EXPAND, a dose-finding study of ruxolitinib in patients with myelofibrosis and low platelet counts: 48-week follow-up analysis.

EEXPAND (phase Ib, dose-finding study) evaluated the starting dose of ruxolitinib in patients with myelofibrosis with baseline platelet counts of 50-99×109/L. The study consisted of dose-escalation and safety-expansion phases. Based on the baseline platelet counts, patients were assigned to stratum 1 (75-99×109/L) or stratum 2 (50-74×109/L), with the primary objective of determining the maximum safe starting dose (MSSD); key secondary objectives included safety and efficacy. At week 48 data cutoff (stratum 1, n=44; stratum 2, n=25), 24.6% (17 out of 69) of patients were still receiving treatment. The MSSD was established as ruxolitinib 10 mg twice daily in both strata. Thrombocytopenia [grade 4 (stratum 1, n=1; stratum 2, n=2)] was the only reported dose-limiting toxicity (study drug related) at 10 mg twice daily. In the MSSD cohort (stratum 1, n=20; stratum 2, n=18), adverse events (regardless of study drug relationship) led to treatment discontinuation in 15.0% and 33.3% of patients in stratum 1 and stratum 2, respectively, and dose adjustment/interruption in 45.0% and 66.7% of patients in stratum 1 and stratum 2, respectively. Three cases of on-treatment deaths were reported at the MSSD. Spleen response was achieved at week 48 in 33.3% and 30.0% of patients in stratum 1 and stratum 2, respectively. Improvements in the Total Symptom Score were also observed. In this study, ruxolitinib demonstrated acceptable tolerability in both the strata at the MSSD of 10 mg twice daily. (Registered at: clinicaltrials.gov identifier: 01317875).

Outcome of Ph negative myeloproliferative neoplasms transforming to accelerated or leukemic phase.

Myeloproliferative neoplasms (MPN) are chronic disorders that can sometimes evolve into accelerated or leukemic phases. We retrospectively identified 122 patients with such blastic phases. The overall median survival was four months: 10.2 months for patients treated with intensive treatments compared to three months for best supportive care (p = .005). Azacytidine, intensive chemotherapies, or allogeneic stem cell transplantation gave the highest median survivals with 9, 10.2, and 19.4 months, respectively. Accelerated phases (AP) had a longer median survival compared to acute leukemia (4.8 months vs. 3.1 months; p = .02). In this retrospective and observational study, we observe that the longest survivals are seen in patients eligible for intensive treatments. Azacytidine shows interesting results in patients non-fit for intensive chemotherapy. Supportive care should probably be restricted to elderly patients and those with unfavorable karyotype. An early diagnosis of AP could also result in a better survival rate.

Benefits and pitfalls of pegylated interferon-α2a therapy in patients with myeloproliferative neoplasm-associated myelofibrosis: a French Intergroup of Myeloproliferative neoplasms (FIM) study.

We have previously described the safety and efficacy of pegylated interferon-α2a therapy in a cohort of 62 patients with myeloproliferative neoplasm-associated myelofibrosis followed in centers affiliated to the French Intergroup of Myeloproliferative neoplasms. In this study, we report their long-term outcomes and correlations with mutational patterns of driver and non-driver mutations analyzed by targeted next generation sequencing. The median age at diagnosis was 66 years old, the median follow-up since starting pegylated interferon was 58 months. At the time of analysis, 30 (48.4%) patients were alive including 16 still being treated with pegylated interferon. The median survival of patients with intermediate and high-risk prognostic Lille and dynamic International Prognostic Scoring System scores treated with pegylated interferon was increased in comparison to that of historical cohorts. In addition, overall survival was significantly correlated with the duration of pegylated interferon therapy (70 versus 30 months after 2 years of treatment, P<10-12). JAK2V617F allele burden was decreased by more than 50% in 58.8% of patients and two patients even achieved complete molecular response. Next-generation sequencing analyses performed in 49 patients showed that 28 (57.1%) of them carried non-driver mutations. The presence of at least one additional mutation was associated with a reduction of both overall and leukemia-free survival. These findings in a large series of patients with myelofibrosis suggest that pegylated interferon therapy may provide a survival benefit for patients with intermediate- or high-risk Lille and dynamic International Prognostic Scoring System scores. It also reduced the JAK2V617F allele burden in most patients. These results further support the use of pegylated interferon in selected patients with myelofibrosis.

Efficacy and safety of pegylated-interferon α-2a in myelofibrosis: a study by the FIM and GEM French cooperative groups.

Myeloproliferative neoplasm-related myelofibrosis is associated with cytopenic or proliferative phases, splenomegaly and constitutional symptoms. Few effective treatments are available and small series suggested that interferon could be an option for myelofibrosis therapy. We performed a retrospective study of pegylated-interferon α-2a (Peg-IFNα-2a) therapy in myelofibrosis. Sixty-two patients treated with Peg-IFNα-2a at 17 French and Belgian centres were included. Responses were determined based on the criteria established by the International Working Group for Myelofibrosis Research and Treatment. Mean follow-up was 26 months. Sixteen of 25 anaemic patients (64%) (eight concomitantly receiving recombinant erythropoietin) achieved a complete response and transfusion-independence was obtained in 5/13 patients (38·5%). Constitutional symptoms resolved in 82% of patients. All five leucopenic patients normalized their leucocyte counts, whereas a normal platelet count was obtained in 5/8 thrombocytopenic patients. Splenomegaly was reduced in 46·5% of patients, and complete resolution of thrombocytosis and leucocytosis were observed in 82·8% and 68·8% of patients, respectively. Side effects (mostly haematological) were mainly of grade 1-2. The only factor independently associated with treatment failure was a spleen enlargement of more than 6 cm below the costal margin. In conclusion, Peg-IFNα-2a induced high response rates with acceptable toxicity in a large proportion of patients with primary and secondary myelofibrosis, especially in early phases.