Vadastuximab talirine (SGN-CD33A, 33A) is an antibody-drug conjugate consisting of pyrrolobenzodiazepine dimers linked to a monoclonal antibody targeting CD33, which is expressed in the majority of ...acute myeloid leukemia (AML) patients. This phase 1 study evaluated the safety, pharmacokinetics, and preliminary activity of vadastuximab talirine and determined the recommended monotherapy dose in patients with relapsed or refractory AML. Additional expansion cohorts tested vadastuximab talirine in specific subpopulations of relapsed AML, and in a cohort of older, treatment-naive patients. Patients received vadastuximab talirine IV on day 1 (5-60 µg/kg) or on days 1 and 4 (20 µg/kg) of 21-day cycles. A total of 131 patients (median age, 73 years range, 26-89 years) had intermediate I-II (48%) or adverse (34%) risk by European LeukemiaNet classification; 50% of patients had underlying myelodysplasia. Two dose-limiting toxicities (grade 2 pulmonary embolism and grade 4 hypocellular marrow) occurred during dose finding. Most adverse events (AEs) were consistent with myelosuppression; nonhematologic AEs included fatigue, nausea, and diarrhea. The 30-day mortality was 8%. At the recommended monotherapy dose of 40 µg/kg, the complete remission + CRi rate was 28% (5 of 18 patients); 50% of patients who responded achieved minimal residual disease negativity. In patients across dose levels who achieved CR or CRi, the median time to full count recovery was 6.4 weeks for neutrophils (≥1000/µL) and 10.6 weeks for platelets (≥100 × 109/L). Vadastuximab talirine demonstrates activity and a tolerable safety profile as a single agent in patients with AML. The recommended monotherapy dose of vadastuximab talirine is 40 µg/kg. This trial was registered at www.clinicaltrials.gov as # NCT01902329.
•Vadastuximab talirine, a novel antibody-drug conjugate, consists of an anti-CD33 monoclonal antibody conjugated to pyrrolobenzodiazepine dimers.•In a phase 1 trial, vadastuximab talirine demonstrated single-agent activity and minimal nonhematologic toxicity in patients with AML.
Treatment of acute leukemia has been delivered predominantly in academic and larger leukemia treatment centers with the infrastructure and staff needed to manage patients receiving complex ...therapeutic regimens and supportive care. However, in recent years, several oral agents and less-myelosuppressive regimens were approved, making it possible for these patients to receive therapy in smaller community hospitals and oncology office practices. In this review, we discuss the optimum community setting, type of patient who can be treated, agents that can be applied, and an appropriate clinical circumstance in which a referral to a tertiary center should be made.
Abstract
Objective
Patients with light chain–predominant multiple myeloma have been shown to exhibit shorter survival. Retrospective comparison of clinical and laboratory data was undertaken to ...ascertain the likely cause(s) of this observation.
Methods
Records of patients with multiple myeloma seen at 1 institution revealed 316 patients with conventional and 71 patients with light chain–predominant multiple myelomas with secretion of intact immunoglobulins. Laboratory and clinical findings in the 2 groups were compared.
Results
Patients with light chain–predominant multiple myeloma had a significantly higher death rate, a higher rate of chronic dialysis, a lower estimated glomerular filtration rate and serum albumin, a significantly higher urine protein concentration, and a significantly higher prevalence of hypertension and blood transfusion requirements. Other clinical and laboratory parameters surveyed were not significantly different between the 2 groups.
Conclusion
The shorter survival of patients with light chain–predominant multiple myeloma is clearly associated with renal damage caused by excess free immunoglobulin light chains. Renal damage may be ameliorated by early aggressive treatment with chemotherapy, plasmapheresis, and dialysis; a multi-institutional prospective controlled trial would be needed to test this hypothesis.
The mutant JAK2V617F tyrosine kinase (TK) is present in the majority of patients with BCR-ABL–negative myeloproliferative neoplasms (MPNs). JAK2V617F activates downstream signaling through the signal ...transducers and activators of transcription (STAT), RAS/mitogen-activated protein kinase (MAPK), and phosphatidylinositol 3 (PI3)/AKT pathways, conferring proliferative and survival advantages in the MPN hematopoietic progenitor cells (HPCs). Treatment with the pan-histone deacetylase (HDAC) inhibitor panobinostat (PS) is known to inhibit the chaperone function of heat shock protein 90, as well as induce growth arrest and apoptosis of transformed HPCs. Here, we demonstrate that PS treatment depletes the autophosphorylation, expression, and downstream signaling of JAK2V617F. Treatment with PS also disrupted the chaperone association of JAK2V617F with hsp90, promoting proteasomal degradation of JAK2V617F. PS also induced apoptosis of the cultured JAK2V617F-expressing human erythroleukemia HEL92.1.7 and Ba/F3-JAK2V617F cells. Treatment with the JAK2 TK inhibitor TG101209 attenuated JAK2V617F autophosphorylation and induced apoptosis of HEL92.1.7 and Ba/F3-JAK2V617F cells. Cotreatment with PS and TG101209 further depleted JAK/STAT signaling and synergistically induced apoptosis of HEL92.1.7 and Ba/F3-JAK2V617F cells. Cotreatment with TG101209 and PS exerted greater cytotoxicity against primary CD34+ MPN cells than normal CD34+ HPCs. These in vitro findings suggest combination therapy with HDAC and JAK2V617F inhibitors is of potential value for the treatment of JAK2V617F-positive MPN.
Relapse is the major cause of allogeneic hematopoietic stem cell transplantation failure in high-risk Philadelphia chromosome-positive (Ph+) leukemia. Post-transplant maintenance therapy is a ...promising strategy. We found maintenance imatinib and dose-reduced newer generation tyrosine kinase inhibitors to be feasible and generally well tolerated. This approach might reduce the incidence of relapse and improve the outcomes after allogeneic hematopoietic stem cell transplantation for high-risk Ph+ leukemia.
The effect of post-transplant maintenance tyrosine kinase inhibitors (TKIs) on the outcomes of allogeneic hematopoietic stem cell transplantation in high-risk Philadelphia chromosome-positive (Ph+) leukemia remains unknown.
A retrospective analysis that included allograft recipients with accelerated phase and blast phase chronic myeloid leukemia or Ph+ acute lymphoblastic leukemia who had received post-transplant maintenance TKI therapy from 2004 to 2014.
A total of 26 patients, 9 with accelerated phase/blast phase CML and 17 with Ph+ acute lymphoblastic leukemia, received maintenance post-transplant therapy with imatinib, dasatinib, nilotinib, or ponatinib. The TKI was selected according to the pretransplantation TKI response, anticipated toxicities, and ABL1 domain mutations, when present. Newer generation TKIs were initiated at a ≥ 50% dose reduction from the standard pretransplantation dosing to limit the toxicities and avoid therapy interruptions. TKIs were started a median of 100 days (range, 28-238 days) after transplantation and were administered for a median of 16 months (range, 8 days to 105 months). Eight patients discontinued therapy because of adverse events. With a median follow-up of 3.6 years (range, 4 months to 8.7 years), the 5-year relapse-free survival rate was 61%. All 3 patients who developed a relapse underwent successful salvage treatment and remained disease-free. The 5-year overall survival rate was 78%.
Maintenance TKI therapy after transplantation is feasible and might reduce the incidence of relapses and improve outcomes after allogeneic hematopoietic stem cell transplantation for patients with high-risk Ph+ leukemia.
There is a wide variation in the number of CD34+ cells infused for an autologous transplantation. While the minimum number of hematopoietic stem cells for a successful transplantation has been ...established, there is no definite information on the optimum number or the maximum number of stem cells. It is generally agreed that a minimum dose of 2.5 x 10(6) CD34+ cells is necessary for successful engraftment. Although engraftment of neutrophils and platelets is achieved at that dose, it is delayed and is also negatively influenced by other factors. Reinfusion of 5.0 x 10(6) CD34+ cells results in prompt engraftment of all three cell lines and should be the preferred target. At least one study indicated that a very large number of cells (>15 x 10(6) CD34+ cells) resulted in further improvement in engraftment, decreased packed red blood cell and platelet transfusion, shorter hospitalization, and overall decreased costs. In contrast, a few studies showed that reinfusion of a large number of CD34+ cells causes fever and engraftment syndrome and may result in prolongation of the inpatient stay. Marrow culture assays performed post-transplant have shown decreased hematopoietic reserve as well as changes in the stromal cells. These changes persist for several years after the transplant. Generally, salvage chemotherapy is poorly tolerated post-transplant due to impaired marrow reserve. This hypothesis has not been validated by systematic clinical studies. It is undetermined if larger doses of stem cells improves the marrow reserve.
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