Sunita D. Nasta

Safety, Pharmacokinetics, and Preliminary Clinical Activity of Inotuzumab Ozogamicin, a Novel Immunoconjugate for the Treatment of B-Cell Non-Hodgkin's Lymphoma: Results of a Phase I Study

PURPOSE Inotuzumab ozogamicin (CMC-544) is an antibody-targeted chemotherapy agent composed of a humanized anti-CD22 antibody conjugated to calicheamicin, a potent cytotoxic agent. This was a phase I study to determine the maximum-tolerated dose (MTD), safety, and preliminary efficacy of inotuzumab ozogamicin in an expanded MTD cohort of patients with relapsed or refractory CD22(+) B-cell non-Hodgkins lymphoma (NHL). PATIENTS AND METHODS Inotuzumab ozogamicin was administered intravenously as a single agent once every 3 or 4 weeks at doses ranging from 0.4 to 2.4 mg/m(2). Outcomes included MTD, safety, pharmacokinetics, response, progression-free survival (PFS), and overall survival. Results Seventy-nine patients were enrolled. The MTD was determined to be 1.8 mg/m(2). Common adverse events at the MTD were thrombocytopenia (90%), asthenia (67%), and nausea and neutropenia (51% each). The objective response rate at the end of treatment was 39% for the 79 enrolled patients, 68% for all patients with follicular NHL treated at the MTD, and 15% for all patients with diffuse large B-cell lymphoma treated at the MTD. Median PFS was 317 days (approximately 10.4 months) and 49 days for patients with follicular NHL and diffuse large B-cell lymphoma, respectively. CONCLUSION Inotuzumab ozogamicin has demonstrated efficacy against CD22(+) B-cell NHL, with reversible thrombocytopenia as the main toxicity.

Bortezomib in patients with relapsed or refractory mantle cell lymphoma: updated time-to-event analyses of the multicenter phase 2 PINNACLE study

BACKGROUND We previously reported results of the phase 2, multicenter PINNACLE study, which confirmed the substantial single-agent activity of bortezomib in patients with relapsed or refractory mantle cell lymphoma (MCL). MATERIALS AND METHODS We report updated time-to-event data, in all patients and by response to treatment, after extended follow-up (median 26.4 months). RESULTS Median time to progression (TTP) was 6.7 months. Median time to next therapy (TTNT) was 7.4 months. Median overall survival (OS) was 23.5 months. In responding patients, median TTP was 12.4 months, median duration of response (DOR) was 9.2 months, median TTNT was 14.3 months, and median OS was 35.4 months. Patients achieving complete response had heterogeneous disease characteristics; among these patients, median TTP and DOR were not reached, and median OS was 36.0 months. One-year survival rate was 69% overall and 91% in responding patients. Median OS from diagnosis was 61.1 months, after median follow-up of 63.7 months. Activity was seen in patients with refractory disease and patients relapsing following high-intensity treatment. Toxicity was generally manageable. CONCLUSIONS Single-agent bortezomib is associated with lengthy responses and notable survival in patients with relapsed or refractory MCL, with considerable TTP and TTNT in responding patients, suggesting substantial clinical benefit.

Treatment of PTLD with Rituximab or Chemotherapy

Information regarding treatment of post‐transplant lymphoproliferative disease (PTLD) beyond reduction in immunosuppression (RI) is limited. We retrospectively evaluated patients receiving rituximab and/or chemotherapy for PTLD for response, time to treatment failure (TTF) and overall survival (OS). Thirty‐five patients met inclusion criteria. Twenty‐two underwent rituximab treatment, with overall response rate (ORR) 68%. Median TTF was not reached at 19 months and estimated OS was 31 months. In univariable analysis, Epstein‐Barr virus (EBV) positivity predicted response and TTF. LDH elevation predicted shorter OS. No patient died of rituximab toxicity and all patients who progressed underwent further treatment with chemotherapy. Twenty‐three patients received chemotherapy. ORR was 74%, median TTF was 10.5 months and estimated OS was 42 months. Prognostic factors for response included stage, LDH and allograft involvement by tumor. These factors and lack of complete response (CR) predicted poor survival. Twenty‐six percent of the patients receiving chemotherapy died of toxicity. Rituximab and chemotherapy are effective in patients with PTLD who fail or do not tolerate RI. While rituximab is well tolerated, toxicity of chemotherapy is marked. PTLD patients requiring therapy beyond RI should be considered for rituximab, especially with EBV‐positive disease. Chemotherapy should be reserved for patients who fail rituximab, have EBV‐negative tumors or need a rapid response.

Blockade of Lymphocyte Chemotaxis in Visceral Graft-versus-Host Disease

BACKGROUND Graft-versus-host disease (GVHD) is a major barrier to successful allogeneic hematopoietic stem-cell transplantation (HSCT). The chemokine receptor CCR5 appears to play a role in alloreactivity. We tested whether CCR5 blockade would be safe and limit GVHD in humans. METHODS We tested the in vitro effect of the CCR5 antagonist maraviroc on lymphocyte function and chemotaxis. We then enrolled 38 high-risk patients in a single-group phase 1 and 2 study of reduced-intensity allogeneic HSCT that combined maraviroc with standard GVHD prophylaxis. RESULTS Maraviroc inhibited CCR5 internalization and lymphocyte chemotaxis in vitro without impairing T-cell function or formation of hematopoietic-cell colonies. In 35 patients who could be evaluated, the cumulative incidence rate (±SE) of grade II to IV acute GVHD was low at 14.7±6.2% on day 100 and 23.6±7.4% on day 180. Acute liver and gut GVHD were not observed before day 100 and remained uncommon before day 180, resulting in a low cumulative incidence of grade III or IV GVHD on day 180 (5.9±4.1%). The 1-year rate of death that was not preceded by disease relapse was 11.7±5.6% without excessive rates of relapse or infection. Serum from patients receiving maraviroc prevented CCR5 internalization by CCL5 and blocked T-cell chemotaxis in vitro, providing evidence of antichemotactic activity. CONCLUSIONS In this study, inhibition of lymphocyte trafficking was a specific and potentially effective new strategy to prevent visceral acute GVHD. (Funded by Pfizer and others; ClinicalTrials.gov number, NCT00948753.).

Chimeric Antigen Receptor T Cells in Refractory B-Cell Lymphomas

Background Patients with diffuse large B‐cell lymphoma or follicular lymphoma that is refractory to or that relapses after immunochemotherapy and transplantation have a poor prognosis. High response rates have been reported with the use of T cells modified by chimeric antigen receptor (CAR) that target CD19 in B‐cell cancers, although data regarding B‐cell lymphomas are limited. Methods We used autologous T cells that express a CD19‐directed CAR (CTL019) to treat patients with diffuse large B‐cell lymphoma or follicular lymphoma that had relapsed or was refractory to previous treatments. Patients were monitored for response to treatment, toxic effects, the expansion and persistence of CTL019 cells in vivo, and immune recovery. Results A total of 28 adult patients with lymphoma received CTL019 cells, and 18 of 28 had a response (64%; 95% confidence interval [CI], 44 to 81). Complete remission occurred in 6 of 14 patients with diffuse large B‐cell lymphoma (43%; 95% CI, 18 to 71) and 10 of 14 patients with follicular lymphoma (71%; 95% CI, 42 to 92). CTL019 cells proliferated in vivo and were detectable in the blood and bone marrow of patients who had a response and patients who did not have a response. Sustained remissions were achieved, and at a median follow‐up of 28.6 months, 86% of patients with diffuse large B‐cell lymphoma who had a response (95% CI, 33 to 98) and 89% of patients with follicular lymphoma who had a response (95% CI, 43 to 98) had maintained the response. Severe cytokine‐release syndrome occurred in 5 patients (18%). Serious encephalopathy occurred in 3 patients (11%); 2 cases were self‐limiting and 1 case was fatal. All patients in complete remission by 6 months remained in remission at 7.7 to 37.9 months (median, 29.3 months) after induction, with a sustained reappearance of B cells in 8 of 16 patients and with improvement in levels of IgG in 4 of 10 patients and of IgM in 6 of 10 patients at 6 months or later and in levels of IgA in 3 of 10 patients at 18 months or later. Conclusions CTL019 cells can be effective in the treatment of relapsed or refractory diffuse large B‐cell lymphoma and follicular lymphoma. High rates of durable remission were observed, with recovery of B cells and immunoglobulins in some patients. Transient encephalopathy developed in approximately one in three patients and severe cytokine‐release syndrome developed in one in five patients. (Funded by Novartis and others; ClinicalTrials.gov number, NCT02030834.)

A Phase I Study of the Mammalian Target of Rapamycin Inhibitor Sirolimus and MEC Chemotherapy in Relapsed and Refractory Acute Myelogenous Leukemia

Purpose: Inhibiting mammalian target of rapamycin (mTOR) signaling in acute myelogenous leukemia (AML) blasts and leukemic stem cells may enhance their sensitivity to cytotoxic agents. We sought to determine the safety and describe the toxicity of this approach by adding the mTOR inhibitor, sirolimus (rapamycin), to intensive AML induction chemotherapy. Experimental Design: We performed a phase I dose escalation study of sirolimus with the chemotherapy regimen MEC (mitoxantrone, etoposide, and cytarabine) in patients with relapsed, refractory, or untreated secondary AML. Results: Twenty-nine subjects received sirolimus and MEC across five dose levels. Dose-limiting toxicities were irreversible marrow aplasia and multiorgan failure. The maximum tolerated dose (MTD) of sirolimus was determined to be a 12 mg loading dose on day 1 followed by 4 mg/d on days 2 to 7, concurrent with MEC chemotherapy. Complete or partial remissions occurred in 6 (22%) of the 27 subjects who completed chemotherapy, including 3 (25%) of the 12 subjects treated at the MTD. At the MTD, measured rapamycin trough levels were within the therapeutic range for solid organ transplantation. However, direct measurement of the mTOR target p70 S6 kinase phosphorylation in marrow blasts from these subjects only showed definite target inhibition in one of five evaluable samples. Conclusions: Sirolimus and MEC is an active and feasible regimen. However, as administered in this study, the synergy between MEC and sirolimus was not confirmed. Future studies are planned with different schedules to clarify the clinical and biochemical effects of sirolimus in AML and to determine whether target inhibition predicts chemotherapy response. (Clin Cancer Res 2009;15(21):6732–9)

Prognostic value of FDG-PET scan imaging in lymphoma patients undergoing autologous stem cell transplantation

We conducted a retrospective analysis of 50 lymphoma patients (Hodgkins disease and non-Hodgkins lymphoma) who had an 18F-fluoro-deoxyglucose positron emission tomography (FDG-PET) scan after at least two cycles of salvage chemotherapy and before autologous stem cell transplantation (ASCT) at our institution. The patients were categorized into FDG-PET negative (N=32) and positive (N=18) groups. The median follow-up after ASCT was 19 months (range: 3–59). In the FDG-PET-negative group, the median progression-free survival (PFS) was 19 months (range: 2–59) with 15 (54%) patients without progression at 12 months after ASCT. The median overall survival (OS) for this group was not reached. In the FDG-PET-positive group, the median PFS was 5 months (range: 1–19) with only one (7%) patient without progression at 12 months after ASCT. The median OS was 19 months (range: 1–34). In the FDG-PET-negative group, chemotherapy-resistant patients by CT-based criteria had a comparable outcome to those with chemotherapy-sensitive disease. A positive FDG-PET scan after salvage chemotherapy and prior ASCT indicates an extremely poor chance of durable response after ASCT.

Regression of a Plasmablastic Lymphoma in a Patient with HIV on Highly Active Antiretroviral Therapy

We describe an HIV-infected 44-year-old man who presented 1 month after discontinuation of HAART therapy with a large mass extending from the mediastinum, enclosing the heart and extending through the diaphragm to the epigastric region. Biopsies subsequently revealed a highly aggressive non-Hodgkins lymphoma (NHL) producing sheets of cells with an organoid distribution. The cells had abundant basophilic cytoplasm and a plasmacytic appearance. Although immunohistochemistry failed to show either B- or T-cell markers, antigens consistent with plasma cells were found. An immunoglobulin heavy chain clonal rearrangement was identified by PCR analysis. These studies were supportive of a diagnosis of a plasmablastic lymphoma. While awaiting the results of these tests, the patient was reinitiated on his HAART regimen. He was found on follow-up a month later to have complete resolution of his bulky mediastinal mass. He remained free of disease for 3 months with subsequent rectal and abdominal recurrence. Treatment with CHOP chemotherapy with filgrastim support was begun which resulted in another remission. Plasmablastic lymphoma is now reported in some studies to account for 2.6% of all HIV-related NHL. Originally described in 1997 in a series of 16 patients, this entity is highly associated with HIV infection in its later stages. Often, patients present with oral or jaw lesions with a rapidly progressive course. The tumors have the morphologic appearance of a plasmacytoid tumor with high proliferative index. Markers are positive mainly for LCA, CD79a, VS38C, and CD138. Co-infection with HHV-8 and EBV has not been consistently reported. Therapy with standard regimens has variable response. One case has been reported with a 3.5 year disease free survival. The regression of disease after resumption of HAART therapy alone in this patient suggests that HAART has an important role in the treatment of lymphoma in the HIV infected patient.

Gemtuzumab ozogamicin (Mylotarg) monotherapy for relapsed AML after hematopoietic stem cell transplant: efficacy and incidence of hepatic veno-occlusive disease

Gemtuzumab ozogamicin (GO) (Mylotarg, CMA-676) is a novel chemotherapeutic agent consisting of an anti-CD33 monoclonal antibody linked to calicheamicin, and is associated with a 30% response rate in patients with CD33-positive acute myeloid leukemia (AML) in first relapse. GO therapy has a 20% incidence of grade 3 or 4 hepatotoxicity, and has recently been associated with hepatic veno-occlusive disease (VOD). The efficacy and toxicity of GO in patients with AML who have relapsed after hematopoietic stem cell transplant (HSCT) is unknown, as this population was largely excluded from phase II studies. We reviewed the outcomes of eight consecutive patients with AML who received GO following relapse after HSCT. Two (25%) had responses to GO. One patient, who had had two previous HSCT and prior hyperbilirubinemia, developed severe VOD and died 14 days after GO therapy. The other seven patients did not meet diagnostic criteria for VOD. We conclude that GO can be safe and effective in patients who relapse following HSCT, but that caution is warranted in patients with multiple risk factors for VOD.

Front‐line, dose‐escalated immunochemotherapy is associated with a significant progression‐free survival advantage in patients with double‐hit lymphomas: a systematic review and meta‐analysis

‘Double‐hit lymphomas’ (DHL), defined by concurrent MYC and BCL2 (or, alternatively, BCL6) rearrangements, have a very poor outcome compared to standard‐risk, diffuse large B‐cell lymphomas (DLBCL). Consequently, dose‐intensive (DI) therapies and/or consolidation with high‐dose therapy and transplant have been explored in DHL, although benefit has been debated. This meta‐analysis compared survival outcomes in DHL patients receiving dose‐escalated regimens [DI: R‐Hyper‐CVAD (rituximab, cyclophosphamide, vincristine, doxorubicin, dexamethasone) or R‐CODOX‐M/IVAC (rituximab, cyclophosphamide, doxorubicin, vincristine, methotrexate/ifosfamide, etoposide, high dose cytarabine); or intermediate‐dose: R‐EPOCH (rituximab, etoposide, doxorubicin, cyclophosphamide, vincristine, prednisone)] versus standard‐dose regimens (R‐CHOP; rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone) in the first‐line setting. Data were synthesized to estimate hazard ratios of dose‐escalated treatments versus R‐CHOP using a Weibull proportional hazards model within a Bayesian meta‐analysis framework. Eleven studies examining 394 patients were included. Patients were treated with either front‐line R‐CHOP (n = 180), R‐EPOCH (n = 91), or R‐Hyper‐CVAD/rituximab, methotrexate, cytarabine (R‐M/C), R‐CODOX‐M/R‐IVAC (DI) (n = 123). Our meta‐analysis revealed that median progression‐free survival (n = 350) for the R‐CHOP, R‐EPOCH and DI groups was 12·1, 22·2, and 18·9 months, respectively. First‐line treatment with R‐EPOCH significantly reduced the risk of a progression compared with R‐CHOP (relative risk reduction of 34%; P = 0·032); however, overall survival (n = 374) was not significantly different across treatment approaches. A subset of patients might benefit from intensive induction with/without transplant. Further investigation into the role of transplant and novel therapy combinations is necessary.