Ilene C. Weitz

Eculizumab in Pregnant Patients with Paroxysmal Nocturnal Hemoglobinuria

BACKGROUND Eculizumab, a humanized monoclonal antibody against complement protein C5 that inhibits terminal complement activation, has been shown to prevent complications of paroxysmal nocturnal hemoglobinuria (PNH) and improve quality of life and overall survival, but data on the use of eculizumab in women during pregnancy are scarce. METHODS We designed a questionnaire to solicit data on pregnancies in women with PNH and sent it to the members of the International PNH Interest Group and to the physicians participating in the International PNH Registry. We assessed the safety and efficacy of eculizumab in pregnant patients with PNH by examining the birth and developmental records of the children born and adverse events in the mothers. RESULTS Of the 94 questionnaires that were sent out, 75 were returned, representing a response rate of 80%. Data on 75 pregnancies in 61 women with PNH were evaluated. There were no maternal deaths and three fetal deaths (4%). Six miscarriages (8%) occurred during the first trimester. Requirements for transfusion of red cells increased during pregnancy, from a mean of 0.14 units per month in the 6 months before pregnancy to 0.92 units per month during pregnancy. Platelet transfusions were given in 16 pregnancies. In 54% of pregnancies that progressed past the first trimester, the dose or the frequency of use of eculizumab had to be increased. Low-molecular-weight heparin was used in 88% of the pregnancies. Ten hemorrhagic events and 2 thrombotic events were documented; both thrombotic events occurred during the postpartum period. A total of 22 births (29%) were premature. Twenty cord-blood samples were examined for the presence of eculizumab; the drug was detected in 7 of the samples. A total of 25 babies were breast-fed, and in 10 of these cases, breast milk was examined for the presence of eculizumab; the drug was not detected in any of the 10 breast-milk samples. CONCLUSIONS Eculizumab provided benefit for women with PNH during pregnancy, as evidenced by a high rate of fetal survival and a low rate of maternal complications. (ClinicalTrials.gov number, NCT01374360.).

Eculizumab therapy results in rapid and sustained decreases in markers of thrombin generation and inflammation in patients with PNH independent of its effects on hemolysis and microparticle formation

Paroxysmal Nocturnal Hemoglobinuria (PNH) is a clonal bone marrow disorder which results in the loss of glycosylphosphatidyl inositol (GPI) anchors from cell membranes. As a consequence, membrane inhibitors of complement are lost rendering the cells more susceptible to complement mediated destruction. This results in hemolysis, leukopenia, thrombocytopenia and thrombophilia. Eculizumab, a monoclonal antibody to complement protein 5, has been approved for the treatment of PNH and is associated with a significant reduction in hemolysis, thromboembolic events and fatigue. We prospectively studied the effect of Eculizumab therapy on plasma markers of thrombin generation (D-Dimers, TAT), inflammation (IL-6), soluble P-selectin (sP-selectin), antigenic (TFMP) and functional (fTFMP) tissue factor bearing microparticles and total plasma microparticle ex vivo factor Xa generation (MPFXa) in eleven Eculizumab naive PNH patients. Blood sampling occurred day 1, prior to Eculizumab treatment, then on days 8,15,22,29, 43, 90. Our results demonstrate a statistically significant reduction in D-Dimer, TAT, IL-6, sP-selectin, and TFMP during the induction phase of treatment (day 1-29) which was sustained during the maintenance treatment (day 29-90). Although the serum LDH levels decreased rapidly, there was no correlation between the change in LDH and the markers of thrombin generation and inflammation. Although there was a statistically significant decrease in TFMP, this decrease did not correlate with changes in markers of thrombin generation or inflammation. Ex vivo MPFXa generation did not decrease with Eculizumab treatment suggesting continued microparticle formation despite inhibition of hemolysis. Ex vivo total microparticle FXa generation was found to have an inverse correlation with markers of thrombin generation, suggesting that in PNH patients in vivo thrombin generation occurs by a pathway independent of hemolysis and microparticle generation.

Enhancement of Fluorouracil Uptake in Human Colorectal and Gastric Cancers by Interferon or by High-Dose Methotrexate: An In Vivo Human Study Using Noninvasive 19F-Magnetic Resonance Spectroscopy

PURPOSE To study whether two modulators, high-dose methotrexate (MTX) and interferon alfa-2a (IFNalpha-2a) will alter the intratumoral pharmacokinetics of fluorouracil (5-FU). PATIENTS AND METHODS Five patients, two with gastric cancer and three with colorectal cancer, who had metastatic tumor nodules in their livers were studied dynamically in vivo after 5-FU injection. In a magnetic resonance imaging unit, noninvasive (19)F-magnetic resonance spectroscopy (MRS) was used to detect (19)F signals from 5-FU and its metabolites. RESULTS The intratumoral half-life (t(1/2)) of 5-FU in these tumors ranged from 18.8 minutes to 42.3 minutes. Four of the five patients exhibited increases in the t(1/2) of 5-FU after intravenous (IV) administration of MTX or IFNalpha-2a. In the two patients with gastric cancer who received IV high-dose MTX followed by IV 5-FU, increases were seen in either the total t(1/2) of 5-FU (41.8%) or in the t(1/2) of the alpha phase (150%). In the three patients with colorectal cancer who received IV IFNalpha-2a followed by IV 5-FU, the two patients with partial responses had increases in the t(1/2) of 5-FU of 41% and 30.2%, whereas the nonresponder had a nonsignificant increase (5.6%) in the t(1/2) of 5-FU. CONCLUSIONS These results document that the in vivo modulation of the tumoral pharmacokinetics of 5-FU can be measured noninvasively by (19)F-MRS and suggest that such information correlates with subsequent clinical outcomes. The findings also indicate that IFNalpha-2a and high-dose MTX can increase the intratumoral 5-FU in some patients. Such information, obtained prospectively in vivo, may assist in better individual cancer patient management and in developing novel drug combinations.

A prospective multicenter study of paroxysmal nocturnal hemoglobinuria cells in patients with bone marrow failure

Paroxysmal nocturnal hemoglobinuria (PNH), a rare clonal hematopoietic stem cell disorder, is characterized by chronic, uncontrolled complement activation leading to intravascular hemolysis and an inflammatory prothrombotic state. The EXPLORE study aimed to determine the prevalence of undiagnosed PNH in patients with aplastic anemia (AA), myelodysplastic syndrome (MDS), and/or other bone marrow failure (BMF) syndromes and the effect of PNH clone size on hemolysis.

Thrombosis in patients with paroxysmal nocturnal hemoglobinuria.

Paroxysmal nocturnal hemoglobinuria is a disorder associated with hemolysis, pancytopenia, and thrombosis due to the loss of the glycosylphosphatidylinositol (GPI) anchored complement regulatory proteins. The mechanism of thrombosis is multifactorial. Although intravascular hemolysis has been implicated as the etiology, the effect of complement on GPI anchor-deficient platelets, granulocytes, monocytes, and endothelial cells contributes significantly to the risk of thrombosis. Moreover, there appears to be an underlying inflammatory state that is linked to hemostatic activation that may induce thrombosis through a pathway independent of hemolysis.

Autoimmune Hemolytic Anemia

Autoimmune hemolytic anemia is an acquired autoimmune disorder resulting in the production of antibodies directed against red blood cell antigens causing shortened erythrocyte survival. The disorders can present as a primary disorder (idiopathic) or secondary to other autoimmune disorders, malignancies, or infections. Treatment involves immune modulation with corticosteroids and other agents.

Life‐threatening delayed hyperhemolytic transfusion reaction in a patient with sickle cell disease: effective treatment with eculizumab followed by rituximab

Hyperhemolysis in sickle cell disease is a rare and potentially life‐threatening complication of transfusion.

Does leucovorin alter the intratumoral pharmacokinetics of 5-fluorouracil (5-FU)? A Southwest Oncology Group study.

AbstractPurpose and design: We previouslydocumented that there was an associationbetween the intra-tumoral pharmacokinetics(TPK) of 5-FU and response to therapy with5-FU and leucovorin (p < .0001). Since wehave shown that other modulators of 5-FU,such as methotrexate, interferon andneutrexin alter its TPK, it was of interestto determine if the modulating effect ofleucovorin would also alter the tumoral PKof 5-FU. In order to determine the effectof leucovorin on intratumoral 5-FUpharmacokinetics, 23 patients (21evaluable) underwent 19F magneticresonance spectroscopy 19F-MRS)twice. The first 19F-MRS was following5-FU 600 mg/m2 alone, and the second19F-MRS was following by leucovorin500 mg/m2 and then 5-FU 600 mg/m2. Results: A comparison of theintratumoral 5-FU pharmacokineticsindicated that there was no general effectof leucovorin on the intratumoral half-lifeof 5-FU. In only two of these 21 patientswas the half-life of 5-FU altered, and inboth cases it was decreased by more than20%. Partial responses to 5-FU plusleucovorin therapy were seen only inpatients with a long intratumoral half-life(trapping) of 5-FU (3 PR in 11 patientswith T1/2 ≥ 20 minutes, comparedto 0 PR in 11 patients with T1/2 <20 minutes). There was a statisticallysignificant correlation between tumorresponse and the intratumoral T1/2 of5-FU, consistent with our prior results ina larger number of patients. However, therewas no statistically significantcorrelation of time-to-progression orsurvival with classification of thepatients into trappers or non-trappers,probably due to the small sample size inthis current study. Conclusion: The data reported hereare compatible with the hypothesis thatleucovorin enhancement of 5-fluorouracilantitumor responses is not mediated by thelevels of 5-FU in tumors, but rather, isdue to the modulation by leucovorin ofcellular metabolic processes that followthe uptake of free 5-FU into the tumorcell. The MRS technique may be useful inselected instances for elucidating thepossible metabolic interactions of drugsin vivo.

Cross-sectional validation study of patient-reported outcomes in patients with paroxysmal nocturnal haemoglobinuria

Paroxysmal nocturnal haemoglobinuria (PNH) is a rare, acquired, clonal haemopoietic stem cell disorder that causes chronic intravascular haemolysis, increases the risk of thrombosis and results in significant patient morbidity and mortality. The symptoms of PNH may have a major impact on patient quality of life.

A novel approach to the evaluation of bleeding-related episodes in patients with chronic immune thrombocytopenia

Abstract Objective: In clinical studies of patients with severe thrombocytopenia, rescue treatments are used to prevent or stop bleeding. Estimating risk reductions of bleeding for clinical study medications can be challenging. This study evaluated a new and possibly more accurate way of assessing the effects of a treatment intervention on bleeding-related outcomes. We developed a composite endpoint, termed bleeding-related episodes (BRE). Research design and methods: BREs were assessed in a post-hoc analysis of patients with chronic immune thrombocytopenia (ITP) who participated in two romiplostim, phase 3, placebo-controlled studies. Patients received romiplostim or placebo once weekly for 24 weeks. A BRE was defined as an actual bleeding event and/or the use of rescue medication. In total, 125 patients (41 placebo, 84 romiplostim) with platelet counts <30 K were enrolled. Clinical trial registration: NCT00102323/NCT00102336. Results: The rate of all BREs across all studies was reduced by 56% in patients receiving romiplostim compared with placebo. The rate of BREs using immunoglobulin (IVIg or anti-D Ig) was reduced by 89% in patients receiving romiplostim compared with placebo. BREs were more frequent in both groups at platelet counts <50 × 109/L. Results were similar between splenectomized and nonsplenectomized patients. We believe that prior to the development of this tool, bleeding events were underdiagnosed. The BRE tool allowed the identification of multiple interventions within bleeding episodes, which may have required separate interventions and were therefore considered to be additional BREs. Conclusions: In this study, the composite endpoint of a bleeding event and the use of rescue medication within close proximity of the bleeding event appears to be feasible and informative. The BRE tool allows for more precise understanding of the effect of rescue therapies in ITP and has broader applications to future clinical trials where assessment of bleeding risk can be complicated or masked by rescue interventions. Limitations: This was a post hoc analysis. The assignment of platelet counts to a BRE was based on the platelet count on the first day of a BRE, which may not reflect the platelet count during the entire episode, and the assignment of platelet counts was based on the estimation required for events that occurred between weekly measurements.