Exposure-response analysis of Camidanlumab tesirine in patients with relapsed or refractory classical Hodgkin lymphoma and non-Hodgkin lymphoma.

PURPOSE: To investigate camidanlumab tesirine (Cami) exposure-response (E-R) relationships, using an integrated population pharmacokinetic model, for patients with classical Hodgkin lymphoma (cHL) and non-Hodgkin lymphoma enrolled in an open-label, phase 1 study (NCT02432235). METHODS: Exploratory analyses investigated relationships between exposure measures (Cmaxss, Cminss, and Cavgss) and the occurrence of binary variables (overall response rate [ORR] and selected adverse events [AEs]) and nonbinary variables (overall survival [OS]). RESULTS: Exploratory analyses showed a significant, positive relationship between exposure and ORR/OS. The final model showed this effect was non-significant due to the covariate effects. Cami exposures were higher in patients with selected grade ≥ 2 AEs at cycle 6 (the anticipated steady-state exposure level), confirmed in the final E-R models. CONCLUSIONS: Based on univariate results, Cmaxss was used as the exposure measure in all models, except for the autoimmune AE full E-R model in which Cavgss was used. The positive relationship between exposure and ORR/OS (higher exposure significantly associated with higher probabilities of ORR/OS) was not statistically significant in the final models. The final safety E-R models demonstrated a significant positive association between Cami exposure and selected grade ≥ 2 AEs, with higher exposures associated with higher probabilities of experiencing the grade ≥ 2 AEs at cycle 6. The results identify preliminary predictors of efficacy and safety and provide a basis for a dosing rationale and benefit-risk profile of Cami in patients with relapsed/refractory cHL.

Population pharmacokinetics analysis of camidanlumab tesirine in patients with relapsed or refractory Hodgkin lymphoma and non-Hodgkin lymphoma.

PURPOSE: The objective of this analysis was to develop a population pharmacokinetic (PPK) model to characterize camidanlumab tesirine (Cami) pharmacokinetics based on the phase 1 study in relapsed/refractory lymphoma (NCT02432235). METHODS: An initial PPK model was developed based on a two-compartment model with parallel linear and nonlinear elimination pathways. Pharmacokinetic parameters were evaluated for correlation with potential demographic covariates; significant covariates were retained in the final model. RESULTS: In the final PPK model, baseline weight effects were included on clearance (CL), intercompartmental clearance (Q), and the volumes of distribution in the central (V1) and peripheral (V2) compartments. The baseline soluble CD25 (sCD25) effect was included on CL and maximum velocity of saturable clearance (Vmax); sex effect was included on CL and V1; and ethnicity effect was included on deconjugation clearance (CLdec). For a typical patient, CL and CLdec were 0.516 and 0.21 L/day, respectively (tAb elimination half-life: 18.72 days); V1 and V2 were 4.41 and 2.67 L, respectively; Vmax was 0.49 mg/day; the Michaelis-Menten constant (Km) was 0.409 µg/mL; and the first-order rate for decrease of Vmax (KDES) was 0.0197/day. Cami exposure was higher for patients with low baseline sCD25, higher body weight, and females. CONCLUSIONS: The final model described the observed data well, estimates of PK parameters were obtained, and covariates with significant effects on Cami exposure were identified. Altogether, this final PPK model provides a robust basis for analysis of Cami exposure-response relationships and further supports identification of the optimal Cami dosing schedule for patients with relapsed/refractory lymphoma.

Effect of inotuzumab ozogamicin on the QT interval in patients with haematologic malignancies using QTc-concentration modelling.

AIM: The aim of this study was to characterize the effect of inotuzumab ozogamicin on QT interval in patients with B-cell malignancies. METHODS: Data were pooled from three clinical studies including 250 patients (n = 2743) who received inotuzumab ozogamicin monotherapy. Patients with relapsed/refractory acute lymphoblastic leukaemia (NCT01564784 and NCT01363297) received 1.8 mg m-2 per cycle in divided doses (mean Cmax 371 ng ml-1 ; considered therapeutic) and patients with relapsed/refractory non-Hodgkin lymphoma (NCT00868608) received 1.8 mg m-2 per cycle as a single dose (mean Cmax 569 ng ml-1 ; considered supratherapeutic). Triplicate 12-lead electrocardiograms were performed at baseline and predefined time points postdose with paired pharmacokinetic collections. The exposure-response relationship between corrected QT interval (QTc: QT interval corrected using population-specific formula [QTcS] or QT interval corrected using Fridericia's formula [QTcF]) and inotuzumab ozogamicin concentration was characterized using a linear mixed-effects model, and simulations were performed using the final validated model. Full model development involved testing for covariates that may account for part of the identified variability. RESULTS: QTc intervals had a small but positive correlation with inotuzumab ozogamicin concentration. Based on 1000 simulations, median (upper 95% CI) QTcS and QTcF changes from baseline were <10 ms at both therapeutic (2.70 ms [5.40 ms] and 2.53 ms [4.92 ms], respectively) and supratherapeutic (4.14 ms [8.28 ms] and 3.87 ms [7.54 ms], respectively) concentrations. CONCLUSIONS: Inotuzumab ozogamicin (1.8 mg m-2 per cycle) is not predicted to pose a clinically significant safety risk for QT prolongation in patients with acute lymphoblastic leukaemia or non-Hodgkin lymphoma.

Oral and intravenously administered mTOR inhibitors for metastatic renal cell carcinoma: pharmacokinetic considerations and clinical implications.

Identification of the role of biological pathways in metastatic renal cell carcinoma (mRCC) has led to the development of targeted agents for its treatment, in particular those that inhibit the vascular endothelial growth factor pathway, and inhibitors of mammalian target of rapamycin (mTOR). mTOR is central to signalling pathways that regulate cellular growth, proliferation and survival, and this paper focuses on the two currently licensed mTOR inhibitors, temsirolimus and everolimus. These agents are administered via different routes (intravenously and orally, respectively), and this has an impact on their pharmacokinetics; intravenous temsirolimus is not affected by variable absorption in the gastrointestinal tract or by food intake, unlike the orally administered mTOR inhibitor everolimus. Temsirolimus is administered weekly, whereas everolimus is currently approved for daily dosing. In general, intravenous administration is likely to ensure better control of plasma drug concentrations, greater treatment adherence, and more regular monitoring of toxicity and therapeutic response, although it can be uncomfortable and inconvenient for patients. Oral administration is preferred by patients for its convenience, but can be associated with suboptimal adherence to treatment, and poor and variable bioavailability. Temsirolimus and everolimus have both been associated with improved outcomes in patients with mRCC but, as reviewed in this paper, the pharmacokinetic characteristics of these agents differ in many respects.

A single-dose placebo- and moxifloxacin-controlled study of the effects of temsirolimus on cardiac repolarization in healthy adults.

PURPOSE: Temsirolimus, a selective inhibitor of mammalian target of rapamycin, is an approved treatment for patients with advanced renal cell carcinoma (RCC). This study assessed the effect of intravenous (i.v.) temsirolimus 25 mg, the recommended dose for patients with RCC, on the corrected QT (QTc) interval. METHODS: This 3-period crossover study enrolled healthy subjects. In periods 1 and 2, subjects received i.v. placebo either alone or with open-label oral moxifloxacin. In period 3, subjects received a single dose of temsirolimus 25 mg. The primary statistical objective was to estimate the effect of temsirolimus compared with placebo on change from time-matched baseline QTc at the end of infusion (0.5 h). Assay sensitivity was evaluated by the effect of moxifloxacin on change from time-matched baseline QTc compared with placebo. RESULTS: In total, 58 subjects were enrolled. Temsirolimus had no effect on QTc interval in the primary analysis. At 11 of 12 secondary time points, the upper bound for the temsirolimus QTc 90% confidence intervals for the time-matched change from baseline difference from placebo was <10 ms, with no evidence of QTc trends or relationship to concentrations of temsirolimus or its major metabolite, sirolimus. Moxifloxacin, the positive control, produced a significant increase in the QTc interval compared with placebo 0.5-4 h post-dose (P < 0.0001). No subject had a QTc interval exceeding 450 ms or a change from baseline of >30 ms. CONCLUSIONS: Therapeutic exposure to temsirolimus is not associated with clinically significant changes in QTc intervals in healthy adults.

Phase II trial of temsirolimus in children with high-grade glioma, neuroblastoma and rhabdomyosarcoma.

PURPOSE: A phase II study of temsirolimus was conducted in children and adolescents with high-grade glioma, neuroblastoma or rhabdomyosarcoma. PATIENTS AND METHODS: Temsirolimus 75 mg/m(2) was administered once weekly until disease progression or intolerance. Using the Simon 2-stage design, further enrolment in each disease cohort required ≥ 2 objective responses within the first 12 weeks for the first 12 evaluable patients (those who received ≥ 3 temsirolimus doses). RESULTS: Fifty-two heavily pretreated patients with relapsed (12%) or refractory (88%) disease, median age 8 years (range 1-21 years), were enroled and treated. One patient with neuroblastoma achieved confirmed partial response within the first 12 weeks; thus, none of the 3 cohorts met the criterion for continued enrolment. Disease stabilisation at week 12 was observed in 7 of 17 patients (41%) with high-grade glioma (5 diffuse pontine gliomas, 1 glioblastoma multiforme and 1 anaplastic astrocytoma), 6 of 19 (32%) with neuroblastoma and 1 of 16 (6%) with rhabdomyosarcoma (partial response confirmed at week 18). In the three cohorts, median duration of stable disease or better was 128, 663 and 75 d, respectively. The most common treatment-related adverse events were thrombocytopaenia, hyperlipidaemia and aesthenia. Pharmacokinetic findings were similar to those observed in adults. CONCLUSIONS: Temsirolimus administered weekly at the dose of 75 mg/m(2) did not meet the primary objective efficacy threshold in children with high-grade glioma, neuroblastoma or rhabdomyosarcoma; however, meaningful prolonged stable disease merits further evaluation in combination therapy.

Phase I study of temsirolimus in pediatric patients with recurrent/refractory solid tumors.

PURPOSE: To determine dose-limiting toxicities, maximum-tolerated dose (MTD), pharmacokinetics, and pharmacodynamics of weekly intravenous temsirolimus, a mammalian target of rapamycin (mTOR) signaling pathway inhibitor, in pediatric patients with recurrent or refractory solid tumors. PATIENTS AND METHODS: Cohorts of three to six patients 1 to 21 years of age with recurrent or refractory solid tumors were treated with a 1-hour intravenous infusion of temsirolimus weekly for 3 weeks per course at one of four dose levels: 10, 25, 75, or 150 mg/m(2). During the first two courses, pharmacokinetic and pharmacodynamic evaluations (phosphorylation of S6, AKT, and 4EBP1 in peripheral-blood mononuclear cells) were performed. RESULTS: Dose-limiting toxicity (grade 3 anorexia) occurred in one of 18 evaluable patients at the 150 mg/m(2) level, which was determined to be tolerable, and an MTD was not identified. In 13 patients evaluable for response after two courses of therapy, one had complete response (CR; neuroblastoma) and five had stable disease (SD). Four patients (three SDs + one CR) remained on treatment for more than 4 months. The sum of temsirolimus and sirolimus areas under the concentration-time curve was comparable to values in adults. AKT and 4EBP1 phosphorylation were inhibited at all dose levels, particularly after two courses. CONCLUSION: Weekly intravenous temsirolimus is well tolerated in children with recurrent solid tumors, demonstrates antitumor activity, has pharmacokinetics similar to those in adults, and inhibits the mTOR signaling pathway in peripheral-blood mononuclear cells. Further studies are needed to define the optimal dose for use in combination with other antineoplastic agents in pediatric patients.

Phase I, pharmacokinetic study of temsirolimus administered orally to patients with advanced cancer.

An oral formulation of temsirolimus (Torisel), an inhibitor of the mammalian target of rapamycin, was evaluated on an intermittent schedule (once daily for 5 days every 2 weeks) in patients with advanced cancer. The maximum tolerated dose was determined to be 75 mg after dose-limiting toxicities of grade 3 elevated aminotransferases (1 patient) and grade 3 rash (1 patient) occurred with a 100-mg dose. The most common temsirolimus-related adverse events were mucositis, rash/maculopapular rash, and asthenia. Six of 12 patients who received the 75-mg dose required dose reductions due to temsirolimus-related adverse events. Two patients who received 75-mg temsirolimus and did not have dose reductions had minor tumor responses. Relative exposure from contributions of both temsirolimus and sirolimus, the principal metabolite, was 17.9% of the 75-mg dose. Thus, oral temsirolimus, 75 mg administered once daily for 5 days every 2 weeks, was further evaluated in patients with metastatic breast cancer.

Intravenous temsirolimus in cancer patients: clinical pharmacology and dosing considerations.

Temsirolimus, a highly specific inhibitor of mammalian target of rapamycin (mTOR), is a novel anticancer targeted therapy with a new mechanism of action. The prototype mTOR inhibitor, oral rapamycin, is poorly soluble and undergoes extensive first-pass metabolism, leading to low and potentially variable absorption and exposure. For some tumors, maximizing the bioavailability and dose intensity via intravenous (IV) administration may provide optimal clinical benefit. Temsirolimus is an ester analog of rapamycin that retains its potent intrinsic mTOR inhibitory activity while exhibiting better solubility for IV formulation. In the treatment of advanced renal cell carcinoma, temsirolimus is administered as a 30- to 60-minute IV infusion once weekly at a flat dose of 25 mg. This dosage results in high peak temsirolimus concentrations and limited immunosuppressive activity. Because temsirolimus is active and well tolerated, different dosages and schedules are being explored for other solid and hematologic malignancies, including mantle cell lymphoma. Temsirolimus exhibits a high volume of distribution that, together with IV administration, leads to extensive distribution into peripheral tissues. In addition, significant and protracted exposures are attained with sirolimus (rapamycin), the major equipotent metabolite of temsirolimus. Whereas temsirolimus and sirolimus are both metabolized by cytochrome P450 (CYP) 3A4, drug interaction studies with agents that induce or inhibit CYP3A4 activity indicate that exposure to the sirolimus metabolite is somewhat sensitive to pharmacokinetic (PK) drug interaction. Therefore, temsirolimus dose adjustments are warranted if coadministration cannot be avoided. Despite its complexity, the PK profile of IV temsirolimus is well characterized in cancer patients and provides a strong basis for its future study as a monotherapy or in combination with other anticancer agents.

Phase I/II trial of temsirolimus combined with interferon alfa for advanced renal cell carcinoma.

PURPOSE: Temsirolimus, an inhibitor of the mammalian target of rapamycin, has single-agent activity against advanced renal cell carcinoma (RCC). A recommended dose and safety profile for the combination of temsirolimus and interferon alfa (IFN) were determined in patients with advanced RCC. PATIENTS AND METHODS: Patients were enrolled onto a multicenter, ascending-dose study of temsirolimus (5, 10, 15, 20, or 25 mg) administered intravenously once a week combined with IFN (6 or 9 million units [MU]) administered subcutaneously three times per week. An expanded cohort was treated at the recommended dose to obtain additional safety and efficacy information. RESULTS: Seventy-one patients were entered to receive one of six dose levels. The recommended dose was temsirolimus 15 mg/IFN 6 MU based on dose-limiting toxicities of stomatitis, fatigue, and nausea/vomiting, which were observed at higher doses of temsirolimus and IFN. The most frequent grade 3 or 4 toxicities occurring in any cycle included leukopenia, hypophosphatemia, asthenia, anemia, and hypertriglyceridemia for all patients and those who received the recommended dose. Among patients who received the recommended dose (n = 39), 8% achieved partial response and 36% had stable disease for at least 24 weeks. Median progression-free survival for all patients in the study was 9.1 months. CONCLUSION: The combination of temsirolimus and IFN has an acceptable safety profile and displays antitumor activity in patients with advanced RCC. Temsirolimus 15 mg plus IFN 6 MU is the recommended dose for evaluation in a randomized phase III study.

A phase I and pharmacokinetic study of temsirolimus (CCI-779) administered intravenously daily for 5 days every 2 weeks to patients with advanced cancer.

PURPOSE: Patients with advanced cancer received temsirolimus (Torisel, CCI-779), a novel inhibitor of mammalian target of rapamycin, i.v. once daily for 5 days every 2 weeks to determine the maximum tolerated dose, toxicity profile, pharmacokinetics, and preliminary antitumor efficacy. EXPERIMENTAL DESIGN: Doses were escalated in successive cohorts of patients using a conventional phase I clinical trial design. Samples of whole blood and plasma were collected to determine the pharmacokinetics of temsirolimus and sirolimus, its principal metabolite. RESULTS: Sixty-three patients were treated with temsirolimus (0.75-24 mg/m(2)/d). The most common drug-related toxicities were asthenia, mucositis, nausea, and cutaneous toxicity. The maximum tolerated dose was 15 mg/m(2)/d for patients with extensive prior treatment because, in the 19 mg/m(2)/d cohort, two patients had dose-limiting toxicities (one with grade 3 vomiting, diarrhea, and asthenia and one with elevated transaminases) and three patients required dose reductions. For minimally pretreated patients, in the 24 mg/m(2)/d cohort, one patient developed a dose-limiting toxicity of grade 3 stomatitis and two patients required dose reductions, establishing 19 mg/m(2)/d as the maximum acceptable dose. Immunologic studies did not show any consistent trend toward immunosuppression. Temsirolimus exposure increased with dose in a less than proportional manner. Terminal half-life was 13 to 25 hours. Sirolimus-to-temsirolimus exposure ratios were 0.6 to 1.8. A patient with non-small cell lung cancer achieved a confirmed partial response, which lasted for 12.7 months. Three patients had unconfirmed partial responses; two patients had stable disease for >/=24 weeks. CONCLUSION: Temsirolimus was generally well tolerated on this intermittent schedule. Encouraging preliminary antitumor activity was observed.

Phase I study of EKB-569, an irreversible inhibitor of the epidermal growth factor receptor, in patients with advanced solid tumors.

PURPOSE: The maximum tolerated dose (MTD) and the dose-limiting toxicities of EKB-569, a selective, irreversible inhibitor of the epidermal growth factor receptor (EGFR), when administered orally once daily on an intermittent-dose schedule (14 days of a 28-day cycle) or on a continuous-dose schedule (each day of a 28-day cycle), were determined in patients with advanced solid tumors. PATIENTS AND METHODS: Planned dose escalation was 25, 50, 75, 125, 175, and 225 mg. Pharmacokinetic sampling was performed on days 1 and 14 for the intermittent-dose cohort and on days 1 and 15 for the continuous-dose cohort. RESULTS: Thirty patients received a median of two cycles (range, one to 10 cycles) in the intermittent-dose cohort; 29 patients received a median of three cycles (range, one to eight cycles) in the continuous-dose cohort. Dose-limiting toxicity was grade 3 diarrhea, and the MTD was 75 mg EKB-569 per day for both cohorts. Other common toxicities included rash, nausea, and asthenia. Exposure to EKB-569 was dose proportional. At the MTD, the mean +/- standard deviation terminal half-life was 21.7 +/- 4.2 hours and peak concentration increased 1.2-fold from day 1 to day 14/15. No major antitumor responses were observed. However, one patient with non-small-cell lung cancer and one with cutaneous squamous cell carcinoma had stable disease for 33 and 24 weeks, respectively. CONCLUSION: The MTD of once-daily oral EKB-569 is 75 mg. The tolerable toxicity profile and long half-life of this irreversible EGFR inhibitor warrant its further evaluation as a single agent and in combination with other drugs.

Population pharmacokinetics of CCI-779: correlations to safety and pharmacogenomic responses in patients with advanced renal cancer.

OBJECTIVE: Our objective was to estimate the pharmacokinetic parameters of CCI-779 and its metabolite, sirolimus, and evaluate associations of exposure parameters with safety and clinical activity. Exposure parameters were also correlated with pharmacogenomic responses in peripheral blood mononuclear cells (PBMCs). METHODS: In this randomized, double-blind, multicenter trial, once-weekly intravenous doses of 25, 75, or 250 mg CCI-779 were administered to patients with advanced renal cancer. Whole blood for CCI-779 and sirolimus concentrations was drawn. Population pharmacokinetic analyses yielded Bayesian-predicted exposure metrics that were correlated with severity and duration of adverse events and survival. PBMC samples taken before and after treatment were examined for pharmacogenomic responses. Ribonucleic acid samples were converted to labeled probes and hybridized to oligonucleotide arrays containing more than 12,600 human sequences. RESULTS: The final population pharmacokinetic models of CCI-779 and sirolimus included 235 and 305 observations, respectively, from 50 patients. For CCI-779, dose, single versus multiple dose, and body surface area were significant pharmacokinetic covariates. For sirolimus, dose and hematocrit were significant covariates. Age, sex, or race did not influence drug disposition. CCI-779 area under the curve correlated with adverse event severity for thrombocytopenia (P = .007), pruritus (P = .011), and hyperlipemia (P = .040). Exposure (CCI-779 cumulative area under the curve) correlated with a specific subset of gene transcripts in PBMCs following 16 weeks after therapy (P < .001, Spearman correlation). CONCLUSIONS: Concentrations of CCI-779 and sirolimus were adequately described with a population model incorporating factors for dose, attenuated exposure of multiple doses, body surface area, and hematocrit. Correlations with adverse event severity and duration profiles were provided to aid in the detection of treatment-emergent effects. Pharmacogenomic profiling of PBMCs identified altered ribonucleic acid transcript expression levels that correlate with exposure. These transcripts represent potential biomarkers of CCI-779 exposure in peripheral blood.

Randomized phase II study of multiple dose levels of CCI-779, a novel mammalian target of rapamycin kinase inhibitor, in patients with advanced refractory renal cell carcinoma.

PURPOSE: To evaluate the efficacy, safety, and pharmacokinetics of multiple doses of CCI-779, a novel mammalian target of rapamycin kinase inhibitor, in patients with advanced refractory renal cell carcinoma (RCC). PATIENTS AND METHODS: Patients (n = 111) were randomly assigned to receive 25, 75, or 250 mg CCI-779 weekly as a 30-minute intravenous infusion. Patients were evaluated for tumor response, time to tumor progression, survival, and adverse events. Blood samples were collected to determine CCI-779 pharmacokinetics. RESULTS: CCI-779 produced an objective response rate of 7% (one complete response and seven partial responses) and minor responses in 26% of these advanced RCC patients. Median time to tumor progression was 5.8 months and median survival was 15.0 months. The most frequently occurring CCI-779-related adverse events of all grades were maculopapular rash (76%), mucositis (70%), asthenia (50%), and nausea (43%). The most frequently occurring grade 3 or 4 adverse events were hyperglycemia (17%), hypophosphatemia (13%), anemia (9%), and hypertriglyceridemia (6%). Neither toxicity nor efficacy was significantly influenced by CCI-779 dose level. Patients were retrospectively classified into good-, intermediate-, or poor-risk groups on the basis of criteria used by Motzer et al for a first-line metastatic RCC population treated with interferon alfa. Within each risk group, the median survivals of patients at each dose level were similar. CONCLUSION: In patients with advanced RCC, CCI-779 showed antitumor activity and encouraging survival and was generally well tolerated over the three dose levels tested.