Palliative splenectomy in myelofibrosis with myeloid metaplasia

Treatment of anemia in myelofibrosis: focusing on novel therapeutic options

INTRODUCTION

Myelofibrosis is a clonal myeloproliferative neoplasm associated with the proliferation of hematopoietic stem cells, increased bone marrow fibrosis, extramedullary hematopoiesis, hepatosplenomegaly, abnormal cytokine production, and constitutional symptoms. These and many other factors contribute to the development of anemia in myelofibrosis patients.

AREAS COVERED

This review summarizes novel and promising treatments for anemia in myelofibrosis including transforming growth factor-β inhibitors luspatercept and KER-050, JAK inhibitors momelotinib, pacritinib, and jaktinib, BET inhibitors pelabresib and ABBV-744, antifibrotic PRM-151, BCL2/BCL-XL inhibitor navitoclax, and telomerase inhibitor imetelstat.

EXPERT OPINION

Standard approaches to treat myelofibrosis-related anemia have limited efficacy and are associated with toxicity. New drugs have shown positive results in myelofibrosis-associated anemia when used alone or in combination.

Improving symptom burden and quality of life in patients with myelofibrosis: current strategies and future directions

INTRODUCTION

Myelofibrosis (MF) is a complex and aggressive hematologic malignancy resulting from JAK/STAT-driven myeloproliferation and abnormal fibrogenesis. The clinical manifestations are heterogeneous and negatively impact quality of life and survival. JAK inhibitors improve symptoms and splenomegaly to a variable degree in a proportion of patients, but the effects for many patients are insufficient or short-lived.

AREAS COVERED

This review examines the constellation of symptoms that befall patients with MF, describes methods to quantify and serially monitor these symptoms, and evaluates pharmacologic and non-pharmacologic interventions for disease-related symptoms. The review also includes a discussion of areas of unmet medical need, and proposes future methods for meeting this need.

EXPERT OPINION

The treatment landscape for MF is evolving rapidly. The most effective therapies or combinations of therapies will likely simultaneously impact both the malignant hematopoietic stem cell and mechanisms of aberrant fibrogenesis that drive this disease. The goals of treatment for patients with myelofibrosis should be to improve length and quality of life. Clinical trials must be designed with these goals in mind, with endpoints focused on overall survival and symptom reduction, as opposed to surrogate endpoints such as spleen volume reduction.

The diagnostic role of Next Generation Sequencing in uncovering isolated splenomegaly: A case report

Many diseases can induce splenomegaly, however, about 5% of splenomegalies are idiopathic. When there is no underlying treatable cause, and the splenomegaly significantly affects the quality of life, splenectomy is the best therapeutic choice. A 67-year-old woman had idiopathic and asymptomatic splenomegaly. The increase in splenomegaly resulted in hypersplenism with cytopenia and symptoms related to abdominal discomfort. The patient underwent splenectomy which led to clinical improvement. A histological examination showed the presence of hematopoietic tissue. Peripheral blood Next Generation Sequencing with the myeloid panel SOPHiA Genetics showed the following mutations: ASXL1, SRSF2, KRAS and TET2. Three out of these four mutations were also found in the splenic tissue. Next Generation Sequencing could be useful in the diagnosis of splenomegalies associated with myeloproliferative neoplasms otherwise defined as idiopathic, in order to address a therapeutic strategy.

Indications and outcome of splenectomy in hematologic disease

Splenectomy is part of the therapeutic arsenal for benign or malignant hematological disorders that constitute the main indication for elective splenectomy. With the development of minimally invasive approaches, and in particular, laparoscopy, as well as the advent of monoclonal antibody therapy, the indications and the outcomes of splenectomy for hematologic disease have changed in recent years. Nonetheless, splenectomy has its place in hemoglobinopathies and hemolytic diseases, improves thrombocytopenia in refractory immune thrombocytopenic purpura, can reverse sequelae linked to voluminous splenomegaly secondary to myelofibrosis, or can be used for diagnostic purposes or for splenomegaly in lymphoproliferative syndromes.

Overcoming treatment challenges in myelofibrosis and polycythemia vera: the role of ruxolitinib

Myelofibrosis (MF) and polycythemia vera (PV) are BCR-ABL1-negative myeloproliferative neoplasms associated with somatic hematopoietic stem cell mutations leading to over activation of JAK-STAT signaling. MF and PV are pathogenically related and share specific clinical features such as splenomegaly and constitutional symptoms. The MF phenotype is dominated by the effects of progressive bone marrow fibrosis resulting in shortened survival. In contrast, elevated thrombosis risk due to erythrocytosis is the primary clinical concern in PV. Ruxolitinib, an oral JAK1/JAK2 inhibitor, is approved in the USA for the treatment of patients with intermediate- or high-risk MF and patients with PV who have had an inadequate response to or are intolerant of hydroxyurea. For MF, results of two phase III studies demonstrated that ruxolitinib therapy reduced spleen volume and MF-related symptom burden, improved quality-of-life measures, and was associated with prolonged overall survival. Treatment benefits were generally sustained with continued therapy. Dose-dependent cytopenias were common but generally manageable with transfusions (for anemia), dose reduction, or treatment interruption. Optimal dosing management is critical to maintain long-term treatment benefit, because cessation of therapy resulted in rapid return of symptoms to baseline levels. Results of the phase III PV trial showed that ruxolitinib was significantly more effective than standard therapy in controlling hematocrit levels and improving splenomegaly and PV-related symptoms. Only 1 of 110 patients in the ruxolitinib arm compared with 6 of 112 patients in the control arm experienced a thromboembolic event through week 32. Grade ≥3 cytopenias were uncommon.

Splenectomy in patients with myeloproliferative neoplasms: efficacy, complications and impact on survival and transformation

Splenectomy may be an effective therapeutic option for treating massive splenomegaly in patients with myeloproliferative neoplasms (MPNs). There are still limited data on its short- and long-term benefits and risks. Efficacy and short-term complications were analyzed in 94 patients with different MPNs who underwent splenectomy at M. D. Anderson Cancer Center. The long-term impact of splenectomy on overall survival (OS) and transformation free survival (TFS) was evaluated in 461 patients with myelofibrosis (MF) seen at M. D. Anderson, including 50 who underwent splenectomy during disease evolution. Splenectomy improved anemia and thrombocytopenia in 47% and 66% of patients, respectively. The most common complications were leukocytosis (76%), thrombocytosis (43%) and venous thromboembolism (16%). Post-operative mortality was 5%. Among patients with MF, splenectomy during disease evolution was associated with decreased OS (hazard ratio [HR] = 2.17, p < 0.0001) and TFS (HR = 2.17, p < 0.0001). This effect was independent of the Dynamic International Prognostic Scoring System. Splenectomy is a possible therapeutic option for patients with MF and other MPNs, and its greatest benefits are related to improvement in spleen pain and discomfort, anemia and thrombocytopenia. However, in patients with MF it appears to be associated with increased mortality.

Thrombocytopenia in myelodysplastic syndromes and myelofibrosis

Myelodysplastic syndromes (MDS) are a group of hematopoietic stem cell disorders characterized by ineffective hematopoeisis and an increased risk of transforming to acute myelogenous leukemia (AML). Determining the molecular basis of the disease has been hampered by its heterogeneity. Thrombocytopenia is often a manifestation of MDS and needs to be monitored and treated accordingly. Treating the underlying disorder with a variety of differentiation and immunosuppressive agents alleviates the problem in a small percentage of patients but more often complicates the issue. Several treatments used for primary immune thrombocytopenic purpura (ITP) have been tried in MDS patients, though with only modest success rates. Preliminary studies suggest that the use of a thrombopoietic growth factor may afford substantial increases in platelet levels without excessive deleterious side effects. Primary myelofibrosis (MF) is a chronic myeloproliferative disorder associated with hepatosplenomegaly and refractory cytopenias. Immunomodulatory agents have shown promise in treating the anemia associated with this MF. However, there are currently no standard therapies to treat the thrombocytopenia that is often found in patients with this disease.

Darbepoetin-alpha for the anaemia of myelofibrosis with myeloid metaplasia

Darbepoetin-alpha, a novel hyperglycosylated erythropoiesis-stimulating protein, was administered to 20 patients with myelofibrosis with myeloid metaplasia and anaemia. The initial weekly dose, 150 mug, was increased to 300 mug when no response was observed after 4-8 weeks. Eight patients (40%) responded to treatment, including six complete and two partial responses, and five maintained their response at a median follow-up of 12 months (range 4-22). Univariate analysis indicated that older age was the only factor associated with a favourable response to treatment (P = 0.006). None of the patients with appropriate serum erythropoietin levels responded. Treatment was usually well tolerated.

[Splenectomy for thrombocytopenic purpura. Retrospective analysis of the postoperative course]

BACKGROUND

Idiopathic thrombocytopenic purpura (ITP) comprises approximately 8% of all haemorrhagic diseases. Typical findings are a very low platelet count which manifests as petechial bleeding. Therapy consists of medication and removal of the spleen if conservative therapy fails.

PATIENTS AND METHODS

Between 1988 and 1999, 47 patients with ITP were splenectomized in our surgical department. We examine the postoperative development of platelet counts and long-term results in 33 of these patients.

RESULTS

After splenectomy, more then 75% of our patients had normal platelet counts. In long-term examination, 58% remained in stable condition with normal platelet counts. Retrospectively we tried to identify preoperative clinical features that could predict the long-term outcome of splenectomy in ITP but were unable to find reliable factors.

CONCLUSION

Idiopathic thrombocytopenic purpura can be treated by surgical means but should be considered only when conservative treatment has failed. The long-term outcome of splenectomy is not predictable. Reliable predictive factors have to be identified through further research.

Erythropoietin treatment of the anaemia of myelofibrosis with myeloid metaplasia: results in 20 patients and review of the literature

Recombinant human erythropoietin (rHuEPO) is an effective treatment for the anaemia that occurs secondary to various conditions, but its role in myelofibrosis with myeloid metaplasia (MMM) is not well established. rHuEPO, at an initial dose of 10 000 U thrice a week, was given to 20 patients with MMM and anaemia. Complete response (CR) was defined as transfusion cessation with normal haemoglobin (Hb) levels and partial response (PR) as a transfusion decrease > or =50% and Hb > 10 g/dl maintained for at least 8 weeks. Nine patients (45%) showed a favourable response to treatment, including four CR and five PR, four of whom have maintained their response at a median follow-up of 12.5 months (range: 4-21 months) from the start of treatment. The pretreatment factors associated with a favourable response were lack of transfusion requirement (P = 0.002) and higher Hb at start treatment of (P = 0.01). An analysis of the present series (n = 20) and 31 patients from the literature identified 28 (55%) favourable responses to rHuEPO, including 16 CR and 12 PR. In the multivariate analysis, serum erythropoietin level <125 U/l was found to be associated with a favourable response to rHuEPO, whereas lack of transfusional support had borderline significance.