Roger M. Lyons

A Double-Blind Placebo-Controlled Trial of Ruxolitinib for Myelofibrosis

BACKGROUND Ruxolitinib, a selective inhibitor of Janus kinase (JAK) 1 and 2, has clinically significant activity in myelofibrosis. METHODS In this double-blind trial, we randomly assigned patients with intermediate-2 or high-risk myelofibrosis to twice-daily oral ruxolitinib (155 patients) or placebo (154 patients). The primary end point was the proportion of patients with a reduction in spleen volume of 35% or more at 24 weeks, assessed by means of magnetic resonance imaging. Secondary end points included the durability of response, changes in symptom burden (assessed by the total symptom score), and overall survival. RESULTS The primary end point was reached in 41.9% of patients in the ruxolitinib group as compared with 0.7% in the placebo group (P<0.001). A reduction in spleen volume was maintained in patients who received ruxolitinib; 67.0% of the patients with a response had the response for 48 weeks or more. There was an improvement of 50% or more in the total symptom score at 24 weeks in 45.9% of patients who received ruxolitinib as compared with 5.3% of patients who received placebo (P<0.001). Thirteen deaths occurred in the ruxolitinib group as compared with 24 deaths in the placebo group (hazard ratio, 0.50; 95% confidence interval, 0.25 to 0.98; P=0.04). The rate of discontinuation of the study drug because of adverse events was 11.0% in the ruxolitinib group and 10.6% in the placebo group. Among patients who received ruxolitinib, anemia and thrombocytopenia were the most common adverse events, but they rarely led to discontinuation of the drug (in one patient for each event). Two patients had transformation to acute myeloid leukemia; both were in the ruxolitinib group. CONCLUSIONS Ruxolitinib, as compared with placebo, provided significant clinical benefits in patients with myelofibrosis by reducing spleen size, ameliorating debilitating myelofibrosis-related symptoms, and improving overall survival. These benefits came at the cost of more frequent anemia and thrombocytopenia in the early part of the treatment period. (Funded by Incyte; COMFORT-I ClinicalTrials.gov number, NCT00952289.).

Efficacy of romiplostim in patients with chronic immune thrombocytopenic purpura: a double-blind randomised controlled trial

BACKGROUND Chronic immune thrombocytopenic purpura (ITP) is characterised by accelerated platelet destruction and decreased platelet production. Short-term administration of the thrombopoiesis-stimulating protein, romiplostim, has been shown to increase platelet counts in most patients with chronic ITP. We assessed the long-term administration of romiplostim in splenectomised and non-splenectomised patients with ITP. METHODS In two parallel trials, 63 splenectomised and 62 non-splenectomised patients with ITP and a mean of three platelet counts 30x10(9)/L or less were randomly assigned 2:1 to subcutaneous injections of romiplostim (n=42 in splenectomised study and n=41 in non-splenectomised study) or placebo (n=21 in both studies) every week for 24 weeks. Doses of study drug were adjusted to maintain platelet counts of 50x10(9)/L to 200x10(9)/L. The primary objectives were to assess the efficacy of romiplostim as measured by a durable platelet response (platelet count > or =50x10(9)/L during 6 or more of the last 8 weeks of treatment) and treatment safety. Analysis was per protocol. These studies are registered with ClinicalTrials.gov, numbers NCT00102323 and NCT00102336. FINDINGS A durable platelet response was achieved by 16 of 42 splenectomised patients given romplostim versus none of 21 given placebo (difference in proportion of patients responding 38% [95% CI 23.4-52.8], p=0.0013), and by 25 of 41 non-splenectomised patients given romplostim versus one of 21 given placebo (56% [38.7-73.7], p<0.0001). The overall platelet response rate (either durable or transient platelet response) was noted in 88% (36/41) of non-splenectomised and 79% (33/42) of splenectomised patients given romiplostim compared with 14% (three of 21) of non-splenectomised and no splenectomised patients given placebo (p<0.0001). Patients given romiplostim achieved platelet counts of 50x10(9)/L or more on a mean of 13.8 (SE 0.9) weeks (mean 12.3 [1.2] weeks in splenectomised group vs 15.2 [1.2] weeks in non-splenectomised group) compared with 0.8 (0.4) weeks for those given placebo (0.2 [0.1] weeks vs 1.3 [0.8] weeks). 87% (20/23) of patients given romiplostim (12/12 splenectomised and eight of 11 non-splenectomised patients) reduced or discontinued concurrent therapy compared with 38% (six of 16) of those given placebo (one of six splenectomised and five of ten non-splenectomised patients). Adverse events were much the same in patients given romiplostim and placebo. No antibodies against romiplostim or thrombopoietin were detected. INTERPRETATION Romiplostim was well tolerated, and increased and maintained platelet counts in splenectomised and non-splenectomised patients with ITP. Many patients were able to reduce or discontinue other ITP medications. Stimulation of platelet production by romiplostim may provide a new therapeutic option for patients with ITP.

Safety and efficacy of long-term treatment with romiplostim in thrombocytopenic patients with chronic ITP

Chronic immune thrombocytopenic purpura (ITP) is characterized by low platelet counts and mucocutaneous bleeding. In previous studies romiplostim (AMG531), a thrombopoiesis-stimulating protein, increased platelet counts in most patients with chronic ITP. This ongoing, long-term open-label, single-arm study investigated safety and efficacy in patients who completed a previous romiplostim study and had platelet counts less than or equal to 50 [corrected] x 10(9)/L. One hundred forty-two patients were treated for up to 156 weeks (mean, 69 weeks). Platelet responses (platelet count > or = 50 x 10(9)/L and double baseline) were observed in 87% of all patients and occurred on average 67% of the time in responding patients. In 77% of patients, the romiplostim dose remained within 2 microg/kg of their most frequent dose at least 90% of the time. Ninety patients (63%) received treatment by self-administration. Treatment-related serious adverse events were reported in 13 patients (9%). Bone marrow reticulin was observed in 8 patients; marrows were not routinely performed in this study, so the true incidence of this event cannot be determined. Severe bleeding events were reported in 12 patients (9%). Thrombotic events occurred in 7 patients (5%). In conclusion, romiplostim increased platelet counts in most patients for up to 156 weeks without tachyphylaxis and had an acceptable safety profile. (ClinicalTrials.gov Identifier NCT00116688).

Secondary prevention of venous thromboembolic events in patients with active cancer: enoxaparin alone versus initial enoxaparin followed by warfarin for a 180-day period.

This study evaluated enoxaparin alone versus initial enoxaparin followed by warfarin in secondary prevention of venous thromboembolic events in adults with active malignancy. Cancer patients (n = 122) with acute symptomatic venous thromboembolic events were randomly allocated to receive subcutaneous enoxaparin 1.0 mg/kg every 12 hours for 5 days, followed by 1.0 mg/kg daily (group 1a) or 1.5 mg/kg daily (group 1b) for 175 days, or subcutaneous enoxaparin 1.0 mg/kg every 12 hours for at least 5 days and until a stable international normalized ratio of 2 to 3 was achieved on oral warfarin begun on day 2 and continued to day 180 (group 2). There were no significant differences in major and minor bleeding rates between treatment groups. No bleeding events were intracranial or fatal. Enoxaparin treatment was feasible, generally well tolerated, and effective for a 180-day period in the secondary prevention of venous thromboembolic events in patients with active malignancy.

Hematologic Response to Three Alternative Dosing Schedules of Azacitidine in Patients With Myelodysplastic Syndromes

PURPOSE Azacitidine (AZA) is effective treatment for myelodysplastic syndromes (MDS) at a dosing schedule of 75 mg/m(2)/d subcutaneously for 7 days every 4 weeks. The initial phase of this ongoing multicenter, community-based, open-label study evaluated three alternative AZA dosing schedules without weekend dosing. PATIENTS AND METHODS MDS patients were randomly assigned to one of three regimens every 4 weeks for six cycles: AZA 5-2-2 (75 mg/m(2)/d subcutaneously for 5 days, followed by 2 days no treatment, then 75 mg/m(2)/d for 2 days); AZA 5-2-5 (50 mg/m(2)/d subcutaneously for 5 days, followed by 2 days no treatment, then 50 mg/m(2)/d for 5 days); or AZA 5 (75 mg/m(2)/d subcutaneously for 5 days). RESULTS Of patients randomly assigned to AZA 5-2-2 (n = 50), AZA 5-2-5 (n = 51), or AZA 5 (n = 50), most were French-American-British (FAB) lower risk (refractory anemia [RA]/RA with ringed sideroblasts/chronic myelomonocytic leukemia with < 5% bone marrow blasts, 63%) or RA with excess blasts (30%), and 79 (52%) completed > or = six treatment cycles. Hematologic improvement (HI) was achieved by 44% (22 of 50), 45% (23 of 51), and 56% (28 of 50) of AZA 5-2-2, AZA 5-2-5, and AZA 5 arms, respectively. Proportions of RBC transfusion-dependent patients who achieved transfusion independence were 50% (12 of 24), 55% (12 of 22), and 64% (16 of 25), and of FAB lower-risk transfusion-dependent patients were 53% (nine of 17), 50% (six of 12), and 61% (11 of 18), respectively. In the AZA 5-2-2, AZA 5-2-5, and AZA 5 groups, 84%, 77%, and 58%, respectively, experienced > or = 1 grade 3 to 4 adverse events. CONCLUSION All three alternative dosing regimens produced HI, RBC transfusion independence, and safety responses consistent with the currently approved AZA regimen. These results support AZA benefits in transfusion-dependent lower-risk MDS patients.

Efficacy, safety, and survival with ruxolitinib in patients with myelofibrosis: results of a median 3-year follow-up of COMFORT-I

COMFORT-I is a randomized, double-blind, placebo-controlled trial of the Janus kinase 1/Janus kinase 2 inhibitor ruxolitinib in 309 patients with intermediate-2 or high-risk myelofibrosis. This analysis of COMFORT-I describes the long-term efficacy and safety of ruxolitinib (median follow-up, 2 years). Spleen volume was measured by magnetic resonance imaging, and quality of life was evaluated using the EORTC QLQ-C30. Overall survival was determined according to randomized treatment group. At the time of this analysis, 100 of 155 patients randomized to ruxolitinib were still receiving treatment. All patients randomized to placebo crossed over to ruxolitinib or discontinued within 3 months of the primary analysis (median time to crossover, 41 weeks). Mean spleen volume reductions in the ruxolitinib group were 31.6% at week 24 and 34.9% at week 96; improvements in quality of life measures were also maintained. Improved survival was observed for ruxolitinib (n=27 deaths) versus placebo (n=41 deaths) (hazard ratio=0.58; 95% confidence interval: 0.36, 0.95; P=0.03). The incidence of new-onset grade 3 or 4 anemia and thrombocytopenia decreased over time to levels observed in patients receiving placebo. These data indicate that ruxolitinib treatment provides durable reductions in spleen volume and improvements in quality of life and suggest a continued survival advantage for ruxolitinib over placebo.

Phase II Study of Clofarabine Monotherapy in Previously Untreated Older Adults With Acute Myeloid Leukemia and Unfavorable Prognostic Factors

PURPOSE This phase II study assessed clofarabine monotherapy in older adults (>or= 60 years of age) with untreated acute myeloid leukemia (AML) and at least one unfavorable baseline prognostic factor. PATIENTS AND METHODS Clofarabine was administered intravenously for 5 days at 30 mg/m(2)/d during induction and 20 mg/m(2)/d during reinduction/consolidation (six cycles maximum). The primary end point was overall remission rate (ORR; ie, complete remission [CR] plus CR with incomplete platelet recovery [CRp]). RESULTS In 112 evaluable patients who were treated (median age, 71 years; range, 60 to 88 years), the ORR was 46% (38% CR, 8% CRp). ORR by unfavorable prognostic factor was 39% for patients >or= 70 years of age; 32% for Eastern Cooperative Oncology Group (ECOG) performance status 2; 51% for antecedent hematologic disorder; 54% for intermediate karyotype; 42% for unfavorable karyotype; and 48%, 51%, and 38% for one, two, and three risk factors, respectively. The median disease-free survival was 37 weeks (95% CI, 26 to 56 weeks). Median duration of remission was 56 weeks (95% CI, 33 to not estimable). The estimated median overall survival was 41 weeks (95% CI, 28 to 53 weeks) for all patients, 59 weeks for patients with CR/CRp, and 72 weeks for patients with CR. The 30-day all-cause mortality was 9.8%. The most common non-laboratory drug-related toxicities (>or= 20% patients) were nausea, febrile neutropenia, vomiting, diarrhea, rash, and fatigue. CONCLUSION Clofarabine is an active agent with acceptable toxicity in patients age 60 years or older with untreated AML who have at least one unfavorable prognostic factor. ORR did not seem affected by the presence of multiple unfavorable prognostic factors.

The incidence and impact of thrombocytopenia in myelodysplastic syndromes

Thrombocytopenia and platelet dysfunction contribute to hemorrhagic complications in the myelodysplastic syndromes (MDS). Reliable data regarding the frequency and consequences of thrombocytopenia in MDS are lacking. An extensive literature review indicated that the prevalence of thrombocytopenia (platelets <100 × 109/L) in MDS ranged from 40% to 65%; the median frequency of thrombocytopenia prior to any MDS therapy was 65% (range, 23–93%). A retrospective review of patients who were referred to the University of Texas M. D. Anderson Cancer Center (MDACC) identified 1605 of 2410 patients (67%) with thrombocytopenia at referral. Of these, 1756 patients were classified using the International Prognostic Scoring System (IPSS), and 896 patients (51%) had intermediate‐2 or high‐risk disease. Treatment‐related thrombocytopenia was observed in studies that involved azacitidine, tipifarnib, decitabine, lenalidomide, sirolimus, and combination chemotherapy with idarubicin, cytarabine, and topotecan. The reported incidence of hemorrhagic complications in the literature ranged from 3% to 53%, and the frequency of hemorrhagic deaths ranged from 14% to 24%. At MDACC, 460 patients had a coded cause of death: hemorrhage as a contributory cause of death, 20%; hemorrhage as the only cause of death, 10%. Thrombocytopenia was common in MDS, and there was an increased prevalence in higher risk IPSS categories. Many approved and investigational MDS therapies caused or exacerbated preexisting thrombocytopenia. The incidence of severe bleeding in MDS was greater than reported in current guidelines. Cancer 2007.

Long‐term treatment with romiplostim in patients with chronic immune thrombocytopenia: safety and efficacy

Romiplostim was effective, safe, and well‐tolerated over 6–12 months of continuous treatment in Phase 3 trials in patients with immune thrombocytopenia (ITP). This report describes up to 5 years of weekly treatment with romiplostim in 292 adult ITP patients in a long‐term, single‐arm, open‐label study. Outcome measures included adverse events (including bleeding, thrombosis, malignancy, and reticulin/fibrosis), platelet response (platelet count >50 × 109 per litre), and the proportion of patients requiring rescue treatments. Treatment–related serious adverse events were infrequent and did not increase with longer treatment. No new classes of adverse events emerged. Thrombotic events occurred in 6·5% of patients and were not associated with platelet count. Median platelet counts of 50–200 × 109 per litre were maintained with stable doses of romiplostim (mean 5–8 μg/kg; generally self‐administered at home) throughout the study. A platelet response was achieved at least once by 95% of patients, with a platelet response maintained by all patients on a median 92% of study visits. There was a low rate of bleeding and infrequent need for rescue treatments. In conclusion, this study demonstrated that romiplostim was safe and well‐tolerated over 614 patient‐years of exposure in ITP patients, and that efficacy was maintained with stable dosing for up to 5 years of continuous treatment.

Safety and efficacy of romiplostim in patients with lower-risk myelodysplastic syndrome and thrombocytopenia.

PURPOSE To assess the safety and efficacy of romiplostim, a peptibody that increases platelet production, for treatment of thrombocytopenic patients with myelodysplastic syndromes (MDS). PATIENTS AND METHODS Eligible patients had lower-risk MDS (International Prognostic Scoring System low or intermediate 1), a mean baseline platelet count <or= 50 x 10(9)/L, and were only receiving supportive care. Patients received three injections of 300, 700, 1,000, or 1,500 microg romiplostim at weekly intervals. After evaluation of platelet response at week 4, patients could continue to receive romiplostim in a treatment extension phase for up to 1 year. RESULTS All 44 patients who enrolled completed the treatment phase; 41 patients continued into the extension phase. Median platelet counts increased throughout the study, from fewer than 30 x 10(9)/L at baseline to 60, 73, 38, and 58 x 10(9)/L at week 4 for the 300-, 700-, 1,000-, and 1,500 -microg dose cohorts, respectively. A durable platelet response (per International Working Group 2000 criteria for 8 consecutive weeks independent of platelet transfusions) was achieved by 19 patients (46%). The incidence of bleeding events and platelet transfusions was less common among patients who achieved a durable platelet response than those who did not (4.3 v 39.3 per 100 patient-weeks). Forty-three patients (98%) reported one or more adverse events. Treatment-related serious adverse events were reported in five patients (11%), all of whom were in the 1,500-microg dose cohort. Two patients progressed to acute myeloid leukemia during the study. No neutralizing antibodies to either romiplostim or endogenous thrombopoietin were seen. CONCLUSION Romiplostim appeared well-tolerated in this study and may be a useful treatment for patients with MDS and thrombocytopenia.