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Ixazomib has been approved in several countries as single‐agent maintenance therapy in newly diagnosed multiple myeloma, in both posttransplant and transplant‐ineligible settings, based on two phase III studies. In these maintenance studies, patients were initially administered 3 mg ixazomib, escalating to 4 mg if the initial dose level was well tolerated through Cycles 1–4. Here, we report the results of exposure–response analyses of TOURMALINE‐MM4, wherein relationships between exposure and clinical response, dose adjustments, and selected adverse events were evaluated. Similar progression‐free survival benefits were observed across the range of ixazomib exposures achieved in the study. Moreover, increased ixazomib exposures corresponded to a higher probability of maintaining complete response. Exposure was not a significant predictor (P > 0.05) of hematological adverse events (anemia, neutropenia, thrombocytopenia) and peripheral neuropathy; however, higher exposures did correlate to increased probabilities of experiencing diarrhea, vomiting, nausea, rash, and fatigue. While ixazomib exposure was not predictive of dose reductions, lower apparent clearance values (corresponding to higher systemic exposures) were correlated with a reduced likelihood of escalating to the 4 mg dose. Thus, the dose titration approach balanced patient benefit and risk; it ensured that only patients for whom the 3 mg dose was safe/tolerable escalated to the higher dose, while maximizing the fraction of patients (85%) who were able to derive additional clinical benefit at 4 mg. Collectively, these results highlight the value of safety‐driven personalized dosing to maximize patient benefit/risk. [ABSTRACT FROM AUTHOR]

Ixazomib is an oral proteasome inhibitor approved in combination with lenalidomide and dexamethasone for the treatment of relapsed/refractory multiple myeloma (MM). Approval in the United States, Europe, and additional countries was based on results from the phase III TOURMALINE‐MM1 (C16010) study. Here, joint population pharmacokinetic/pharmacodynamic time‐to‐event (TTE) and discrete time Markov models were developed to describe key safety (rash and diarrhea events, and platelet counts) and efficacy (myeloma protein [M‐protein] and progression‐free survival [PFS]) outcomes observed in TOURMALINE‐MM1. Models reliably described observed safety and efficacy results; prior immunomodulatory drug therapy and race were significant covariates for diarrhea and rash events, respectively, whereas M‐protein dynamics were sufficiently characterized using TTE models of relapse and dropout. Moreover, baseline M‐protein was identified as a significant covariate for observed PFS. The developed framework represents an integrated approach to describing safety and efficacy with MM therapy, enabling the simulation of prospective trials and potential alternate dosing regimens. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the safety and efficacy of maintenance therapy with the oral proteasome inhibitor ixazomib in patients with newly diagnosed multiple myeloma (NDMM) not undergoing transplantation. Methods: Data were pooled from four NDMM phase I/II studies; patients received induction therapy with once‐ or twice‐weekly ixazomib plus lenalidomide‐dexamethasone (IRd), melphalan‐prednisone (IMP), or cyclophosphamide‐dexamethasone (ICd), followed by single‐agent ixazomib maintenance, given at the last tolerated dose during induction, until disease progression, death, or unacceptable toxicity. Results: A total of 121 patients achieved stable disease or better after induction (weekly IRd, n = 25; twice‐weekly IRd, n = 18; weekly or twice‐weekly IMP, n = 35; weekly ICd, n = 43) and received ≥ 1 dose of ixazomib maintenance. Grade ≥ 3 drug‐related adverse events occurred in 24% of patients during maintenance; each event was reported in ≤2% of patients. Rates of complete response were 22% after induction and 35% after maintenance. A total of 28 patients (23%) improved their response during maintenance. Conclusions: Ixazomib maintenance following ixazomib‐based induction is associated with deepening of responses and a positive safety profile with no cumulative toxicity in patients with NDMM not undergoing transplantation, suggesting that ixazomib is feasible for long‐term administration. Phase III investigation of ixazomib maintenance is ongoing. [ABSTRACT FROM AUTHOR]

Summary: There is a need for efficacious, convenient treatments with long‐term tolerability for patients with relapsed/refractory multiple myeloma (RRMM). This phase 2 study evaluated the all‐oral combination of ixazomib, cyclophosphamide and dexamethasone (ICd). Patients with RRMM received ixazomib 4 mg and cyclophosphamide 300 mg/m2 on days 1, 8 and 15, and dexamethasone 40 mg on days 1, 8, 15 and 22 in 28‐day cycles. The primary endpoint was overall response rate (ORR). Seventy‐eight patients were enrolled (median age 63·5 years). At data cut‐off, patients had received a median of 12 treatment cycles; 31% remained on treatment. ORR was 48% [16% very good partial response or better (≥VGPR)]. ORR was 64% and 32% in patients aged ≥65 and <65 years (25% and 16% ≥VGPR), respectively. At a median follow‐up of 15·2 months, median progression‐free survival (PFS) was 14·2 months, with a trend towards better PFS in patients aged ≥65 years vs. <65 years (median 18·7 months vs. 12·0 months; hazard ratio 0·62, P = 0·14). ICd was well tolerated. The most common treatment‐emergent adverse events were diarrhoea (33%), nausea (24%), upper respiratory tract infection (24%), and thrombocytopenia (22%); 10 patients (13%) had peripheral neuropathy (one grade 3). This study is registered at ClinicalTrials.gov (NCT02046070). [ABSTRACT FROM AUTHOR]

Model‐informed drug development (MIDD) was central to the development of the oral proteasome inhibitor ixazomib, facilitating internal decisions (switch from body surface area (BSA)‐based to fixed dosing, inclusive phase III trials, portfolio prioritization of ixazomib‐based combinations, phase III dose for maintenance treatment), regulatory review (model‐informed QT analysis, benefit–risk of 4 mg dose), and product labeling (absolute bioavailability and intrinsic/extrinsic factors). This review discusses the impact of MIDD in enabling patient‐centric therapeutic optimization during the development of ixazomib. [ABSTRACT FROM AUTHOR]

Abstract: The failure rate for phase III trials in oncology is high; quantitative predictive approaches are needed. We developed a model‐based meta‐analysis (MBMA) framework to predict progression‐free survival (PFS) from overall response rates (ORR) in relapsed/refractory multiple myeloma (RRMM), using data from seven phase III trials. A Bayesian analysis was used to predict the probability of technical success (PTS) for achieving desired phase III PFS targets based on phase II ORR data. The model demonstrated a strongly correlated (R2 = 0.84) linear relationship between ORR and median PFS. As a representative application of the framework, MBMA predicted that an ORR of ∼66% would be needed in a phase II study of 50 patients to achieve a target median PFS of 13.5 months in a phase III study. This model can be used to help estimate PTS to achieve gold‐standard targets in a target product profile, thereby enabling objectively informed decision‐making. [ABSTRACT FROM AUTHOR]

Transfusional iron overload represents a substantial challenge in the management of patients with sickle cell disease ( SCD) who receive chronic or episodic red blood cell transfusions. Iron-induced cardiomyopathy is a leading cause of death in other chronically transfused populations but rarely seen in SCD. Study objectives were to: (i) examine the extent of myocardial and hepatic siderosis using magnetic resonance imaging ( MRI) in chronically transfused SCD patients, and (ii) evaluate the relationship between long-term (over the 5 years prior to enrolment) mean serum ferritin ( MSF), spot-ferritin values and liver iron content ( LIC) measured using MRI and liver biopsy. Thirty-two SCD patients (median age 15 years) with transfusional iron overload were recruited from two U.S. institutions. Long-term MSF and spot-ferritin values significantly correlated with LIC by MRI-R2* ( r = 0·77, P < 0·001; r = 0·82, P < 0·001, respectively). LIC by MRI-R2* had strong positive correlation with LIC by liver biopsy ( r = 0·98, P < 0·001) but modest inverse correlation with cardiac MRI-T2* ( r = −0·41, P = 0·02). Moderate to severe transfusional iron overload in SCD was not associated with aberrations in other measures of cardiac function based on echocardiogram or serum biomarkers. Our results suggest that SCD patients receiving chronic transfusions may not demonstrate significant cardiac iron loading irrespective of ferritin trends, LIC and erythropoiesis suppression. [ABSTRACT FROM AUTHOR]

Aim The aim of the present study was to characterize the pharmacokinetics of the oral proteasome inhibitor, ixazomib, in patients with solid tumours and moderate or severe hepatic impairment, to provide posology recommendations. Methods Eligible adults with advanced malignancies for which no further effective therapy was available received a single dose of ixazomib on day 1 of the pharmacokinetic cycle; patients with normal hepatic function, moderate hepatic impairment or severe hepatic impairment received 4 mg, 2.3 mg or 1.5 mg, respectively. Blood samples for single-dose pharmacokinetic characterization were collected over 336 h postdose. After sampling, patients could continue to receive ixazomib on days 1, 8 and 15 in 28-day cycles. Results Of 48 enrolled patients (13, 15 and 20 in the normal, moderate and severe groups, respectively), 43 were pharmacokinetics-evaluable. Ixazomib was rapidly absorbed (median time to reach peak concentration was 0.95-1.5 h) and highly bound to plasma proteins, with a similar mean fraction bound (~99%) across the three groups. In patients with moderate/severe hepatic impairment (combined group), the geometric least squares mean ratios (90% confidence interval) for unbound and total dose-normalized area under the plasma concentration vs. time curve from time zero to the time of the last quantifiable concentration in reference to the normal hepatic function group were 1.27 (0.75, 2.16) and 1.20 (0.79, 1.82), respectively. Seven (15%) of the 48 patients experienced a grade 3 drug-related adverse event; there were no drug-related grade 4 adverse events. Conclusions In patients with moderate/severe hepatic impairment, unbound and total systemic exposures of ixazomib were 27% and 20% higher, respectively, vs. normal hepatic function. A reduced ixazomib starting dose of 3 mg is recommended for patients with moderate or severe hepatic impairment. [ABSTRACT FROM AUTHOR]

Acute chest syndrome ( ACS) is defined as fever, respiratory symptoms and a new pulmonary infiltrate in an individual with sickle cell disease ( SCD). Nearly half of ACS episodes occur in SCD patients already hospitalized, potentially permitting pre-emptive therapy in high-risk patients. Simple transfusion of red blood cells may abort ACS if given to patients hospitalized for pain who develop fever and elevated levels of secretory phospholipase A2 ( sPLA2). In a feasibility study ( PROACTIVE; NCT00951808), patients hospitalized for pain who developed fever and elevated sPLA2 were eligible for randomization to transfusion or observation; all others were enrolled in an observational arm. Of 237 enrolled, only 10 were randomized; one of the four to receive transfusion had delayed treatment. Of 233 subjects receiving standard care, 22 developed ACS. A threshold level of sPLA2 ≥ 48 ng/ml gave optimal sensitivity (73%), specificity (71%) and accuracy (71%), but a positive predictive value of only 24%. The predictive value of sPLA2 was improved in adults and patients with chest or back pain, lower haemoglobin concentration and higher white blood cell counts, and in those receiving less than two-thirds maintenance fluids. The hurdles identified in PROACTIVE should facilitate design of a larger, definitive, phase 3 randomized controlled trial. [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) treatment guidelines recommend waiting for formal progression criteria (FPC) to be met before proceeding to the next line of therapy. As predicting progression may allow early switching to next‐line therapy while the disease burden is relatively low, we evaluated the predictive accuracy of a mathematical model to anticipate relapse 180 days before the FPC is met. A subset of 470/1143 patients from the IA16 dataset who were initially treated with VRd (Velcade (bortezomib), Revlimid (lenalidomide), and dexamethasone) in the CoMMpass study (NCT01454297) were randomly split 2:1 into training and testing sets. A model of M‐protein dynamics was developed using the training set and used to predict relapse probability in patients in the testing set given their response histories up to 12 or more months of treatment. The predictive accuracy of this model and M‐protein “velocity” were assessed via receiver operating characteristics (ROC) analysis. The final model was a two‐population tumor growth inhibition model with additive drug effect and transit delay compartments for cell killing. The ROC area under the curve value of relapse prediction 180 days ahead of observed relapse by FPC was 0.828 using at least 360 days of response data, which was superior to the M‐protein velocity ROC score of 0.706 under the same conditions. The model can predict future relapse from early M‐protein responses and can be used in a future clinical trial to test whether early switching to second‐line therapy results in better outcomes in MM. [ABSTRACT FROM AUTHOR]

Acute chest syndrome (ACS) is defined as fever, respiratory symptoms and a new pulmonary infiltrate in an individual with sickle cell disease (SCD). Nearly half of ACS episodes occur in SCD patients already hospitalized, potentially permitting pre-emptive therapy in high-risk patients. Simple transfusion of red blood cells may abort ACS if given to patients hospitalized for pain who develop fever and elevated levels of secretory phospholipase A2 (sPLA2). In a feasibility study (PROACTIVE; ClinicalTrials.gov NCT00951808), patients hospitalized for pain who developed fever and elevated sPLA2 were eligible for randomization to transfusion or observation; all others were enrolled in an observational arm. Of 237 enrolled, only 10 were randomized; one of the four to receive transfusion had delayed treatment. Of 233 subjects receiving standard care, 22 developed ACS. A threshold level of sPLA2 ≥ 48 ng/ml gave optimal sensitivity (73%), specificity (71%) and accuracy (71%), but a positive predictive value of only 24%. The predictive value of sPLA2 was improved in adults and patients with chest or back pain, lower haemoglobin concentration and higher white blood cell counts, and in those receiving less than two-thirds maintenance fluids. The hurdles identified in PROACTIVE should facilitate design of a larger, definitive, phase 3 randomized controlled trial., (© 2012 Blackwell Publishing Ltd.)