Joseph Boni

Safety and Clinical Activity of a Combination Therapy Comprising Two Antibody-Based Targeting Agents for the Treatment of Non-Hodgkin Lymphoma: Results of a Phase I/II Study Evaluating the Immunoconjugate Inotuzumab Ozogamicin With Rituximab

PURPOSE Inotuzumab ozogamicin (INO) is an antibody-targeted chemotherapy agent composed of a humanized anti-CD22 antibody conjugated to calicheamicin, a potent cytotoxic agent. We performed a phase I/II study to determine the maximum-tolerated dose (MTD), safety, efficacy, and pharmacokinetics of INO plus rituximab (R-INO) for treatment of relapsed/refractory CD20(+)/CD22(+) B-cell non-Hodgkin lymphoma (NHL). PATIENTS AND METHODS A dose-escalation phase to determine the MTD of R-INO was followed by an expanded cohort to further evaluate the efficacy and safety at the MTD. Patients with relapsed follicular lymphoma (FL), relapsed diffuse large B-cell lymphoma (DLBCL), or refractory aggressive NHL received R-INO every 4 weeks for up to eight cycles. RESULTS In all, 118 patients received one or more cycles of R-INO (median, four cycles). Most common grade 3 to 4 adverse events were thrombocytopenia (31%) and neutropenia (22%). Common low-grade toxicities included hyperbilirubinemia (25%) and increased AST (36%). The MTD of INO in combination with rituximab (375 mg/m(2)) was confirmed to be the same as that for single-agent INO (1.8 mg/m(2)). Treatment at the MTD yielded objective response rates of 87%, 74%, and 20% for relapsed FL (n = 39), relapsed DLBCL (n = 42), and refractory aggressive NHL (n = 30), respectively. The 2-year progression-free survival (PFS) rate was 68% (median, not reached) for FL and 42% (median, 17.1 months) for relapsed DLBCL. CONCLUSION R-INO demonstrated high response rates and long PFS in patients with relapsed FL or DLBCL. This and the manageable toxicity profile suggest that R-INO may be a promising option for CD20(+)/CD22(+) B-cell NHL.

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.

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.

Preclinical and clinical pharmacokinetic/pharmacodynamic considerations for antibody–drug conjugates

Antibody-drug conjugates (ADCs) represent a promising therapeutic modality for the clinical management of cancer. Here we discuss the clinical pharmacology and safety of ADCs that are either approved or in late stages of clinical development. We have taken examples of ADCs employing either DNA damaging payloads (such as calicheamicin) or tubulin depolymerizing agents (such as auristatins and maytansinoids) to discuss the impact of dose and dosage intervals on pharmacokinetics/pharmacodynamics (PK/PD) and safety of ADCs. We also discuss the development of PK/PD models that were validated using preclinical and clinical data from two approved ADCs (ado-trastuzumab emtansine (T-DM1, Kadcyla™) and brentuximab vedotin (SGN-35, Adcetris™). These models could be used to predict clinical efficacious doses of ADCs.

Preclinical to Clinical Translation of Antibody-Drug Conjugates Using PK/PD Modeling: a Retrospective Analysis of Inotuzumab Ozogamicin

ABSTRACTA mechanism-based pharmacokinetic/pharmacodynamic (PK/PD) model was used for preclinical to clinical translation of inotuzumab ozogamicin, a CD22-targeting antibody-drug conjugate (ADC) for B cell malignancies including non-Hodgkin’s lymphoma (NHL) and acute lymphocytic leukemia (ALL). Preclinical data was integrated in a PK/PD model which included (1) a plasma PK model characterizing disposition and clearance of inotuzumab ozogamicin and its released payload N-Ac-γ-calicheamicin DMH, (2) a tumor disposition model describing ADC diffusion into the tumor extracellular environment, (3) a cellular model describing inotuzumab ozogamicin binding to CD22, internalization, intracellular N-Ac-γ-calicheamicin DMH release, binding to DNA, or efflux from the tumor cell, and (4) tumor growth and inhibition in mouse xenograft models. The preclinical model was translated to the clinic by incorporating human PK for inotuzumab ozogamicin and clinically relevant tumor volumes, tumor growth rates, and values for CD22 expression in the relevant patient populations. The resulting stochastic models predicted progression-free survival (PFS) rates for inotuzumab ozogamicin in patients comparable to the observed clinical results. The model suggested that a fractionated dosing regimen is superior to a conventional dosing regimen for ALL but not for NHL. Simulations indicated that tumor growth is a highly sensitive parameter and predictive of successful outcome. Inotuzumab ozogamicin PK and N-Ac-γ-calicheamicin DMH efflux are also sensitive parameters and would be considered more useful predictors of outcome than CD22 receptor expression. In summary, a multiscale, mechanism-based model has been developed for inotuzumab ozogamicin, which can integrate preclinical biomeasures and PK/PD data to predict clinical response.

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.

Inotuzumab ozogamicin in adults with relapsed or refractory CD22-positive acute lymphoblastic leukemia: a phase 1/2 study

This study evaluated the safety, antitumor activity, pharmacokinetics, and pharmacodynamics of inotuzumab ozogamicin (InO) for CD22-positive relapsed/refractory acute lymphoblastic leukemia. In phase 1, patients received InO 1.2 (n = 3), 1.6 (n = 12), or 1.8 (n = 9) mg/m2 per cycle on days 1, 8, and 15 over a 28-day cycle (≤6 cycles). The recommended phase 2 dose (RP2D) was confirmed (expansion cohort; n = 13); safety and activity of InO were assessed in patients receiving the RP2D in phase 2 (n = 35) and in all treated patients (n = 72). The RP2D was 1.8 mg/m2 per cycle (0.8 mg/m2 on day 1; 0.5 mg/m2 on days 8 and 15), with reduction to 1.6 mg/m2 per cycle after complete remission (CR) or CR with incomplete marrow recovery (CRi). Treatment-related toxicities were primarily cytopenias. Four patients experienced treatment-related venoocclusive disease/sinusoidal obstruction syndrome (VOD/SOS; 1 fatal). Two VOD/SOS events occurred during treatment without intervening transplant; of 24 patients proceeding to poststudy transplant, 2 experienced VOD/SOS after transplant. Forty-nine (68%) patients had CR/CRi, with 41 (84%) achieving minimal residual disease (MRD) negativity. Median progression-free survival was 3.9 (95% confidence interval, 2.9-5.4) months; median overall survival was 7.4 (5.7-9.2) months for all treated patients, with median 23.7 (range, 6.8-29.8) months of follow-up for all treated patients alive at data cutoff. Achievement of MRD negativity was associated with higher InO exposure. InO was well tolerated and demonstrated high single-agent activity and MRD-negativity rates. This trial was registered at www.clinicaltrials.gov as #NCT01363297.

Phase I Study of Inotuzumab Ozogamicin Combined with R-CVP for Relapsed/Refractory CD22+ B-cell Non-Hodgkin Lymphoma

Purpose: To evaluate the safety, preliminary efficacy, and pharmacokinetics of inotuzumab ozogamicin, an anti-CD22 antibody conjugated to calicheamicin, in combination with the immunochemotherapeutic regimen, rituximab, cyclophosphamide, vincristine, and prednisone (R-CVP), in patients with relapsed/refractory CD22+ B-cell non-Hodgkin lymphoma (NHL). Experimental Design: In part 1 (n = 16), patients received inotuzumab ozogamicin plus R-CVP on a 21-day cycle with escalating doses of cyclophosphamide first then inotuzumab ozogamicin. Part 2 (n = 10) confirmed the safety and tolerability of the maximum tolerated dose (MTD), which required a dose-limiting toxicity rate of <33% in cycle 1 and <33% of patients discontinuing before cycle 3 due to treatment-related adverse events (AEs). Part 3 (n = 22) evaluated the preliminary efficacy of inotuzumab ozogamicin plus R-CVP. Results: The MTD was determined to be standard-dose R-CVP plus inotuzumab ozogamicin 0.8 mg/m2. The most common treatment-related grade ≥3 AEs in the MTD cohort (n = 38) were hematologic: neutropenia (74%), thrombocytopenia (50%), lymphopenia (42%), and leukopenia (47%). Among the 48 patients treated in the study, 13 discontinued due to AEs, most commonly thrombocytopenia (n = 10). Overall, 13 patients died, including one death due to treatment-related pneumonia secondary to neutropenia. Among patients receiving the MTD (n = 38), the overall response rate (ORR) was 84% (n = 32), including 24% (n = 9) with complete response; the ORR was 100% for patients with indolent lymphoma (n = 27) and 57% for those with aggressive histology lymphoma (n = 21). Conclusions: Inotuzumab ozogamicin at 0.8 mg/m2 plus full dose R-CVP was associated with manageable toxicities and demonstrated a high rate of response in patients with relapsed/refractory CD22+ B-cell NHL. The study is registered at ClinicalTrials.gov (NCT01055496). Clin Cancer Res; 22(19); 4807–16. ©2016 AACR.

Phase 1 study of inotuzumab ozogamicin combined with R-GDP for the treatment of patients with relapsed/refractory CD22+ B-cell non-Hodgkin lymphoma

Abstract Objective: To evaluate safety, tolerability, and preliminary activity of inotuzumab ozogamicin (InO) plus rituximab, gemcitabine, dexamethasone, and cisplatin (R-GDP) in patients with relapsed/refractory CD22+ B-cell non-Hodgkin lymphoma (NHL). Methods: Patients received InO plus R-GDP (21-day cycle; six-cycle maximum) using up-and-down dose-escalation schema for gemcitabine and cisplatin to define the highest dosage regimen(s) with acceptable toxicity (Part 1; n = 27). Part 2 (n = 10) confirmed safety and tolerability; Part 3 (n = 18) evaluated preliminary efficacy. Results: Among 55 patients enrolled, 42% were refractory at baseline (median 2 [range, 1–6] prior therapies); 38% had diffuse large B-cell lymphoma (DLBCL). The highest dosage regimen with acceptable toxicity was InO 0.8 mg/m2, rituximab 375 mg/m2, cisplatin 50 mg/m2, gemcitabine 500 mg/m2 (day 1 only) and dexamethasone 40 mg (days 1–4); this was confirmed in Part 2, in which three patients had dose-limiting toxicities (grade 4 thrombocytopenia [n = 2], febrile neutropenia [n = 2]). Most frequent treatment-related adverse events were thrombocytopenia (any grade, 85%; grade ≥3, 75%) and neutropenia (69%; 62%). Overall (objective) response rate (ORR) was 53% (11 complete, 18 partial responses); ORR was 71%, 33%, and 62% in patients with follicular lymphoma (n = 14), DLBCL (n = 21), and mantle cell lymphoma (n = 13), respectively. Conclusions: InO 0.8 mg/m2 plus R-GDP was associated with manageable toxicity, although gemcitabine and cisplatin doses were lower than in the standard R-GDP regimen due to hematologic toxicity. Evidence of antitumor activity was observed; however, these exploratory data should be interpreted with caution due to the small sample size and short follow-up duration (Clinicaltrials.gov number: NCT01055496).