A phase 3b, multicenter, open-label extension study of the long-term safety of anagrelide in Japanese adults with essential thrombocythemia

Essential Thrombocythemia and Post-Essential Thrombocythemia Myelofibrosis: Updates on Diagnosis, Clinical Aspects, and Management

Although several decades have passed since the description of myeloproliferative neoplasms (MPN), many aspects of their pathophysiology have not been elucidated. In this review, we discuss the mutational landscape of patients with essential thrombocythemia (ET), prognostic scores and salient pathology, and clinical points. We discuss also the diagnostic challenges of differentiating ET from prefibrotic MF. We then focus on post-essential thrombocythemia myelofibrosis (post-ET MF), a rare subset of MPN that is usually studied in conjunction with post-polycythemia vera MF. The transition of ET to post-ET MF is not well studied on a molecular level, and we present available data. Patients with secondary MF could benefit from allogenic hematopoietic stem cell transplantation, and we present available data focusing on post-ET MF.

Safety and efficacy of anagrelide in Japanese post-marketing surveillance, with subgroup analyses on the effect of previous cytoreductive therapies, age, and starting dose

BACKGROUND

In Japan, anagrelide has been approved for use in patients with essential thrombocythemia. Here, the safety and efficacy of anagrelide was assessed in clinical practice as post-marketing surveillance. Subgroup analyses were conducted to compare patients (1) with or without a history of cytoreductive therapy (CRT), (2) <60 or ≥60 years of age, and (3) with an anagrelide starting dose of ≤0.5 mg/day or 1.0 mg/day.

METHODS

Data were collected for all patients who received anagrelide, with an observation period of 12 months after treatment initiation.

RESULTS

Of the 648 patients, 54.3% experienced adverse drug reactions (ADRs). The most commonly reported ADRs were headaches, palpitations, and anemia. No significant difference was observed in overall ADRs across patient subgroups. A significantly higher incidence of headaches was observed in patients < 60 years versus those ≥ 60 years (P < 0.001). The incidence of anemia and serious ADRs were significantly higher in patients ≥ 60 years, and those with a history of CRT (P < 0.05). The discontinuation rate at 6 months was significantly lower in patients started at the lower anagrelide dose (P < 0.05). Platelet counts decreased in all analyzed groups.

CONCLUSIONS

This surveillance showed that anagrelide has a tolerable safety and efficacy profile.

Comparison of starting doses of anagrelide as a first-line therapy in patients with cytoreductive therapy-naïve essential thrombocythemia: difference between starting at 0.5 and 1.0 mg/day

Anagrelide is widely used for cytoreductive therapy in patients with essential thrombocythemia who are at high risk for thrombosis. The recommended starting dose in the package insert of anagrelide varies by country. A high starting dose leads to an early onset of action, but causes a higher incidence of adverse events. This relationship indicates that both the onset of action and side effects of anagrelide are dose dependent. We retrospectively compared the efficacy and safety of anagrelide as a first-line drug between patients with essential thrombocythemia who started at 0.5 or 1.0 mg/day. Incidence of total adverse events and anagrelide-related palpitation, discontinuation rates, and the median daily dose of anagrelide were lower in the 0.5 mg/day group than in the 1.0 mg/day group; however, comparable platelet-lowering effects were achieved in both groups. These data suggest that a low starting dose of anagrelide followed by dose escalation may result in fewer adverse events and lower discontinuation rates, while providing desirable platelet-lowering effects. Initiating anagrelide at a lower dose may be a useful approach in actual clinical practice.

Cecal cancer with essential thrombocythemia treated by laparoscopic ileocecal resection: a case report

Background

Essential thrombocythemia (ET) is a myeloproliferative disorder characterized by thrombocytosis and a propensity for both thrombotic and hemorrhagic events. ET rarely occurs simultaneously with colorectal cancer. Here, we report a case of colorectal cancer in an ET patient treated using laparoscopic ileocecal resection.

Case presentation

A 40-year-old woman was admitted to our hospital after presenting with liver dysfunction. She had been previously diagnosed with ET; aspirin and anagrelide had been prescribed. Subsequent examination at our hospital revealed cecal cancer. Distant metastasis was absent; laparoscopic ileocecal resection was performed. Anagrelide was discontinued only on the surgery day. She was discharged on the seventh postoperative day without thrombosis or hemorrhage. However, when capecitabine and oxaliplatin were administered as adjuvant chemotherapy with continued anagrelide administration, she experienced hepatic dysfunction and thrombocytopenia; thus, anagrelide was discontinued. Five days later, her platelet count recovered. Subsequently, anagrelide and aspirin administration was resumed, without any adjuvant chemotherapy. Her liver function normalized gradually in 4 months. One-year post operation, she is well without tumor recurrence or new metastasis.

Conclusions

To our knowledge, this is the first report of laparoscopic colectomy performed on an ET patient receiving anagrelide. Our report shows that complications such as bleeding or thrombosis can be avoided by anagrelide administration. Contrastingly, thrombocytopenia due to anagrelide intake should be considered when chemotherapy that could cause bone marrow suppression is administered.

Emerging drugs for essential thrombocythemia

Introduction: Despite our recent progress in the understanding of essential thrombocythemia (ET) pathogenesis, the therapeutic management of this disease has remained largely unchanged in the past decades. Treatment has mostly focused on decreasing the risk of complications, especially prevention of thrombotic or hemorrhagic events. Areas covered: Over recent years, the treatment options of ET have been expanding with some novel agents on the horizon. The classes of agents described in this review include targeted and immunomodulatory agents, such as JAK1/2 inhibitors, interferon-α, histone deacetylase inhibitors, telomerase inhibitors and human double minute 2 inhibitors. These compounds entered various stages of development, albeit the only portion of them is currently actively undergoing evaluation in clinical trials. In this review, we look at the current therapies and discuss novel agents available in the management of ET. Expert opinion: The drug development in ET possesses several challenges stemming from its relatively benign and prolonged disease course. Therapy focused on reducing the risk of thrombotic and hemorrhagic complications and symptom management needs to be chosen wisely as a vast majority of these patients have a near-normal life expectancy. To date, no therapy has shown effective and definitive alteration of the disease behavior. Although novel agents are in development and hopefully some of them will extend treatment armamentarium of ET, their exact role remains to be determined.