Rhu GM-CSF Research Articles

279. Inhaled Sargramostim (rhu GM-CSF) Leads to Enhanced SARS-CoV-2 Virus-Specific Immune Response and Viral Clearance: Results of the Biomarker Cohort of a Randomized, Double-Blind, Placebo-Controlled Phase 2b Trial in Non-Hospitalized Patients with COVID-19

Abstract Background Progression from mild to severe SARS-CoV-2 infection correlates with humoral and cellular immune signatures that adjust to a multiplying viral load. Enhancing immunity with host-directed therapy, such as sargramostim (yeast-derived, recombinant human granulocyte-macrophage colony-stimulating factor [GM-CSF]), may prevent disease progression and reduce severity. Methods This prospective, randomized, double-blind, placebo-controlled study enrolled symptomatic vaccinated and unvaccinated non-hospitalized patients with mild/moderate COVID-19 at high risk for progression. Patients received daily sargramostim 250 mcg or placebo, inhaled via nebulizer, for 5 days. Figure 1 lists study endpoints. Results From April 28, 2021 to January 31, 2022, 101 patients consented and provided samples for the biomarker cohort (Fig 2). No difference was seen in the overall study primary endpoint (n=21/301 sargramostim, n=16/299 placebo, p=0.4). Treatment-emergent adverse events were similar in both arms. In the biomarker cohort, SARS-CoV-2 viral clearance by day 14 was enhanced on the sargramostim arm (p=0.0064, Fig 3). Virus was undetectable in a larger proportion on the sargramostim arm. Sargramostim reduced viral load more in vaccinated than unvaccinated patients. Inflammatory cytokine levels did not increase with treatment. Kinetics and magnitude of antibody response against SARS-CoV-2 antigens differed by group. After an initial IgM-titer peak at day 14, IgM titers at day 28 were lower in the vaccinated-sargramostim arm than the vaccinated-placebo arm (Fig 4A). The unvaccinated-sargramostim arm maintained higher IgM titers than the unvaccinated-placebo arm. Overall IgG titers were higher for vaccinated patients across both treatment arms. However, the vaccinated-sargramostim arm had higher IgG4 titers associated with IgG4-isotype-class switching than the vaccinated-placebo arm (Fig 4B). Conclusion The primary clinical endpoint was not met. Biomarker analyses suggest inhaled sargramostim reduces SARS-CoV-2 viral load and alters humoral kinetics and expression, more so in those vaccinated. Results suggest the potential of sargramostim as a virus agnostic, host-directed immunomodulator. Disclosures Ila Joshi, PhD, Partner Therapeutics, Inc.: Patents|Partner Therapeutics, Inc.: Salary|Partner Therapeutics, Inc.: Stocks/Bonds Fiona Garner, PhD, Partner Therapeutics, Inc.: Employment|Partner Therapeutics, Inc.: Stocks/Bonds Debasish F. Roychowdhury, MD, Partner Therapeutics, Inc.: Employment|Partner Therapeutics, Inc.: Ownership Interest|Partner Therapeutics, Inc.: Stocks/Bonds Lorinda Simms, MSc, Partner Therapeutics, Inc.: Advisor/Consultant|Partner Therapeutics, Inc.: Stocks/Bonds Sanjeev Ahuja, MD, Partner Therapeutics, Inc.: Employment|Partner Therapeutics, Inc.: Stocks/Bonds|Scioto Biosciences: Past Employee John L. McManus, n/a, JPEO-CBRND's Joint Project Manager for Chemical, Biological, Radiological, and Nuclear Medical: Project agreement MCDC2006-012. Included references to commercial products do not constitute an endorsement by the US DoD or the JPEO-CBRND.|Partner Therapeutics, Inc.: Employment|Partner Therapeutics, Inc.: Stocks/Bonds Edwin P. Rock, MD, PhD, Partner Therapeutics: Employment Robert Paine III, MD, Partner Therapeutics, Inc.: Advisor/Consultant

Utility of monocyte HLA-DR and rationale for therapeutic GM-CSF in sepsis immunoparalysis.

Sepsis, a heterogeneous clinical syndrome, features a systemic inflammatory response to tissue injury or infection, followed by a state of reduced immune responsiveness. Measurable alterations occur in both the innate and adaptive immune systems. Immunoparalysis, an immunosuppressed state, associates with worsened outcomes, including multiple organ dysfunction syndrome, secondary infections, and increased mortality. Multiple immune markers to identify sepsis immunoparalysis have been proposed, and some might offer clinical utility. Sepsis immunoparalysis is characterized by reduced lymphocyte numbers and downregulation of class II human leukocyte antigens (HLA) on innate immune monocytes. Class II HLA proteins present peptide antigens for recognition by and activation of antigen-specific T lymphocytes. One monocyte class II protein, mHLA-DR, can be measured by flow cytometry. Downregulated mHLA-DR indicates reduced monocyte responsiveness, as measured by ex-vivo cytokine production in response to endotoxin stimulation. Our literature survey reveals low mHLA-DR expression on peripheral blood monocytes correlates with increased risks for infection and death. For mHLA-DR, 15,000 antibodies/cell appears clinically acceptable as the lower limit of immunocompetence. Values less than 15,000 antibodies/cell are correlated with sepsis severity; and values at or less than 8000 antibodies/cell are identified as severe immunoparalysis. Several experimental immunotherapies have been evaluated for reversal of sepsis immunoparalysis. In particular, sargramostim, a recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF), has demonstrated clinical benefit by reducing hospitalization duration and lowering secondary infection risk. Lowered infection risk correlates with increased mHLA-DR expression on peripheral blood monocytes in these patients. Although mHLA-DR has shown promising utility for identifying sepsis immunoparalysis, absence of a standardized, analytically validated method has thus far prevented widespread adoption. A clinically useful approach for patient inclusion and identification of clinically correlated output parameters could address the persistent high unmet medical need for effective targeted therapies in sepsis.

Sargramostim in acute radiation syndrome

ABSTRACT Introduction Since 1944, nearly 400 radiologic accidents/incidents have exposed about 3,000 people to substantial doses of ionizing radiation, with more than 125 deaths. Known are the Chernobyl and Fukushima nuclear power facility accidents, but the recent war in Ukraine has refocused attention on this issue. Therapy of acute, high-dose, whole-body exposures to ionizing radiation includes transfusions, antimicrobial drugs, molecularly cloned hematopoietic growth factors, and hematopoietic cell transplants (HCT). Areas covered We focus on approved therapies including recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF, sargramostim). Animal data indicate sargramostim accelerates marrow recovery and increases survival. In 2018, the United States Food and Drug Administration approved sargramostim for persons acutely exposed to myelosuppressive radiation doses based on two large nonhuman primate studies. In seven radiation accidents since 1986, 28 victims exposed to acute high-dose ionizing radiation received rhu GM-CSF alone or with other hematopoietic growth factors. Therapy appeared effective with few, if any, adverse events; 18 survived. Expert opinion This favorable benefit-to-risk ratio suggests giving sargramostim soon after exposure and is favored over HCT based on greater safety and fewer resource requirements, especially in the context of large-scale exposures which might occur after use of a tactical nuclear weapon or nuclear terrorism.

Low-dose topical recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) therapy for chronic venous leg ulcers, 10-year follow-up

The treatment of leg ulcers is an enormous problem worldwide. Chronic venous ulceration affects 1% of the population and often has aprotracted course. Recurrence rate is high, ranging up to 69% in the first year after healing. To determine whether topical application of low-dose topical recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) is safe in venous leg ulcer treatment, and whether it accelerates healing rates and reduces recurrence rates. Consecutive patients with chronic venous leg ulcers received topical treatment with low-dose rhu GM-CSF (10 µg/mL 0.9% sodium chloride solution; 1.0-2.3 µg rhu GM-CSF/cm2) in combination with treatment of venous insufficiency. All patients were previously treated with other topical wound remedies for several weeks (median 8weeks) without success. In 119 of 130patients, the wounds healed completely (91.5%). No local or systemic adverse reactions were observed. The mean time to healing was 24weeks (median 14weeks). Median follow-up of the 119patients with healed ulcers was 84months. The recurrence rates were 5.2% after 1year, 18.9% after 4years and 32.0% after 10years. Topical low-dose rhu GM-CSF proved to be safe and highly effective. Healing rates were comparable to those reported in the ESCHAR study (Effects of Surgery and Compression on Healing And Recurrence in venous ulceration) and recurrence rates were the lowest reported in the literature. Topical therapy with rhu GM-CSF can be applied in an outpatient setting and does not require hospitalization.

Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor (rhu GM-CSF) as Adjuvant Therapy for Invasive Fungal Diseases.

Sargramostim (yeast-derived, glycosylated recombinant human granulocyte-macrophage colony-stimulating factor [rhu GM-CSF]) augments innate and adaptive immune responses and accelerates hematopoietic recovery of chemotherapy-induced neutropenia. However, considerably less is known about its efficacy as adjunctive immunotherapy against invasive fungal diseases (IFDs). The clinical courses of 15 patients with pediatric malignancies and IFDs treated adjunctively with sargramostim at a single institution were analyzed in a retrospective cohort review. Further, a systematic review of published reports of rhu GM-CSF for IFDs was also conducted. Among 65 cases, 15 were newly described pediatric patients and 50 were previously published cases of IFDs treated with rhu GM-CSF. Among the newly reported pediatric patients, IFDs were caused by Candida spp., Trichosporon sp., and molds (Aspergillus spp., Rhizopus sp., Lichtheimia sp., and Scedosporium sp). Twelve (80%) were neutropenic at baseline, and 12 (80%) were refractory to antifungal therapy. Among 12 evaluable patients, the overall response rate was 92% (8 [67%] complete responses, 3 [25%] partial responses, and 1 [8%] stable). Treatment is ongoing in the remaining 3 patients. Among 50 published cases (15 Candida spp., 13 Mucorales, 11 Aspergillus spp., 11 other organisms), 20 (40%) had baseline neutropenia and 36 (72%) were refractory to standard therapy before rhu GM-CSF administration. Consistent with responses in the newly reported patients, the overall response rate in the literature review was 82% (40 [80%] complete responses, 1 [2%] partial response, and 9 [18%] no response). Sargramostim may be a potential adjunctive immunomodulator for selected patients with hematological malignancies and refractory IFDs.

Sargramostim (rhu GM-CSF) Improves Survival of Non-Human Primates with Severe Bone Marrow Suppression after Acute, High-Dose, Whole-Body Irradiation.

Exposure to acute, high-dose, whole-body ionizing radiation results in bone marrow failure (hematopoietic acute radiation syndrome with resultant infection, bleeding, anemia, and increased risk of death). Sargramostim (yeast-derived rhu GM-CSF), a yeast-derived, molecularly cloned, hematopoietic growth factor and pleiotropic cytokine supports proliferation, differentiation, maturation and survival of cells of several myeloid lineages. We evaluated the efficacy of sargramostim in non-human primates (rhesus macaques) exposed to whole-body ionizing radiation at a 50-60% lethal dose. The primary end point was day 60 survival. Non-human primates received daily subcutaneous sargramostim (7 mcg/kg/day) or control. To reflect the anticipated setting of a nuclear or radiologic event, treatment began 48 h postirradiation, and non-human primates received only moderate supportive care (no whole blood transfusions or individualized antibiotics). Sargramostim significantly increased day 60 survival to 78% (95% confidence interval, 61-90%) vs. 42% (26-59%; P = 0.0018) in controls. Neutrophil, platelet and lymphocyte recovery rates were accelerated and infection rates decreased. Improved survival when sargramostim was started 48 h postirradiation, without use of intensive supportive care, suggests sargramostim may be effective in treating humans exposed to acute, high-dose whole-body, ionizing radiation in a scenario such as a mass casualty event.

Efficacy of delayed administration of sargramostim up to 120 hours post exposure in a nonhuman primate total body radiation model

Background High dose ionizing radiation exposure is associated with myelo-depression leading to pancytopenia and the expected clinical manifestations of acute radiation syndrome (ARS). Herein, we evaluated the efficacy of sargramostim (Leukine®, yeast-derived rhu GM-CSF), with regimens delivered at 48, 72, 96, or 120 h after radiation exposure. Methods A randomized and blinded nonhuman primate (NHP) study was conducted to assess the effects of sargramostim treatment on ARS. NHPs were exposed to total body radiation (LD83/60 or lethal dose 83% by Day 60) and were randomized to groups receiving daily subcutaneous dosing of sargramostim starting from either 48, 72, 96, or 120 h post-irradiation. Additionally, separate groups receiving sargramostim treatment at 48 h post-irradiation also received prophylactic treatment with azithromycin. Sargramostim treatment of each animal continued until the preliminary absolute neutrophil count (ANC) returned to ≥1000/μL post-nadir for three consecutive days or the preliminary ANC exceeded 10,000/μL, which amounted to be an average of 15.95 days for all treatment groups. Prophylactic administration of enrofloxacin was included in the supportive care given to all animals in all groups. All animals were monitored for 60 days post-irradiation for mortality, hematological parameters, and sepsis. Results Delayed sargramostim treatment at 48 h post-irradiation significantly reduced mortality (p = .0032) and improved hematological parameters including neutrophil but also lymphocyte and platelet counts. Additional delays in sargramostim administration at 72, 96, and 120 h post-irradiation were also similarly effective at enhancing the recovery of lymphocyte, neutrophil, and platelet counts compared to control. Sargramostim treatment also improved the survival of the animals when administered at up to 96 h post-irradiation. While sargramostim treatment at 48 h significantly reduced mortality associated with sepsis (p ≤ .01), the additional prophylactic treatment with azithromycin did not have clinically significant effects. Conclusion In a NHP ARS model, sargramostim administered starting at 48 h post-radiation was effective to improve survival, while beneficial hematological effects were observed with sargramostim initiated up to 120 h post exposure.

Boosting Abscopal Response to Radiotherapy with Sargramostim: A Review of Data and Ongoing Studies.

Drug development in oncology today routinely focuses on approaches that utilize the patients’ immune system to destroy the malignancy. Combinatorial approaches of antineoplastic agents, both new and old, are being incorporated in the armamentarium of cancer treatments. The overarching goal of therapy remains the achievement of a complete and durable response with long term remission or cure. One approach in advancing treatment is aimed at strategies that improve immunological memory to induce long lasting immunity against the tumor. Although radiation therapy has not traditionally been thought to elicit an immunological effect, an increasing number of reports document the induction of an immune response against a tumor that kills cancer cells distant to the original site of treatment after local irradiation to a tumor. This phenomenon is called an abscopal effect. Since radiation alone is rarely associated with such a response, it is being combined with immuno-oncology drugs in an attempt to enhance response. One such strategy combines sargramostim, a recombinant human granulocyte macrophage colony stimulating factor (rhu GM-CSF), with radiotherapy. GM-CSF is a cytokine secreted by multiple cells types that promotes maturation of dendritic cells and enables the presentation of tumor-associated antigens to generate a T-cell response. This review article discusses the outcomes of clinical trials and case reports examining the efficacy and safety of combining radiation therapy with this immunomodulatory agent. We will also examine future studies and challenges facing the translation of this therapeutic approach.

Generation of alpha-Type-1 Polarized Dendritic Cells as a Potent Immunogen in Patients with Chronic Lymphocytic Leukemia.

We tested the feasibility of generating alpha-type-1 polarized DC (αDC1) from the blood of chronic lymphocytic leukemia (CLL) patients and the in vitro effectiveness of autologous tumor-loaded αDC1s in inducing CTLs against CLL. CD14+ cells were isolated from the peripheral blood of CLL patients and were cultured in rhu GM-CSF and IL-4. On day 6, DC maturation was induced using either a standard cytokine cocktail (in IL-1β, TNFα, IL-6, and PGE2) or αDC1-polarizing cocktail (in IL-1β, TNFα, IFNα, IFNγ, and poly-I:C). In either case, the maturing DCs were loaded with gamma-irradiated autologous CLL cells. αDC1s from CLL patients expressed substantially higher levels of several costimulatory molecules (CD83, CD86, CD80, CD11c and CD40) than standard DCs (sDCs) while CCR7 showed lower expression. Gamma-irradiated CLL cells were more efficienly taken up by DCs compared to UVC-irradiated CLL cells, but the ability of tumor antigen uptake was similar between αDC1 and sDCs. The capacity of IL-12p70 secretion in DCs (baseline and after stimulation with CD40L-transfected J558 cells) was significantly elevated in αDC1s (10–60 times) compared to sDCs. αDC1s also induced significantly higher numbers of functional CD8+ T cells against CLL cells, as determined by IFN-γ ELISPOT, using anti-MHC class I blocking mAb (W6/32) to verify the specificity of CTL responses. Our data demonstrate that αDC1s are a potent alternative to standard DCs as inducers of T cells for adoptive immunotherapy in patients with CLL and a clinical trial will be initiated.

A randomized, double-blind, placebo-controlled trial of prophylactic recombinant human granulocyte-macrophage colony-stimulating factor to reduce nosocomial infections in very low birth weight neonates

Objective: We carried out a randomized placebo-controlled trial in very low birth weight neonates (VLBWNs), comparing the incidence of nosocomial infections after the prophylactic use of recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) versus placebo in VLBWNs. Study design: VLBWNs (n = 264), weighing 501 to 1000 g, ≤72 hours of age were randomly assigned to receive rhu GM-CSF (8 μg/kg/d), administered intravenously (n = 134) over 2 hours daily × 7 days and every other day for 21 days, or placebo (n = 130). The safety, incidence of nosocomial infections, days of absolute neutrophil count ≥4000/mm, 3 peripheral blood progenitor studies, and 24-hour polymorphonuclear leukocyte C3bi receptor expression were compared between the 2 treatment groups. Results: No (grade III/IV) toxicity or adverse events were associated with rhu GM-CSF. The absolute neutrophil count and absolute eosinophil count were significantly elevated in the rhu GM-CSF group on days 7 ( P = .001), 14 ( P = .001), and 21 ( P = .007) and on days 7 and 28 ( P = .012 and P = .001, respectively). However, there was no difference in the incidence of confirmed nosocomial infections between the 2 treatment groups in this trial (40% vs 39%, rhu GM-CSF vs placebo; P = NS). Conclusion: In a large randomized placebo-controlled trial, prophylactic administration of rhu GM-CSF in VLBWNs does not appear to decrease the incidence of nosocomial infections. (J Pediatr 1999;134:64-70)

The effect of rHu GM-CSF and rHu G-CSF administration on neutrophil chemiluminescence assay in patients following cyclic chemotherapy

The effect of rHu GM-CSF and rHu G-CSF administration on neutrophil chemiluminescence assay in patients following cyclic chemotherapy

Immediate Hypersensitivity to Human Recombinant Granulocyte-Macrophage Colony-Stimulating Factor Associated with a Positive Prick Skin Test Reaction

Recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF), also known as sargramostim, is used to accelerate myeloid recovery following bone marrow transplantation or cytotoxic chemotherapy. "Anaphylactic" reactions to sargramostim have been reported on a limited basis and are poorly characterized. It is the purpose of this report to describe an adverse reaction to sargramostim treatment involving palmar itching, urticaria, angioedema, and throat tightness and to demonstrate the utility of prick skin testing to determine type I sensitization. Prick skin testing with 100 and 250 micrograms/mL sargramostim and 300 micrograms/mL rhu G-CSF (filgrastim) was performed in the patient and four control subjects. The patient experienced an immediate wheal and flare reaction with both concentrations of sargramostim while the control subjects demonstrated no reaction. There was also no reaction with filgrastim (rhu G-CSF) in either group and the patient subsequently tolerated filgrastim therapy. Prick skin testing with rhu GM-CSF and rhu G-CSF may be useful to demonstrate type I sensitization. Additional studies are needed to determine the incidence and prevalence of skin test reactions in larger numbers of patients with cytokine therapy exposure.

A multicentre, randomised, double-blind, placebo controlled, parallel group study to investigate the efficacy and tolerability of leucomax® (molgramostim; rHu GM-CSF) in conjunction with combination chemotherapy in the treatment of intermediate / poor prognosis patients with small cell lung cancer (SCLC) : R. Milroy 1, C. Cameron, K. McGregor, S.R. Bicknell, A. Dorward, on behalf of the West of Scotland Lung

A multicentre, randomised, double-blind, placebo controlled, parallel group study to investigate the efficacy and tolerability of leucomax® (molgramostim; rHu GM-CSF) in conjunction with combination chemotherapy in the treatment of intermediate / poor prognosis patients with small cell lung cancer (SCLC) : R. Milroy 1, C. Cameron, K. McGregor, S.R. Bicknell, A. Dorward, on behalf of the West of Scotland Lung

Recombinant Human Granulocyte-Macrophage Colony-Stimulating Factor After High-Dose Chemotherapy and Autologous Bone Marrow Transplantation With Unpurged and Purged Marrow in Non-Hodgkin’s Lymphoma: A Double-Blind Placebo-Controlled Trial

AbstractThe toxicity of autologous bone marrow transplantation (ABMT) is correlated to neutropenia. Although recombinant human granulocyte- macrophage colony-stimulating factor (rhu GM-CSF) seems to hold promise in accelerating neutrophil recovery, few analyses from randomized studies are presently available. Ninety-one patients with non-Hodgkin's lymphoma receiving high-dose ablative chemotherapy followed by ABMT with unpurged or purged marrow were included in a randomized, double- blind, placebo-controlled trial. Forty-four patients received 250 micrograms rhu GM-CSF (Escherichia coli)/m2 and 47 patients received placebo. Treatment was administered daily as continuous infusion from day of ABMT until the absolute neutrophil count (ANC) reached 0.5 × 10(9)/L for 7 days or until day 30, whichever was first. With rhu GM- CSF, 50% of the patients reached an ANC count greater than 0.5 × 10(9)/L at day 14 as opposed to day 21 with placebo (P less than .0001). Patients transplanted with marrow purged by mafosfamide also recovered earlier when treated with rhu GM-CSF (16 v 20.5 days, P = .013). The hospitalization duration was shorter in the rhu GM-CSF group (median, 23 v 28 days, P less than .05). No difference was observed in fever, number of infections, and antibiotic administration between the two groups. The major adverse event ascribed to rhu GM-CSF was a capillary leak syndrome in three patients graded as severe in two patients, moderate in one, and reversible in all three patients. In addition, one patient in the rhu GM-CSF group died suddenly with no explanation. In long term follow-up, the relapse rate was identical in both groups and there was no significant difference in the number of deaths at 1 year (12 with rhu GM-CSF v 9 with placebo), although deaths seemed to occur slightly earlier in the rhu GM-CSF group. We conclude that after ABMT with purged or unpurged marrow, rhu GM-CSF (E coli) significantly reduces neutropenia duration and hospitalization stay. A positive causative relation between the study drug and/or its mode of application with an increased toxicity as compared with GM-CSF from other sources and/or other modes of application cannot be deduced from the experiences in this study. Additional randomized trials would be necessary for an appropriate answer.

Recombinant human granulocyte-macrophage colony-stimulating factor after high-dose chemotherapy and autologous bone marrow transplantation with unpurged and purged marrow in non-Hodgkin's lymphoma: a double- blind placebo-controlled trial

The toxicity of autologous bone marrow transplantation (ABMT) is correlated to neutropenia. Although recombinant human granulocyte- macrophage colony-stimulating factor (rhu GM-CSF) seems to hold promise in accelerating neutrophil recovery, few analyses from randomized studies are presently available. Ninety-one patients with non-Hodgkin's lymphoma receiving high-dose ablative chemotherapy followed by ABMT with unpurged or purged marrow were included in a randomized, double- blind, placebo-controlled trial. Forty-four patients received 250 micrograms rhu GM-CSF (Escherichia coli)/m2 and 47 patients received placebo. Treatment was administered daily as continuous infusion from day of ABMT until the absolute neutrophil count (ANC) reached 0.5 x 10(9)/L for 7 days or until day 30, whichever was first. With rhu GM- CSF, 50% of the patients reached an ANC count greater than 0.5 x 10(9)/L at day 14 as opposed to day 21 with placebo (P less than .0001). Patients transplanted with marrow purged by mafosfamide also recovered earlier when treated with rhu GM-CSF (16 v 20.5 days, P = .013). The hospitalization duration was shorter in the rhu GM-CSF group (median, 23 v 28 days, P less than .05). No difference was observed in fever, number of infections, and antibiotic administration between the two groups. The major adverse event ascribed to rhu GM-CSF was a capillary leak syndrome in three patients graded as severe in two patients, moderate in one, and reversible in all three patients. In addition, one patient in the rhu GM-CSF group died suddenly with no explanation. In long term follow-up, the relapse rate was identical in both groups and there was no significant difference in the number of deaths at 1 year (12 with rhu GM-CSF v 9 with placebo), although deaths seemed to occur slightly earlier in the rhu GM-CSF group. We conclude that after ABMT with purged or unpurged marrow, rhu GM-CSF (E coli) significantly reduces neutropenia duration and hospitalization stay. A positive causative relation between the study drug and/or its mode of application with an increased toxicity as compared with GM-CSF from other sources and/or other modes of application cannot be deduced from the experiences in this study. Additional randomized trials would be necessary for an appropriate answer.

Leukemia Inhibitory Factor/Human Interleukin for DA Cells: A Growth Factor That Stimulates the In Vitro Development of Multipotential Human Hematopoietic Progenitors

We investigated the in vitro hematopoietic stimulatory activity of leukemia inhibitory factor/human interleukin for DA cells (LIF/HILDA) on bone marrow progenitor populations in 17 normal individuals. In serum-free cultures LIF/HILDA did not induce colony growth. In serum containing media, LIF/HILDA stimulated the growth of colony forming unit (CFU)-MIX and CFU-EO in a dose-dependent fashion and resulted in an increased CFU-MIX and burst forming unit-erythrocytes (BFU-E) colony size. Similar stimulatory effects were seen on a highly purified hematopoietic progenitor population obtained after immunomagnetic depletion of mature myeloid precursors and lymphoid cells. Addition of LIF/HILDA to cultures containing maximally stimulatory concentrations of recombinant human interleukin-3 (rhuIL3), rhuIL3 + rhuIL6, or rhu granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) in serum containing media significantly increased the number of CFU-MIX and eosinophil colonies and increased size and cluster number of CFU-MIX and BFU-E. Depletion of accessory T lymphocytes or monocytes from bone marrow progenitors did not alter the response of hematopoietic precursors to LIF/HILDA. A similar increased colony growth was seen when LIF/HILDA was added to cultures of positively selected CD34/HLA-DR+ or CD34+/HLA-DR- bone marrow hematopoietic progenitor cells stimulated with maximally stimulatory concentrations of rhuIL3 + rhuIL6. LIF/HILDA is a novel cytokine capable of stimulating growth and proliferation of multi-lineage, erythroid, and eosinophil colonies in the presence of serum. LIF/HILDA exerts its activity by direct interaction with highly purified immature bone marrow progenitor cells, has an additive effect when used with other cytokines known to stimulate primitive hematopoietic precursors, and does not require accessory cells.

Leukemia inhibitory factor/human interleukin for DA cells: a growth factor that stimulates the in vitro development of multipotential human hematopoietic progenitors

We investigated the in vitro hematopoietic stimulatory activity of leukemia inhibitory factor/human interleukin for DA cells (LIF/HILDA) on bone marrow progenitor populations in 17 normal individuals. In serum-free cultures LIF/HILDA did not induce colony growth. In serum containing media, LIF/HILDA stimulated the growth of colony forming unit (CFU)-MIX and CFU-EO in a dose-dependent fashion and resulted in an increased CFU-MIX and burst forming unit-erythrocytes (BFU-E) colony size. Similar stimulatory effects were seen on a highly purified hematopoietic progenitor population obtained after immunomagnetic depletion of mature myeloid precursors and lymphoid cells. Addition of LIF/HILDA to cultures containing maximally stimulatory concentrations of recombinant human interleukin-3 (rhuIL3), rhuIL3 + rhuIL6, or rhu granulocyte-macrophage colony-stimulating factor (rhu GM-CSF) in serum containing media significantly increased the number of CFU-MIX and eosinophil colonies and increased size and cluster number of CFU-MIX and BFU-E. Depletion of accessory T lymphocytes or monocytes from bone marrow progenitors did not alter the response of hematopoietic precursors to LIF/HILDA. A similar increased colony growth was seen when LIF/HILDA was added to cultures of positively selected CD34/HLA- DR+ or CD34+/HLA-DR- bone marrow hematopoietic progenitor cells stimulated with maximally stimulatory concentrations of rhuIL3 + rhuIL6. LIF/HILDA is a novel cytokine capable of stimulating growth and proliferation of multi-lineage, erythroid, and eosinophil colonies in the presence of serum. LIF/HILDA exerts its activity by direct interaction with highly purified immature bone marrow progenitor cells, has an additive effect when used with other cytokines known to stimulate primitive hematopoietic precursors, and does not require accessory cells.

Influence of IL-1 alpha and -1 beta on the survival of human bone marrow cells responding to hematopoietic colony-stimulating factors.

Purified recombinant human (rhu) IL-1 alpha and IL-1 beta were evaluated for their effects on the proliferation and survival of granulocyte-macrophage (CFU-GM) and erythroid (BFU-E) progenitor cells from normal human bone marrow (BM). Using nonadherent low density T lymphocyte depleted (NALT-) BM cells cultured in the presence or absence of IL-1, CSF-deprivation studies demonstrated that IL-1 alpha or IL-1 beta by itself did not enhance the proliferation of CFU-GM or BFU-E. They did, however, promote the survival of progenitors responding to the delayed addition of media conditioned by the 5637 cell line (5637 conditioned medium), rhu GM-CSF and erythropoietin. The survival promoting effects of IL-1 alpha on CFU-GM and BFU-E were neutralized by anti-IL-1 alpha mAb added to the cultures. The survival promoting effect of IL-1 alpha did not appear to be mediated by CSF, because neither CSF nor erythroid burst promoting activity were detectable in cultures in which NALT- cells were incubated with rhuIL-1 alpha. In addition, suboptimal concentrations of rhu macrophage CSF (CSF-1), G-CSF, GM-CSF, and IL-3, which were just below the levels that would stimulate colony formation, did not enhance progenitor cell survival. Survival of CFU-GM and BFU-E in low density (LD) bone marrow cells did not decrease as drastically as that in NALT- BM cells, and exogenously added IL-1 did not enhance progenitor cell survival of CFU-GM and BFU-E in LD BM cells. However, addition of anti-IL-1 beta decreased survival of CFU-GM and BFU-E in LD BM cells. These results implicate IL-1 in the prolonged survival of human CFU-GM and BFU-E.

Synergistic effects of purified recombinant human and murine B cell growth factor-1/IL-4 on colony formation in vitro by hematopoietic progenitor cells. Multiple actions.

Purified recombinant human B cell growth factor-1/IL-4 was evaluated, alone and in combination, with purified preparations of recombinant human (rhu) CSF or erythropoietin (Epo) for effects on colony formation by human bone marrow CFU-GM progenitor cells (GM) and burst forming unit-E progenitor cells. rhu IL-4 synergized with rhu G-CSF to enhance granulocyte colony formation, but had no effect on CFU-GM colony formation stimulated by rhu GM-CSF, rhu IL-3, or rhu CSF-1. Rhu IL-4 synergized with Epo to enhance BFU-E colony formation equal to that of Epo plus either rhu IL-3, rhu GM-CSF, or rhu G-CSF. Removal of adherent cells and T lymphocytes did not influence the synergistic activities of rhu IL-4. Rmu IL-4, synergized with rhu G-CSF, but not with rmu GM-CSF, rmu IL-3, or natural mu CSF-1, to enhance CFU-GM (mainly granulocyte) colony numbers by a greater than 90% pure preparation of murine CFU-GM. Also, rhu IL-4 at low concentrations enhanced release of CSF and at higher concentrations the release also of suppressor molecules from human monocytes and PHA-stimulated human T lymphocytes. Use of specific CSF antibodies suggested that rhu IL-4 was enhancing the release of G-CSF and CSF-1 from monocytes and the release of GM-CSF and possibly G-CSF from PHA-stimulated T lymphocytes. Use of antibodies for TNF-alpha, IFN-gamma, or TNF-beta as well as measurement of TNF and IFN titers suggested that the suppressor molecule(s) released from monocytes were acting with TNF-alpha and those released from PHA-stimulated T lymphocytes were acting with IFN-gamma. These results implicate B cell growth factor-1/IL-4 as a synergistic activity for hematopoietic progenitors and suggest that the actions can be on both progenitor and accessory cells.