Prevention Of Thrombocytopenia Research Articles

New Advances in Supportive Care: Chemoprotective Agents as Novel Opportunities in Geriatric Oncology.

To explore the effectiveness of trilaciclib and ALRN-6924 in the prevention of cancer chemotherapy-induced toxicity in older patients. New chemoprotective agents are necessary because age is the main risk factor for chemotherapy complications that account largely for the poorer outcome of cancer in the elderly. Trilaciclib and ALRN-6924 cause a reversible block of the proliferation of normal cells through cell cycle arrest (CCA). With this mechanism, they may prevent the toxicity of cycle-active cancer treatment including neutropenia, anemia, thrombocytopenia, lymphopenia, mucositis, and alopecia. Myelopoietic growth factors may prevent neutropenia in the aged, but they may cause severe bone pain, may aggravate thrombocytopenia and anemia, and may cause myelodysplasia and acute leukemia as a late complication. The prevention of thrombocytopenia, anemia, mucositis, and alopecia is unsatisfactory at present. These complications may jeopardize the treatment outcome as they require a reduction of treatment dose/intensity and because many patients find the resulting symptoms intolerable. In three studies of patients with extensive disease small cell lung cancer (ES-SCLC), trilaciclib reduced the severity and duration of neutropenia and thrombocytopenia as well as the need for blood transfusions. In addition, it produced a significant expansion of T-cell clones. Trilaciclib received FDA approval for the prevention of chemotherapy-induced myelosuppression in patients with ES-SCLC. ALRN-6924 is currently studied in phase II study of ES-SCLC. In a phase IB of 38 patients, ALRN-6924 prevented myelosuppression to an extent comparable with trilaciclib. Both drugs proved as effective in patients 65 and older as they were in the younger ones. In an "ex vivo" study, ALRN-6924 protected the epithelial stem cells of hair follicles from taxanes and promised to prevent alopecia. The possibility that CCA of tumor cells may reduce the effectiveness of cycle-active chemotherapy is a major concern. For this reason, the use of trilaciclib, an inhibitor of CDK 4/6, should be limited to tumors with inactivated RB1, and the use of ALRN-6924, an inhibitor of P53, should be limited to tumors with inactivated P53. Chemotherapy-related toxicities limit dose intensity and contribute to significant morbidity and mortality in elderly cancer patients. Trilaciclib and ALRN-6924 are of particular interest to geriatric oncologists because of their novel mechanism of action. Ameliorating chemotherapy-induced toxicities holds the promise of transforming the practice of geriatric oncology by enabling chemotherapeutic regimens that are currently not feasible for this patient population. Specifically, these agents may prevent chemotherapy-induced neutropenia and thrombocytopenia, perhaps the most life-threatening complications of cytotoxic chemotherapy, thereby obviating the need for the use of rescue strategies such as hematopoietic growth factors. In addition, these agents offer the potential for broad tissue protection from other chemotherapy-related toxicities, including mucositis, diarrhea, and alopecia, which historically have been poorly managed. Importantly, by preventing a spectrum of chemotherapy-related toxicities, these agents may permit the administration of chemotherapy at full-dose intensity, prevent functional decline, and grant maintenance of resilience to older cancer patients. As a result, the successful prevention of chemotherapy-induced side effects may not only mitigate the costs of care but also improve patient outcomes and quality of life. Finally, chemoprotective strategies offer the opportunity to apply geriatric principles to clinical trials of cancer treatment. In particular, they may allow the testing of prolongation of "active life expectancy" as a major goal of clinical trials in elderly patients. They may also enable novel and more practical forms of clinical trials. By assessing the risk of chemotherapy-related toxicity with the Chemotherapy Risk Assessment Scale for High Age Patients (CRASH) or the Cancer and Aging Research Group (CARG) instruments, these agents may permit researchers to utilize patients as their own controls and endorse the approval of supportive care drugs based upon the risk profile of individual patients.

Prophylactic Administration of Recombinant Human Thrombopoietin in the Secondary Prevention of Thrombocytopenia Induced by XELOX Adjuvant Chemotherapy in Patients With Stage III Colorectal Cancer: Erratum.

Prophylactic Administration of Recombinant Human Thrombopoietin in the Secondary Prevention of Thrombocytopenia Induced by XELOX Adjuvant Chemotherapy in Patients With Stage III Colorectal Cancer: Erratum.

Dengue Fever: Therapeutic Potential of Carica papaya L. Leaves.

Dengue, a very widespread mosquito-borne infectious disease caused by Aedes aegypti virus, has been occurring during the monsoons every year. The prevalence and incidence of dengue fever and death due to its complications have been increased drastically in these recent years in Bangladesh, Philippines, Thailand, Brazil, and India. Recently, dengue had spread in an epidemic form in Bangladesh, Thailand, and Philippines. Although the infection affected a large number of people around the world, there is no established specific and effective treatment by synthetic medicines. In this subcontinent, Malaysia could effectively control its incidences and death of patients using alternative medication treatment mainly prepared from Carica papaya L. leaves along with proper care and hospitalization. Papaya leaves, their juice or extract, as well as their different forms of preparation have long been used traditionally for treating dengue fever and its complications to save patients’ lives. Although it is recommended by traditional healers, and the general public use Papaya leaves juice or their other preparations in dengue fever, this treatment option is strictly denied by the physicians offering treatment in hospitals in Bangladesh as they do not believe in the effectiveness of papaya leaves, thus suggesting to patients that they should not use them. In Bangladesh, 1,01,354 dengue patients have been hospitalized, with 179 deaths in the year 2019 according to information from the Institute of Epidemiology, Disease Control, and Research as well as the Directorate General of Health Services of Bangladesh. Most of the patients died because of the falling down of platelets to dangerous levels and hemorrhage or serious bleeding. Therefore, this paper aims to critically review the scientific basis and effectiveness of Carica papaya L. leaves in treating dengue fever based on preclinical and clinical reports. Thrombocytopenia is one of the major conditions that is typical in cases of dengue infection. Besides, the infection and impairment of immunity are concerned with dengue patients. This review summarizes all the scientific reports on Carica papaya L. for its ability on three aspects of dengue: antiviral activities, prevention of thrombocytopenia and improvement of immunity during dengue fever.

Prophylactic Administration of Recombinant Human Thrombopoietin in the Secondary Prevention of Thrombocytopenia Induced by XELOX Adjuvant Chemotherapy in Patients With Stage III Colorectal Cancer.

Prophylactic Administration of Recombinant Human Thrombopoietin in the Secondary Prevention of Thrombocytopenia Induced by XELOX Adjuvant Chemotherapy in Patients With Stage III Colorectal Cancer.

The incidence of thrombocytopenia in adult patients receiving chemotherapy for solid tumors or hematologic malignancies.

ObjectivesTo estimate the risk of thrombocytopenia in various cancers and chemotherapy regimens.MethodsStructured patient‐level data from the Flatiron Health Electronic Health Record database were used to identify adult patients who received chemotherapy for a solid tumor or hematologic malignancy from 2012 to 2017. Three‐month cumulative incidence of thrombocytopenia was assessed based on platelet counts, overall and by grade of thrombocytopenia. Co‐occurrence of anemia, neutropenia, and leukopenia was evaluated.ResultsOf 15,521 patients with solid tumors, 13% had thrombocytopenia within 3 months (platelet count < 100 × 109/L); 4% had grade 3 (25 to < 50 × 109/L), and 2% grade 4 (<25 × 109/L) thrombocytopenia. Of 2537 patients with hematologic malignancies, 28% had any thrombocytopenia, 16% with grade 3, and 12% with grade 4. Among patients with thrombocytopenia, it occurred without another cytopenia in 18% of solid tumors and 7% of hematologic malignancies.ConclusionsIn a large, US‐representative sample of patients undergoing chemotherapy in clinical practice, thrombocytopenia incidence varied across tumor and regimen types. Despite recommendations to alter chemotherapy to avoid severe thrombocytopenia, 4% of patients with solid tumors and 16% with hematologic malignancies experienced grade 3 thrombocytopenia. Prediction and prevention of thrombocytopenia may help oncologists avoid dose modifications and their adverse effects on survival.

Topical issues in the treatment of thrombocytopenia caused by chemotherapy: the view of a hematologist

Objective. Thrombocytopenia is a common complication of chemotherapy, which is characterized by a decrease in platelet count &lt;150×10⁹/l duration. Early diagnosis and correction of thrombocytopenia are important points in the treatment of patients with cancer. Currently, thromboconcentrate transfusions, recombinant human thrombopoietin, and eltrombopag are used to treat thrombocytopenia.&#x0D; Materials and methods. 200 patients were treated with recombinant human thrombopoietin in the hematology department from 2019 till 2020.&#x0D; Results and discussion. Patients were divided into two groups. 150 patients received thrombopoietin to prevent predicted chemotherapy-induced thrombocytopenia at a dose of 300 IU/kg subcutaneously after 4 consecutive days. In 50 patients Rl-TPO was used for therapeutic purposes, in the presence of thrombocytopenia, at a dose of 300 IU/kg subcutaneously daily 10-14 consecutive injections. In the 1st study group, the level of platelets when using Rl-TPO according to the scheme did not decrease by less than 150×10⁹/l. In the 2nd group, the level of platelets from 50-65×10⁹/l when using thrombopoietin for therapeutic purposes in 87 % patients began to rise for 4-5 days after administration, normalized on day 12-13, in 13 % patients began to rise on day 7-8, normalized for 15-16 days.&#x0D; Conclusions. Prevention of thrombocytopenia due to early administration of recombinant human thrombopoietin to the patient, rather than correction of pre-existing thrombocytopenia, can increase the effectiveness of chemotherapy through strict adherence to the schedule and recommended dosage, to avoid possible side effects directly from the patient.

Clinical research of thrombocytopenia induced by craniospinal irradiation

Objective To evaluate the clinical efficacy and adverse events of recombinant human interleukin-11(rhIL-11) in the prevention of thrombocytopenia induced by craniospinal irradiation. Methods In this randomized control study, 100 patients were randomly divided into A (rhIL-11 group, n=50) and B groups (control group, n=50). In the A group, subcutaneous injection of rhIL-11 was delivered at a dose of 50 μg/kg/d, once daily when the platelet count was 50% compared with the baseline level. The administration of rhIL-11 was terminated when the platelet count was ≥ 200×109/L. In the B group, the same protocol was conducted when the platelet count was< 50×109/L and terminated until the platelet count was ≥ 100×109/L. The clinical efficacy was assessed in 92 patients. Subcutaneous injection of rhIL-11 could significantly elevate the minimal platelet count during craniospinal irradiation (P<0.01), considerably shorten the duration of thrombocytopenia (P<0.01) and effectively shorten the duration of radiotherapy (P<0.01). Main adverse events included mild pain at the injection site, sclerosis, redness and fatigue, etc. Conclusions Injection of rhIL-11 can significantly enhance the platelet count, effectively reduce the incidence of thrombocytopenia throughout craniospinal irradiation, guarantee the success of radiotherapy and yield mild adverse events. Key words: Craniospinal irradiation; Interleukin-11; Thrombocytopenia/prevention

Is Dose Adjustment Based on Several Factors of Body Size Descriptors Effective for Prevention of Thrombocytopenia by Linezolid Therapy in Hemodialysis Patients?

Previous study suggested that low body weight was one of the risk factors of thrombocytopenia induced by linezolid in non-hemodialysis patients. However, there have been little investigations for the linezolid-induced thrombocytopenia in hemodialysis patients. This study was to evaluate the association between several factors of body size descriptors and thrombocytopenia in hemodialysis-patients. No factor of body size descriptors showed significant correlation with linezolid-induced thrombocytopenia (patients with thrombocytopenia vs patients without thrombocytopenia: body weight; 60.0 kg vs 55.3 kg, p = 0.82: body mass indices; 21.1 kg/m2 vs 21.2 mg/m2, p = 0.44: ideal body weight; 61.2 kg vs 59.5 kg, p = 0.21: lean body weight; 50.1 kg vs 45.7 kg, p = 0.64: dosage amount; 20.0 mg/kg vs 21.7 mg/kg, p = 0.74: body surface area; 1.65 m2 vs 1.54 m2, p = 0.43). There were not significant differences in the body size descriptors between linezolid therapy for more than 14 days and for less than 13 days (more than 14 days vs less than 13 days: body weight; 53.5 kg vs 56.8 kg, p = 0.75: body mass indices; 20.9 kg/m2 vs 21.1 mg/m2, p = 0.47: ideal body weight; 60.3 kg vs 59.9 kg, p = 0.17: lean body weight; 44.3 kg vs 47.7 kg, p = 0.56: dosage amount; 22.4 mg/kg vs 21.1 mg/kg, p = 0.67: body surface area; 1.51 m2 vs 1.59 m2, p = 0.37). Our data suggested that dosage adjustment of linezolid based on body weight was not recommended in hemodialysis-patients.

Prevention of thrombocytopenia using thrombopoietin in high-dose cytarabine treatment of non-Hodgkin lymphoma.

e19532 Background: High-dose cytarabine treatment of non-Hodgkin lymphoma most likely cause severe thrombocytopenia which may be fatal. Thrombopoietin (TPO) specifically stimulates megakaryopoiesis...

Primate Recipients of Porcine Livers Develop Fatal Coagulopathy Despite Prevention of Thrombocytopenia

Background: While allogeneic liver transplantation has evolved to the standard of care for end-stage cirrhosis, it is severely limited by organ shortage. Previous attempts to pursue xenogeneic transplantation, placing GalT-KO swine livers into non-human primates, have yielded only short-term survival primarily ascribed to the immediate post-implantation thrombocytopenia observed leading to subsequent fatal coagulopathy. We have shown that aminocaproic acid (Amicar) dramatically preserves platelet levels, but that fatal hemorrhage still prevails. Methods: Three baboons received orthotropic hepatic xenografts from size-matched miniature swine under immunosuppression, proven adequate for xenotransplantation of other organs. Two baboons received, in addition, treatment with Amicar starting on POD 0 or 5 following transplantation. Results: The recipients survived, with good liver function, for 6, 8, and 9 days respectively. The platelet counts plummeted shortly after transplantation. In the first animal (B274), progressive platelet loss was unresponsive to transfusion of allogeneic platelets. In the second recipient (B291) Amicar was started on POD 5, following which platelet counts stabilized in the 30-60 k/μl range throughout a 9-day survival period, the longest reported to date. The third animal (B317) survived for 8 days with platelet numbers rescued to > 100 k/μl during continuous Amicar treatment started before reperfusion. Serial xenograft biopsies did not show any signs of rejection at any time point. Liver function parameters were within normal limits and the recipient animals appeared clinically well. Nevertheless, all animals eventually developed internal hemorrhage. The causes of death were therapy refractory coagulopathy, which in B291 and B317 possibly was exacerbated by enterococcal infection, detected in ascites cultures. Conclusions: These observations indicate for the first time that thrombocytopenia after liver xenotransplantation can be controlled by Amicar. The finding that fatal hemorrhage occurred despite satisfactory platelet levels, suggests that other incompatibilities between porcine and primate coagulation pathways may exist. Our results suggest that improved immunosuppressive regimens to reduce the risk of infection and additional measures to address coagulation factor incompatibilities will likely be required to achieve long-term survival of xenogeneic livers.Table: [Platelet count]

Absence of cytokine modulation following therapeutic infusion of intravenous immunoglobulin or anti‐red blood cell antibodies in a mouse model of immune thrombocytopenic purpura

Human intravenous immunoglobulin (IVIg) and anti-D immunoglobulin preparations are used in the treatment of immune thrombocytopenic purpura (ITP). One mechanism proposed to explain their therapeutic effects in ITP patients is the induction of expression of anti-inflammatory cytokines, such as interleukin (IL)-10 or IL-1ra, leading to a reduction of phagocytic activity of the reticuloendothelial system. However, increased expression of pro-inflammatory cytokines was also noted following treatment of ITP patients, raising doubt on the actual contribution of anti-inflammatory cytokines in the therapeutic effects of IVIg and anti-D immunoglobulins. The present study evaluated the in vivo modulation of expression of a large array of inflammatory cytokines using a mouse model of thrombocytopenia. IVIg was not found to modulate cytokine expression although it efficiently prevented thrombocytopenia. In contrast, protective (M1/69) and non-protective (TER-119) anti-mouse red blood cell (RBC) antibodies (mimicking anti-D treatment) both increased the expression of CXCL-1 and CXCL-5. Thus, there was no relationship between inflammatory cytokine expression and prevention of thrombocytopenia by IVIg or anti-mouse RBC in the ITP mouse model. These results suggest that the increase in cytokine expression observed in ITP patients following IVIg or anti-D infusion is not required for their therapeutic effects but may rather represent a side-effect of the treatment.

Prevention of Thrombocytopenia by Thrombopoietin in Myelosuppressed Rhesus Monkeys Accompanied by Prominent Erythropoietic Stimulation and Iron Depletion

AbstractThe effectiveness of thrombopoietin (TPO) in alleviating thrombocytopenia was evaluated in a placebo-controlled study involving rhesus monkeys exposed to 5 Gy total-body irradiation (TBI) (300-kV x-rays) to result in 3 weeks of pancytopenia. Supraoptimal treatment with human recombinant TPO (10 μg/kg/d subcutaneously, days 1 to 21 after TBI) was highly effective in preventing thrombocytopenia, with nadirs for thrombocytes, on average, far higher than 100 × 109/L, a greatly accelerated recovery to normal values, and no need for thrombocyte transfusions. TPO appeared to act selectively in that neutrophil regeneration was not influenced but red blood cell lineage recovery was prominently stimulated, with reticulocyte regeneration being initiated 10 days earlier than in placebo-treated animals. The reticulocytosis was followed by a normoblastosis that occurred earlier and was more pronounced than in placebo-treated monkeys. The effect of TPO on the red blood cell lineage was also reflected in a less profound nadir for hemoglobin (Hb) and hematocrit values than in placebo controls. However, this effect was not followed by a rapid recovery to normal values, due to development of a microcytic hypochromic anemia. Iron depletion was demonstrated by measurements of total serum iron and total iron-binding capacity (TIBC) and could be prevented by prophylactic intramuscular (IM) iron before TBI or corrected by IM iron after TPO treatment. Rechallenging with TPO in week 8 after TBI demonstrated a homogenous thrombocyte response similar in magnitude to the initial response, but a greatly diminished reticulocyte response. This demonstrated that the erythropoietic response to TPO administration depends on the hemopoietic state of the animal and may reflect multiple TPO target cells. It is postulated that the extremely rapid erythropoiesis due to TPO treatment in the initial regeneration phase following myelosuppression results in iron depletion by a mechanism similar to that seen following erythropoietin treatment in patients with end-stage renal failure. It is concluded that protracted TPO therapy to counteract thrombocytopenic states may result in iron depletion and that the iron status should be monitored before, during, and after TPO treatment.

Prevention of Thrombocytopenia by Thrombopoietin in Myelosuppressed Rhesus Monkeys Accompanied by Prominent Erythropoietic Stimulation and Iron Depletion

The effectiveness of thrombopoietin (TPO) in alleviating thrombocytopenia was evaluated in a placebo-controlled study involving rhesus monkeys exposed to 5 Gy total-body irradiation (TBI) (300-kV x-rays) to result in 3 weeks of pancytopenia. Supraoptimal treatment with human recombinant TPO (10 μg/kg/d subcutaneously, days 1 to 21 after TBI) was highly effective in preventing thrombocytopenia, with nadirs for thrombocytes, on average, far higher than 100 × 109/L, a greatly accelerated recovery to normal values, and no need for thrombocyte transfusions. TPO appeared to act selectively in that neutrophil regeneration was not influenced but red blood cell lineage recovery was prominently stimulated, with reticulocyte regeneration being initiated 10 days earlier than in placebo-treated animals. The reticulocytosis was followed by a normoblastosis that occurred earlier and was more pronounced than in placebo-treated monkeys. The effect of TPO on the red blood cell lineage was also reflected in a less profound nadir for hemoglobin (Hb) and hematocrit values than in placebo controls. However, this effect was not followed by a rapid recovery to normal values, due to development of a microcytic hypochromic anemia. Iron depletion was demonstrated by measurements of total serum iron and total iron-binding capacity (TIBC) and could be prevented by prophylactic intramuscular (IM) iron before TBI or corrected by IM iron after TPO treatment. Rechallenging with TPO in week 8 after TBI demonstrated a homogenous thrombocyte response similar in magnitude to the initial response, but a greatly diminished reticulocyte response. This demonstrated that the erythropoietic response to TPO administration depends on the hemopoietic state of the animal and may reflect multiple TPO target cells. It is postulated that the extremely rapid erythropoiesis due to TPO treatment in the initial regeneration phase following myelosuppression results in iron depletion by a mechanism similar to that seen following erythropoietin treatment in patients with end-stage renal failure. It is concluded that protracted TPO therapy to counteract thrombocytopenic states may result in iron depletion and that the iron status should be monitored before, during, and after TPO treatment.

Prevention of Thrombocytopenia and Neutropenia in a Nonhuman Primate Model of Marrow Suppressive Chemotherapy by Combining Pegylated Recombinant Human Megakaryocyte Growth and Development Factor and Recombinant Human Granulocyte Colony-Stimulating Factor

This report examines the effects on hematopoietic regeneration of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF ) (2.5 μg/kg/d) alone and in combination with recombinant human granulocyte colony stimulating factor (rHu-GCSF ) (10 μg/kg/d) for 21 days in rhesus macaques receiving intense marrow suppression produced by single bolus injections of hepsulfam (1.5 g/m2). In six hepsulfam-only control animals thrombocytopenia (platelet count &lt;100 × 109/L) was observed between days 12 and 25 (nadir 39 ± 20 × 109/L on day 17), and neutropenia (absolute neutrophil count &lt;1 × 109/L) occurred between days 8 and 30 (nadir 0.167 ± 0.120 × 109/L on day 15). PEG-rHuMGDF (2.5 μg/kg/d) injected subcutaneously into four animals from day 1 to day 22 following hepsulfam administration produced trough serum concentrations of 1.9 ± 0.2 ng/mL and increased the platelet count twofold over basal prechemotherapy levels (856 ± 594 × 109/L v baseline of 416 ± 88 × 109/L; P = .01). PEG-rHuMGDF alone also shortened the period of posthepsulfam neutropenia from 22 days to 12 days (P = .01), although the neutropenic nadir was not significantly altered (neutrophil count 0.224 ± 0.112 × 109/L v 0.167 ± 0.120 × 109/L; P &lt; .3). rHu-GCSF (10 μg/kg/d) injected subcutaneously into four animals from day 1 to day 22 following hepsulfam administration produced trough serum concentrations of 1.4 ± 1.1 ng/mL, and reduced the time for the postchemotherapy neutrophil count to attain 1 × 109/L from 22 days to 4 days (P = .005). The postchemotherapy neutropenic nadir was 0.554 ± 0.490 × 109neutrophils/L (P = .3 v hepsulfam-only control of 0.167 ± 0.120 × 109/L). However, thrombocytopenia of &lt;100 × 109 platelets/L was not shortened (persisted from day 12 to day 25), or less severe (nadir of 56 ± 32 × 109 platelets/L on day 14; P = .7 compared with untreated hepsulfam animals). The concurrent administration of rHu-GCSF (10 μg/kg/d) and PEG-rHuMGDF (2.5 μg/kg/d) in four animals resulted in postchemotherapy peripheral platelet counts of 127 ± 85 × 109/L (P = .03 compared with 39 ± 20 × 109/L for untreated hepsulfam alone, and P = .02 compared with 856 ± 594 × 109/L for PEG-rHuMGDF alone), and shortened the period of neutropenia &lt;1 × 109/L from 22 days to 4 days (P = .8 compared with rHu-GCSF alone). Increasing PEG-rHuMGDF to 10 μg/kg/d and maintaining the 21-day schedule of coadministration with rHu-GCSF (10 μg/kg/d) in another four animals produced postchemotherapy platelet counts of 509 ± 459 × 109/L (P &lt; 10−4compared with untreated hepsulfam alone, and P = .04 compared with 2.5 μg/kg/d PEG-rHuMGDF alone), and 4 days of neutropenia. Coadministration of rHu-GCSF and PEG-rHuMGDF did not significantly alter the pharmacokinetics of either agent. The administration of PEG-rHuMGDF (2.5 μg/kg/d) from day 1 through day 22 and rHu-GCSF (10 μg/kg/d) from day 8 through day 22 in six animals produced peak postchemotherapy platelet counts of 747 ± 317 × 109/L (P &lt; 10−4 compared with untreated hepsulfam alone, and P = .7 compared with PEG-rHuMGDF alone), and maintained the neutrophil count &lt; 3.5 × 109/L (P = .008 v rHu-GCSF therapy alone). Thus, both thrombocytopenia and neutropenia are eliminated by initiating daily PEG-rHuMGDF therapy on day 1 and subsequently adding daily rHu-GCSF after 1 week in the rhesus model of hepsulfam marrow suppression. This improvement in platelet and neutrophil responses by delaying the addition of rHu-GCSF to PEG-rHuMGDF therapy demonstrates the importance of optimizing the dose and schedule of cytokine combinations after severe myelosuppressive chemotherapy.

Prevention of Thrombocytopenia and Neutropenia in a Nonhuman Primate Model of Marrow Suppressive Chemotherapy by Combining Pegylated Recombinant Human Megakaryocyte Growth and Development Factor and Recombinant Human Granulocyte Colony-Stimulating Factor

AbstractThis report examines the effects on hematopoietic regeneration of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF ) (2.5 μg/kg/d) alone and in combination with recombinant human granulocyte colony stimulating factor (rHu-GCSF ) (10 μg/kg/d) for 21 days in rhesus macaques receiving intense marrow suppression produced by single bolus injections of hepsulfam (1.5 g/m2). In six hepsulfam-only control animals thrombocytopenia (platelet count <100 × 109/L) was observed between days 12 and 25 (nadir 39 ± 20 × 109/L on day 17), and neutropenia (absolute neutrophil count <1 × 109/L) occurred between days 8 and 30 (nadir 0.167 ± 0.120 × 109/L on day 15). PEG-rHuMGDF (2.5 μg/kg/d) injected subcutaneously into four animals from day 1 to day 22 following hepsulfam administration produced trough serum concentrations of 1.9 ± 0.2 ng/mL and increased the platelet count twofold over basal prechemotherapy levels (856 ± 594 × 109/L v baseline of 416 ± 88 × 109/L; P = .01). PEG-rHuMGDF alone also shortened the period of posthepsulfam neutropenia from 22 days to 12 days (P = .01), although the neutropenic nadir was not significantly altered (neutrophil count 0.224 ± 0.112 × 109/L v 0.167 ± 0.120 × 109/L; P < .3). rHu-GCSF (10 μg/kg/d) injected subcutaneously into four animals from day 1 to day 22 following hepsulfam administration produced trough serum concentrations of 1.4 ± 1.1 ng/mL, and reduced the time for the postchemotherapy neutrophil count to attain 1 × 109/L from 22 days to 4 days (P = .005). The postchemotherapy neutropenic nadir was 0.554 ± 0.490 × 109neutrophils/L (P = .3 v hepsulfam-only control of 0.167 ± 0.120 × 109/L). However, thrombocytopenia of <100 × 109 platelets/L was not shortened (persisted from day 12 to day 25), or less severe (nadir of 56 ± 32 × 109 platelets/L on day 14; P = .7 compared with untreated hepsulfam animals). The concurrent administration of rHu-GCSF (10 μg/kg/d) and PEG-rHuMGDF (2.5 μg/kg/d) in four animals resulted in postchemotherapy peripheral platelet counts of 127 ± 85 × 109/L (P = .03 compared with 39 ± 20 × 109/L for untreated hepsulfam alone, and P = .02 compared with 856 ± 594 × 109/L for PEG-rHuMGDF alone), and shortened the period of neutropenia <1 × 109/L from 22 days to 4 days (P = .8 compared with rHu-GCSF alone). Increasing PEG-rHuMGDF to 10 μg/kg/d and maintaining the 21-day schedule of coadministration with rHu-GCSF (10 μg/kg/d) in another four animals produced postchemotherapy platelet counts of 509 ± 459 × 109/L (P < 10−4compared with untreated hepsulfam alone, and P = .04 compared with 2.5 μg/kg/d PEG-rHuMGDF alone), and 4 days of neutropenia. Coadministration of rHu-GCSF and PEG-rHuMGDF did not significantly alter the pharmacokinetics of either agent. The administration of PEG-rHuMGDF (2.5 μg/kg/d) from day 1 through day 22 and rHu-GCSF (10 μg/kg/d) from day 8 through day 22 in six animals produced peak postchemotherapy platelet counts of 747 ± 317 × 109/L (P < 10−4 compared with untreated hepsulfam alone, and P = .7 compared with PEG-rHuMGDF alone), and maintained the neutrophil count < 3.5 × 109/L (P = .008 v rHu-GCSF therapy alone). Thus, both thrombocytopenia and neutropenia are eliminated by initiating daily PEG-rHuMGDF therapy on day 1 and subsequently adding daily rHu-GCSF after 1 week in the rhesus model of hepsulfam marrow suppression. This improvement in platelet and neutrophil responses by delaying the addition of rHu-GCSF to PEG-rHuMGDF therapy demonstrates the importance of optimizing the dose and schedule of cytokine combinations after severe myelosuppressive chemotherapy.

254 Interleukin 3 (IL3) in the treatment of thrombocytopenia after standard dose of chemotherapy

Neutropenia and/or Thrombocytopenia are the most important toxicities in several chemotherapy regimens, which result in dose- or interval modifications, which may cause a dose intensity reduction. IL3 is a glycoprotein with an in vitro and in vivo broad spectrum of activity on hematopoiesis with either prompt neutrophil and platelet counts recovery and prevention of significant periods of neutropenia and prevention of thrombocytopenia. This action is based on ability of IL3 to stimulate the differentiation and proliferation of pluripotent precursor cells in bone marrow. With this background, we treated 14 patients (8 females and 6 males, who all gave their informed consent for this pilot study) with thrombocytopenia after standard dose of chemotherapy. Eleven pts were evaluated for response (2 pts too early, 1 pt dropout of the study after only one administration). The sites of diseases were: breast 5 pts, stomach 3 pts, lung 1 pt, LNH 1 pt, mesothelioma 1 pt, neuroblastoma 1 pt, leiomyosarcoma 1 pt, unknown primary site 1 pt. IL3 was given at a dose of 10 mcg/kg/die s.c. from the onset of G1–G4 thrombocytopenia and continued until recovery. IL3 was given for a mean of 5. 7 days (range 2–10) and a median of 5 days. So far 17 out 21 cycles of chemotherapy with thrombocytopenia are evaluable. At present our results are as follows: •thrombocytopenia G1 (4 cycles): mean increase of platelet counts = 32% within a period of 4.75 days (range 2–10); •thrombocytopenia G2 (8 cycles): mean increase of platelet counts = 31% within a period of 5.75 days (range 2–10); •thrombocytopenia G3–4 (5 cycles): mean increase of platelet counts = 157% within a period of 7 days (range 4–10). The main toxicities were: fever G1–2 8 pts; tremor 3 pts; erythema 1 pts; flu-like symptoms 4 pts; nausea/vomiting G2 1 pts; myalgia G2 6 pts; mental derangement 1 pt 1 pt, after first administration, has developed acute hypersensitivity with lipothymia. These data seem to show that IL3 is an active drug in the treatment of thrombocytopenia following a standard dose of chemotherapy. The study is still ongoing and definitive results will be discussed.

The effect of heparin on multiple organ failure and disseminated intravascular coagulation in a sepsis model

In order to elucidate a possible role of hypercoagulability leadir to disseminated intravascular coagulation (DIC) in the pathogenesi of multiple organ failure (MOF), unfractionated heparin and the related agents were administered to septic rabbits which manifest DIC and MOF. Administration of heparin resulted in prevention of thrombocytopenia, leukopenia and elevation of plasma bilirubin and creatinine. The morphological hepatic damage was also ameliorated by heparin. Similar favorable effects were obtained by the admini tration of low molecular weight heparin. Dextran sulfate prevente the hepatic damage to some extent without improvement on other parameters. No significant effect was observed by the administrat of a synthetic thrombin inhibitor (MD805). These results indicate that the favorable effect of heparin is due to its anticoagulant property, especially anti-Xa activity. Thereby, it is concluded that the hypercoagulable state leading to DIC is a prerequisite for the occurrence of MOF in sepsis.