Incidence and Risk of Cardiac Events in Patients With Previously Treated Multiple Myeloma Versus Matched Patients Without Multiple Myeloma: An Observational, Retrospective, Cohort Study.

BACKGROUND: Multiple myeloma (MM) patients have age-, disease-, and treatment-related risk factors for cardiac events. MATERIALS AND METHODS: We analyzed the 2006 to 2011 MarketScan database to determine whether the risk of cardiac events is greater in MM patients than in non-MM patients. Included were 1723 MM patients treated with corticosteroids and ≥ 3 drugs (bortezomib, immunomodulatory derivatives, and alkylating agents or anthracyclines). The index date (ID) was the date on which the 3-drug exposure criterion was met. Also included were 8615 age- and gender-matched non-MM patients (5:1). The distribution of non-MM patients' IDs matched that of the MM patients' IDs. Baseline was 6 months before the ID. The follow-up duration was from the ID to study end (ie, 2011 or end of enrollment or prescription drug coverage). Hazard ratios (HRs) and 95% confidence intervals (CIs) were adjusted for baseline variables when the univariate analyses showed a 10% difference. RESULTS: The median duration of observation was 9 months (range, 0-60 months) for MM patients and 19 months (range, 0-66 months) for non-MM patients. The risk of any cardiac event (HR, 2.2; 95% CI, 1.9-2.5), dysrhythmia (HR, 4.1; 95% CI, 3.5-4.8), congestive heart failure (HR, 2.9; 95% CI, 2.2-3.7), cardiomyopathy (HR, 2.6; 95% CI, 1.8-3.8), and conduction disorders (HR, 1.7; 95% CI, 1.2-2.5) was significantly greater for MM than for non-MM patients. The incidence of hypertensive or arterial events and ischemic heart disease was similar between the 2 groups. CONCLUSION: The present study provides the first known comparison of cardiac event risk in patients with MM versus age- and gender-matched patients without MM. The cardiac event risk was greater in MM patients with ≥ 3 previous drugs for any cardiac event, dysrhythmias, congestive heart failure, cardiomyopathy, and conduction disorders compared with patients without MM.

Population Pharmacokinetics and Exposure-Response Relationship of Carfilzomib in Patients With Multiple Myeloma.

A population pharmacokinetic (PK) model and exposure-response (E-R) analysis was developed using data collected from 5 phase 1b/2 and 2 phase 3 studies in subjects with multiple myeloma. Subjects receiving intravenous infusion on 2 consecutive days each week for 3 weeks (days 1, 2, 8, 9, 15, and 16) in each cycle at doses ranging from 15 to 20/56 mg/m2 (20 mg/m2 in cycle 1 and, if tolerated, escalated to 56 mg/m2 on day 8 of cycle 1). The population PK analysis indicated that among all the covariates tested, the only statistically significant covariate was body surface area on carfilzomib clearance; however, this covariate was unlikely to be clinically significant. Despite inclusion of different populations (relapsed or relapsed/refractory), treatments (carfilzomib monotherapy or combination therapy), infusion lengths (2 to 10 minutes or 30 minutes), and different doses, the E-R analysis of efficacy showed that after adjusting for baseline characteristics, higher area under the concentration-time curve was associated with improved overall response rate (ORR), from 15 to 20/56 mg/m2 . No positive relationships between maximum concentration and ORR were identified, indicating that ORR would not be expected to be impacted by infusion length. For safety end points, no statistically significant relationship between exposure and increasing risk of adverse events was identified. The results of an E-R analysis provided strong support for a carfilzomib dose at 20/56 mg/m2 as a 30-minute infusion for monotherapy and combination therapy. This article illustrates an example of application of E-R analysis to support labeling dose recommendation in the absence of extensive clinical data.

Relationship Between Carfilzomib Dose and Efficacy Outcomes in Patients With Relapsed and/or Refractory Multiple Myeloma.

BACKGROUND: Carfilzomib is approved by the US Food and Drug Administration for the treatment of patients with relapsed and refractory multiple myeloma (MM) who have received at least 2 previous treatments. The approval was based on phase II trials that used a starting dose of 20 mg/m(2) escalated to a target dose of 27 mg/m(2) in cycle 2. We examined dose-outcome relationships in MM patients who received these 2 carfilzomib doses. MATERIALS AND METHODS: Patient data from 4 cohorts of MM patients treated with single-agent carfilzomib in phase II trials were examined post hoc. The relationship between administered doses and overall response rate (ORR) was assessed using logistic regression models. Secondary analyses were performed using Cox regression models to assess the association between administered doses and time to event outcomes and using generalized estimating equations for cycle-specific response status (CSRS). RESULTS: A total of 476 intention to treat patients were enrolled, 461 of whom were evaluable for efficacy. In the primary analysis, adjustment for cohort and baseline covariates yielded an odds ratio for ORR of 1.28 (95% confidence interval, 1.16-1.41; P < .001) for each 1 mg/m(2) increase in the average administered dose of carfilzomib per patient (up to 27 mg/m(2)). Qualitatively similar and statistically significant results were seen for the association between administered dose and CSRS, duration of response, time to progression, progression-free survival, and overall survival when adjusted for cohort and baseline covariates. CONCLUSION: This post hoc analysis provides evidence for a dose-response relationship between the administered dose of carfilzomib and efficacy.

Integrated safety profile of single-agent carfilzomib: experience from 526 patients enrolled in 4 phase II clinical studies.

Carfilzomib, a selective proteasome inhibitor, was approved in 2012 for the treatment of relapsed and refractory multiple myeloma. Safety data for single-agent carfilzomib have been analyzed for 526 patients with advanced multiple myeloma who took part in one of 4 phase II studies (PX-171-003-A0, PX-171-003-A1, PX-171-004, and PX-171-005). Overall analyses of adverse events and treatment modifications are presented, as well as specific analyses of adverse events by organ system. Overall, the most common adverse events of any grade included fatigue (55.5%), anemia (46.8%), and nausea (44.9%). In the grouped analyses, any grade adverse events were reported in 22.1% for any cardiac (7.2% cardiac failure), 69.0% for any respiratory (42.2% dyspnea), and 33.1% for any grouped renal impairment adverse event (24.1% increased serum creatinine). The most common non-hematologic adverse events were generally Grade 1 or 2 in severity, while Grade 3/4 adverse events were primarily hematologic and mostly reversible. There was no evidence of cumulative bone marrow suppression, either neutropenia or thrombocytopenia, and febrile neutropenia occurred infrequently (1.1%). Notably, the incidence of peripheral neuropathy was low overall (13.9%), including patients with baseline peripheral neuropathy (12.7%). Additionally, the incidence of discontinuations or dose reductions attributable to adverse events was low. These data demonstrate that single-agent carfilzomib has an acceptable safety profile in heavily pre-treated patients with relapsed/refractory multiple myeloma. The tolerable safety profile allows for administration of full-dose carfilzomib, both for extended periods and in a wide spectrum of patients with advanced multiple myeloma, including those with pre-existing comorbidities.

Capturing the stem cell paracrine effect using heparin-presenting nanofibres to treat cardiovascular diseases.

The mechanism for stem cell-mediated improvement following acute myocardial infarction has been actively debated. We support hypotheses that the stem cell effect is primarily paracrine factor-linked. We used a heparin-presenting injectable nanofibre network to bind and deliver paracrine factors derived from hypoxic conditioned stem cell media to mimic this stem cell paracrine effect. Our self-assembling peptide nanofibres presenting heparin were capable of binding paracrine factors from a medium phase. When these factor-loaded materials were injected into the heart following coronary artery ligation in a mouse ischaemia-reperfusion model of acute myocardial infarction, we found significant preservation of haemodynamic function. Through media manipulation, we were able to determine that crucial factors are primarily < 30 kDa and primarily heparin-binding. Using recombinant VEGF- and bFGF-loaded nanofibre networks, the effect observed with conditioned media was recapitulated. When evaluated in another disease model, a chronic rat ischaemic hind limb, our factor-loaded materials contributed to extensive limb revascularization. These experiments demonstrate the potency of the paracrine effect associated with stem cell therapies and the potential of a biomaterial to bind and deliver these factors, pointing to a potential therapy based on synthetic materials and recombinant factors as an acellular therapy.

Peptide amphiphile nanostructure-heparin interactions and their relationship to bioactivity.

Heparin-protein interactions are important in many physiological processes including angiogenesis, the growth of new blood vessels from existing ones. We have previously developed a highly angiogenic self-assembling gel, wherein the self-assembly process is triggered by the interactions between heparin and peptide amphiphiles (PAs) with a consensus heparin binding sequence. In this report, this consensus sequence was scrambled and incorporated into a new peptide amphiphile in order to study its importance in heparin interaction and bioactivity. Heparin was able to trigger gel formation of the scrambled peptide amphiphile (SPA). Furthermore, the affinity of the scrambled molecule for heparin was unchanged as shown by isothermal titration calorimetry and high Förster resonance emission transfer efficiency. However, both the mobile fraction and the dissociation rate constant of heparin, using fluorescence recovery after photobleaching, were markedly higher in its interaction with the scrambled molecule implying a weaker association. Importantly, the scrambled peptide amphiphile-heparin gel had significantly less angiogenic bioactivity as shown by decreased tubule formation of sandwiched endothelial cells. Hence, we believe that the presence of the consensus sequence stabilizes the interaction with heparin and is important for the bioactivity of these new materials.

Modulation of fluorescence through coassembly of molecules in organic nanostructures.

This paper describes the fluorescence of bimolecular coassemblies that form one-dimensional nanostructures. One molecule is a fluorescent peptide amphiphile containing its branched stilbene chromophore covalently linked to the hydrophilic end of the amphiphile, and the second molecule is a shorter, nonfluorescent peptide amphiphile of complementary charge. Using circular dichroism we observe that mixing both molecules results in coassemblies that exhibit a beta-sheet signature in the peptide region indicative of these types of nanostructures. The nature of the coassembly is dependent on the molar ratio of each component, and the changing CD spectra suggest the formation of domains along the length of the nanofibers with decreasing concentrations of the fluorescent component. In coassemblies with dilute concentrations of the fluorophore, we observe an increase in fluorescence intensity and quantum yield, as well as chiral transfer to the achiral segment of the fluorescent peptide amphiphile. The coassemblies studied containing a fluorescent component at a low molar ratio exhibit fluorescence resonance energy transfer to fluorescent acceptors in solution. When the nonfluorescent peptide amphiphile component is designed to bind the important bioactive polysaccharide heparin, a selective transfer of energy is observed between fluorescein-tagged heparin and the coassemblies in both dilute solution and in macroscopic gels.

Heparin binding nanostructures to promote growth of blood vessels.

Controlling new blood vessel formation is of interest in regenerative medicine and cancer treatment. Heparin, a biopolymer that binds to angiogenic growth factors, was used to nucleate the self-assembly of nanostructures from designed peptide amphiphile molecules. This process yields rigid nanofibers that display heparin chains to orient proteins for cell signaling. In vivo, the nanostructures stimulated extensive new blood vessel formation using nanogram amounts of growth-factor proteins that by themselves did not induce any detectable angiogenesis.