A comparison of CD34+ mobilization effects of standard dose pegfilgrastim (Peg) versus low-dose peg combined with plinabulin (Plin).

2020 ◽  
Vol 38 (15_suppl) ◽  
pp. e20000-e20000
Author(s):  
Douglas W. Blayney ◽  
Lan Huang ◽  
Ramon W. Mohanlal
Keyword(s):  
Adverse Events ◽  
Bone Pain ◽  
Low Dose ◽  
Standard Dose ◽  
Single Agent ◽  
Tolerability Profile ◽  
Hematopoietic Stem ◽  
Full Dose ◽  
Cell Counts

e20000 Background: Plin is a novel, small molecule immune-enhancing agent with in vitro anticancer activity currently in Phase (Ph) 3 clinical trials for NSCLC treatment and Chemotherapy (Chemo)-Induced Neutropenia (CIN). Single agent (SA) Plin is equally effective as Peg for the prevention of CIN, however does not cause bone pain and is given on the same day of Chemo by 30 min IV infusion, 30 min after Chemo (Blayney ASH 2018). SA Plin also mobilizes CD34+ cells to clinically relevant levels (Blayney ASH 2019). Plin has been administered to > 600 patients (pts) and has a favorable safety/tolerability profile. In clinical practice, Peg dose is often reduced to 3 mg in patients (pts) experiencing side effects with standard dose (6 mg) Peg, such as bone pain, myalgia and leucocytosis (Kim ASCO 2010; Goodman Oncology Times 2008; Lacovelli JHOP 2012; Lower Cancer Chemother Pharmacol 2018). We evaluated CD34+ cell counts and adverse events (AE) with low dose Peg combined with Plin vs full dose Peg. Methods: In a subset of Breast Cancer pts in the CIN Ph 2 trial BPI-2358-106 (NCT0329457) receiving TAC (taxotere (75), doxorubicin (50 ) and cyclophosphamide (500) mg/m2, pts also received either Peg 6mg (n = 7) or low dose peg ( n = 9, of which 7pts received 3mg and 2 pts 1.5 mg Peg) combined with Plin (20 mg/m2). CD34+ counts were obtained by central laboratory FACS analysis (Covance) at screening (SC), Day (D) 6,8 and 21 cycle 1 (see table below) and AE frequency was collected. Results: Clinical trial information: NCT0329457 . Frequency of bone pain, myalgia and leukocytosis was numerically lower with low dose Peg/Plin vs 6mg Peg. Conclusions: Under highly myelosuppressive TAC Chemo conditions, CD34+ counts increased significantly (p < 0.03) vs predose SC in cycle 1 in the low dose Peg/Plin goup. CD34+ counts were not different for full dose Peg vs low dose Peg/Plin in cycle 1. Adverse Events were fewer with the low dose Peg/Plin. The Peg/Plin combination is worthy of test in hematopoietic stem cell mobilization regimens. [Table: see text]

Baby-step chemotherapy as a way to deliver chemotherapy in poor PS small cell lung cancer.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e17500-e17500
Author(s):  
Vanita Noronha ◽  
Vijay Patil ◽  
Amit Joshi ◽  
Vamshi Muddu ◽  
Kumar Prabhash
Keyword(s):  
Low Dose ◽  
Positive Impact ◽  
Standard Dose ◽  
Performance Status ◽  
Single Agent ◽  
Median Number ◽  
Ecog Performance Status ◽  
Full Dose ◽  
Grade 3 ◽  
Low Dose Chemotherapy

e17500 Background: Majority of patients with SCLC present with advanced stage and poor ECOG performance status. Hence delivery of adequate dose of chemotherapy is compromised. We hypothesized that initial low-dose chemotherapy might improve PS and enable administration of standard-dose chemotherapy, thus extending benefit of chemotherapy to otherwise ineligible patients. Methods: 30 patients with ECOG performance status 2-4 received low-dose chemotherapy consisting of either single agent carboplatin at AUC 2 or an abbreviated course of platinum-etoposide. Patients whose PS improved got full-dose chemotherapy with the standard regimen of platinum-etoposide. Demographic details, toxicity, time to progression and overall survival were analyzed. Univariate and multivariate analysis was performed to determine factors associated with TTP and OS. Results: Median age was 58 years with male predominance. The PS was IV in 9, III in 20 and II in 1 patient. Extensive-stage and limited-stage disease was seen in 24 and 6 patients respectively.15 patients received single-agent carboplatin, 10 patients abbreviated cisplatin-etoposide, 1 patient each cyclophosphamide and cisplatin-etoposide and 3 patients refused chemotherapy. Major grade 3-4 toxicity was mucositis in 1, loose motions in 1 and hyponatremia in 4 patients. There was no grade 3- 4 haematological toxicity. The median number of dose-reduced cycles was 1 and 3 patients received more than 2 cycles. 22 patients were eligible and willing for full-dose chemotherapy. The median time to start of full-dose chemotherapy was 11.5 days (4-26 days). The median number of cycles of standard-dose chemotherapy was 5 (1-6) with 16 completing planned schedule. Grade 3-4 toxicity was neutropenia in 50%, febrile neutropenia in 25%, loose motions in 25% and hyponatremia in 40%. The overall TTP and OS was 182 days and 263 days respectively. Presence of SIADH (p = 0.02) and completion of standard treatment (p = 0.001) had a positive impact on TTP while completion of treatment (p = 0.01) and normal LDH (p = 0.03) had a positive impact on OS. Conclusions: Low-dose chemotherapy is well-tolerated and might help in extending the benefit of standard-dose chemotherapy to otherwise ineligible patients.

scholarly journals Bcl-2 antagonist apogossypol (NSC736630) displays single-agent activity in Bcl-2–transgenic mice and has superior efficacy with less toxicity compared with gossypol (NSC19048)

Blood ◽  
2008 ◽  
Vol 111 (6) ◽  
pp. 3211-3219 ◽  
Author(s):  
Shinichi Kitada ◽  
Christina L. Kress ◽  
Maryla Krajewska ◽  
Lee Jia ◽  
Maurizio Pellecchia ◽  
...  
Keyword(s):  
B Cells ◽  
Transgenic Mice ◽  
Parent Compound ◽  
Single Agent ◽  
Maximum Tolerated Dose ◽  
Low Grade ◽  
Altered Expression ◽  
Cell Counts

Abstract Altered expression of Bcl-2 family proteins plays central roles in apoptosis dysregulation in cancer and leukemia, promoting malignant cell expansion and contributing to chemoresistance. In this study, we compared the toxicity and efficacy in mice of natural product gossypol and its semisynthetic derivative apo-gossypol, compounds that bind and inhibit antiapoptotic Bcl-2 family proteins. Daily oral dosing studies showed that mice tolerate doses of apogossypol 2- to 4-times higher than gossypol. Hepatotoxicity and gastrointestinal toxicity represented the major adverse activities of gossypol, with apogossypol far less toxic. Efficacy was tested in transgenic mice in which Bcl-2 is overexpressed in B cells, resembling low-grade follicular lymphoma in humans. In vitro, Bcl-2–expressing B cells from transgenic mice were more sensitive to cytotoxicity induced by apogossypol than gossypol, with LD50 values of 3 to 5 μM and 7.5 to 10 μM, respectively. In vivo, using the maximum tolerated dose of gossypol for sequential daily dosing, apogossypol displayed superior activity to gossypol in terms of reducing splenomegaly and reducing B-cell counts in spleens of Bcl-2–transgenic mice. Taken together, these studies indicate that apogossypol is superior to parent compound gossypol with respect to toxicology and efficacy, suggesting that further development of this compound for cancer therapy is warranted.

A pilot study of preoperative nivolumab in high-risk nonmetastatic renal cell carcinoma.

2021 ◽  
Vol 39 (6_suppl) ◽  
pp. 323-323
Author(s):  
Maria Isabel Carlo ◽  
Kyrollis Attalla ◽  
Sujata Patil ◽  
Samuel J. Murray ◽  
Ying-Bei Chen ◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Pilot Study ◽  
Adverse Events ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Standard Dose ◽  
Single Agent ◽  
Chylous Ascites ◽  
Neoadjuvant Immunotherapy ◽  
Renal Mri

323 Background: Immunotherapy improves survival in patients with advanced renal cell carcinoma (RCC), but has no established role for perioperative use in patients with localized RCC. Neoadjuvant immunotherapy is a promising strategy in several cancers, and may leverage the primary tumor as antigen source. Methods: We conducted a single institution pilot study of neoadjuvant nivolumab in patients with RCC undergoing nephrectomy with curative intent. Patients were eligible if their risk of metastatic recurrence within the first 12 years was >20% by an established nomogram. After confirmatory biopsy and renal MRI, patients were treated with standard dose nivolumab every 2 weeks for 4 treatments, with a follow-up renal MRI prior to nephrectomy. The primary end points of the study were safety and feasibility defined as being able to complete 3/4 treatments without surgical delay. We evaluated adverse events by CTCAE, surgical safety by Clavien-Dindo classification, and tumor radiographic response by RECIST 1.1. Results: Eighteen (11 men, 7 women; median age 60) were enrolled. All patients had clear cell RCC, median tumor size at baseline was 8.8cm (range 6.4-14.2cm). Median predicted 12-year probability of recurrence was 45% (range 25-71%). All received at least 1 dose of nivolumab; 16/18 patients completed all 4 doses. 17/18 (94%) patients completed at least 3 doses. No patient had notable delay in the timing of their nephrectomy. 4 patients had surgical complications per Clavien-Dindo classification, including 2 with grade 3a chylous ascites after lymphadenectomy. Two patients had nivolumab discontinued for immune-related adverse events, including grade 3 transaminitis and grade 2 arthralgias; a third patient developed grade 4 colitis 4 months after completing nivolumab. All patients had stable disease as the best response prior to surgery. Recurrence-free survival at 2 years was 0.74 (95%CI 0.45-0.90). We analyzed an additional 21 patients with metastatic RCC (20 ccRCC, 1 epithelioid AML) who subsequently had nephrectomy after standard immunotherapy. 15 patients had received ipilimumab+nivolumab, 6 received single-agent PD-1 or PD-L1 inhibitors. 3 (14%) patients achieved a near or complete pathologic response, including a patient with epithelioid AML. Analysis of radiologic and pathologic biomarkers of response are ongoing and will be presented at conference. Conclusions: In this pilot study, there were no new safety signals or delays in surgery with preoperative nivolumab. Neoadjuvant immunotherapy shows preliminary evidence of safety, feasibility and efficacy; biomarker studies may help identify individuals who may have a higher likelihood of response. Clinical trial information: NCT02595918 .

scholarly journals Successful hematopoietic stem cell mobilization and apheresis collection using plerixafor alone in sickle cell patients

2018 ◽  
Vol 2 (19) ◽  
pp. 2505-2512 ◽  
Author(s):  
Erica B. Esrick ◽  
John P. Manis ◽  
Heather Daley ◽  
Cristina Baricordi ◽  
Hélène Trébéden-Negre ◽  
...  
Keyword(s):  
Sickle Cell ◽  
Standard Dose ◽  
Genetically Engineered ◽  
Hematopoietic Stem ◽  
Cell Counts ◽  
Cd34 Cells ◽  
Stem And Progenitor Cells ◽  
Hematopoietic Stem Cell Mobilization ◽  
Cell Mobilization ◽  
Single Standard

Abstract Novel therapies for sickle cell disease (SCD) based on genetically engineered autologous hematopoietic stem and progenitor cells (HSPCs) are critically dependent on a safe and effective strategy for cell procurement. We sought to assess the safety and efficacy of plerixafor when used in transfused patients with SCD for HSC mobilization. Six adult patients with SCD were recruited to receive a single dose of plerixafor, tested at lower than standard (180 µg/kg) and standard (240 µg/kg) doses, followed by CD34+ cell monitoring in peripheral blood and apheresis collection. The procedures were safe and well-tolerated. Mobilization was successful, with higher peripheral CD34+ cell counts in the standard vs the low-dose group. Among our 6 donors, we improved apheresis cell collection results by using a deep collection interface and starting apheresis within 4 hours after plerixafor administration. In the subjects who received a single standard dose of plerixafor and followed the optimized collection protocol, yields of up to 24.5 × 106 CD34+ cells/kg were achieved. Interestingly, the collected CD34+ cells were enriched in immunophenotypically defined long-term HSCs and early progenitors. Thus, we demonstrate that plerixafor can be employed safely in patients with SCD to obtain sufficient HSCs for potential use in gene therapy.

Efficacy of STI571, an Abl tyrosine kinase inhibitor, in conjunction with other antileukemic agents against Bcr-Abl–positive cells

Blood ◽  
2000 ◽  
Vol 96 (9) ◽  
pp. 3195-3199 ◽  
Author(s):  
J. Tyler Thiesing ◽  
Sayuri Ohno-Jones ◽  
Kathryn S. Kolibaba ◽  
Brian J. Druker
Keyword(s):  
Clinical Trials ◽  
Tyrosine Kinase ◽  
Tyrosine Kinase Inhibitor ◽  
Kinase Inhibitor ◽  
Single Agent ◽  
Myelogenous Leukemia ◽  
Hematopoietic Stem ◽  
Abl Tyrosine Kinase ◽  
Abl Tyrosine Kinase Inhibitor

Abstract Chronic myelogenous leukemia (CML), a malignancy of a hematopoietic stem cell, is caused by the Bcr-Abl tyrosine kinase. STI571(formerly CGP 57148B), an Abl tyrosine kinase inhibitor, has specific in vitro antileukemic activity against Bcr-Abl–positive cells and is currently in Phase II clinical trials. As it is likely that resistance to a single agent would be observed, combinations of STI571 with other antileukemic agents have been evaluated for activity against Bcr-Abl–positive cell lines and in colony-forming assays in vitro. The specific antileukemic agents tested included several agents currently used for the treatment of CML: interferon-alpha (IFN), hydroxyurea (HU), daunorubicin (DNR), and cytosine arabinoside (Ara-C). In proliferation assays that use Bcr-Abl–expressing cells lines, the combination of STI571 with IFN, DNR, and Ara-C showed additive or synergistic effects, whereas the combination of STI571 and HU demonstrated antagonistic effects. However, in colony-forming assays that use CML patient samples, all combinations showed increased antiproliferative effects as compared with STI571 alone. These data indicate that combinations of STI571 with IFN, DNR, or Ara-C may be more useful than STI571 alone in the treatment of CML and suggest consideration of clinical trials of these combinations.

scholarly journals Thiopurines in the Management of Crohn’s Disease: Safety and Efficacy Profile in Patients with Normal TPMT Activity—A Retrospective Study

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Amine Benmassaoud ◽  
Xuanqian Xie ◽  
Motaz AlYafi ◽  
Yves Theoret ◽  
Alain Bitton ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Retrospective Study ◽  
Crohn's Disease ◽  
Adverse Events ◽  
Low Dose ◽  
Tpmt Activity ◽  
Safety And Efficacy ◽  
Full Dose ◽  
Index Treatment ◽  
Efficacy Profile

Background and Aims.Thiopurines are used in the treatment of Crohn’s disease (CD) and thiopurine S-methyltransferase (TPMT) activity can guide thiopurine dosing to avoid adverse events. This retrospective study evaluated the safety and efficacy of starting thiopurines at low dose versus full dose in patients with CD and normal TPMT.Methods.This was a single center retrospective study including adult CD patients with normal TPMT levels (≥25 nmol/hr/g Hgb) who were followed for 1 year. Patients started at full dose of azathioprine (2–2.5 mg/kg) or 6-mercaptopurine (1–1.5 mg/kg) were compared to patients started at low dose. Harvey-Bradshaw index, treatment failure, and drug-related adverse events were recorded.Results.Our study included 134 patients. Both groups had similar incidences of drug-related adverse events and discontinuation of therapy due to side effects. Fifty-six percent of all adverse events occurred within 31 days and 92% occurred within 3 months of therapy. Clinical response favored the full-dose group at 6 months (69% versus 27%,p=0.0542).Conclusions.Our study indicates that it is safe to start patients on full-dose thiopurine when they have a normal TPMT given its very similar toxicity profile to patients started on low dose. This may also positively impact efficacy.

Latexin: A Potential Tumor Suppressor.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1805-1805
Author(s):  
Ying Liang ◽  
Gary Van Zant
Keyword(s):  
Cell Proliferation ◽  
Stem Cell ◽  
Tumor Suppressor ◽  
Cell Lines ◽  
Negative Regulator ◽  
Stem Cell Population ◽  
Western Blots ◽  
Hematopoietic Stem ◽  
Cell Counts

Abstract We recently found that latexin is a negative regulator of the size of the hematopoietic stem cell population in mice. It acts by increasing apoptosis and decreasing cell proliferation. This 29 kD protein bears a strong structural resemblance to tazarotene-induced gene 1 (TIG1), a tumor suppressor down-regulated in a variety of cancers. The structural similarity and close genetic linkage led us to hypothesize that latexin also may have tumor suppressor properties. We found that latexin was down-regulated in a variety of human leukemias and lymphomas as determined by a survey of malignant cell lines and by analysis of CD34+ cells isolated from the blood and marrow of patients diagnosed with these malignancies and presenting with very high white cell counts. Bisulfite sequencing revealed that methylation of CpG dinucleotides in the latexin promoter at least partially accounted for latexin down-regulation. 5-aza-deoxycytidine treatment reinitiated or significantly increased latexin expression in K562, Molt4, CRF-CEM, Jurkat, U937, HL60, KG-1, and Sup B15 cell lines. To test the hypothesis that ectopic latexin expression in tumor cells would inhibit their growth, we developed a retrovirus-based expression vector with which we infected the murine lymphoma cell lines, WEHI231 and A20, neither of which contained significant latexin levels by Western blot. A vector containing GFP, but not latexin, was used to infect control cells. In triplicate experiments, the growth of both cell lines in vitro was inhibited an average 48% by infection with the latexin vector. Western blots revealed that latexin was durably expressed throughout the 2-week culture period at 2- to 4-fold the level expressed in normal T and B cells. As we found in our normal stem cell studies, latexin caused growth inhibition of lymphoma cells by significantly increasing apoptosis by 6-fold, and by suppressing cell proliferation by 2-fold. To test whether tumor inhibition extended to lymphomas in vivo, we injected either control or latexin vector-infected A20 cells subcutaneously in the flanks of BALB/c mice. Three weeks following adoptive transfer of identical numbers of cells, in duplicate experiments the latexin-expressing cells developed tumors only half the volume of those caused by the control cells. These results are consistent with a tumor suppressor role for latexin and suggest that latexin, or molecular mimics thereof, may have clinical efficacy in the treatment of malignancies.

A Retrospective Comparison of Matched Elderly Patients Treated with Laromustine (Cloretazine®) or Best Supportive Care or Low Dose Ara-C in the LRF AML14 Trial

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2960-2960 ◽  
Author(s):  
Robert Hills ◽  
Susan O’Brien ◽  
Verena Karsten ◽  
Alan K. Burnett ◽  
Francis Giles
Keyword(s):  
High Risk ◽  
Supportive Care ◽  
Low Dose ◽  
De Novo ◽  
Performance Status ◽  
Single Agent ◽  
Best Supportive Care ◽  
Cell Counts ◽  
Retrospective Comparison ◽  
De Novo Aml

Abstract Background : A substantial proportion of older patients with AML are considered unlikely to benefit from an intensive treatment approach. They often receive either best supportive care (BSC), low dose treatment such as Low Dose Ara-C (LDAC), or clinical trials of novel agents. In one of the few randomised studies where patients were prospectively considered likely to be unfit for intensive therapy, LDAC was superior to BSC with 18% v 1% patients achieving CR. No patients with high risk cytogenetics (Grimwade 1998), achieved CR (Burnett 2007). Laromustine (Cloretazine®) is a novel sulfonylhydrazine alkylating agent which preferentially targets the O6 position of guanine resulting in DNA cross-links. Laromustine has previously shown clinical activity in patients with de novo AML and high risk MDS (Giles et al. JCO 2007). A confirmatory phase II study of single agent laromustine was conducted in previously untreated patients ≥ 60 years old with de novo AML, prospectively considered likely to be unfit for intensive chemotherapy. Patients had at least one poor risk factor, defined by age ≥70, performance status 2, unfavorable cytogenetics, or cardiac, pulmonary or hepatic dysfunction. Eighty-five patients received induction therapy with 600 mg/m2 laromustine. Second induction cycles were administered in 14 patients after partial response or hematologic improvement. Eighteen patients received at least one consolidation cycle of cytarabine 400 mg/m2/day CIV for 5 days. Methods: A retrospective non-randomised comparison was performed between the 85 patients treated with laromustine, and 121 patients satisfying the same entry criteria, treated in the AML 14 trial with either BSC or LDAC. Outcomes were compared using Mantel-Haenszel and logrank methods for unadjusted comparisons, and regression methods for adjusted analyses. Results : Patients in AML14 were slightly older than those treated with laromustine (median age 75 v 73), and tended to have higher white blood cell counts; by contrast, there were significantly fewer cardiac or respiratory comorbidities reported in the AML14 population. Other important risk factors such as performance status and cytogenetics were similar between the groups. Responses overall (CR/CRp) were seen in 33% (28/85) of patients treated with laromustine, compared with 2% (1/60) and 23% (14/61) in patients treated with BSC and LDAC (p&lt;0.0001, p=0.2, respectively). In particular, 1 patient with −5/del(5q), and 3 patients with −7/del(7q) cytogenetics experienced a CR with laromustine; patients in AML 14 with adverse cytogenetics saw no remissions. Survival was significantly improved in the laromustine group compared to BSC (1 year survival 20% v 8%, unadjusted HR 0.58 [0.40–0.84] p=0.004), and roughly comparable to that of LDAC (1 year survival 20% v 25%, HR 1.04 [0.73–1.49] p=0.8). Analyses adjusted for differences in baseline demographics, and using propensity scores gave consistent figures. Conclusions: Retrospective comparison of unrandomised data has significant limitations even though care has been taken to match for factors known to be predictive for survival. Laromustine was able to achieve a higher CR rate than LDAC or BSC, and produced remissions in groups where no remissions have previously been seen with LDAC or BSC. Laromustine gave significantly better survival than BSC, and demonstrated similar survival to LDAC.

Anti-CD19 BiTE Blinatumomab Induces High Complete Remission Rate In Adult Patients with Relapsed B-Precursor ALL: Updated Results of An Ongoing Phase II Trial

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 252-252 ◽  
Author(s):  
Max S. Topp ◽  
Nicola Goekbuget ◽  
Gerhard Zugmaier ◽  
Andreas Viardot ◽  
Matthias Stelljes ◽  
...  
Keyword(s):  
Complete Remission ◽  
Adverse Events ◽  
Phase Ii ◽  
Phase Ii Trial ◽  
Lymphoblastic Leukemia ◽  
Single Agent ◽  
Adult Patients ◽  
Quantitative Detection ◽  
Hematopoietic Stem ◽  
Dismal Prognosis

Abstract Abstract 252 Adult patients with relapsed/refractory B-precursor acute lymphoblastic leukemia (ALL) have a dismal prognosis with low complete remission (CR) rates with intensive salvage chemotherapy which are not durable. Blinatumomab is a bispecific T-cell engaging (BiTE®) antibody construct that directs cytotoxic T-cells to CD19 expressing B-cells. In collaboration with the German Multicenter Study Group for Adult Lymphoblastic Leukemia (GMALL), an open-label, multicenter, single-arm, exploratory phase II trial is being conducted to evaluate efficacy and safety of blinatumomab in adult patients with relapsed/refractory B-precursor ALL. The primary endpoint for this trial is the rate of patients who reach CR or CR with partial hematological recovery (CRh*) within 2 cycles of blinatumomab treatment. Secondary endpoints are the rate of minimal residual disease (MRD) response (defined by an MRD level below the quantitative detection limit of 10−4), time to hematological relapse and overall survival. Blinatumomab is administered by continuous intravenous infusion for 28-days followed by a 14-day treatment-free interval. Responding patients could proceed to allogeneic hematopoietic stem cell transplantation (HSCT) or receive a total of up to 5 cycles of blinatumomab treatment. Three dose levels have been explored as shown in Table 1.Table 1.Summary of Dose Cohorts and OutcomesCohortPatients TreatedInitial Dose Week 1, Cycle 1 μg/m2/dayDose Week 2, Cycle 1 μg/m2/dayDose Weeks 3–4, Cycle 1 μg/m2/dayMaintenance Dose, Subsequent Cycles μg/m2/dayCR or CRh*Serious Adverse EventsnPts171515151551562a551515154222b65153030354310 planned5151515n.a.n.a.n.a. As of June 30, 2011, 43 cycles have been administered to a total of 18 patients (range 1–5; median 2). Twelve out of 18 patients have reached a complete remission within the first 2 cycles of single agent blinatumomab corresponding to a response rate of 67%. Of these 12 responding patients, 75% had complete hematologic recovery of peripheral blood counts. All 12 responders reached MRD negativity within the first 2 cycles and included 3 patients with t(4;11) and 1 patient with Ph-positive B-precursor ALL. Four responders proceeded to allogeneic HSCT; one experienced a CD19-negative hematological relapse after HSCT. Two responders relapsed during treatment; one had a CD19-positive extramedullary, and one a CD19-negative bone marrow relapse. The remaining 6 non-transplanted responders are still in hematological complete remission. The most common adverse events were pyrexia and chills. In cohort 1, one patient with a high tumor burden developed disseminated intravascular coagulation (DIC)/cytokine release syndrome (CRS) leading to treatment discontinuation. The implementation of a cytoreductive pre-phase and a lower initial dosing at 5μg/m2/day during the first week prevented further treatment discontinuations in such patients. Four patients had fully reversible CNS serious adverse events that led in 1 patient to discontinuation of treatment, and in 3 patients to temporary interruption of treatment. These 3 patients resumed treatment at a lower dose without further interruptions during the following cycles. There were no deaths related to blinatumomab. Blinatumomab as single agent induced an unprecedented high rate of complete hematological and MRD responses in adult patients with relapsed/refractory B-precursor ALL. A lower dose of 5μg/m2/day for the initial week of treatment, as tested in cohort 2a, demonstrated a favorable safety profile while maintaining efficacy. A maintenance dose of 30μg/m2/day, as tested in cohort 2b, did not further improve the already high efficacy but increased the number of adverse events. Therefore, the dosing of cohort 2a was selected as the basis for cohort 3 and will be applied to further clinical development in this patient population. Updated results of the study will be presented. Disclosures: Topp: Micromet: Consultancy, Honoraria. Goekbuget:Micromet: Consultancy. Zugmaier:Micromet: Employment. Klappers:Micromet AG: Employment. Mergen:Micromet Inc: Employment. Bargou:Micromet: Consultancy, Honoraria.

Prolonged Thrombocytopenia After Allogeneic Hematopoietic Stem Cell Transplantation (allo-HSCT) and Its Association with an Increase in CD8+ CX3CR1+ Cells in Bone Marrow.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3077-3077
Author(s):  
Xiao-hui Zhang ◽  
Guo-xiang Wang ◽  
Yan-rong Liu ◽  
Lan-Ping Xu ◽  
Kai-Yan Liu ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
T Cell ◽  
Cd8 T Cells ◽  
Surface Expression ◽  
T Cell Subsets ◽  
Control Group ◽  
Hematopoietic Stem ◽  
Cell Counts

Abstract Abstract 3077 Background: Since prolonged thrombocytopenia (PT) is an independent risk factor for poor clinical outcome after allogeneic hematopoietic stem cell transplantation (allo-HSCT), the underlying mechanisms need to be understood in order to develop selective treatments. Previous studies1–4 have suggested that abnormalities in B cells may play a role in the pathogenesis of PT. However, abnormalities in B cells alone do not fully explain the complete pathogenic mechanisms of PT. Our previous studies5 showed that the frequency of megakaryocytes with a ploidy value ≤ 8N was significantly increased in patients who developed PT after allo-HSCT compared to the control group. Mechanisms concerning the megakaryocyte hypoplasia in PT after allo-HSCT are not well understood. Design and Methods: PT was defined as a platelet count ≤80 × 109/L for more than 3 months after HSCT, recovery of all other cell counts, and no apparent cause for thrombocytopenia, such as aGVHD, disease recurrence, CMV infection, or antiviral drug treatment at three months post-HSCT when all other blood cell counts had return to normal.5 We analyzed T cell subsets in bone marrow (BM) and peripheral blood (PB) from allo-HSCT recipients with and without PT (n = 23 and 17, respectively) and investigated the expression characteristics of homing receptors CX3CR1, CXCR4 and VLA-4 by flow cytometry. Futhermore, Mononuclear cells (MNCs) from PT patients and controls were cultured with and without autologous CD8+ T cells in vitro, and clarify the effect of activated CD8+ T cells on the ploidy and apoptosis of megakaryocytes in the bone marrow. Results: The results demonstrated that the percentage of CD3+ T cells in the BM was significantly higher in PT patients than the experimental controls (76.00 ± 13.04% and 57.49 ± 9.11%, respectively, P < 0.001), whereas this difference was not significant for the PB (71.01 ± 11.49% and 70.49 ± 12.89%, respectively, P = 0.911). While, some T cell subsets in the BM and PB from allo-HSCT recipients with PT were not significantly different from that of the experimental control group, such as CD8+ T cells, CD4+ T cells, CD4+ CD25bright T cells (regulatory T cells), CD44hi CD62Llo CD8+ T cells and naive T cells (CD11a+ CD45RA+). Furthermore, the surface expression of homing receptor CX3CR1 on BM T cells (64.16 ± 14.07% and 37.45 ± 19.66%, respectively, P < 0.001) and CD8+ T cells (56.25 ± 14.54% and 35.16 ± 20.81%, respectively, P = 0.036), but not in blood, were significantly increased in PT patients compared to controls. For these two groups of patients, the surface expression of CXCR4 and VLA-4 on T cells and CD8+ T cells from both BM and PB did not show significant differences. Through the study in vitro, we found that the activated CD8+ T cells in bone marrow of patients with PT might suppress apoptosis (MNC group and Co-culture group: 18.02 ± 3.60% and 13.39 ± 4.22%, P < 0.05, respectively) and Fas expression (MNC group and Co-culture group: 21.10 ± 3.93 and 15.10 ± 2.33, P <0.05, respectively) of megakaryocyte. In addition, megakaryocyte with a ploidy value ≤ 8N (MNC group: 40.03 ± 6.42% and 24.54 ± 4.31%, respectively, P < 0.05) was significantly increased in patients with PT compared to the control group. Conclusions: In conclusion, an increased surface expression of CX3CR1 on T cells may mediate the recruitment of CD8+ T cells into the bone marrow in patients with PT who received an allo-HSCT. Moreover, CD8+CX3CR1+ T cells, which can have significantly increased numbers in bone marrow of patients with PT, likely caused a reduction in the megakaryocyte ploidy, and suppressed megakaryocyte apoptosis via CD8+ T cell-mediated cytotoxic effect, possibly leading to impaired platelet production. Therefore, treatment targeting CX3CR1 should be considered as a reasonable therapeutic strategy for PT following allo-HSCT. Disclosures: No relevant conflicts of interest to declare.

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