A model-based approach leveraging in vitro data to support dose selection from the outset: A framework for bispecific antibodies in immuno-oncology.

FAP-4-1BBL is a bispecific antibody exerting 4-1BB-associated T-cell activation only while simultaneously bound to the fibroblast activation protein (FAP) receptor, expressed on the surface of cancer-associated fibroblasts. The trimeric complex formed when FAP-4-1BBL is simultaneously bound to FAP and 4-1BB represents a promising mechanism to achieve tumor-specific 4-1BB stimulation. We integrated in vitro data with mathematical modeling to characterize the pharmacology of FAP-4-1BBL as a function of trimeric complex formation when combined with the T-cell engager cibisatamab. This relationship was used to prospectively predict a range of clinical doses where trimeric complex formation is expected to be at its maximum. Depending on the dosing schedule and FAP-4-1BBL plasma: tumor distribution, doses between 2 and 145 mg could lead to maximum trimeric complex formation in the clinic. Due to the expected variability in both pharmacokinetic and FAP expression in the patient population, we predict that detecting a clear dose-response relationship would remain difficult without a large number of patients per dose level, highlighting that mathematical modeling techniques based on in vitro data could aid dose selection.

A first-in-human study of the fibroblast activation protein-targeted, 4-1BB agonist RO7122290 in patients with advanced solid tumors.

This first-in-human study evaluated RO7122290, a bispecific fusion protein carrying a split trimeric 4-1BB (CD137) ligand and a fibroblast activation protein α (FAP) binding site that costimulates T cells for improved tumor cell killing in FAP-expressing tumors. Patients with advanced or metastatic solid tumors received escalating weekly intravenous doses of RO7122290 as a single agent (n = 65) or in combination with a 1200-milligram fixed dose of the anti-programmed death-ligand 1 (anti-PD-L1) antibody atezolizumab given every 3 weeks (n = 50), across a tested RO7122290 dose range of 5 to 2000 milligrams and 45 to 2000 milligrams, respectively. Three dose-limiting toxicities were reported, two at different RO7122290 single-agent doses (grade 3 febrile neutropenia and grade 3 cytokine release syndrome) and one for the combination (grade 3 pneumonitis). No maximum tolerated dose was identified. The pharmacokinetic profile of RO7122290 suggested nonlinearity in elimination. The observed changes in peripheral and tissue pharmacodynamic (PD) biomarkers were consistent with the postulated mechanism of action. Treatment-induced PD changes included an increase in proliferating and activated T cells in peripheral blood both in the single-agent and combination arms. Increased infiltration of intratumoral CD8+ and Ki67+CD8+ T cells was observed for both treatment regimens, accompanied by the up-regulation of T cell activation genes and gene signatures. Eleven patients experienced a complete or partial response, six of whom were confirmed to be immune checkpoint inhibitor naive. These results support further evaluation of RO7122290 in combination with atezolizumab or other immune-oncology agents for the treatment of solid tumors.

Quantitative Clinical Pharmacology Supports the Bridging From i.v. Dosing and Approval of s.c. Rituximab in B-Cell Hematological Malignancies.

A fixed-dose subcutaneous (s.c.) formulation of the anti-CD20 antibody, rituximab, has been developed to address safety, infusion time, and patient comfort concerns relating to intravenous (i.v.) dosing, and has been approved based upon a pharmacokinetic (PK)-clinical bridging strategy, which demonstrated noninferiority of s.c. vs. i.v. dosing in malignancies, including follicular lymphoma (FL) and chronic lymphocytic leukemia (CLL). A clinical development plan was undertaken to identify rituximab s.c. doses achieving noninferior exposure to rituximab i.v., and to confirm PK-clinical bridging, with the same efficacy and similar safety. This drew upon data from 1,579 patients with FL, CLL, or diffuse large B-cell lymphoma in 5 clinical studies, and showed minimum steady-state serum concentration (Ctrough ) as the most appropriate exposure bridging measure. Population PK models were developed, simulations were run using covariates and PK parameters from clinical studies, and exposure-efficacy and -safety analyses performed. Population PKs showed a two-compartment model with time-dependent and -independent clearances. Clearance and volume were predominantly influenced by body surface area; disposition and elimination were similar for the s.c. and i.v. formulations. After s.c. administration, patients with FL and CLL achieved noninferior exposures to i.v. dosing. Overall, rituximab exposure and route of administration did not influence clinical responses in patients with FL or CLL, and there was no association between exposure and safety events. Ctrough was shown to be an effective pharmacologic-clinical bridging parameter for rituximab in patients with FL or CLL. Clinically effective exposures are achieved with either s.c. or i.v. dosing.

Effect of Vemurafenib on the Pharmacokinetics of a Single Dose of Tizanidine (a CYP1A2 Substrate) in Patients With BRAFV600 Mutation-Positive Malignancies.

This phase 1 open-label, multicenter, 3-period, fixed-sequence study evaluated the effect of multiple doses of vemurafenib on the pharmacokinetics of 1 dose of tizanidine, a probe CYP1A2 substrate, in patients with BRAFV600 mutation-positive metastatic malignancy. Patients received 1 dose of tizanidine 2 mg on day 1 (period A), vemurafenib 960 mg twice daily on days 2-21 (period B), and 1 dose of tizanidine 2 mg and vemurafenib 960 mg twice daily on day 22 (period C). Log-transformed area under the concentration-time curve (AUC) and maximum plasma concentration (Cmax ) values for tizanidine in 16 patients were compared between periods A (tizanidine alone) and C (tizanidine plus vemurafenib) using an analysis of variance model. Multiple doses of vemurafenib increased plasma exposure of 1 dose of tizanidine, with geometric mean ratios (period C/period A) for Cmax , AUCinf , and AUClast of 2.15 (90%CI, 1.71-2.71), 4.22 (90%CI, 3.37-5.28), and 4.74 (90%CI, 3.55-6.33), respectively; 90%CIs were all outside predefined limits for lack of drug-drug interaction (0.82-1.22). This study confirmed vemurafenib as a moderate inhibitor of CYP1A2 in vivo, with a statistically significant drug-drug interaction with tizanidine. Caution should be exercised when dosing vemurafenib concurrently with CYP1A2 substrates.

Effect of Rifampicin on the Pharmacokinetics of a Single Dose of Vemurafenib in Patients With BRAFV600 Mutation-Positive Metastatic Malignancy.

Vemurafenib prolongs survival in patients with BRAFV600 -mutated advanced melanoma. In vitro studies show cytochrome P450 (CYP) 3A4 is involved in vemurafenib metabolism, but the effect of strong inducers or inhibitors of CYP3A4 on vemurafenib exposure in vivo is unknown. This phase 1, open-label, multicenter study evaluated the effect of rifampicin, a CYP3A4 inducer, on the pharmacokinetics of single-dose vemurafenib in 27 patients with BRAFV600 mutation-positive metastatic malignancy. Patients received a single oral dose of vemurafenib 960 mg on day 1, oral rifampicin 600 mg daily on days 8-16 (period B), and a single oral dose of vemurafenib 960 mg on day 17 and rifampicin 600 mg daily for days 17-23 (period C), with plasma samples obtained up to 168 hours after vemurafenib dosing. The geometric mean ratio (period C/period A) of area under the concentration-time curve from time zero to last measurable concentration time point and area under the concentration-time curve from time zero to infinity for vemurafenib (n = 23 for the pharmacokinetic analysis) was 0.61 (90% confidence interval, 0.48-0.78) and 0.60 (90% confidence interval, 0.47-0.76), respectively, indicating rifampicin significantly decreased vemurafenib plasma exposure by approximately 40%. The geometric mean ratio of the maximum concentration for vemurafenib was 1.1; this slight increase is likely owing to one outlier in period C. Adverse events were consistent with those previously seen for rifampicin and for vemurafenib monotherapy. Caution is advised when dosing vemurafenib concurrently with CYP3A4 inducers.

A continuous-time multistate Markov model to describe the occurrence and severity of diarrhea events in metastatic breast cancer patients treated with lumretuzumab in combination with pertuzumab and paclitaxel.

PURPOSE: To inform lumretuzumab and pertuzumab dose modifications in order to decrease the incidence, severity, and duration of the diarrhea events in metastatic breast cancer patients treated with a combination therapy of lumretuzumab (anti-HER3) in combination with pertuzumab (anti-HER2) and paclitaxel using quantitative clinical pharmacology modeling approaches. METHODS: The safety and pharmacokinetic (PK) data from three clinical trials (lumretuzumab monotherapy n = 47, pertuzumab monotherapy n = 78, and the combination therapy of lumretuzumab, pertuzumab and paclitaxel n = 35) were pooled together to develop a continuous-time discrete states Markov model describing the dynamics of the diarrhea events. RESULTS: The model was able to capture the time course of different severities of diarrhea reasonably well. The effect of lumretuzumab and pertuzumab was well described by an Emax function indicating an increased rate of transition from moderate to mild or more severe diarrhea with higher doses. The concentration needed to trigger or worsen diarrhea episodes was estimated to be 120-fold lower in combination therapy compared to monotherapy, suggesting strong synergy between the two monoclonal antibodies. The prophylactic effect of loperamide in a subset of patients was also well captured by the model with a clear tendency to reduce the occurrence of diarrhea events. CONCLUSIONS: This work shows that PK-toxicity modeling provides insight into how the severity of key adverse events evolves over time and highlights the potential use to support decision making in drug development.

Effect of Vemurafenib on the Pharmacokinetics of a Single Dose of Digoxin in Patients With BRAFV600 Mutation-Positive Metastatic Malignancy.

The primary objective of this phase 1, open-label, multicenter, 3-period, fixed-sequence study was to evaluate the effect of multiple doses of vemurafenib on the pharmacokinetics of a single dose of digoxin, a probe P-glycoprotein (P-gp) substrate, in patients with BRAFV600 mutation-positive metastatic malignancy. Following a 28-day screening period, patients received a single oral dose of digoxin 0.25 mg on day 1 in period A, oral vemurafenib 960 mg twice daily for 21 days in period B (days 8-28), and a single oral dose of digoxin 0.25 mg on day 29 and vemurafenib 960 mg twice a day for 7 days (days 29-35) in period C. Log-transformed area under the concentration-time curve and peak concentration values for digoxin were compared between periods A (digoxin alone) and C (digoxin + vemurafenib) using an analysis of variance model. Twenty-six patients were evaluated for the primary pharmacokinetic analysis. The geometric mean ratio (period C/period A) of area under the curve to the last measurable concentration for digoxin was 1.82 (90%CI 1.63 to 2.02), and the geometric mean ratio of peak concentrations was 1.47 (90%CI 1.30 to 1.65); the 90%CIs were outside of the equivalence limits of 0.82 to 1.22, indicating an effect of vemurafenib on digoxin. Multiple oral doses of vemurafenib were generally well tolerated, with an adverse event profile similar to that previously seen in phase 2 and 3 studies of vemurafenib monotherapy. This study confirmed vemurafenib as an inhibitor of P-gp in vivo with a statistically significant drug-drug interaction with digoxin. Caution should be exercised when dosing vemurafenib concurrently with P-gp substrates.

Mechanistic Investigations of Diarrhea Toxicity Induced by Anti-HER2/3 Combination Therapy.

Combination of targeted therapies is expected to provide superior efficacy in the treatment of cancer either by enhanced antitumor activity or by preventing or delaying the development of resistance. Common challenges in developing combination therapies include the potential of additive and aggravated toxicities associated with pharmacologically related adverse effects. We have recently reported that combination of anti-HER2 and anti-HER3 antibodies, pertuzumab and lumretuzumab, along with paclitaxel chemotherapy in metastatic breast cancer, resulted in a high incidence of diarrhea that ultimately limited further clinical development of this combination. Here, we further dissected the diarrhea profile of the various patient dose cohorts and carried out in vitro investigations in human colon cell lines and explants to decipher the contribution and the mechanism of anti-HER2/3 therapeutic antibodies to intestinal epithelium malfunction. Our clinical investigations in patients revealed that while dose reduction of lumretuzumab, omission of pertuzumab loading dose, and introduction of a prophylactic antidiarrheal treatment reduced most severe adverse events, patients still suffered from persistent diarrhea during the treatment. Our in vitro investigations showed that pertuzumab and lumretuzumab combination treatment resulted in upregulation of chloride channel activity without indication of intestinal barrier disruption. Overall, our findings provide a mechanistic rationale to explore alternative of conventional antigut motility using medication targeting chloride channel activity to mitigate diarrhea of HER combination therapies. Mol Cancer Ther; 17(7); 1464-74. ©2018 AACR.

A pediatric brain tumor consortium phase II trial of capecitabine rapidly disintegrating tablets with concomitant radiation therapy in children with newly diagnosed diffuse intrinsic pontine gliomas.

BACKGROUND: We conducted a phase II study of oral capecitabine rapidly disintegrating tablets given concurrently with radiation therapy (RT) to assess progression-free survival (PFS) in children with newly diagnosed diffuse intrinsic pontine gliomas (DIPG). PATIENTS AND METHODS: Children 3-17 years with newly diagnosed DIPG were eligible. Capecitabine, 650 mg/m2 /dose BID (maximum tolerated dose [MTD] in children with concurrent radiation), was administered for 9 weeks starting the first day of RT. Following a 2-week break, three courses of capecitabine, 1,250 mg/m2 /dose BID for 14 days followed by a 7-day rest, were administered. As prospectively designed, 10 evaluable patients treated at the MTD on the phase I trial were included in the phase II analyses. The design was based on comparison of the PFS distribution to a contemporary historical control (n = 140) with 90% power to detect a 15% absolute improvement in the 1-year PFS with a type-1 error rate, α = 0.10. RESULTS: Forty-four patients were evaluable for the phase II objectives. Capecitabine and RT was well tolerated with low-grade palmar plantar erythrodyesthesia, increased alanine aminotransferase, cytopenias, and vomiting the most commonly reported toxicities. Findings were significant for earlier progression with 1-year PFS of 7.21% (SE = 3.47%) in the capecitabine-treated cohort versus 15.59% (SE = 3.05%) in the historical control (P = 0.007), but there was no difference for overall survival (OS) distributions (P = 0.30). Tumor enhancement at diagnosis was associated with shorter PFS and OS. Capecitabine was rapidly absorbed and converted to its metabolites. CONCLUSION: Capecitabine did not improve the outcome for children with newly diagnosed DIPG.

Subcutaneous Rituximab for the Treatment of B-Cell Hematologic Malignancies: A Review of the Scientific Rationale and Clinical Development.

Rituximab (MabThera®/Rituxan®), a chimeric murine/human monoclonal antibody that binds specifically to the transmembrane antigen CD20, was the first therapeutic antibody to enter clinical practice for the treatment of cancer. As monotherapy and in combination with chemotherapy, rituximab has been shown to prolong progression-free survival and, in some indications overall survival, in patients with various B-cell malignancies, while having a well-established and manageable safety profile and a wide therapeutic window. As a result, rituximab is considered to have revolutionized treatment practices for patients with B-cell malignancies. A subcutaneous (SC) formulation of rituximab has been developed, comprising the same monoclonal antibody as the originally marketed formulation [rituximab concentrate for solution for intravenous (IV) infusion], and has undergone a detailed, sequential clinical development program. This program demonstrated that, at fixed doses, rituximab SC achieves non-inferior serum trough concentrations in patients with non-Hodgkin lymphoma and chronic lymphocytic leukemia, with comparable efficacy and safety relative to the IV formulation. The added benefit of rituximab SC was demonstrated in dedicated studies showing that rituximab SC allows for simplified and shortened drug preparation and administration times resulting in a reduced treatment burden for patients as well as improved resource utilization (efficiency) at the treatment facility. The improved efficiency of delivering rituximab's benefit to patients may broaden patient access to rituximab therapy in areas with low levels of healthcare resources, including IV-chair capacity constraints. This article is a companion paper to G. Salles, et al., which is also published in this issue. FUNDING: F. Hoffmann-La Roche Ltd.

Accelerating drug development by efficiently using emerging PK/PD data from an adaptable entry-into-human trial: example of lumretuzumab.

PURPOSE: This study aimed at evaluating if pharmacokinetic and pharmacodynamic data from the first few patients treated with an investigational monoclonal antibody in a dose-escalation study can be used to guide the early initiation of potentially more efficacious combination regimens. METHODS: Emerging pharmacokinetic and pharmacodynamic data from the first nine patients treated with lumretuzumab (a glycoengineered anti-HER3 monoclonal antibody) monotherapy at doses from 100 to 400 mg q2w were used along with a pharmacokinetic model that incorporated target-mediated drug disposition to guide the selection of the starting dose for use in combination regimens. RESULTS: The dose-escalation study investigated lumretuzumab doses up to 2000 mg q2w and a maximum tolerated dose was not reached. However, the model described in this report predicted linear lumretuzumab pharmacokinetics and >95% target saturation at doses ≥400 mg q2w. These data, along with safety data, contributed to the decision to begin dose-escalation studies in combination with cetuximab and erlotinib using a starting dose of 400 mg lumretuzumab. Pharmacokinetic data from patients treated with lumretuzumab 400-2000 mg q2w in combination regimens were consistent with the model predictions. CONCLUSION: PK/PD modelling of emerging clinical data might accelerate development programs by enabling additional parts of a trial to commence before completion of the monotherapy part. The dose and schedule of lumretuzumab were optimised for concomitant therapy at doses substantially below the highest dose investigated.

Pharmacokinetics, safety, and efficacy of subcutaneous versus intravenous rituximab plus chemotherapy as treatment for chronic lymphocytic leukaemia (SAWYER): a phase 1b, open-label, randomised controlled non-inferiority trial.

BACKGROUND: Part one of the two-part SAWYER study predicted that subcutaneous rituximab 1600 mg would achieve trough serum concentrations that were non-inferior to those achieved with intravenous rituximab 500 mg/m(2) in patients with chronic lymphocytic leukaemia. In part two of the study, we aimed to confirm the pharmacokinetic non-inferiority of subcutaneous rituximab, and investigate its safety and efficacy. METHODS: We did this phase 1b, open-label, randomised controlled non-inferiority study at 68 centres in 19 countries in Europe, North America, South America, and Australasia. Patients aged 18 years or older with untreated chronic lymphocytic leukaemia were randomly assigned, via an interactive voice-response system with a permuted block randomisation scheme (block size of ten), to receive subcutaneous rituximab 1600 mg or intravenous rituximab 500 mg/m(2) plus fludarabine and cyclophosphamide every 4 weeks for up to six cycles. In cycle one, all patients received intravenous rituximab 375 mg/m(2). Randomisation was stratified by Binet stage and fludarabine and cyclophosphamide administration route (oral vs intravenous). Study investigators and patients were not masked to group allocation, but allocation was concealed from the statistician, clinical scientist, and clinical pharmacologist. The primary endpoint was trough serum concentration at cycle five, with a non-inferiority margin of 0·8 for the adjusted geometric mean ratio of the subcutaneous to the intravenous dose. We did the primary analysis in patients in the intention-to-treat population with complete pharmacokinetic data (pharmacokinetic population). This trial is registered with ClinicalTrials.gov, number NCT01292603, and is ongoing, although the treatment stage is now complete. FINDINGS: Between Aug 20, 2012, and June 17, 2013, we randomly assigned 176 patients to receive subcutaneous rituximab (n=88) or intravenous rituximab (n=88); 134 (76%) patients comprised the pharmacokinetic population. As of May 7, 2014, median follow-up was 13·9 months (IQR 11·9-16·0) for patients in the subcutaneous group and 14·1 months (11·6-16·5) for patients in the intravenous group. At cycle five, the geometric mean trough serum concentration in patients given subcutaneous rituximab was non-inferior to that in patients given intravenous rituximab (97·5 µg/mL vs 61·5 µg/mL), with an adjusted geometric mean ratio of 1·53 (90% CI 1·27-1·85). In the safety analysis, the proportion of patients reporting adverse events was similar between the subcutaneous and intravenous groups (all grades: 82 [96%] of 85 patients and 81 [91%] of 89 patients; serious adverse events: 25 [29%] and 29 [33%] patients; grade ≥3: 59 [69%] and 63 [71%] patients, respectively). The most common adverse event of grade 3 or higher was neutropenia (48 [56%] patients in the subcutaneous group and 46 [52%] patients in the intravenous group); the most common serious adverse event was febrile neutropenia (n=9 [11%] and n=4 [4%], respectively). We recorded administration-related reactions in 37 (44%) patients given subcutaneous rituximab and 40 (45%) patients given the intravenous dose, with differences between administration routes for injection-site erythema (n=10 [12%] and n=0, respectively) and nausea (n=2 [2%] and n=11 [12%], respectively). More patients reported local cutaneous reactions after subcutaneous rituximab (n=36 [42%]) than after intravenous rituximab (n=2 [2%]); most of these reactions were grade 1 or 2. INTERPRETATION: When combined with fludarabine and cyclophosphamide, subcutaneous rituximab 1600 mg achieved trough serum concentrations that were pharmacokinetically non-inferior to those achieved with intravenous rituximab 500 mg/m(2), with a similar safety and efficacy profile between the two groups. Treatment with subcutaneous rituximab should allow patients with chronic lymphocytic leukaemia to receive clinical benefit from the drug via a more convenient delivery method than the intravenous route, and might also be used in combination regimens with approved and emerging oral regimens. FUNDING: F Hoffmann-La Roche.

Pharmacokinetics and safety of subcutaneous rituximab plus fludarabine and cyclophosphamide for patients with chronic lymphocytic leukaemia.

AIMS: The aim of the phase Ib, two part SAWYER study (BO25341; NCT01292603) was to investigate the pharmacokinetics and safety of subcutaneous (s.c.) rituximab compared with intravenous (i.v.) rituximab, both in combination with fludarabine and cyclophosphamide (FC), as first line treatment for patients with chronic lymphocytic leukaemia (CLL). METHODS: During part 1 (dose-finding), CLL patients received rituximab i.v. followed by a single dose of rituximab s.c. at one of three fixed doses (1400, 1600 or 1870 mg) in cycle 6. The primary objective was to identify a fixed s.c. dose that would achieve comparable rituximab serum trough concentrations (Ctrough ) to those achieved with the standard 4 weekly 500 mg m(-2) rituximab i.v. dose. RESULTS: Fifty-five patients received a fixed dose of rituximab s.c., 16 received 1400 mg, 17 received 1600 mg and 22 received 1870 mg. The 1600 mg dose was predicted to achieve non-inferior Ctrough to standard rituximab i.v. TREATMENT: The rituximab s.c. safety profile was comparable with rituximab i.v., except that local administration-related reactions, mainly mild/moderate injection site reactions, occurred more frequently with rituximab s.c., which was not unexpected. Subcutaneous administration was preferred to i.v. administration by >90% of patients and nurses (n = 112). CONCLUSIONS: SAWYER part 1 data predict that rituximab s.c. 1600 mg will achieve non-inferior Ctrough concentrations to rituximab i.v. 500 mg m(-2) , administered 4 weekly. This fixed s.c. dose is currently undergoing formal non-inferiority assessment in SAWYER part 2. In future, CLL treatment regimens comprising rituximab s.c. and oral FC could substantially reduce i.v. chair time.

Comparison of subcutaneous versus intravenous administration of rituximab as maintenance treatment for follicular lymphoma: results from a two-stage, phase IB study.

PURPOSE: This two-stage phase IB study investigated the pharmacokinetics and safety of subcutaneous (SC) versus intravenous (IV) administration of rituximab as maintenance therapy in follicular lymphoma. PATIENTS AND METHODS: In stage 1 (dose finding), 124 patients who responded to rituximab induction were randomly assigned to SC rituximab (375 mg/m2, 625 mg/m2, or an additional group at 800 mg/m2) or IV rituximab (375 mg/m2). The objective was to determine an SC dose that would yield a rituximab serum trough concentration (Ctrough) in the same range as that of IV rituximab. In stage 2, 154 additional patients were randomly assigned (1:1) to SC rituximab (1,400 mg) or IV rituximab (375 mg/m2) given at 2- or 3-month intervals. The objective was to demonstrate noninferior rituximab Ctrough of SC rituximab relative to IV rituximab 375 mg/m2. RESULTS: Stage 1 data predicted that a fixed dose of 1,400 mg SC rituximab would result in a serum Ctrough in the range of that of IV rituximab. Noninferiority (ie, meeting the prespecified 90% CI lower limit of 0.8) was then confirmed in stage 2, with geometric mean Ctrough SC:Ctrough IV ratios for the 2- and 3-month regimens of 1.24 (90% CI, 1.02 to 1.51) and 1.12 (90% CI, 0.86 to 1.45), respectively. Overall safety profiles were similar between formulations (in stage 2, 79% of patients experienced one or more adverse events in each group). Local administration-related reactions (mainly mild to moderate) occurred more frequently after SC administration. CONCLUSION: The fixed dose of 1,400 mg SC rituximab predicted by using stage 1 results was confirmed to have noninferior Ctrough levels relative to IV rituximab 375 mg/m2 dosing during maintenance, with a comparable safety profile. Additional investigation will be required to determine whether the SC route of administration for rituximab provides equivalent efficacy compared with that of IV administration.

Pharmacokinetics and safety of subcutaneous rituximab in follicular lymphoma (SABRINA): stage 1 analysis of a randomised phase 3 study.

BACKGROUND: Intravenous rituximab is a mainstay of treatment for follicular lymphoma. A subcutaneous formulation that achieves equivalent rituximab serum concentrations might improve convenience and save health-care resources without sacrificing clinical activity. We aimed to assess pharmacokinetic non-inferiority of 3 week cycles of fixed-dose subcutaneous rituximab versus standard intravenous rituximab. METHODS: In our two-stage, randomised, open-label, phase 3 trial, we enrolled patients with previously untreated grade 1-3a, CD20-positive follicular lymphoma at 67 centres in 23 countries. In stage 1, we randomly allocated patients 1:1 with the Pocock and Simon algorithm to intravenous rituximab (375 mg/m(2)) or fixed-dose subcutaneous rituximab (1400 mg), stratified by induction chemotherapy regimen (cyclophosphamide, doxorubicin, vincristine, prednisone or cyclophosphamide, vincristine, prednisone), Follicular Lymphoma International Prognostic Index score, and region. After randomisation, patients received one induction dose of intravenous rituximab in cycle 1 and then allocated treatment for cycles 2-8. Patients with a complete or partial response following induction therapy continued intravenous or subcutaneous rituximab as maintenance every 8 weeks. The primary endpoint was the ratio of observed rituximab serum trough concentrations (Ctrough) between groups at cycle 7 (before cycle 8 dosing) of induction treatment in a per-protocol population. Patients were analysed as treated for safety endpoints. Stage 2 follow-up is ongoing and is fully accrued. This study is registered with ClinicalTrials.gov, number NCT01200758. FINDINGS: Between Feb 4, 2010, and Oct 21, 2011, we enrolled 127 patients. Pharmacokinetic data were available for 48 (75%) of 64 patients randomly allocated intravenous rituximab and 54 (86%) of 63 patients randomly allocated subcutaneous rituximab. Geometric mean Ctrough was 83·13 µg/mL in the intravenous group and 134·58 µg/mL in the subcutaneous group (ratio 1·62, 90% CI 1·36-1·94), showing non-inferiority of subcutaneous rituximab. 57 (88%) of 65 patients in the intravenous rituximab safety population had adverse events (30 [46%] grade ≥3), as did 57 (92%) of 62 patients in the subcutaneous rituximab safety population (29 [47%] grade ≥3). The most common grade 3 or worse adverse event in both groups was neutropenia (14 [22%] patients in the intravenous group and 16 [26%] patients in the subcutaneous group). Adverse events related to administration were mostly grade 1-2 and occurred in 21 (32%) patients in the intravenous group and 31 (50%) patients in the subcutaneous group. INTERPRETATION: Stage 1 data show that the pharmacokinetic profile of subcutaneous rituximab was non-inferior to intravenous rituximab and was not associated with new safety concerns. Stage 2 will provide data for efficacy and safety of the subcutaneous administration. FUNDING: F Hoffmann-La Roche.

Pharmacokinetics and pharmacodynamics of single subcutaneous doses of tocilizumab administered with or without rHuPH20.

OBJECTIVES: To investigate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of tocilizumab with and without rHuPH20 (a recombinant human hyaluronidase) in healthy volunteers. METHODS: This was an open-label, single ascending dose study. Subjects were assigned to tocilizumab 162 mg or tocilizumab 162, 324, or 648 mg plus rHuPH20. PK and PD samples were collected after dosing and were estimated with non-compartmental methods. Geometric mean ratio (GMR) for area under the plasma concentration-time curve from zero to infinity (AUC0-∞) and (maximum serum concentration) Cmax with and without rHuPH20 was estimated using one-way analysis of variance. Safety and tolerability were monitored throughout the study. RESULTS: 48 subjects (12/cohort) received a single dose of tocilizumab with or without rHuPH20. For tocilizumab 162 mg, tocilizumab 162 mg/rHuPH20, tocilizumab 324 mg/rHuPH20, and tocilizumab 648 mg/rHuPH20, mean ± SD tocilizumab PK parameters were 2,510 ± 1,060, 2,860 ± 468, 10,800 ± 3,220, and 29,900 ± 5,280 µg×h/ml for AUC0-∞; 11.5 ± 3.7, 16.2 ± 2.8, 43.8 ± 12.4, and 77.8 ± 14.5 µg/ml for Cmax; and 89.1 ± 41.1, 54.0 ± 19.5, 66.0 ± 26.8, and 86.1 ± 50.6 h for tmax, respectively. Coadministration of tocilizumab 162 mg with rHuPH20 resulted in slightly increased exposure: GMR (90% confidence interval) for AUC0-∞, 1.20 (1.00 - 1.44) and Cmax, 1.45 (1.24 - 1.70). Increasing tocilizumab doses resulted in significant deviation from dose proportionality for tocilizumab Cmax (p = 0.0057) and AUC0-∞ (p < 0.0001). Changes in interleukin-6, soluble interleukin- 6 receptor, and C-reactive protein were also dose dependent and similar with and without rHuPH20. CONCLUSIONS: Tocilizumab in combination with rHuPH20 resulted in slightly increased tocilizumab exposure compared with tocilizumab alone, whereas PD markers were comparable. Subcutaneous administration of tocilizumab with rHuPH20 was well tolerated.

Comparison of Subcutaneous and Intravenous Administration of Trastuzumab: A Phase I/Ib Trial in Healthy Male Volunteers and Patients With HER2-Positive Breast Cancer.

Trastuzumab is a key component of treatment for human epidermal growth factor receptor 2 (HER2)-positive breast cancer in both the early and metastatic settings. It is administered intravenously, with between 17 and 52 infusions in standard regimens over 1 year. Intravenous administration of trastuzumab requires substantial time commitments for patients and health care professionals and can result in patient discomfort. A subcutaneous formulation of trastuzumab, containing recombinant human hyaluronidase to overcome subcutaneous absorption barriers, would reduce the administration duration and remove the need to establish intravenous access, thus improving the overall convenience of trastuzumab administration. This open-label, 2-part, phase I/Ib study (NCT00800436) was undertaken in healthy male volunteers and female patients with HER2-positive early breast cancer to identify the dose of subcutaneous trastuzumab that resulted in exposure comparable with the approved intravenous trastuzumab dose. A subcutaneous trastuzumab dose of 8 mg/kg was found to result in exposure comparable with the intravenous trastuzumab dose of 6 mg/kg. The subcutaneous formulation was well tolerated, with a trend toward fewer adverse events versus intravenous administration; most adverse events were mild in intensity. These results support an ongoing phase III efficacy and safety study comparing a fixed subcutaneous trastuzumab dose with intravenous trastuzumab administration.

Comparison of subcutaneous and intravenous administration of trastuzumab: a phase I/Ib trial in healthy male volunteers and patients with HER2-positive breast cancer.

Trastuzumab is a key component of treatment for human epidermal growth factor receptor 2 (HER2)-positive breast cancer in both the early and metastatic settings. It is administered intravenously, with between 17 and 52 infusions in standard regimens over 1 year. Intravenous administration of trastuzumab requires substantial time commitments for patients and health care professionals and can result in patient discomfort. A subcutaneous formulation of trastuzumab, containing recombinant human hyaluronidase to overcome subcutaneous absorption barriers, would reduce the administration duration and remove the need to establish intravenous access, thus improving the overall convenience of trastuzumab administration. This open-label, 2-part, phase I/Ib study (NCT00800436) was undertaken in healthy male volunteers and female patients with HER2-positive early breast cancer to identify the dose of subcutaneous trastuzumab that resulted in exposure comparable with the approved intravenous trastuzumab dose. A subcutaneous trastuzumab dose of 8 mg/kg was found to result in exposure comparable with the intravenous trastuzumab dose of 6 mg/kg. The subcutaneous formulation was well tolerated, with a trend toward fewer adverse events versus intravenous administration; most adverse events were mild in intensity. These results support an ongoing phase III efficacy and safety study comparing a fixed subcutaneous trastuzumab dose with intravenous trastuzumab administration.

Effect of food on the pharmacokinetics and pharmacodynamics of R1663, an oral factor Xa inhibitor, in healthy male volunteers.

AIMS: To explore the effect of food intake on the relative bioavailability of R1663 and on its pharmacodynamic effects (prothrombin time (PT) and activated partial thromboplastin time (aPTT)) after a single oral dose of 200 mg. METHODS: This was a prospective, open-label, randomized, two-way crossover study. Eight healthy male volunteers received R1663 on two occasions, after a high fat/high calorie breakfast and after an overnight fast of 10 h, with a 7-day washout between doses. Blood was sampled up to 48 h for the pharmacokinetic and pharmacodynamic evaluation of R1663. Pharmacokinetic parameters (area under the plasma concentration-time curve from Time 0 extrapolated to infinity (AUC(0-∞)) and maximal concentration (C(max)) as well as pharmacodynamic parameters (area under the effect curve over 48 h (AUE(0-48)) and maximal effect (E(max)) were determined on both occasions. Geometric mean ratios fed/ fasted (GMR) and 90% confidence intervals (CI) were calculated for AUC(0-∞) and C(max) of R1663 and AUE(0-48) and E(max) of PT and aPTT. RESULTS: Following food intake, C(max) was reduced by 10% with CI extended outside the bioequivalence range (GMR, 0.90; CI 0.72 - 1.13). R1663 t(max) was delayed in the fed state (4 h) as compared to the fasted state (1 h). There was no significant food effect on R1663 AUC(0-∞) (GMR, 1.09; CI 0.97 - 1.24). Although the Emax of PT showed statistically significant reduction with food, the 90% CIs for Emax and AUE(0-48) of PT and aPTT were all contained within the bioequivalence range (0.80 - 1.25). CONCLUSIONS: These findings will allow the administration of R1663 without regard to food in the upcoming trials.