Treatment of agnogenic myeloid metaplasia with danazol: a report of four cases

Standard care and investigational drugs in the treatment of myelofibrosis

Myelofibrosis (MF) is a heterogeneous disorder characterized by splenomegaly, constitutional symptoms, ineffective hematopoiesis, and an increased risk of leukemic transformation. The ongoing research in understanding the pathophysiology of the disease has allowed for the development of targeted drugs optimizing patient management. Furthermore, disease prognostication has significantly improved. Current therapeutic interventions are only partially effective with only allogeneic stem cell transplant potentially curative. Ruxolitinib is the only approved therapy for MF by the US Food and Drug Administration. However, despite efficacy in reducing splenomegaly and controlling symptomatology, it is not associated with consistent molecular or pathologic responses. Drug discontinuation is associated with a dismal outcome. The therapeutic landscape in MF has significantly improved, and emerging drugs with different target pathways, alone or in combination with ruxolitinib, seem promising.

Managing side effects of JAK inhibitors for myelofibrosis in clinical practice

INTRODUCTION

Myelofibrosis (MF) is characterized by bone marrow fibrosis, abnormalities in peripheral counts, extramedullary hematopoiesis, splenomegaly and an increased risk of transformation to acute myeloid leukaemia. The disease course is often heterogeneous and management can range from observation alone through to allogeneic stem cell transplantation. As of 2017, the only approved medication for MF remains the JAK Inhibitor (JAKi), ruxolitinib (Novartis Pharmaceuticals, Basel, Switzerland; Incyte, Wilmington, Detroit, USA) although several others have reached advanced stages of clinical trials. Areas covered: In this review, we focus on the management of both common and uncommon side effects arising from the use of currently approved and clinical trial JAKi. Most of the discussion concerns ruxolitinib although we also cover both pacritinib (CTI BioPharma) and momelotinib (Gilead Sciences, Foster City, California) which have been in recent large, multinational phase III trials. The various approaches to management of JAKi-related side effects are discussed - with particular emphasis to anaemia, thrombocytopaenia and infection risk. Expert commentary: JAK inhibitors are effective in many individuals with MF and have revolutionized the current treatment paradigm. The side effect profile, in the most, is predictable and manageable with high degrees of clinical surveillance and dose modifications.

Danazol therapy combined with intermittent application of chemotherapy induces lasting remission in myeloproliferative disorder (MPD): an alternative for the elderly with advanced MPD

There is no good alternative therapy available for elderly patients with advanced myeloproliferative disorders (MPD) who failed on conventional therapies and are not candidates for bone marrow transplant. We report here an effective therapy that induced exceptionally long-lasting remissions and improved quality of life. Eighteen elderly patients (mean age: 70·6 years) (16 myelofibrosis and 2 thrombocythemia) who had failed on conventional therapies were treated. Danazol was administered daily at 200-800 mg throughout the study. Chemotherapy was applied intermittently as needed to reduce spleen size and blood counts. Busulfan (2-4 mg/day) was used most often and 6-mercaptopurine (6-MP) (50-100 mg/day) and/or cytarabine (100-200 mg/m(2)) if the white blood cell (WBC) count rose rapidly. When MPD stabilized, chemotherapy was discontinued and dosage of danazol was reduced. Therapy was well tolerated. Overall, 61% of patients responded with unexpectedly long-lasting remissions and improved quality of life. Three (17%) had excellent (E) response, defined by normalization of blood counts and non-palpable spleen, while eight (44%) had good (G) response, defined by rise of Hct by ≥7% and ≥50% reduction of spleen. Mean duration of remission was 45 months (10-78 months) in E responders and 11 months in G responders (2-22 months). This regimen offers a safe and effective alternative for advanced MPD in the elderly.

New drugs for the treatment of myelofibrosis

Managing patients with myelofibrosis (MF)-either those with primary MF or those whose MF has evolved from antecedent polycythemia vera or essential thrombocythemia-presents many challenges to the hematologist. Cure is potentially achievable through allogeneic stem cell transplantation, but this therapy is either inappropriate or not feasible for most patients. MF patients suffer from a range of debilitating disease manifestations (eg, massive splenomegaly, cytopenias, constitutional symptoms, and transformation to a treatment-refractory blast phase). Currently available therapies are palliative but can be of significant value to some MF patients for anemia, splenomegaly, or sometimes both manifestations. New medical therapies for MF revolve around three main themes: immunomodulation (to assist anemia), hypomethylation strategies, and (the most robust pipeline) the use of targeted JAK2 inhibitors. These latter agents have shown the ability to improve MF-associated splenomegaly and MF-associated symptoms but do not improve (and may exacerbate) anemia or thrombocytopenia. Future targeted agents, and perhaps combinations of agents that currently show complementary benefits, are anticipated to further enhance the efficacy of medical therapy for MF.

Recombinant human erythropoietin for the treatment of anaemia in patients with chronic idiopathic myelofibrosis

BACKGROUND

Patients with chronic idiopathic myelofibrosis (CIMF) usually present with anaemia. Treatment is often palliative and the majority of patients receive regular red blood cell (RBC) transfusions. Although recombinant human erythropoietin (rhu-EPO) has been proved effective for the treatment of anaemia in several chronic diseases, including haematological malignancies, its role in the treatment of the anaemia in CIMF is not well established. We report the beneficial effect of rhu-EPO administration in 20 patients with CIMF and discuss the parameters predicting favourable response.

PATIENTS

Twenty patients with CIMF (9 women and 11 men) regularly treated with supportive RBC transfusions were included in the study. The median age was 70 years (range 45-81 years). Rhu-EPO, 10,000 U, was given subcutaneously 3 times a week. The median duration of therapy was 83 months, ranging from 13 to 87 months.

RESULTS

Treatment was considered effective if haemoglobin levels increased over 2 g/dl within 12 weeks after enrolment or the RBC transfusion requirements were reduced by 50% within the same interval. Twelve patients (60%) responded to therapy. Responders were mainly female, had smaller spleen size (p = 0.024), low RBC transfusion requirements (< or = 1-2 units per month), and significantly lower endogenous serum erythropoietin (EPO) and beta2-microglobulin (beta2-M) levels when compared with non-responders (p < 0.0001 and 0.00001, respectively). Treatment was well tolerated and none of the patients was withdrawn from the treatment protocol because of side effects.

CONCLUSIONS

Rhu-EPO administration is an effective, safe and well-tolerated treatment for patients with CIMF and anaemia leading to a significant reduction in RBC transfusion requirements. Factors predicting favourable response are low endogenous EPO and beta2-M serum levels and slight to moderate splenomegaly.

Idiopathic myelofibrosis: pathogenesis to treatment

Idiopathic myelofibrosis (IMF) is the least common of the chronic myeloproliferative disorders and carries the worst prognosis with a median survival of 4 years. It is a clonal haematopoietic stem-cell disorder and, although the pathogenesis remains unclear, approximately 50% of cases are known to possess an activating JAK2 V617F mutation. In contrast, the characteristic stromal proliferation is a reactive, or secondary, event that results from the aberrant release of a variety of growth factors from megakaryocytes and monocytes. Treatment for most cases is supportive, although androgens, recombinant erythropoietin, steroids and thalidomide are effective modalities for the amelioration of anaemia. Myelosuppression, splenectomy and irradiation are valuable therapeutic modalities for specific clinical situations. Prognostic scores are available to aid the identification of cases for whom bone marrow transplantation should be considered. Recently, the use of reduced intensity conditioning has resulted in prolonged survival and lower transplant-related mortality. This review summarises the recent advances in the disease's pathogenesis and discusses the role of the various therapeutic options.

Efficacy and tolerability of danazol as a treatment for the anaemia of myelofibrosis with myeloid metaplasia: long-term results in 30 patients

Androgens are considered the treatment of choice for the anaemia of myelofibrosis with myeloid metaplasia (MMM). Good results have been reported in a few patients treated with danazol, a synthetic attenuated androgen. The long-term efficacy and tolerability of danazol as treatment for the anaemia of MMM was evaluated in 30 patients, who received 600 mg/d, with progressive tapering to the minimum effective dose in the responders after 6 months. Complete response (CR) was defined as transfusion cessation with normal Hb and partial response (PR) as an Hb increase >/=1.5 g/dl with transfusion-independent Hb values >10 g/dl maintained for at least 8 weeks. Median follow-up was 20.5 months (range: 3.5-58 months). Response was achieved in 11 patients (37%), including eight CRs and three PRs. Median time to response was 5 months (range: 1-9 months). Four patients stopped responding at 6-24 months, two responders discontinued treatment because of toxicity, and five maintained response at 3.5-42 months. Pretreatment variables associated with response were lack of transfusion requirement (P= 0.001) and higher Hb at treatment start (P= 0.02). Toxicity was usually moderate, leading to treatment withdrawal in only two cases. Danazol is effective and well tolerated in a substantial proportion of MMM patients with anaemia.

Modern management of myelofibrosis

The conventional treatment of myelofibrosis involves a wait-and-see approach for asymptomatic patients, oral chemotherapy for the hyperproliferative forms of the disease, androgens or erythropoietin for the anaemia, and splenectomy in selected patients. Low-dose thalidomide plus prednisone is a well-tolerated therapy for the anaemia and the thrombocytopenia of myelofibrosis, whereas imatinib has shown little efficacy. Allogeneic stem cell transplantation (allo-SCT) is the only curative therapy for myelofibrosis. Its standard modality has an associated mortality of about 30% and can be applied to younger patients with high-risk disease or resistant to conventional treatment. Reduced-intensity conditioning allo-SCT involves a low mortality and is a promising therapy for patients aged 45-70 years old with the above characteristics. Autologous SCT is a palliative therapy for patients resistant to conventional treatment who lack a suitable donor. The next candidates for the treatment of myelofibrosis are the thalidomide derivatives, the proteasome inhibitors, and vascular endothelial growth factor neutralizing antibodies.

In vitro antiproliferative activity of the farnesyltransferase inhibitor R115777 in hematopoietic progenitors from patients with myelofibrosis with myeloid metaplasia

R115777 is an orally bioavailable farnesyltransferase inhibitor (FTI) that has displayed encouraging activity in patients with acute myeloid leukemia. To determine whether R115777 might exert similar activity in myelofibrosis with myeloid metaplasia (MMM), we evaluated its effects on circulating myeloid progenitor cells from patients with MMM (n=25) using in vitro colony-forming assays. The median R115777 concentrations that inhibited colony formation by 50% were 34 and 2.7 nM for myeloid and megakaryocytic colonies from MMM patients, respectively. Progenitors from normal controls and patients with other myeloproliferative disorders demonstrated similar sensitivity. Since the ras polypeptides are one putative target of FTIs, the potential role of ras effectors was examined by incubating parallel progenitor assays with the phosphatidyl-inositol-3 (PI-3) kinase inhibitor LY294002 and the mitogen-activated protein kinase 1 inhibitor PD98059. MMM progenitor colonies (n=7) were highly sensitive to LY294002 but not to PD98059, implying that the PI-3 kinase pathway may be critical for survival and proliferation of these cells. In addition to indicating that MMM progenitors are sensitive to clinically achievable R115777 concentrations in vitro, these results provide a potential explanation for the thrombocytopenia observed with R115777 during the treatment of other hematologic malignancies.

The therapy of myelofibrosis: targeting pathogenesis

Myelofibrosis with myeloid metaplasia (MMM) encompasses the diagnoses of agnogenic myeloid metaplasia (idiopathic myelofibrosis), as well as the advanced phases of polycythemia vera and essential thrombocythemia (post polycythemic and post thrombocythemia myeloid metaplasia, respectively). MMM is a clonal, hematopoietic stem cell disorder in which neither the pathogenesis, nor a broadly applicable effective therapy have been described. Clinically, these patients experience progressive marrow replacement by fibrotic tissue, ineffective hematopoiesis, problematic cytopenia's, significant hepato-splenomegaly, extramedullary hematopoiesis, profound constitutional symptoms, and a risk of blastic transformation. Historically, therapies have been targeted at palliating symptoms (i.e. splenectomy, transfusions, hydroxyurea, erythropoietin, androgens, localized radiotherapy). Stem cell transplantation appears promising, but is often toxic and not broadly applicable due to co-morbidities and age of MMM patients. Non-myeloablative approaches to conditioning may broaden the applicability of stem cell transplantation in MMM, yet results to date are preliminary. Although a definitive molecular abnormality responsible for the pathogenesis of MMM has not been described, much has been learned about the aberrant expression of pro-fibrotic cytokines and the presence of increased angiogenesis in MMM. These pathogenetic insights have led to a series of pilot clinical trials with therapeutic agents targeting aberrantly expressed cytokines (and possibly angiogenesis) including Thalidomide (alone or in combination), Etanercept, and STI-571. Amongst these later agents Thalidomide has demonstrated the most promise (palliating disease associated cytopenia's), whereas the TNF-alpha inhibitor Etanercept has aided with MMM associated constitutional symptoms. Although these later trials have been helpful in a subset of patients, no agent to date has led to solid complete responses in MMM across the spectrum of disease manifestations. Further insights into the pathogenetic mechanisms responsible for myeloproliferation (aberrant cell signaling pathways, apoptotic resistance, other) are necessary to guide selection and testing of the expanding number of novel anti-neoplastic agents in chronic myeloid disorders and MMM.

Remission of transformed myelodysplastic syndrome with fibrosis after danazol therapy

Danazol has been used with success in some hematological diseases, but there is no report of this treatment in acute leukemia. We report here a case of remission of myelodysplastic syndrome with myelofibrosis in transformation after danazol therapy in a 72-yr-old man. The role of danazol in remission induction is briefly discussed.

Palliative splenectomy in myelofibrosis with myeloid metaplasia

Myelofibrosis with myeloid metaplasia (MMM) is a chronic myeloproliferative disorder in which the accumulation and growth of circulating myeloid progenitors in the spleen lead to pathologic enlargement of the organ with resulting mechanical discomfort, hypercatabolic symptoms, anemia, thrombocytopenia, and portal hypertension. Medical therapy and splenic irradiation may be of benefit in certain patients, yet many may still require splenectomy to palliate their symptoms. Although there is no clear survival advantage to splenectomy in MMM, the procedure can result in substantial palliation of symptoms. However, the surgical procedure is associated with an approximately 9% mortality rate, and the postsplenectomy occurrence of extreme thrombocytosis, hepatomegaly, and leukemic transformation is of major concern. The management of splenomegaly and the role of splenectomy in MMM are discussed in this review.

Risks and benefits of splenectomy in myelofibrosis with myeloid metaplasia: a retrospective analysis of 26 cases

BACKGROUND AND OBJECTIVES

To evaluate the outcomes of splenectomy in myelofibrosis and myeloid metaplasia (MMM).

METHODS

We retrospectively reviewed our records of 26 patients with MMM who underwent an open splenectomy at Boston University Medical Center between 1979 and 1995. Fourteen patients had agnogenic myeloid metaplasia (AMM) and 12 had myelofibrosis with antecedent myeloproliferative disorders (MF). The main indications for splenectomy were progressive transfusion-dependent anemia, painful splenomegaly, and hypercatabolic symptoms associated with cytopenia.

RESULTS

Median time to splenectomy after the diagnosis of MMM was 29 months ranging from 1 to 96 months. Three patients (11%) died within 1 month after the surgery because of sepsis. The most common peri- and postoperative complications were pneumonia and other bacterial infections (42%), cardiac events (19%), acute bleeding (15%), ileus (15%), and venous thrombosis (12%). Of the eight surviving patients who underwent splenectomy for transfusion dependent anemia, six (75%) had improvement in their hematocrit levels with abolishment of blood transfusions. A durable symptomatic palliation was achieved in all patients. Liver enlargement was noted in seven patients at 1-year evaluation. None of these patients developed hepatic failure. Leukemic transformation occurred in 8 of 18 patients (44%) postsplenectomy. The median overall survival for the entire group was 58.5 and 28 months from the diagnosis of MMM and the time of splenectomy, respectively. There was no difference in survival rates between patients with AMM and MF.

CONCLUSIONS

Splenectomy is an effective palliative procedure with an acceptable morbidity in selected patients with MMM. Progressive transfusion-dependent anemia should also be considered an indication for splenectomy in the absence of leukemic evolution.

Prognostic factors and current practice in treatment of myelofibrosis with myeloid metaplasia: an update anno 2000

Median survival of patients with myelofibrosis with myeloid metaplasia (MMM) ranges from 3.5 to 5 years, but there is a wide variability. The degree of anemia (Hb < 10 g/dL) is the most important prognostic factor, followed by constitutional symptoms and abnormal karyotype. In recent years, different prognostic scoring systems for MMM have been proposed. In some of them three prognostic groups (low, intermediate, and high risk) are recognized, while others recognize a high and a low-risk group only. Median survival of the low-risk group ranges from seven to nine years, while the minority of high-risk patients survive for a median of less than two years. Younger patients with MMM survive longer (median survival above ten years). Among the latter patients, based on Hb value, constitutional symptoms, and blood blast-cell percentage, two prognostic groups can also be identified, with median survival of less than three years and almost 15 years, respectively. Conventional treatment of MMM is mostly palliative and based on cytolytic treatment (usually hydroxyurea), androgen therapy and splenectomy in selected patients. Allogeneic hemopoietic transplant is a therapeutic possibility with the potential for cure in younger patients with bad prognostic features. The role in MMM of newer treatment strategies such as autologous transplantation or the administration of anti-angiogenic drugs such as thalidomide is currently being evaluated.

Radiation therapy for symptomatic hepatomegaly in myelofibrosis with myeloid metaplasia

OBJECTIVE

To describe the experience with liver irradiation in advanced cases of myelofibrosis with myeloid metaplasia (MMM).

METHODS

Over a 20-yr period, 14 patients with MMM were treated with a total of 25 courses of liver, abdominal, or abdominal and pelvic irradiation for symptomatic hepatomegaly with (5 patients) or without (9 patients) ascites. All 14 patients had advanced disease and 11 (79%) had previous splenectomy. The median radiation therapy (RT) dose per course was 150 cGy (range 50-1000) administered at a median of six fractions. Four patients received two to six courses.

RESULTS

Twelve of the 14 patients (86%) had a transient (median 3 months) subjective response from RT. However, in only 35% of these was there a transient (median 3 months) decrease in palpable liver size. Four of the five patients with ascites experienced a short-term response from RT. Eight of the 13 patients suitable for evaluation (62%) had treatment-associated cytopenia, often in the form of anemia and/or thrombocytopenia. At last follow-up, 10 patients (71%) had died after a median of 7 months (range 0.1-23) and 4 were alive at 3, 20, 33, and 57 months after RT.

CONCLUSIONS

Low-dose abdominal RT for symptomatic hepatomegaly or ascites associated with advanced-stage MMM is myelosuppressive and provides only temporary and mainly subjective and short-lived relief.

Splenectomy in chronic myeloid leukemia and myelofibrosis with myeloid metaplasia

Myelofibrosis with myeloid metaplasia (MMM) is a collective term that describes the related disorders AMM, PPMM, and PTMM. The chronic myeloid disorders include chronic myeloid leukemia, polycythemia vera, essential thrombocythemia, and agnogenic myeloid metaplasia (myelofibrosis). These disorders display varying propensities for pathologic enlargement of the spleen which can lead to mechanical discomfort, hypercatabolic symptoms, anemia, thrombocytopenia, and portal hypertension. Splenectomy has been found to be of little benefit in the early stages of chronic myeloid leukemia. Similarly, the benefit of splenectomy in advanced cases is limited to symptomatic palliation and treatment of delayed engraftment after allogeneic bone marrow transplantation. Although polycythemia vera and essential thrombocythemia are also characterized by splenomegaly, splenectomy is not considered a therapeutic option in the absence of transformation of the disease into myelofibrosis with myeloid metaplasia. Splenectomy has been studied most in myelofibrosis with myeloid metaplasia. Although there is no clear survival advantage to splenectomy in this disorder, the surgical procedure can result in substantial palliation of mechanical discomfort, hypercatabolic symptoms, portal hypertension, and anemia. However, the procedure is associated with an approximately 9% mortality rate, and the postsplenectomy occurrence of extreme thrombocytosis, hepatomegaly, and leukemic transformation is of major concern.

Splenectomy in myelofibrosis with myeloid metaplasia: a single-institution experience with 223 patients

In a 20-year period, 223 patients (median age, 64.8 years) with myelofibrosis with myeloid metaplasia (MMM) had therapeutic splenectomy at our institution. Primary indications for surgery were transfusion-dependent anemia (45.3%), symptomatic splenomegaly (39.0%), portal hypertension (10.8%), and severe thrombocytopenia (4.9%). Operative mortality and morbidity rates were 9% and 31%, respectively. The 203 survivors of surgery had a median postsplenectomy survival time (PSS) of 27 months (range, 0-155). Among preoperative variables, thrombocytopenia (platelet count less than 100 × 109/L) and nonhypercellular bone marrow were identified as independent risk factors for decreased PSS. Durable remissions in constitutional symptoms, transfusion-dependent anemia, portal hypertension, and severe thrombocytopenia were achieved in 67%, 23%, 50%, and 0% of the patients, respectively. Histologic or cytogenetic features of bone marrow obtained before splenectomy did not predict a response in cytopenias. After splenectomy, substantial enlargement of the liver and marked thrombocytosis occurred in 16.1% and 22.0% of the patients, respectively. The thrombocytosis was associated with an increased risk of perioperative thrombosis and decreased PSS. The rate of blast transformation (BT) was 16.3%, and the risk of BT was higher in the presence of increased spleen mass and preoperative thrombocytopenia. However, the PSS of patients with BT was not significantly different from that of patients without BT. We conclude that presplenectomy thrombocytopenia in MMM may be a surrogate for advanced disease and is associated with an increased risk of BT and inferior PSS. However, the development of BT after splenectomy may not affect overall survival and does not undermine the palliative role of the procedure for the other indications.

Splenectomy in myelofibrosis with myeloid metaplasia: a single-institution experience with 223 patients

In a 20-year period, 223 patients (median age, 64.8 years) with myelofibrosis with myeloid metaplasia (MMM) had therapeutic splenectomy at our institution. Primary indications for surgery were transfusion-dependent anemia (45.3%), symptomatic splenomegaly (39.0%), portal hypertension (10.8%), and severe thrombocytopenia (4.9%). Operative mortality and morbidity rates were 9% and 31%, respectively. The 203 survivors of surgery had a median postsplenectomy survival time (PSS) of 27 months (range, 0-155). Among preoperative variables, thrombocytopenia (platelet count less than 100 × 109/L) and nonhypercellular bone marrow were identified as independent risk factors for decreased PSS. Durable remissions in constitutional symptoms, transfusion-dependent anemia, portal hypertension, and severe thrombocytopenia were achieved in 67%, 23%, 50%, and 0% of the patients, respectively. Histologic or cytogenetic features of bone marrow obtained before splenectomy did not predict a response in cytopenias. After splenectomy, substantial enlargement of the liver and marked thrombocytosis occurred in 16.1% and 22.0% of the patients, respectively. The thrombocytosis was associated with an increased risk of perioperative thrombosis and decreased PSS. The rate of blast transformation (BT) was 16.3%, and the risk of BT was higher in the presence of increased spleen mass and preoperative thrombocytopenia. However, the PSS of patients with BT was not significantly different from that of patients without BT. We conclude that presplenectomy thrombocytopenia in MMM may be a surrogate for advanced disease and is associated with an increased risk of BT and inferior PSS. However, the development of BT after splenectomy may not affect overall survival and does not undermine the palliative role of the procedure for the other indications.

Pathogenesis and management of idiopathic myelofibrosis

Idiopathic myelofibrosis is the least common and carries the worst prognosis of the chronic myeloproliferative disorders. The primary disease process is a clonal haematopoietic stem cell disorder which results in a chronic myeloproliferation and an atypical megakaryocyte hyperplasia. In contrast, the characteristic stromal proliferation is a reactive phenomenon, resulting from the inappropriate release of megakaryocyte/platelet-derived growth factors, including PDGF, TGF-beta bFGF and calmodulin. The median survival is approximately 4 years, although individual survival varies greatly. A variety of prognostic schema have been developed which enable the identification of high-risk patients, for whom bone marrow transplantation should be considered. Management for the majority of patients, however, is directed towards the alleviation of symptoms and improvement in quality of life. This review summarizes the recent advances in our understanding of the disease's pathogenesis and discusses the limited therapeutic options available to clinicians.