Hepatic adverse event profile of inotuzumab ozogamicin in adult patients with relapsed or refractory acute lymphoblastic leukaemia: results from the open-label, randomised, phase 3 INO-VATE study.

BACKGROUND: The INO-VATE study demonstrated efficacy and safety of inotuzumab ozogamicin versus standard care in adults with relapsed or refractory B-cell acute lymphoblastic leukaemia. Here, we report the frequency of, and potential risk factors for, hepatotoxicity in patients in this trial and after treatment and subsequent haemopoietic stem-cell transplantation (HSCT). METHODS: In this open-label, phase 3, multicentre, international study, adults with relapsed or refractory, CD22-positive, Philadelphia chromosome (Ph)-positive or Ph-negative B-cell acute lymphoblastic leukaemia who were due to receive first or second salvage treatment were randomly assigned (1:1) via an interactive voice response system to receive inotuzumab ozogamicin (starting dose 1·8 mg/m2 per cycle [0·8 mg/m2 on day 1; 0·5 mg/m2 on days 8 and 15 of a 21-28 day cycle for ≤6 cycles]) or standard care (either fludarabine plus cytarabine plus granulocyte colony-stimulating factor, mitoxantrone plus cytarabine, or high-dose cytarabine). Stratification factors at randomisation were duration of first remission (<12 months vs ≥12 months), salvage treatment phase (first vs second), and age (<55 years vs ≥55 years). We present data up to March 8, 2016. At this cutoff date, all patients had been discontinued from treatment but 54 patients were continuing in long-term follow-up. Long-term follow-up has now been completed, with the final patient's last visit on Jan 4, 2017. This prespecified safety analysis describes investigator-assessed treatment-emergent hepatotoxicity, including sinusoidal obstruction syndrome (also known as veno-occlusive disease) in patients during study treatment or thereafter (without follow-up HSCT) and after study treatment and subsequent HSCT, for all patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, number NCT01564784. FINDINGS: Between Aug 27, 2012, and and the data cutoff of March 8, 2016, 326 patients were randomly assigned to receive inotuzumab ozogamicin (n=164) or standard care (n=162). 164 patients in the inotuzumab ozogamicin group and 143 in the standard care group received at least one dose of study treatment and were included in the safety population. At data cutoff, median duration of treatment (induction) was 8·9 weeks (IQR 4·1-13·1) in the inotuzumab ozogamicin group and 0·9 weeks (0·9-1·1) in the standard care group. Treatment-emergent hepatotoxicities (of all grades) were more frequent in the inotuzumab ozogamicin group (83 [51%] of 164 patients) than in the standard care group (49 [34%] of 143 patients). The frequency of sinusoidal obstruction syndrome-comprising events occurring during treatment (or follow-up without HSCT) and after treatment and subsequent HSCT-was higher in the inotuzumab ozogamicin group (22 [13%]; 18 [82%] of which were grade 3 or worse) than in the standard care group (one [<1%]). During study therapy or follow-up without HSCT, five (3%) patients in the inotuzumab ozogamicin group developed sinusoidal obstruction syndrome compared with no patients in the standard care group. Of the 77 patients who received inotuzumab ozogamicin and proceeded to HSCT, 17 (22%) had sinusoidal obstruction syndrome; five events after follow-up HSCT were fatal. Of 32 patients who received standard care and proceeded to HSCT, one (3%) had (non-fatal) sinusoidal obstruction syndrome that was ongoing at the time of death due to septic shock. In multivariate analysis, conditioning with two alkylating agents (p=0·015 vs one alkylating agent) and last available pre-HSCT bilirubin concentration of greater than or equal to the upper limit of normal (ULN; p=0·009 vs

A phase 2 study of inotuzumab ozogamicin and rituximab, followed by autologous stem cell transplant in patients with relapsed/refractory diffuse large B-cell lymphoma.

This study evaluated the safety and efficacy of inotuzumab ozogamicin (INO), a targeted humanized anti-CD22 antibody conjugated to calicheamicin, plus rituximab (R-INO) every 3 weeks, up to six cycles, followed by high dose therapy and autologous stem cell transplant (HDT-aSCT) in patients with high-risk relapsed/refractory diffuse large B-cell lymphoma (DLBCL). The primary endpoint was overall response (OR) rate after three cycles of R-INO. Sixty-three patients were enrolled. Common grade 3/4 adverse events during R-INO treatment were thrombocytopenia, lymphopenia and neutropenia. OR rate after three cycles of R-INO was 28.6% (95% confidence interval: 17.9-41.4). Eighteen patients underwent HDT-aSCT; 2-year progression-free survival (PFS) for these patients was 61.1%. Serious infections and hepatic toxicity following aSCT occurred in 33% and 22%, respectively. One- and 2-year PFS rates for all enrolled patients were 28.9% and 25.3%, respectively (median, 3.0 months). R-INO had lower than expected activity as a salvage regimen for transplant eligible patients with DLBCL.

Par4 is required for platelet thrombus propagation but not fibrin generation in a mouse model of thrombosis.

Thrombin, a central mediator of hemostasis and thrombosis, converts fibrinogen to fibrin and is a potent platelet activator. Activated platelets provide a surface for assembly of the tenase and prothrombinase complexes required for thrombin generation. The role of thrombin-induced platelet activation in platelet accumulation and its interplay with fibrin deposition during thrombus assembly has not been fully defined. We studied these processes during laser-induced thrombus formation by using real-time digital fluorescence microscopy in mice lacking protease-activated receptor-4 (Par4), which is necessary for thrombin responsiveness in mouse platelets. Juxtamural platelet accumulation immediately after laser injury was not different in wild-type and Par4(-/-) mice. However, subsequent growth of platelet thrombi was markedly diminished in Par4(-/-) mice. At the time of maximal thrombus size in wild type, platelet accumulation was more than 10-fold higher in wild type than in Par4(-/-) mice. P-selectin expression, a marker of platelet activation, was reduced and delayed in Par4(-/-) thrombi. In contrast to platelet activation and accumulation, the rate and amount of fibrin deposition, predominantly intramural and juxtamural in this model, were indistinguishable in Par4(-/-) and wild-type mice. These results suggest that platelet activation by thrombin is necessary for normal propagation of a platelet thrombus at a distance from the injured vessel wall and hence for normal thrombus growth. However, platelet activation by thrombin is unnecessary for initial and limited accumulation of platelets at or near the vessel wall, and this limited accumulation of platelets and/or platelet-independent mechanism(s) of thrombin generation are sufficient for normal fibrin deposition in this model.

Drug-associated disease: hematologic dysfunction.

Hematologic dysfunction, including thrombocytopenia, anemia, neutropenia, thromboses, and coagulopathy, occur commonly during critical illnesses. A major challenge is to identify drug-induced causes of hematologic dysfunction. Given the wide variety of drug-induced hematologic effects, clinicians always should consider any concomitant drugs in the differential diagnosis of acquired hematologic dysfunction. The most severe effects include drug-induced aplastic anemia, heparin-induced thrombocytopenia, and drug-induced thrombotic microangiopathy. Certain drugs are associated with multiple hematologic effects. For example, cisplatin can cause hemolytic uremia syndrome and erythropoietin deficiency, and quinine can precipitate immune-mediated thrombocytopenia, immune-mediated thrombocytopenia, and thrombotic microangiopathy.

Role of P-selectin and PSGL-1 in coagulation and thrombosis.

P-selectin and PSGL-1 are cell adhesion molecules, regulating the initial interactions between leukocytes and the blood vessel wall as well as between activated platelets and leukocytes. P-selectin is expressed on activated endothelial cells and platelets, while its major ligand PSGL-1 is expressed on leukocytes. Multiple studies have shown that these adhesion molecules are required for the normal recruitment of leukocytes during an inflammatory reaction. More recently, these adhesion molecules have been implicated in recruitment of leukocytes and leukocyte microparticles to thrombi. The P-selectin- and PSGL-1-dependent delivery of circulating microparticles to thrombi appears to be important for normal tissue factor accumulation and fibrin generation in thrombi.