnosis, but because of the invasive nature of the puncture, repeated examination is not possible to dynamically monitor the disease process. In addition, due to the focal nature of puncture biopsy, it can not accurately reflect the systemic disease. 18F-FDG PET/CT provides visual assessment of MF, but its diagnostic effectiveness decreases as MF progresses. 18F-FAPI PET/MRI characterizes fiber activation processes in a variety of diseases. This study intends to use a prospective, observational, self-controlled, multi-center study design to evaluate the feasibility and diagnostic efficacy of 18F-FDG PET/CT and 18F-FAPI PET/MRI imaging for the evaluation of systemic fibrosis in MF patients based on the results of bone marrow pathological biopsy, and to analyze the relationship between imaging results and clinical prognosis.

Background: * Multiple myeloma (MM) is an incurable malignancy of plasma cells that leads to destructive bone lesions, renal damage, anemia, and hypercalcemia. MM is the second most common hematologic malignancy. The American Cancer Society estimates that annually over 34,000 new cases of MM will occur in the U.S. and over 12,000 deaths due to MM in 2022. * Overall survival (OS) has improved significantly over the past 20 years with the development of proteasome inhibitors (PIs), immunomodulatory agents (IMiDs) and anti-CD38 monoclonal antibodies. However, despite these advances, patients ultimately relapse requiring multiple subsequent lines of therapy. As MM evolves, it generally becomes more refractory, and patients ultimately succumb to their disease. * With multiple lines of efficacious therapies, the correct early identification of relapsed disease is important to trigger initiation of a new line of therapy. * Limitations in conventional imaging highlight a need for molecular imaging agents with better sensitivity for detecting and measuring tumor burden to improve staging and treatment selection for patients with MM and plasma cell dyscrasias. * 18F-fluciclovine is a radionuclide approved by the FDA for evaluating suspected prostate cancer recurrence but has shown additional ability in detecting MM lesions. Objective: To determine the concordance between 18F-fluciclovine PET/CT and 18F-FDG PET/CT in participants with multiple myeloma Eligibility: * Participants \>= 18 years old * Eastern Cooperative Oncology Group (ECOG) Performance score of 0 to 2 * Participants must have a documented diagnosis of MM defined by the International Myeloma Working Group (IMWG) Criteria * Participants fit criteria for one of the following categories: * Newly diagnosed multiple myeloma (NDMM) without previous treatment (or within the first 3 cycles of front-line treatment) * Relapsed and/or Refractory multiple myeloma (RRMM) with at least 1 prior line of therapy Design: This is an open-label, single center phase 2 study evaluating 18F-fluciclovine PET/CT imaging in up to 50 participants with multiple myeloma. Participants will be enrolled into one of two cohorts based on disease status; newly diagnosed multiple myeloma (NDMM) participants will be enrolled into Cohort 1 and relapsed refractory multiple myeloma (RRMM) participants will be enrolled into Cohort 2. All subjects will undergo an 18F-fluciclovine injection followed by a static whole-body PET/CT at three time points: Timepoint #1, Timepoint #2 (after induction for NDMM or at 6 months for RRMM) and Timepoint #3 (at progression or at 5 years). Results will be compared to 18F-FDG PET/CT imaging at those same timepoints.

OUTLINE: This is a dose-escalation study of 211\^At-BC8-B10. Patients receive 211\^At-BC8-B10 intravenously (IV) over 6-8 hours on day -7 and may receive 131\^I-BC8-B10 IV on day -7 and fludarabine phosphate IV over 30 minutes on days -4, -3 and -2. Patients undergo TBI and peripheral blood stem cell (PBSC) transplant on day 0. Patients also receive cyclosporine orally (PO) or IV every 12 hours on days -3 to 56 and then tapered to day 180 (for patients with related donors), or continuing to day 96 and then tapered to day 150 (for patients with unrelated donors). Patients receive mycophenolate mofetil PO or IV (first dose to occur 4-6 hours after PBSC infusion) every 12 hours on days 0-27 (for patients with related donors) or every 8 hours on day 0 and then reduced to every 12 hours on days 30-150 then tapered to day 180 (for patients with unrelated donors). Patients may undergo single photon emission computed tomography (SPECT), bone marrow aspirate sample and blood sample collection on study. After completion of study treatment, patients are followed up at 100 days and then at 6, 9, 12, 18 and 24 months.

OUTLINE: This is a dose-escalation study of astatine At 211 anti-CD45 monoclonal antibody BC8-B10. PREPARATIVE REGIMEN: Patients receive astatine At 211 anti-CD45 monoclonal antibody BC8-B10 infusion over 6-8 hours on day -8, fludarabine intravenously (IV) over 30 minutes on days -6 to -2, and cyclophosphamide IV over 1 hour on days -6 and -5. Patients also undergo TBI on day -1. TRANSPLANT: Patients undergo peripheral blood stem cell (PBSC) or bone marrow transplant on day 0. GVHD PROPHYLAXIS: Patients receive cyclophosphamide IV over 1-2 hours on days 3-4, mycophenolate mofetil IV or PO three times daily (TID) on days 5-35, and tacrolimus IV over 1-2 hours (changed to PO once tolerated) on days 5-180 with taper beginning on day 84 per physician discretion. Patients also begin granulocyte colony-stimulating factor (G-CSF) IV or subcutaneously (SC) on day 5 to continue until absolute neutrophil count (ANC) \> 1000/mm\^3 x 3 days. Patients undergo bone marrow biopsy and aspiration and blood sample collection throughout the study. After completion of study treatment, patients are followed up at day 100, and at 6, 9, 12, 18, and 24 months.

PRIMARY OBJECTIVES: I. Describe toxicities attributable to actinium Ac 225-DOTA-daratumumab (225Ac-DOTA-anti-CD38 daratumumab) radioimmunotherapy by dose level in patients treated under this regimen. II. Determine the maximum tolerated dose/recommended phase II dose (MTD/RP2D) of 225Ac-DOTA-anti-CD38 daratumumab radioimmunotherapy with fixed doses of organ sparing TMLI (12 Gy), fludarabine and melphalan (FM100) as conditioning regimen for allogeneic hematopoietic cell transplantation (HCT) for treatment of high-risk acute myeloid leukemias, acute lymphoblastic leukemia or myelodysplastic syndrome (MDS), in patients who are not eligible for standard myeloablative regimens. SECONDARY OBJECTIVES: I. Evaluate the safety of the regimen, at each dose level, by assessing the following: Ia. Type, frequency, severity, attribution, time course and duration of adverse events, including acute/chronic graft-versus-host disease (GVHD), infection and delayed engraftment. II. Estimate overall survival (OS), event-free survival (EFS), GVHD relapse free survival (GRFS), cumulative incidence (CI) of relapse/progression, and non-relapse mortality (NRM) at 100 days, 1 year and 2 years. III. Describe biodistribution, pharmacokinetics and organ dosimetry of 225Ac-DOTA-daratumumab. OUTLINE: This is a dose escalation of actinium Ac 225-DOTA-Daratumumab in combination with fludarabine, melphalan and TMLI. Patients receive daratumumab intravenously (IV) over 45 minutes followed by indium In 111-DOTA-daratumumab IV over 15 minutes and actinium Ac 225-DOTA-daratumumab IV over \~20-40 minutes on day -15. Patients receive TMLI twice daily (BID) on days -8 to -5, fludarabine IV on days -4 to -2 and melphalan IV on day -2, followed by HCT on day 0. Patients receive GVHD prophylaxis with sirolimus and tacrolimus starting on day -1. Patients also undergo computed tomography (CT) during screening, nuclear scan and single photon emission computed tomography (SPECT) scans on study, bone marrow biopsy and aspiration, echocardiography, or multigated acquisition scan (MUGA), and blood sample collection during screening and throughout study. After completion of study treatment, patients are followed up twice weekly for the first 100 days post-transplant, then twice monthly up to 6 months post-transplant followed by monthly until discontinuation of immunosuppressive therapy without evidence of GVHD with at least yearly follow-up for 2 years.

OBJECTIVES: Primary * Evaluate the use of 3'-deoxy-3'-\[18F\] fluorothymidine (FLT) positron emission tomography (PET) imaging to measure tumor proliferation and the DNA synthetic pathway (thymidine kinase levels) in patients with cancer. Secondary * Determine the efficacy of FLT PET imaging in detecting lesions and estimating response to treatment. OUTLINE: Patients undergo up to four 3'-deoxy-3'-\[18F\] fluorothymidine positron emission tomography imaging procedures.

This will be a single arm, open label pilot study of 5AZA-alt-DEC. Participants will be treated for a minimum of 24 weeks in the absence of clear evidence of progressive disease. Participants who have any response will be permitted to continue treatment until relapse or progression of disease that is not sensitive to protocol defined dose escalation. The primary objective of this study is to determine Overall Response Rate (ORR) of 5AZA-alt-DEC. The combined response endpoint will include complete response (CR), partial response (PR), and hematologic improvement (HI), with HI criteria specifically as defined by IWG criteria The secondary endpoints of this study include: * Cumulative incidence of response for both CR and overall response * Duration of response (DOR) * Safety evaluation by tabulation of adverse events of grade 3 and higher Correlative endpoints include: * Correlation of DNMT1 depletion with clinical response criteria * Correlation of clinical response with disease biological phenotype measured by morphology and cytogenetics * Exploratory measurements of pyrimidine metabolism pre-treatment and on-therapy

This phase of the protocol (protocol part B), seeks to evaluate the new formulation in healthy normal volunteers to confirm the new formulation provides comparable human dosimetry to which was seen and published in protocol part A. Additionally, the new formulation will be studied utilizing an expanded patient population to include patients with confirmed diagnosis of multiple myeloma (MM), low-grade lymphoma, or MM and lymphoma patients who are status post bone marrow transplant (BMT) with negative imaging and suspected recurrence.

This study uses bone marrow biopsy as a gold standard or reference standard to evaluate the diagnostic efficacy (Sensitivity, Specificity, Positive prediction rate, Negative prediction rate) of 68Ga FAPI PET/CT in myelofibrosis and to identify fibrosis grades.