Granulocyte-macrophage colony-stimulating factor as adjunct therapy in relapsed lymphoid malignancy: implications for economic analyses of phase III clinical trials

Sargramostim (rhu GM-CSF) as Cancer Therapy (Systematic Review) and An Immunomodulator. A Drug Before Its Time?

BACKGROUND

Sargramostim [recombinant human granulocyte-macrophage colony-stimulating factor (rhu GM-CSF)] was approved by US FDA in 1991 to accelerate bone marrow recovery in diverse settings of bone marrow failure and is designated on the list of FDA Essential Medicines, Medical Countermeasures, and Critical Inputs. Other important biological activities including accelerating tissue repair and modulating host immunity to infection and cancer via the innate and adaptive immune systems are reported in pre-clinical models but incompletely studied in humans.

OBJECTIVE

Assess safety and efficacy of sargramostim in cancer and other diverse experimental and clinical settings.

METHODS AND RESULTS

We systematically reviewed PubMed, Cochrane and TRIP databases for clinical data on sargramostim in cancer. In a variety of settings, sargramostim after exposure to bone marrow-suppressing agents accelerated hematologic recovery resulting in fewer infections, less therapy-related toxicity and sometimes improved survival. As an immune modulator, sargramostim also enhanced anti-cancer responses in solid cancers when combined with conventional therapies, for example with immune checkpoint inhibitors and monoclonal antibodies.

CONCLUSIONS

Sargramostim accelerates hematologic recovery in diverse clinical settings and enhances anti-cancer responses with a favorable safety profile. Uses other than in hematologic recovery are less-well studied; more data are needed on immune-enhancing benefits. We envision significantly expanded use of sargramostim in varied immune settings. Sargramostim has the potential to reverse the immune suppression associated with sepsis, trauma, acute respiratory distress syndrome (ARDS) and COVID-19. Further, sargramostim therapy has been promising in the adjuvant setting with vaccines and for anti-microbial-resistant infections and treating autoimmune pulmonary alveolar proteinosis and gastrointestinal, peripheral arterial and neuro-inflammatory diseases. It also may be useful as an adjuvant in anti-cancer immunotherapy.

Meta-Analysis of Randomized Controlled Trials of Prophylactic Granulocyte Colony-Stimulating Factor and Granulocyte-Macrophage Colony-Stimulating Factor After Autologous and Allogeneic Stem Cell Transplantation

Purpose

The primary objective of our meta-analysis was to determine whether prophylactic hematopoietic colony-stimulating factors (CSFs) after hematopoietic autologous and allogeneic stem-cell transplantation (SCT) reduced documented infections. Our secondary objectives were to determine whether prophylactic CSFs affected other outcomes including parenteral antibiotic therapy duration, infection-related mortality, graft-versus-host disease (GVHD), or treatment-related mortality.

Methods

We included studies if there was random assignment between CSFs and placebo/no therapy and CSFs were given after SCT and before recovery of neutrophils. From 3,778 reviewed study articles, 34 were included based on predefined inclusion criteria. All analyses were conducted using a random effects model.

Results

CSFs reduced the risk of documented infections (relative risk [RR] 0.87; 95% CI, 0.76 to 1.00; P = .05) and duration of parenteral antibiotics (weighted mean difference, −1.39 days, 95% CI, −2.56 to −0.22; P = .02) but did not reduce infection-related mortality (RR, 0.76; 95% CI, 0.41 to 1.44; P = .4). CSFs did not increase grade 2 to 4 acute GVHD (RR, 1.03; 95% CI, 0.81 to 1.31; P = .8) or treatment-related mortality (RR, 1.00; 95% CI, 0.78 to 1.29; P = .98).

Conclusion

CSFs were associated with a small reduction in the risk of documented infections but did not affect infection or treatment-related mortality.

Economic assessment in the management of non-Hodgkin’s lymphoma

An increasing need for economic evaluations of non-Hodgkin's lymphoma (NHL) treatments exists. We performed a literature review on the currently available NHL economic evaluations, using PubMed and the Cochrane database. English and Dutch language papers on treatment in adults were selected. A total of 88 publications were found, 44 of which were included. Of these, 6 economic evaluation-specific methodological items are evaluated (study perspective, overhead costs, data sources, charges or prices, sensitivity analysis, presentations of resource use and unit costs), enabling readers to judge the value of these studies. The 11 subjects covered by the economic evaluations are discussed. Many NHL treatments remain to be studied in economic evaluations. Future publications should report on the six methodological items in more detail, and preferably tackle them in the recommended way.

Cost analysis of HLA-identical sibling and voluntary unrelated allogeneic bone marrow and peripheral blood stem cell transplantation in adults with acute myelocytic leukaemia or acute lymphoblastic leukaemia

Allogeneic stem cell transplantation (SCT) is one of the most expensive medical procedures. However, only a few studies to date have addressed the costs of HLA-identical sibling transplantation and only one study has reported costs of unrelated transplantation. No recent cost analysis with a proper follow-up period and donor identification expenses is available on related or voluntary matched unrelated donor (MUD) SCT for adult AML or ALL. Therefore, we calculated direct medical (hospital) costs based on 97 adults who underwent HLA-identical sibling bone marrow transplantation (BMT) or peripheral blood stem cell transplantation (PBSCT), and patients who received a graft from a MUD between 1994 and 1999. The average costs per transplanted patient were Euro 98,334 (BMT), Euro 151,754 (MUD), and Euro 98,977 (PBSCT), including donor identification expenses, 2 years follow-up and costs of patients who were not transplanted after they had been planned to receive an allograft. The majority of these costs was generated during the hospitalisation for graft infusion. For MUD transplants, nearly one-third of these costs was spent on the search for a suitable donor. For patients who were alive after 2 years, cumulative expenses were calculated to be Euro 103,509 (BMT), Euro 173,587 (MUD), and Euro 105,906 (PBSCT).

Economic aspects of high-dose chemotherapy: a clinician's perspective review

Over the last 15 years, the increased use of high-dose chemotherapy (HDC) has led to a considerable increase in the cost of cancer treatments. After making a general economic analysis of the benefits and costs of healthcare initiatives, this paper considers all of the different phases and elements of HDC, as well as the strategies for reducing basic, indirect and out-of-pocket costs. The cost of HDC has decreased by 40-60% over the last decade and its cost-effectiveness ratios are now similar or only slightly higher than those of other widely accepted medical interventions. However, except in the case of some hematological and paediatric neoplasms, the efficacy of the treatment has not yet been clearly defined and so it should only be used in well-designed clinical trials that should also include prospective cost evaluation measures.

Economic analysis of amifostine as adjunctive support for patients with advanced head and neck cancer: preliminary results from a randomized phase II clinical trial from Germany

In a randomized phase II trial in Germany, we investigated the clinical and economic impact of amifostine protection against the hematological and oral toxicities of carboplatin administered concurrently with standard fractions of radiotherapy. 28 patients with squamous cell carcinomas of the head and neck received adjunctive or primary radiotherapy (5 days per week with daily fractions of 2 Gy, up to a total dose of 60 Gy) in conjunction with carboplatin (70 mg/m2) on days 1-5 and days 21-26. All patients received radiation encompassing at least 75% of the major salivary glands. Patients were randomized to receive radiation and carboplatin (RCT) alone or RCT preceded by rapid infusion of amifostine (500 mg) on days carboplatin was administered. The 14 patients who received amifostine, in comparison to 14 patients in the control arm, had significantly fewer episodes of grade 3 or 4 thrombocytopenia (p = 0.001), mucositis (p = 0.001), and xerostomia (p = 0.001). The patients receiving amifostine accrued significantly lower supportive care costs for resources related to infection ($241 vs. $1,275, p < 0.01), red blood cell and platelet support ($286 vs. $1,276 p = 0.06) alimentation ($343 vs. $894, p = .01), and hospitalization ($286 vs. $2,429, p < 0.01). Overall, including the costs of amifostine, mean per patient supportive care costs were $4,401 for the amifostine group and $5,873 (p = .02) for the control group. Our results from a randomized phase II trial indicate that selective cytoprotection with amifostine potentially offers clinical and economic benefits in patients with advanced head and neck cancer receiving radiochemotherapy. Additional economic studies alongside randomized phase III trials and from other countries are needed.

Colony-Stimulating Factors in Stem Cell Transplantation: Effect on Quality of Life

Health-related quality of life (QOL) is poorest during the immediate post-transplantation period, but the impact of medical interventions during this period has not been studied. Colony-stimulating factors (CSFs), which are used to minimize short-term negative outcomes, might be expected to improve QOL; however, little is published about their impact on QOL during this period. We conducted a MEDLINE search to identify studies reporting on outcomes of stem cell transplantation (SCT) affected by the CSFs, mainly sargramostim and filgrastim. End points studied were: mucositis, incidence and type of infection, duration of hospitalization, time to myeloid engraftment, and quantity and quality of harvested cells. To impute the impact of CSFs on QOL post-SCT, we also reviewed the association between QOL and CSF outcomes in other circumstances. Data suggest that both CSFs improve QOL in the early autologous or allogeneic post-bone marrow transplantation period. Poor QOL caused by infection and increased length of hospital stay is expected to be improved by sargramostim. Time to myeloid engraftment, when negatively affecting QOL, is expected to be improved with both CSFs; however, the time to myeloid engraftment is consistently shorter with filgrastim. Current prospective trials designed to study the effects of CSFs in the immediate post-SCT period should collect QOL data.

Economic analysis of a phase III study of G-CSF vs placebo following allogeneic blood stem cell transplantation

Hematopoietic colony-stimulating factors (CSF) decrease the duration of neutropenia following stem cell transplantation (SCT). With CSF-mobilized allogeneic blood SCT (alloBSCT), the yields of CD34+ cells are several-fold higher than in other SCT settings, raising concern that post-transplant CSF use may be unnecessary. In this study, we estimate the resource and cost implications associated with CSF use following alloBSCT. A cost identification analysis was conducted for 44 patients on a randomized, double-blind placebo-controlled trial of G-CSF following alloBSCT. Study drug was given daily until an absolute neutrophil count (ANC) > or = 1000 cells/microl. Billing information from the time of transplant to day +100 was analyzed. The median number of days to an ANC > or = 500 cells/microl was shorter in the G-CSF arm, 10.5 days vs 15 days (P < 0.001), while platelet recovery and rates of acute graft-versus-host disease (GVHD) and survival were similar. Resource use was similar, including days hospitalized, days on antibiotics, blood products transfused and outpatient visits. Total median post-transplant costs were $76577 for G-CSF patients and $78799 for placebo patients (P = 0.93). G-CSF following allogeneic blood SCT decreased the median duration of absolute neutropenia and did not incur additional costs, but did not result in shorter hospitalizations, or less frequent antibiotic use.

Development of a recombinant growth factor and fusion protein: lessons from GM-CSF

Several colony stimulating factors (CSFs) and cytokines have been successfully used to mobilize hematopoietic cells during myeloablative therapy, bone marrow failure, and transplantation and to provide supportive treatment during sepsis. The use of yeast-derived recombinant human granulocyte-macrophage CSF (rhuGM-CSF) and its interleukin-3 fusion protein, PIXY321, provides an example of issues associated with development programs for recombinant hematopoietic growth factors. Species specificity of rhuGM-CSF, different bioactivity of homologous molecules in mice, and production in laboratory animals of antibodies to human proteins limit preclinical evaluation of such molecules. In clinical trials, rhuGM-CSF was efficacious and well tolerated. The derivation of the recombinant molecule, optimal dosing, scheduling, and confounding effects of concurrent disease and treatments are factors that influence efficacy, adverse responses, and immunogenicity reported in patients treated with CSFs. In comparisons of yeast-derived with Escherichia coli-derived rhuGM-CS, the reduced severity and frequency of all adverse events, preponderance of low-grade adverse events, and similarity of positive clinical response versus adverse events reported for granulocyte CSF support safety and efficacy of yeast-derived rhuGM-CSE Enhanced pharmacoeconomic evaluations are beginning to limit and redirect clinical applications in this class of biological agents.

Economic analyses in clinical trials for cooperative groups: operational considerations

Clinical trials have served as valuable tools for evaluating new therapeutic strategies in the treatment of cancer. Traditionally, new pharmaceuticals and procedures have been appraised on the basis of effectiveness, efficacy, and safety. Recently, economic concerns have become increasingly important when considering treatment strategies for cancer patients. The national emphasis on assessing the costs of health care has focused primarily on the cost-effectiveness of resource allocation. Policy makers are exhibiting greater interest in economic data to supplement clinical data of new procedures and pharmaceutical agents before the approval and widespread application of such methodologies. Clinical trials have increasingly become viewed as a proper setting for such economic analyses. In this paper, we review operational details for carrying out economic analyses of clinical trials being conducted in the cancer cooperative group setting.

The true cost of bone marrow transplantation

Bone marrow transplantation is an example of a highly technical therapy that offers hope to patients with bone marrow failure or various malignancies. Bone marrow transplantation is much more costly "up-front" but perhaps not more costly long-term than alternative therapies. Although economic analyses appear relatively simple, interpretation and use can be problematic. Several economic analyses have identified complications that occur frequently and affect the reported cost-effectiveness of high-dose chemotherapy. Efforts to reduce the cost of bone marrow transplantation have focused on new strategies to more effectively control these complications. The introduction of new technologies to speed engraftment, to improve patient selection methods, and the shifting of care to outpatient settings all have resulted in significant reductions in duration of hospital stay, treatment-related mortality, and costs. More studies of long-term outcomes are needed for transplant and nontransplant treatment options to guide present and future applications of this treatment option.

Economic analyses of phase III cooperative cancer group clinical trials: are they feasible?

Both economic and clinical evaluations of new pharmaceutical agents are important to physicians who practice in the current health care environment. While cooperative cancer groups carry out large-scale phase III clinical evaluations of these agents, few cooperative group studies incorporate economic analyses because of concerns over overburdening of data management, investigators, and statistical center personnel. In this study, we describe the results and operational considerations of one of the first completed economic analyses of a phase III cooperative group trial of the Eastern Cooperative Oncology Group (ECOG). We developed an economic model estimating economic benefits of yeast-derived granulocyte-macrophage colony-stimulating factor (GM-CSF) as adjunct therapy for adult patients (56-70 years) with acute myelogenous leukemia. Clinical data were based on prospectively collected information from a recently reported double-blind phase III multi-institutional study carried out by ECOG. Retrospective economic data were obtained from financial information systems at our hospital, one of the study sites. The cost-minimization analyses were based on the perspective of a third-party payer. Indirect costs related to loss of earnings by patients and caregivers as well as quality-of-life adjustments were not incorporated into the model. Clinical trial results indicated that patients treated with GM-CSF had shorter times to recovery of absolute neutrophil count of 500 cells/mm3 and 1000 cells/mm3 and fewer serious infections than patients who received placebo following induction chemotherapy, while no significant differences were noted in red blood cell and platelet transfusion dependency, toxicities, and duration of hospitalization. The economic model estimated that the group treated with GM-CSF was estimated to have lower costs of care, associated with lower frequencies of serious infections and lower overall infection-related costs. Sensitivity analyses indicated that these results held true over a wide range of estimates of costs and infection rates. Prospective economic analyses of phase III cooperative cancer group clinical trials have not been completed to date. Strategies that are not likely to overburden data managers and statistical center personnel are possible to devise. However, these studies require careful planning and coordination between clinical trialists, economists, and health services researchers.