Safety, Tolerability, and Antitumor Activity of Zipalertinib Among Patients With Non-Small-Cell Lung Cancer Harboring Epidermal Growth Factor Receptor Exon 20 Insertions

PURPOSE

Although several agents targeting epidermal growth factor receptor (EGFR) exon 20 insertions (ex20ins) have recently been approved by the US Food and Drug Administration, toxicities related to the inhibition of wild-type (WT) EGFR are common with these agents and affect overall tolerability. Zipalertinib (CLN-081, TAS6417) is an oral EGFR tyrosine kinase inhibitor (TKI) with a novel pyrrolopyrimidine scaffold leading to enhanced selectivity for EGFR ex20ins-mutant versus WT EGFR with potent inhibition of cell growth in EGFR ex20ins-positive cell lines.

METHODS

This phase 1/2a study of zipalertinib enrolled patients with recurrent or metastatic EGFR ex20ins-mutant non-small-cell lung cancer (NSCLC) previously treated with platinum-based chemotherapy.

RESULTS

Seventy-three patients were treated with zipalertinib at dose levels including 30, 45, 65, 100, and 150 mg orally twice a day. Patients were predominantly female (56%), had a median age of 64 years, and were heavily pretreated (median previous systemic therapies 2, range 1-9). Thirty six percent of patients had received previous non-ex20ins EGFR TKIs and 3/73 (4.1%) patients received previous EGFR ex20ins TKIs. The most frequently reported treatment-related adverse events of any grade included rash (80%), paronychia (32%), diarrhea (30%), and fatigue (21%). No cases of grade 3 or higher drug-related rash or diarrhea were observed at 100 mg twice a day or below. Objective responses occurred across all zipalertinib dose levels tested, with confirmed partial response (PR) observed in 28/73 (38.4%) response-evaluable patients. Confirmed PRs were seen in 16/39 (41%) response-evaluable patients at the dose of 100 mg twice a day.

CONCLUSION

Zipalertinib has encouraging preliminary antitumor activity in heavily pretreated patients with EGFR ex20ins-mutant NSCLC, with an acceptable safety profile, including low frequency of high-grade diarrhea and rash.

First-in-human phase I/II, open-label study of the anti-OX40 agonist INCAGN01949 in patients with advanced solid tumors

BACKGROUND

OX40 is a costimulatory receptor upregulated on antigen-activated T cells and constitutively expressed on regulatory T cells (Tregs). INCAGN01949, a fully human immunoglobulin G1κ anti-OX40 agonist monoclonal antibody, was designed to promote tumor-specific immunity by effector T-cell activation and Fcγ receptor-mediated Treg depletion. This first-in-human study was conducted to determine the safety, tolerability, and preliminary efficacy of INCAGN01949.

METHODS

Phase I/II, open-label, non-randomized, dose-escalation and dose-expansion study conducted in patients with advanced or metastatic solid tumors. Patients received INCAGN01949 monotherapy (7-1400 mg) in 14-day cycles while deriving benefit. Safety measures, clinical activity, pharmacokinetics, and pharmacodynamic effects were assessed and summarized with descriptive statistics.

RESULTS

Eighty-seven patients were enrolled; most common tumor types were colorectal (17.2%), ovarian (8.0%), and non-small cell lung (6.9%) cancers. Patients received a median three (range 1-9) prior therapies, including immunotherapy in 24 patients (27.6%). Maximum tolerated dose was not reached; one patient (1.1%) receiving 350 mg dose reported dose-limiting toxicity of grade 3 colitis. Treatment-related adverse events were reported in 45 patients (51.7%), with fatigue (16 (18.4%)), rash (6 (6.9%)), and diarrhea (6 (6.9%)) being most frequent. One patient (1.1%) with metastatic gallbladder cancer achieved a partial response (duration of 6.3 months), and 23 patients (26.4%) achieved stable disease (lasting >6 months in one patient). OX40 receptor occupancy was maintained over 90% among all patients receiving doses of ≥200 mg, while no treatment-emergent antidrug antibodies were detected across all dose levels. Pharmacodynamic results demonstrated that treatment with INCAGN01949 did not enhance proliferation or activation of T cells in peripheral blood or reduce circulating Tregs, and analyses of tumor biopsies did not demonstrate any consistent increase in effector T-cell infiltration or function, or decrease in infiltrating Tregs.

CONCLUSION

No safety concerns were observed with INCAGN01949 monotherapy in patients with metastatic or advanced solid tumors. However, tumor responses and pharmacodynamic effects on T cells in peripheral blood and post-therapy tumor biopsies were limited. Studies evaluating INCAGN01949 in combination with other therapies are needed to further evaluate the potential of OX40 agonism as a therapeutic approach in patients with advanced solid tumors.

TRIAL REGISTRATION NUMBER

NCT02923349.

Sequential therapy with INCAGN01949 followed by ipilimumab and nivolumab in two patients with advanced ovarian carcinoma

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Agonistic antibodies against OX40 are in active clinical development.

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Pre-clinical studies suggest sequential therapy is superior to combinational.

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We report two cases of ovarian cancer treated with OX40 followed by PD-1/CTLA4 Ab.

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Both experienced unusually deep and durable responses.

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The cases support further investigation of the relevance of sequential immunotherapy.

Agonists of the co-stimulatory molecule OX40 (CD134) are in clinical assessment alone and in combination with other immunotherapies. Recent pre-clinical studies have suggested that concurrent administration of OX40 agonists with anti-PD1 therapy is detrimental to the efficacy of such combinations and maximal efficacy may require sequential administration of the OX40 agonist followed by anti-PD1 therapy. In this report, we detail two patients with advanced ovarian carcinoma were treated with INCAGN01949, an agonistic OX40 Ab, as part of a clinical trial until disease progression. Both patients then received the combination of ipilimumab and nivolumab and experienced unusually deep and durable responses. These cases support the hypothesis raised in pre-clinical studies and highlight the potential relevance of sequence in combinational immunotherapy.

PD-1 blockade in subprimed CD8 cells induces dysfunctional PD-1+CD38hi cells and anti-PD-1 resistance

Understanding resistance to antibody to programmed cell death protein 1 (PD-1; anti-PD-1) is crucial for the development of reversal strategies. In anti-PD-1-resistant models, simultaneous anti-PD-1 and vaccine therapy reversed resistance, while PD-1 blockade before antigen priming abolished therapeutic outcomes. This was due to induction of dysfunctional PD-1⁺CD38^hi CD8⁺ cells by PD-1 blockade in suboptimally primed CD8 cell conditions induced by tumors. This results in erroneous T cell receptor signaling and unresponsiveness to antigenic restimulation. On the other hand, PD-1 blockade of optimally primed CD8 cells prevented the induction of dysfunctional CD8 cells, reversing resistance. Depleting PD-1⁺CD38^hi CD8⁺ cells enhanced therapeutic outcomes. Furthermore, non-responding patients showed more PD-1⁺CD38⁺CD8⁺ cells in tumor and blood than responders. In conclusion, the status of CD8⁺ T cell priming is a major contributor to anti-PD-1 therapeutic resistance. PD-1 blockade in unprimed or suboptimally primed CD8 cells induces resistance through the induction of PD-1⁺CD38^hi CD8⁺ cells that is reversed by optimal priming. PD-1⁺CD38^hi CD8⁺ cells serve as a predictive and therapeutic biomarker for anti-PD-1 treatment. Sequencing of anti-PD-1 and vaccine is crucial for successful therapy.

Phase Ia study of the indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor navoximod (GDC-0919) in patients with recurrent advanced solid tumors

BACKGROUND

Indoleamine-2,3-dioxygenase 1 (IDO1) catalyzes the oxidation of tryptophan into kynurenine and is partially responsible for acquired immune tolerance associated with cancer. The IDO1 small molecule inhibitor navoximod (GDC-0919, NLG-919) is active as a combination therapy in multiple tumor models.

METHODS

This open-label Phase Ia study assessed safety, pharmacokinetics (PK), pharmacodynamics (PD), and preliminary anti-tumor activity of navoximod in patients with recurrent/advanced solid tumors, administered as 50-800 mg BID on a 21/28 day and at 600 mg on a 28/28 day schedule. Plasma kynurenine and tryptophan were longitudinally evaluated and tumor assessments were performed.

RESULTS

Patients (n = 22) received a median of 3 cycles of navoximod. No maximum tolerated dose was reached. One dose-limiting toxicity of Grade 4 lower gastrointestinal hemorrhage was reported. Adverse events (AEs) regardless of causality in ≥20% of patients included fatigue (59%), cough, decreased appetite, and pruritus (41% each), nausea (36%), and vomiting (27%). Grade ≥ 3 AEs occurred in 14/22 patients (64%), and were related to navoximod in two patients (9%). Navoximod was rapidly absorbed (Tmax ~ 1 h) and exhibited dose-proportional increases in exposure, with a half-life (t1/2 ~ 11 h) supportive of BID dosing. Navoximod transiently decreased plasma kynurenine from baseline levels with kinetics consistent with its half-life. Of efficacy-evaluable patients, 8 (36%) had stable disease and 10 (46%) had progressive disease.

CONCLUSIONS

Navoximod was well-tolerated at doses up to 800 mg BID decreasing plasma kynurenine levels consistent with its half-life. Stable disease responses were observed.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02048709 .

Concurrent PD-1 Blockade Negates the Effects of OX40 Agonist Antibody in Combination Immunotherapy through Inducing T-cell Apoptosis

Combination therapies that depend on checkpoint inhibitor antibodies (Abs) such as for PD-1 or its ligand (PD-L1) together with immune stimulatory agonist Abs like anti-OX40 are being tested in the clinic to achieve improved antitumor effects. Here, we studied the potential therapeutic and immune effects of one such combination: Ab to PD-1 with agonist Ab to OX40/vaccine. We tested the antitumor effects of different treatment sequencing of this combination. We report that simultaneous addition of anti-PD-1 to anti-OX40 negated the antitumor effects of OX40 Ab. Antigen-specific CD8⁺ T-cell infiltration into the tumor was diminished, the resultant antitumor response weakened, and survival reduced. Although we observed an increase in IFNγ-producing E7-specifc CD8⁺ T cells in the spleens of mice treated with the combination of PD-1 blockade with anti-OX40/vaccine, these cells underwent apoptosis both in the periphery and the tumor. These results indicate that anti-PD-1 added at the initiation of therapy exhibits a detrimental effect on the positive outcome of anti-OX40 agonist Ab. These findings have important implications on the design of combination immunotherapy for cancer, demonstrating the need to test treatment combination and sequencing before moving to the clinic. Cancer Immunol Res; 5(9); 755-66. ©2017 AACR.

Antigen-Specific Antitumor Responses Induced by OX40 Agonist Are Enhanced by the IDO Inhibitor Indoximod

Although an immune response to tumors may be generated using vaccines, so far, this approach has only shown minimal clinical success. This is attributed to the tendency of cancer to escape immune surveillance via multiple immune suppressive mechanisms. Successful cancer immunotherapy requires targeting these inhibitory mechanisms along with enhancement of antigen-specific immune responses to promote sustained tumor-specific immunity. Here, we evaluated the effect of indoximod, an inhibitor of the immunosuppressive indoleamine-(2,3)-dioxygenase (IDO) pathway, on antitumor efficacy of anti-OX40 agonist in the context of vaccine in the IDO^- TC-1 tumor model. We demonstrate that although the addition of anti-OX40 to the vaccine moderately enhances therapeutic efficacy, incorporation of indoximod into this treatment leads to enhanced tumor regression and cure of established tumors in 60% of treated mice. We show that the mechanisms by which the IDO inhibitor leads to this therapeutic potency include (i) an increment of vaccine-induced tumor-infiltrating effector T cells that is facilitated by anti-OX40 and (ii) a decrease of IDO enzyme activity produced by nontumor cells within the tumor microenvironment that results in enhancement of the specificity and the functionality of vaccine-induced effector T cells. Our findings suggest a translatable strategy to enhance the overall efficacy of cancer immunotherapy. Cancer Immunol Res; 6(2); 201-8. ©2018 AACR.

Phase II Study of Alemtuzumab (CAMPATH-1) in Patients with HTLV-1-Associated Adult T-cell Leukemia/lymphoma

PURPOSE

Therapeutic regimens for adult T-cell leukemia/lymphoma (ATL) are limited with unsatisfactory results, thereby warranting development of novel therapies. This study investigated antitumor activity and toxicity of alemtuzumab with regard to response, duration of response, progression-free survival, and overall survival in patients with human T-cell lymphotropic virus-1 (HTLV-1)-associated ATL.

EXPERIMENTAL DESIGN

Twenty-nine patients with chronic, acute, and lymphomatous types of ATL were enrolled in a single-institution, nonrandomized, open-label phase II trial wherein patients received intravenous alemtuzumab 30 mg three times weekly for a maximum of 12 weeks.

RESULTS

Twenty-nine patients were evaluable for response and toxicity. The overall objective response was 15 of 29 patients [95% confidence interval (CI), 32.5%-70.6%]. The 15 patients who responded manifested a median time to response of 1.1 months. Median response duration was 1.4 months for the whole group and 14.5 months among responders. Median progression-free survival was 2.0 months. Median overall survival was 5.9 months. The most common adverse events were 2 with vasovagal episodes (7%) and 3 with hypotensive episodes (10%), leukopenia (41%) grade 3 and (17%) grade 4, lymphocytopenia (59%) grade 3, neutropenia (31%) grade 3, anemia (24%), and thrombocytopenia (10%). All patients developed cytomegalovirus antigenemia (CMV). Three were symptomatic and all responded to antiviral therapy. Grade 3 or 4 infections were reported in 4 (14%) of patients.

CONCLUSIONS

Alemtuzumab induced responses in patients with acute HTLV-1-associated ATL with acceptable toxicity, but with short duration of responses. These studies support inclusion of alemtuzumab in novel multidrug therapies for ATL. Clin Cancer Res; 23(1); 35-42. ©2016 AACR.

Programmed death-1 & its ligands: promising targets for cancer immunotherapy

Novel strategies for cancer treatment involving blockade of immune inhibitors have shown significant progress toward understanding the molecular mechanism of tumor immune evasion. The preclinical findings and clinical responses associated with programmed death-1 (PD-1) and PD-ligand pathway blockade seem promising, making these targets highly sought for cancer immunotherapy. In fact, the anti-PD-1 antibodies, pembrolizumab and nivolumab, were recently approved by the US FDA for the treatment of unresectable and metastatic melanoma resistant to anticytotoxic T-lymphocyte antigen-4 antibody (ipilimumab) and BRAF inhibitor. Here, we discuss strategies of combining PD-1/PD-ligand interaction inhibitors with other immune checkpoint modulators and standard-of-care therapy to break immune tolerance and induce a potent antitumor activity, which is currently a research area of key scientific pursuit.

Safety, efficacy, and pharmacokinetics/pharmacodynamics of daclizumab (anti-CD25) in patients with adult T-cell leukemia/lymphoma

Interleukin-2 receptor α chain (CD25) is overexpressed in human T-cell leukemia virus 1 associated adult T-cell leukemia/lymphoma (ATL). Daclizumab a humanized monoclonal antibody blocks IL-2 binding by recognizing the interleukin-2 receptor α chain (CD25). We conducted a phase I/II trial of daclizumab in 34 patients with ATL. Saturation of surface CD25 on circulating ATL cells was achieved at all doses; however saturation on ATL cells in lymph nodes required 8 mg/kg. Up to 8 mg/kg of daclizumab administered every 3 weeks was well tolerated. No responses were observed in 18 patients with acute or lymphoma ATL; however, 6 partial responses were observed in 16 chronic and smoldering ATL patients. The pharmacokinetics/pharmacodynamics of daclizumab suggest that high-dose daclizumab would be more effective than low-dose daclizumab in treatment of lymphoid malignancies and autoimmune diseases (e.g., multiple sclerosis) since high-dose daclizumab is required to saturate IL-2R alpha in extravascular sites.

Efficacy of alemtuzumab (ALZ) in combination with dose-adjusted EPOCH (DA-EPOCH) in untreated nodal peripheral T-cell lymphoma (PTCL)

8051

Background: The survival of patients (pts) with PTCL (excluding ALCL) is disappointing following anthracycline-based therapy and novel approaches are needed. In diffuse large B-cell lymphoma, the addition of anti-CD20 therapy to CHOP has significantly improved outcome and we investigated if in PTCL, adding ALZ – which targets CD52, expressed on most PTCLs – was feasible and improved outcome. Methods: This was a single-center phase I/II trial of ALZ, in combination with DA-EPOCH in patients with treatment-naïve CD52+ PTCL. The MTD of 30 mg ALZ was combined with DA-EPOCH for phase II evaluation resulting in an intention-to-treat population (ITTP) of 30 pts. Results: Patient (n=30) characteristics: median (range) age 50 (17-77); M:F 1:1; Stage III/IV 27 (90%); IPI ≥2 22 (73%). Histologies: ATLL 11 (37%), PTCL NOS 6 (20%), AITL 5 (16%), Hepatosplenic 3 (10%), Peripheral T NK cell 2 (7%), Other 3 (10%). At 67 months median follow-up, 11 patients were alive, 10 disease-free. Median overall (OS) and event-free survivals (EFS) were 15.4 and 6.7 months respectively. Outcome was substantially better for pts with ‘nodal’ (AITL, PTCL-NOS, Other) compared to ‘non-nodal’ (ATLL and ‘extranodal’ histologies) PTCL subtypes. 3-year OS for the two groups was 58.3% and 27.8% respectively (p=0.082); 3-yrs EFS was 50% (median 27.0 months) and 22.2% (median: 5 months) respectively (p=0.041). Half of the ‘nodal’ PTCL pts had sustained long-term complete remissions demonstrated by a plateau in the EFS curve at 27 months. There were 3 treatment related deaths: 2 from neutropenic sepsis; 1 from toxoplasma. Other toxicities included CMV and BK virus reactivation in 53% and 30% respectively. Febrile neutropenia was seen in 20% and grade 4 thrombocytopenia in 12 % of cycles. Conclusions: Although it has significant infectious toxicity, ALZ 30mg and DA-EPOCHin untreated PTCL is feasible and associated with a long-term favorable outcome in nodal but not extranodal or leukemic PTCL. A phase III study of ALZ 30mg with anthracycline-based therapy is ongoing and we await the results with interest.

Flow cytometric immunophenotypic assessment of T-cell clonality by vβ repertoire analysis in fine-needle aspirates and cerebrospinal fluid

Flow cytometric T-cell receptor V(β) repertoire analysis (TCR-V(β)-R) is a sensitive method to detect T-cell clonality; however, its implementation in low-cellularity specimens has not been established. We developed a strategy to use TCR-V(β)-R in cerebrospinal fluid (CSF) and fine-needle aspirate (FNA) specimens. Initially, full TCR-V(β)-R was evaluated in diagnostic/screening specimens from 8 patients with T-cell neoplasia to determine tumor-specific TCR-V(β) protein expression. Subsequently, an abbreviated, patient-specific TCR-V(β)-R evaluation was performed in 17 paucicellular specimens from the patients (8 CSF, 9 FNA) for staging and monitoring of minimal residual disease (MRD). A single cocktail containing 3 anti-V(β) antibodies (1 tumor-specific and 2 negative controls) in combination with other antibodies chosen to help gate on atypical T cells is highly sensitive and specific for detecting low-level neoplastic T-cell involvement in paucicellular specimens. This TCR-V(β)-R strategy is valuable in staging and evaluating MRD in patients with T-cell non-Hodgkin lymphoma.

MicroRNA profiling of follicular lymphoma identifies microRNAs related to cell proliferation and tumor response

BACKGROUND

MicroRNAs can play an important role in tumorigenesis through post-transcriptional regulation of gene expression, and are not well characterized in follicular lymphoma.

DESIGN AND METHODS

MicroRNA profiles of enriched follicular lymphoma tumor cells from 16 patients were generated by assaying 851 human microRNAs. Tandem gene expression profiles were obtained for predicting microRNA targets.

RESULTS

The expression of 133 microRNAs was significantly different (> 2-fold; P<0.05) between follicular lymphoma and follicular hyperplasia. Forty-four microRNAs in three groups generated a unique follicular lymphoma signature. Of these, ten microRNAs were increased (miR-193a-5p, -193b*, -345, -513b, -574-3p, -584, -663, -1287, -1295, and -1471), 11 microRNAs were decreased (miR-17*, -30a, -33a, -106a*, -141, -202, -205, -222, -301b, -431*, and -570), and 23 microRNAs formed a group that was increased in most cases of follicular lymphoma but showed lower expression in a subset of cases (let-7a, let-7f, miR-7-1*, -9, -9*, -20a, -20b, -30b, -96, -98, -194, -195, -221*, -374a, -374b, -451, -454, -502-3p, -532-3p, -664*, -1274a, -1274b, and -1260). Higher expression of this last group was associated with improved response to chemotherapy. Gene expression analysis revealed increased expression of MAPK1, AKT1, PRKCE, IL4R and DROSHA and decreased expression of CDKN1A/p21, SOCS2, CHEK1, RAD51, KLF4, BLIMP1 and IRF4 in follicular lymphoma. Functional studies indicated that CDKN1A/p21 and SOCS2 expression is directly regulated by miR-20a/-20b and miR-194, respectively.

CONCLUSIONS

Follicular lymphoma is characterized by a unique microRNA signature, containing a subset of microRNAs whose expression correlate with response to chemotherapy. miR-20a/b and miR-194 target CDKN1A and SOCS2 in follicular lymphoma, potentially contributing to tumor cell proliferation and survival.

Brentuximab Vedotin (SGN-35)

Brentuximab vedotin (SGN-35) is an antibody-drug conjugate (ADC) directed against the CD30 antigen expressed on Hodgkin lymphoma and anaplastic large cell lymphoma. SGN-35 consists of the cAC10 chimerized IgG1 monoclonal antibody SGN30, modified by the addition of a valine-citrulline dipeptide linker to permit attachment of the potent inhibitor of microtubule polymerization monomethylauristatin E (MMAE). In phase II trials, SGN-35 produced response rates of 75% in patients with Hodgkin lymphoma (n = 102) and 87% in patients with anaplastic large cell lymphoma (n = 30). Responses to SGN-35 might be related not only to the cytotoxic effect due to release of MMAE within the malignant cell but also to other effects. First, SGN-35 may signal malignant cells through CD30 ligation to deliver an apoptotic or proliferative response. The former would amplify the cytotoxicity of MMAE. A proliferative signal delivered in the context of MMAE intoxication could enhance cell death. Second, the efficacy of SGN-35, particularly in Hodgkin lymphoma, might be attributed to its effect on the tumor microenvironment. Diffusion of free MMAE from the targeted tumor cells could result in a bystander effect that kills the normal supporting cells in close proximity to the malignant cells. The elimination of T regulatory cells that inhibit cytotoxic effector cells and elimination of cells that provide growth factor support for Hodgkin/Reed-Sternberg cells could further enhance the cytotoxic activity of SGN-35. Here we review the biology of SGN-35 and the clinical effects of SGN-35 administration.

Phase I trial of 7-hydroxystaurosporine and fludararbine phosphate: in vivo evidence of 7-hydroxystaurosporine induced apoptosis in chronic lymphocytic leukemia

This is a phase I study of 7-hydroxystaurosporine (UCN-01) and fludararbine monophosphate (FAMP) in relapsed lymphoma. UCN-01 alone was administered in cycle 1 and with FAMP in cycles 2-6. FAMP was escalated in cohorts from 1 to 5 days. UCN-01 and FAMP pharmacokinetics and apoptosis of malignant lymphocytes was evaluated. Eighteen patients were enrolled. Standard FAMP with UCN-01 was tolerated without dose-limiting toxicity (DLT) and those seen were common to either agent alone. One patient died due to Stevens-Johnson syndrome. Seven of 18 patients responded. No pharmacological effect of UCN-01 by FAMP was noted. Lymphocytosis occurred in 15 of 18 patients following UCN-01 to paradoxically increase circulating tumor cells. UCN-01 induced apoptosis in six of eight patients with chronic lymphocytic leukemia (CLL). UCN-01 does not increase FAMP toxicity. Transient lymphocytosis followed by apoptosis occurs with UCN-01. Mobilization from tissue reservoirs may play a role in the induction of cell death in malignant lymphocytes.

Flow cytometric immunophenotypic assessment of T-cell clonality by Vβ repertoire analysis: detection of T-cell clonality at diagnosis and monitoring of minimal residual disease following therapy

Flow cytometric T-cell receptor (TCR)-V(β) repertoire analysis (TCR-V(β)-R) is a sensitive method for detection of T-cell clonality; however, no uniform approach exists to define clonality in neoplastic T cells. TCR-V(β)-R was evaluated in patients with a diagnosis of T-cell neoplasia in initial diagnostic specimens from 41 patients and for minimal residual disease (MRD) monitoring in 61 sequential samples from 14 patients with mature T-cell neoplasia. Gating strategies and criteria for detection of T-cell clonality were determined. In all 41 initial specimens, T-cell clonality was demonstrated via TCR-V(β)-R. The frequency of V(β) usage was consistent with random neoplastic transformation of TCR-V(β) subsets. MRD was successfully detected in follow-up samples from all 14 patients evaluated, Furthermore, MRD after therapy was quantitated in 48 peripheral blood specimens. TCR-V(β)-R analysis is a sensitive method for detection of T-cell clonality and is useful for diagnosis and MRD detection in multiple specimen types.

Vaccination with patient-specific tumor-derived antigen in first remission improves disease-free survival in follicular lymphoma

PURPOSE

Vaccination with hybridoma-derived autologous tumor immunoglobulin (Ig) idiotype (Id) conjugated to keyhole limpet hemocyanin (KLH) and administered with granulocyte-monocyte colony-stimulating factor (GM-CSF) induces follicular lymphoma (FL) -specific immune responses. To determine the clinical benefit of this vaccine, we conducted a double-blind multicenter controlled phase III trial.

PATIENTS AND METHODS

Treatment-naive patients with advanced stage FL achieving complete response (CR) or CR unconfirmed (CRu) after chemotherapy were randomly assigned two to one to receive either Id vaccine (Id-KLH + GM-CSF) or control (KLH + GM-CSF). Primary efficacy end points were disease-free survival (DFS) for all randomly assigned patients and DFS for randomly assigned patients receiving at least one dose of Id vaccine or control.

RESULTS

Of 234 patients enrolled, 177 (81%) achieved CR/CRu after chemotherapy and were randomly assigned. For 177 randomly assigned patients, including 60 patients not vaccinated because of relapse (n = 55) or other reasons (n = 5), median DFS between Id-vaccine and control arms was 23.0 versus 20.6 months, respectively (hazard ratio [HR], 0.81; 95% CI, 0.56 to 1.16; P = .256). For 117 patients who received Id vaccine (n = 76) or control (n = 41), median DFS after randomization was 44.2 months for Id-vaccine arm versus 30.6 months for control arm (HR, 0.62; 95% CI, 0.39 to 0.99; P = .047) at median follow-up of 56.6 months (range, 12.6 to 89.3 months). In an unplanned subgroup analysis, median DFS was significantly prolonged for patients receiving IgM-Id (52.9 v 28.7 months; P = .001) but not IgG-Id vaccine (35.1 v 32.4 months; P = .807) compared with isotype-matched control-treated patients.

CONCLUSION

Vaccination with patient-specific hybridoma-derived Id vaccine after chemotherapy-induced CR/CRu may prolong DFS in patients with FL. Vaccine isotype may affect clinical outcome and explain differing results between this and other controlled Id-vaccine trials.

Disseminated Strongyloides stercoralis infection in HTLV-1-associated adult T-cell leukemia/lymphoma

A 55-year-old woman with human T-cell lymphotropic virus type-1 (HTLV-1)-associated adult T-cell leukemia (ATL) and a history of previously treated Strongyloides stercoralis infection received anti-CD52 monoclonal antibody therapy with alemtuzumab on a clinical trial. After an initial response, she developed ocular involvement by ATL. Alemtuzumab was stopped and high-dose corticosteroid therapy was started to palliate her ocular symptoms. Ten days later, the patient developed diarrhea, vomiting, fever, cough, skin rash, and a deteriorating mental status. She was diagnosed with disseminated S. stercoralis. Corticosteroids were discontinued and the patient received anthelmintic therapy with ivermectin and albendazole with complete clinical recovery.

Impacting tumor cell-fate by targeting the inhibitor of apoptosis protein survivin

Survivin (BIRC5), a member of the inhibitor of apoptosis protein (IAP) family that inhibits caspases and blocks cell death is highly expressed in cancer and is associated with a poorer clinical outcome. Functioning simultaneously during cell division and apoptosis inhibition, survivin plays a pivotal role in determining cell survival. Survivin has consistently been identified by molecular profiling analysis to be associated with higher tumor grade, more advanced disease, abbreviated survival, accelerated rates of recurrence, and chemotherapy and radiation resistance. Survivin's differential expression in cancer compared to normal tissue and its role as a nodal protein in a number of cellular pathways make it a highly flexible therapeutic target, suitable for small-molecule inhibitiors, molecular antagonists, and vaccination-based therapies. By targeting survivin it is hoped that multiple tumor signaling circuitries may be simultaneously disabled. This effect may be applicable to many tumor histologies irrespective of specific genetic makeup. To date, survivin inhibitors have shown modest activity as single agents, but it is anticipated that when given in combination with cytotoxic chemotherapy or monoclonal antibodies they may exhibit enhanced efficacy. This review discusses the complex circuitry of survivin in human cancers and highlights clinical trials involving novel agents that target this important protein.

Tumor markers in hairy cell leukemia

Despite the availability of highly effective therapies for hairy cell leukemia, including cladrabine, deoxycoformycin, and interferon α, a significant fraction of patients relapse. The use of flow cytometry, bone marrow examination for minimal residual disease, and peripheral blood counts provides details about the level of disease activity, but the optimal method for following patient response and risk for relapse has not been established. Flow cytometry provides accurate assessments of circulating malignant cell counts even at very low levels, but does not provide details on the extent of bone marrow involvement. Bone marrow involvement can be assessed by biopsy, but is a painful procedure, and the extent of involvement by hairy cell leukemia is not always uniform. Thus, a single biopsy may not identify active disease when it is present. Magnetic resonance imaging is being evaluated as a means for assessing total body burden of disease in the marrow and shows great promise. Tumor markers that can be measured in the serum provide a method for assessing total body disease burden. Cell surface proteins can be shed by tumor cells through proteolytic cleavage to release portions of their extracellular domains. These proteolytic degradation products can be measured in the serum and provide a tool to monitor disease burden and response to therapy. Three cell surface molecules expressed by the malignant hairy cells, CD25, CD22, and CD307, have been used to monitor disease activity and follow patients at risk for relapse. Serum tumor markers provide a reliable, inexpensive, and non-invasive means of following patients with hairy cell leukemia for response to treatment and relapse.

New strategies in peripheral T-cell lymphoma: understanding tumor biology and developing novel therapies

Peripheral T-cell lymphomas (PTCL) constitute a group of heterogeneous diseases that are uncommon, representing, in Western countries, only approximately 10% of all non-Hodgkin lymphomas. They are typically associated with a poor prognosis compared with their B-cell counterparts and are much less well understood with respect to tumor biology, owing to their rarity and biologic heterogeneity, and to the fact that characteristic cytogenetic abnormalities are few compared with B-cell lymphomas. Although the outcome for patients with anaplastic large cell lymphoma (ALCL), particularly anaplastic lymphoma kinase (ALK)-positive ALCL, is good, other types of PTCLs are associated with a poor prognosis, even with aggressive anthracycline-based chemotherapy. In this respect, there is a need for new approaches in these diseases, and this review focuses on and explores recent experience with novel therapies in PTCL.

Visual inspection versus quantitative flow cytometry to detect aberrant CD2 expression in malignant T cells

BACKGROUND

Abnormal levels of T-cell antigen expression occur in T-cell neoplasia. We examined CD2 expression in malignant and normal T cells to determine if the level of CD2 expression differed significantly and if quantitation assisted in detecting this difference.

METHOD

Flow cytometric immunophenotypic (FCI) evaluation was performed on specimens from 36 patients with mature T-cell neoplasia. Abnormal T cells were identified based upon the abnormal FCI and morphology. Levels of CD2 expression were quantitated using 1:1 PE conjugates of anti-CD2 and QuantiBRITE bead standards to calculate the antibodies bound per cell (ABC). The efficacy of ABC measurement versus simple examination of dots plots was compared.

RESULTS

Abnormal levels of CD2 expression were frequently observed in mature T-cell malignancies. The CD2 ABC values were highly sensitive in detecting differences between malignant and normal T cells (P = 0.0028). In most cases (24/32 specimens, 75%), CD2 ABCs differed by >20%. CD2 ABCs had high variability in normal T cells.

CONCLUSIONS

CD2 expression by malignant T cells differed significantly from that of normal T-cells by CD2 ABC quantitation. The high variability in normal T-cell CD2 ABCs limited the determination of normal reference ranges and, thus, its utility in the diagnosis of T-cell neoplasia. However, examination of CD2 can help in detection of tumor cells when residual normal T cells are present for comparison. Moreover, the increased sensitivity of CD2 quantitation is valuable in confirming FCI cases where abnormalities in CD2 expression are difficult to appreciate by visual inspection alone.

Abstract 2423: Phase I/II study of antitumor vaccination using lung cancer cells expressing murine α(1,3)galactosyltransferase (αGT) in non-small cell lung cancer (NSCLC)

Background: Alpha(1,3)-linked galactose (αGal) epitopes are immunogenic and mediate rejection of non-primate xenografts. Vaccination of αGal knockout mice with tumor expressing αGT stimulated immunity against αGal-negative tumor and induced rejection of tumor. We studied the safety and antitumor activity of a vaccine using allogeneic human NSCLC cells engineered to express murine αGT gene in patients with NSCLC. The vaccine is composed of equal numbers of three αGT transduced human NSCLC cell lines. Methods: Patients with metastatic or recurrent NSCLC, age ≥18, ECOG PS ≤2, ≤2 prior systemic therapies, adequate hematological, hepatic and renal function, and informed consent were eligible. In phase I cohorts of patients received intradermal injections totaling 3, 10, 30, or 100 × 10E+6 vaccine cells every 4-weeks x 4; or 500 × 10E+6 vaccine cells followed by 300 × 10E+6 vaccine cells every 2-weeks × 7. In Phase II, eligible patients received injections totaling 300 × 10E+6 vaccine cells every 2 weeks for 8 doses. Adverse events were assessed using CTC v3.0 and response was determined using modified RECIST criteria. Serum anti-αGal antibody titers were monitored and ELISPOT assays for induction of interferonγ and interleukin-5 by PBMC were examined pre- and post vaccination. Vaccine site biopsies were performed. Results: 17 patients were treated in phase I. No vaccine-related serious adverse events (AE) were observed. Related AE's were ≤CTC grade 2 and included injection site pain/discomfort, local hyperpigmentation, skin reactions, local urticaria, arthralgias/myalgias, dyspnea, fatigue, herpes zoster, hypertension, lymphopenia and mild serum transaminitis. Six patients experienced stable disease for ≥4.0 months (median 8.0, range, 6.0-63.1 months). In phase II, 23 patients treated, 16 patients received one and five patients received two prior treatment regimens and two patients had no prior treatment (one of those had surgery only). Seven patients demonstrated SD ≥4.0 months. Median survival for the entire group was 11.0 months (range, 2.1-35.7 months) and 23.7 months (range, 11.0-35.7 months) for patients that achieved SD. Vaccine sites demonstrated infiltration of lymphocytes, granulocytes and eosinophils. Anti-αGal titers increased in all patients, and release of interferonγ and interleukin-5 during co-culture with vaccine parental and an unrelated NSCLC cell line was detected in some patients. Increases in anti-CEA antibodies were also detected. Conclusions: Antitumor vaccination using genetically altered human lung cancer cells expressing αGT is safe and feasible. A number of patients had prolonged SD and the median survival of vaccinated patients compared favorably to that reported in patients receiving 2nd line chemotherapy for relapsed or progressive advanced NSCLC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2423.

Minimal residual disease detection by flow cytometry in adult T-cell leukemia/lymphoma

Little information exists regarding the detection of minimal residual disease (MRD) in adult T-cell leukemia/lymphoma (ATLL). We evaluated 75 peripheral blood samples from 17 ATLL cases using flow cytometry (FC); 50 of the samples were concurrently evaluated by polymerase chain reaction (PCR) for clonal T-cell receptor gamma chain (TRG) gene rearrangement and the presence of human T-cell lymphotropic virus-1 proviral sequences. Residual ATLL cells were identified using a multiparametric approach to identify aberrant T-cell immunophenotypes. Malignant T cells were CD4+, CD3 dim+, CD26-, CD25 bright, CD7+, and CD27+, with occasional dim expression of CD2 or CD5. FC exhibited a high sensitivity, detecting as few as 0.29% ATLL cells/WBC (4.9 cells/microL) in the peripheral blood. PCR for TRG gene rearrangement was slightly more sensitive, and FC and PCR complemented each other in detecting MRD. In 2 patients, there was complete remission; 4 patients had disease refractory to therapy, and 3 died; 11 others had persistent disease with variable numbers of ATLL cells in the peripheral blood. Higher levels of ATLL cells appeared to correlate with disease severity. FC detection of aberrant T cells permits sensitive and quantitative monitoring of MRD in ATLL.

Reactivation of DNA viruses in association with histone deacetylase inhibitor therapy: a case series report

Histone deacetylase inhibitors are a class of anti-neoplastic agents that induce growth arrest, differentiation, and/or apoptotic cell death of transformed cells in vitro and in vivo. A phase II study exploring the efficacy of romidepsin, an histone deacetylase inhibitor, in patients with cutaneous or peripheral T-cell lymphomas was initiated at the National Cancer Institute. To date, over 120 patients with T-cell lymphoma have been treated on a multi-institutional phase II trial of romidepsin. Reactivation of latent DNA viruses including EBV, HBV, and VZV is well described as a consequence of the immune suppression associated with systemic chemotherapy. The incidence of viral reactivation in patients treated with histone deacetylase inhibitors is not yet known. We report the observation of EBV-associated illnesses in 2 patients and the reactivation of HBV in an additional patient treated with romidepsin. These cases may represent reactivation of DNA viruses due to histone deacetylase inhibitor induced immunosuppression, or direct promotion of viral replication via histone deacetylase inhibitor induced chromatin remodeling, or, alternatively, may be related to the underlying disease process. These observations suggest that vigilance for DNA virus reactivation is needed to quantify the risk in patients treated with histone deacetylase inhibitors.

EBV-related lymphoproliferative disease complicating therapy with the anti-CD2 monoclonal antibody, siplizumab, in patients with T-cell malignancies

PURPOSE

We report an increased incidence of EBV-induced B-cell lymphoproliferative disease (LPD) in patients treated with siplizumab, an anti-CD2 antibody. The development of EBV-LPD has been associated with the use of immunosuppressive agents used in solid organ, bone marrow, and stem cell transplantation and in certain congenital immunodeficiencies.

EXPERIMENTAL DESIGN

We conducted a single-institution phase I dose-escalation trial of siplizumab, a humanized monoclonal antibody to CD2, in 29 patients with T-cell malignancies.

RESULTS

Although initial responses were encouraging, 4 (13.7%) patients developed EBV-LPD and the trial was stopped. Reductions in CD4(+) and CD8(+) cell count numbers in response to therapy were seen in all patients, but in those patients developing EBV-LPD a significantly greater reduction in natural killer (NK) cell number and CD2 expression on T cells was seen. These findings highlight the importance of NK-cell depletion and CD2 expression in addition to T-cell depletion in the etiology of EBV-LPD.

CONCLUSIONS

The emergence of EBV-LPD may be associated with the ability of siplizumab to deplete both T and NK cells without affecting B cells. Agents that deplete T- and NK-cell populations without affecting B cell number should be screened for this potentially serious adverse event.

Variable CD52 expression in mature T cell and NK cell malignancies: implications for alemtuzumab therapy

The anti-CD52 antibody alemtuzumab has been explored as a novel targeted therapy in T cell malignancies. To assess the suitability of alemtuzumab therapy, we carried out a comprehensive study of CD52 expression using flow cytometry (FC) in 78 untreated patients diagnosed with mature T/natural killer (NK) cell neoplasms, including 34 adult T cell leukaemia/lymphomas (ATLL), two anaplastic large cell lymphomas (ALCL), three angioimmunoblastic T cell lymphomas (AITL), 16 cutaneous T cell lymphomas (CTCL), four extra-nodal T/NK cell lymphomas (ENT/NKCL), four hepatosplenic T cell lymphomas (HSTCL), 13 peripheral T cell lymphomas, not otherwise specified (PTCL-NOS) and two T-prolymphocytic leukaemia (T-PLL). The level of CD52 expression was quantified using QuantiBRITE standard beads. The level of CD52 expression varied widely within each diagnostic category. All AITL, HSTCL and T-PLL cases were CD52-positive and the frequency of CD52 expression was high in PTCL-NOS (92.3%), ATLL (94.1%) and CTCL (87.5%), implying a rational role for alemtuzumab in the treatment of these diseases; however, CD52 expression was low in ALCL (50%) and ENT/NKCL (25%). FC testing for cell surface expression of CD52 is indicated in patients with T/NK cell malignancies being considered for alemtuzumab therapy. Further studies are necessary to determine if the level of CD52 expression correlates with response to therapy.

Definition, prognostic factors, treatment, and response criteria of adult T-cell leukemia-lymphoma: a proposal from an international consensus meeting

Adult T-cell leukemia-lymphoma (ATL) is a distinct peripheral T-lymphocytic malignancy associated with a retrovirus designated human T-cell lymphotropic virus type I (HTLV-1). The diversity in clinical features and prognosis of patients with this disease has led to its subclassification into the following four categories: acute, lymphoma, chronic, and smoldering types. The chronic and smoldering subtypes are considered indolent and are usually managed with watchful waiting until disease progression, analogous to the management of some patients with chronic lymphoid leukemia (CLL) or other indolent histology lymphomas. Patients with aggressive ATL generally have a poor prognosis because of multidrug resistance of malignant cells, a large tumor burden with multiorgan failure, hypercalcemia, and/or frequent infectious complications as a result of a profound T-cell immunodeficiency. Under the sponsorship of the 13th International Conference on Human Retrovirology: HTLV, a group of ATL researchers joined to form a consensus statement based on established data to define prognostic factors, clinical subclassifications, and treatment strategies. A set of response criteria specific for ATL reflecting a combination of those for lymphoma and CLL was proposed. Clinical subclassification is useful but is limited because of the diverse prognosis among each subtype. Molecular abnormalities within the host genome, such as tumor suppressor genes, may account for these diversities. A treatment strategy based on the clinical subclassification and prognostic factors is suggested, including watchful waiting approach, chemotherapy, antiviral therapy, allogeneic hematopoietic stem-cell transplantation (alloHSCT), and targeted therapies.

Anti-HTLV antibody profiling reveals an antibody signature for HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP)

Background

HTLV-I is the causal agent of adult T cell leukemia (ATLL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Biomarkers are needed to diagnose and/or predict patients who are at risk for HAM/TSP or ATLL. Therefore, we investigated using luciferase immunoprecipitation technology (LIPS) antibody responses to seven HTLV-I proteins in non-infected controls, asymptomatic HTLV-I-carriers, ATLL and HAM/TSP sera samples. Antibody profiles were correlated with viral load and examined in longitudinal samples.

Results

Anti-GAG antibody titers detected by LIPS differentiated HTLV-infected subjects from uninfected controls with 100% sensitivity and 100% specificity, but did not differ between HTLV-I infected subgroups. However, anti-Env antibody titers were over 4-fold higher in HAM/TSP compared to both asymptomatic HTLV-I (P < 0.0001) and ATLL patients (P < 0.0005). Anti-Env antibody titers above 100,000 LU had 75% positive predictive value and 79% negative predictive value for identifying the HAM/TSP sub-type. Anti-Tax antibody titers were also higher (P < 0.0005) in the HAM/TSP compared to the asymptomatic HTLV-I carriers. Proviral load correlated with anti-Env antibodies in asymptomatic carriers (R = 0.76), but not in HAM/TSP.

Conclusion

These studies indicate that anti-HTLV-I antibody responses detected by LIPS are useful for diagnosis and suggest that elevated anti-Env antibodies are a common feature found in HAM/TSP patients.

Receptor-directed therapy of T-cell leukemias and lymphomas

T-Cell leukemias and lymphomas represent a less common and heterogeneous group of lymphoid neoplasms. Overall, they respond less well to chemotherapy and have a poorer prognosis than their B-cell counterparts. T-Cell tumors express a number of potential targets for receptor-directed antibody therapy; however, there is no available therapeutic monoclonal antibody for these diseases with comparable activity to that of rituximab in B-cell disorders. Despite this, alemtuzumab, a humanized anti-CD52 monoclonal antibody has demonstrated meaningful anti-tumor activity in a variety of T-cell malignancies. A number of other antibodies, modified antibodies and immunotoxins directed against targets such as CD2, CD4, CD5, CD25, CD30 and CD122 expressed on malignant T-cells are under investigation. The current status of receptor-directed antibody therapy for T-cell leukemia and lymphoma is reviewed.

Phase II study of dose-adjusted EPOCH and rituximab in untreated diffuse large B-cell lymphoma with analysis of germinal center and post-germinal center biomarkers

PURPOSE

To assess the clinical outcome and the influence of biomarkers associated with apoptosis inhibition (Bcl-2), tumor proliferation (MIB-1), and cellular differentiation on the outcome with dose-adjusted (DA) EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin) plus rituximab (R) infusional therapy in diffuse large B-cell lymphoma (DLBCL) with analysis of germinal center B-cell (GCB) and post-GCB subtypes by immunohistochemistry.

PATIENTS AND METHODS

Phase II study of 72 patients with untreated de novo DLBCL who were at least 18 years of age and stage II or higher. Radiation consolidation was not permitted.

RESULTS

Patients had a median age of 50 years (range, 19 to 85) and 40% had a high-intermediate or high International Prognostic Index (IPI). At 5 years, progression-free survival (PFS) and overall survival (OS) were 79% and 80%, respectively, with a median potential follow-up of 54 months. PFS was 91%, 90%, 67%, and 47%, and OS was 100%, 90%, 74%, and 37%, for 0 to 1, 2, 3, and 4 to 5 IPI factors, respectively, at 5 years. The Bcl-2 and MIB-1 biomarkers were not associated with PFS or OS. Based on DA-EPOCH historical controls, rituximab only benefited Bcl-2 positive tumors. Bcl-6 expression was associated with higher PFS whereas GCB exhibited a marginally significant higher PFS compared with post-GCB DLBCL.

CONCLUSION

DA-EPOCH-R outcome was not affected by tumor proliferation and rituximab appeared to overcome the adverse effect of Bcl-2. Bcl-6 may identify a biologic program associated with a superior outcome. Overall, DA-EPOCH-R shows promising outcome in low and intermediate IPI groups. A molecular model of treatment outcome with rituximab and chemotherapy is presented.

Mycosis fungoides and Sézary syndrome

Mycosis fungoides and Sézary syndrome are the most common of the cutaneous T-cell lymphomas, which are a heterogeneous group of neoplasms that affect the skin as a primary site. Although the aetiologies of mycosis fungoides and Sézary syndrome are unknown, important insights have been gained in the immunological and genetic perturbations that are associated with these diseases. Unlike some B-cell lymphomas, cutaneous T-cell lymphomas as a group are rarely if ever curable and hence need chronic-disease management. New approaches to treatments are being investigated and include biological and cytotoxic drugs, phototherapy, and monoclonal antibodies that are directed towards novel molecular targets. New molecular technologies such as complementary-DNA microarray have the potential to increase the accuracy of diagnosis and provide important prognostic information. Treatments can be combined to greatly improve clinical outcome without substantially increasing toxic effects in advanced disease that is otherwise difficult to treat. Although present treatment strategies are generally not curative, there is hope that experimental treatments, particularly immunotherapy, might eventually reverse or suppress the abnormalities of mycosis fungoides and Sézary syndrome to the point at which they become non-life-threatening, chronic diseases.

Effective therapy of murine models of human leukemia and lymphoma with radiolabeled anti-CD30 antibody, HeFi-1

CD30 is a member of the TNF receptor superfamily. Overexpression of CD30 on some neoplasms versus limited expression on normal tissues makes this receptor a promising target for antibody-based therapy. Radioimmunotherapy of cancer with radiolabeled antibodies has shown promise. In this study, we evaluated the therapeutic efficacy of an anti-CD30 antibody, HeFi-1, armed with (211)At in a leukemia (karpas299) model and with (90)Y in a lymphoma (SUDHL-1) model. Furthermore, we investigated the combination therapy of (211)At-HeFi-1 with unmodified HeFi-1 in the leukemia model. Treatment with unmodified HeFi-1 significantly prolonged the survival of the karpas299-bearing mice compared with the controls (P < 0.001). Treatment with (211)At-HeFi-1 showed greater therapeutic efficacy than that with unmodified HeFi-1 as shown by survival of the mice (P < 0.001). Combining these two agents further improved the survival of the mice compared with the groups treated with either (211)At-HeFi-1 (P < 0.05) or unmodified HeFi-1 (P < 0.001) alone. In the lymphoma model, the survival of the SUDHL-1-bearing mice was significantly prolonged by the treatment with (90)Y-HeFi-1 compared with the controls (P < 0.001). In summary, radiolabeled HeFi-1 is very promising for the treatment of CD30-expressing leukemias and lymphomas, and the combination regimen of (211)At-HeFi-1 with unmodified HeFi-1 enhanced the therapeutic efficacy.

A pilot study of CTLA-4 blockade after cancer vaccine failure in patients with advanced malignancy

PURPOSE

Eleven patients with progressive advanced malignancy after administration of a cancer vaccine received a fully human anti-CTLA-4 monoclonal antibody (ipilimumab). The primary end point was to determine drug toxicity. Tumor response, tumor-specific CD8+ T-cell immune responses, and modulation of CD4+ CD25+ FoxP3+ regulatory T-cell (Treg) numbers were secondary end points.

EXPERIMENTAL DESIGN

Three patients with colon cancer, four with non-Hodgkin's lymphoma, and four with prostate cancer were treated. The first dose was given at 3 mg/kg and subsequent doses were administered monthly at 1.5 mg/kg for a total of four cycles.

RESULTS

Tumor regression was observed in two patients with lymphoma; one of which obtained a partial response of 14-month duration. Ipilimumab was well tolerated with predominantly grade 1/2 toxicities. One drug-related grade 3 toxicity was observed. One patient died within 30 days of treatment due to progressive colon cancer. No increase in vaccine-specific T-cell responses was observed after therapy. Tregs as detected by expression of CD4+CD25+CD62L+ declined at early time points but rebounded to levels at or above baseline values at the time of the next infusion.

CONCLUSIONS

Ipilimumab treatment depressed Treg numbers at early time points in the treatment cycle but was not accompanied by an increase in vaccine-specific CD8+ T-cell responses in these patients previously treated with a variety of investigational anticancer vaccines. A partial response was observed in one patient with follicular lymphoma. A phase I/II trial evaluating ipilimumab in patients with follicular lymphoma is currently ongoing.

Preclinical and phase I clinical trial of blockade of IL-15 using Mikbeta1 monoclonal antibody in T cell large granular lymphocyte leukemia

Twelve patients with T cell large granular lymphocyte leukemia and associated hematocytopenia were treated in a phase I dose-escalation trial with the murine monoclonal antibody Mikbeta1. Mikbeta1 identifies CD122, the beta-subunit shared by the IL-2 and IL-15 receptors. At the doses administered in this study the antibody inhibited the actions of IL-15 on both natural killer and T cells and that of IL-2 when the intermediate-affinity IL-2 receptor was expressed. Mikbeta1 treatment was not associated with significant toxicity or with the development of an immune response to the infused monoclonal antibody. At these doses of Mikbeta1, >95% saturation of the IL-2/IL-15beta receptor (CD122) on the surfaces of the leukemic cells was achieved. Furthermore, in seven patients this led to the down-modulation of the receptor from the surfaces of the leukemic cells. Nevertheless, no patients manifested a reduction in peripheral leukemic cell count or an amelioration of their hematocytopenia. This latter observation may reflect the fact that the monoclonal T cell large granular lymphocyte leukemia leukemic cells of the patients did not produce IL-2 or IL-15 or require their actions for cell survival. In light of the lack of toxicity and lack of immunogenicity of the antibody observed in the present study and the role for IL-15 in the pathogenesis of autoimmune diseases, clinical trials should be performed using the humanized version of Mikbeta1 in groups of patients with human T cell lymphotropic virus I-associated myelopathy/tropical spastic paraparesis, rheumatoid arthritis, multiple sclerosis and refractory celiac disease.

Vaccine-induced tumor-specific immunity despite severe B-cell depletion in mantle cell lymphoma

The role of B cells in T-cell priming is unclear, and the effects of B-cell depletion on immune responses to cancer vaccines are unknown. Although results from some mouse models suggest that B cells may inhibit induction of T cell-dependent immunity by competing with antigen-presenting cells for antigens, skewing T helper response toward a T helper 2 profile and/or inducing T-cell tolerance, results from others suggest that B cells are necessary for priming as well as generation of T-cell memory. We assessed immune responses to a well-characterized idiotype vaccine in individuals with severe B-cell depletion but normal T cells after CD20-specific antibody-based chemotherapy of mantle cell lymphoma in first remission. Humoral antigen- and tumor-specific responses were detectable but delayed, and they correlated with peripheral blood B-cell recovery. In contrast, vigorous CD4(+) and CD8(+) antitumor type I T-cell cytokine responses were induced in most individuals in the absence of circulating B cells. Analysis of relapsing tumors showed no mutations or change in expression of target antigen to explain escape from therapy. These results show that severe B-cell depletion does not impair T-cell priming in humans. Based on these results, it is justifiable to administer vaccines in the setting of B-cell depletion; however, vaccine boosts after B-cell recovery may be necessary for optimal humoral responses.

B-cell recovery following rituximab-based therapy is associated with perturbations in stromal derived factor-1 and granulocyte homeostasis

The occurrence of delayed neutropenia following rituximab is poorly defined and of unknown cause. We hypothesized it may be related to perturbations of stromal derived factor-1 (SDF-1) and granulocyte homeostasis. Late-onset neutropenia (LON) was investigated in 130 patients with untreated aggressive B-cell lymphoma receiving DA-EPOCH (dose-adjusted etoposide, prednisone, Oncovin [vincristine], cyclophosphamide, and hydroxydaunorubicin) chemotherapy with or without rituximab. All patients were in remission and had no known causes for neutropenia. LON occurred in 6 (8%) of 76 patients receiving rituximab and 0 of 54 patients not receiving rituximab (P = .04). The median onset was 175 days (range, 77-204 days) after treatment with a median duration of 14 days (range, 11-16 days). In a subset of 24 patients, a significant correlation was found between rapid B-cell recovery and granulocyte decline over the 6-month recovery period (R = -0.53; P = .04). Rapid B-cell recovery directly correlated with prerecovery SDF-1 levels (R = 0.65; P = .015) and SDF-1 decline (R = -0.67; P = .013) after recovery. Our results suggest that early B-cell lymphopoiesis is important for B-cell recovery following rituximab, and that perturbation of SDF-1 during B-cell recovery retards neutrophil egress from the bone marrow. These findings illustrate the dual role of SDF-1 in human B-cell and granulocyte homeostasis.

Vaccination by genetically modified dendritic cells expressing a truncated neu oncogene prevents development of breast cancer in transgenic mice

Dendritic cells (DCs) are powerful antigen-presenting cells that process antigens and present peptide epitopes in the context of the major histocompatibility complex molecules to generate immune responses. DCs are being studied as potential anticancer vaccines because of their ability to present antigens to naive T cells and to stimulate the expansion of antigen-specific T-cell populations. We investigated an antitumor vaccination using DCs modified by transfer of a nonsignaling neu oncogene, a homologue of human HER-2/neu, in a transgenic model of breast cancer. BALB-neuT mice develop breast cancers as a consequence of mammary gland-specific expression of an activated neu oncogene. We vaccinated BALB-neuT mice with bone marrow-derived DCs transduced with Ad.Neu, a recombinant adenovirus expressing a truncated neu oncoprotein. The vaccine stimulated the production of specific anti-neu antibodies, enhanced interferon-gamma expression by T cells, and prevented or delayed the onset of mammary carcinomas in the mice. Over 65% of vaccinated mice remained tumor free at 28 weeks of age, whereas all of the mice in the control groups developed tumors. When challenged with a neu-expressing breast cancer cell line, vaccinated tumor-free animals had delayed tumor growth compared with controls. The antitumor effect of the vaccine was specific for expression of neu. Studies showed that CD4+ T cells were required in order to generate antitumor immunity. Importantly, the effectiveness of the vaccine was not diminished by preexisting immunity to adenovirus, whereas the protection afforded by vaccination that used direct injection of Ad.Neu was markedly reduced in mice with anti-adenovirus antibody titers. DCs modified by recombinant adenoviruses expressing tumor-associated antigens may provide an effective antitumor vaccination strategy.

High incidence of occult leptomeningeal disease detected by flow cytometry in newly diagnosed aggressive B-cell lymphomas at risk for central nervous system involvement: the role of flow cytometry versus cytology

We assessed the cerebrospinal fluid (CSF) by flow cytometry and cytology in 51 newly diagnosed and 9 treated aggressive B-cell lymphomas at risk for central nervous system (CNS) involvement to examine the utility of flow cytometry, incidence of CSF disease, and clinical surrogates of CNS spread. Multicolor flow cytometry using multiple antibody panels for light chains and B- and T-cell antigens identified neoplastic clones that constituted as little as 0.2% of total CSF lymphocytes. Among 51 newly diagnosed patients, 11 (22%) had occult CSF involvement. All 11 were detected by flow cytometry but only 1 by cytology (P = .002). Among 9 treated patients, CSF involvement was detected by flow cytometry alone in 2 and also by cytology in 1 case. CSF chemistry and cell counts were similar in patients with and without CSF lymphoma. Only the number of extranodal sites was associated with occult CSF lymphoma in newly diagnosed patients by univariate (P = .006) or logistic regression analysis (P = .012). We hypothesize that the biologic phenotype associated with colonization of extranodal sites leads to CNS spread, possibly related to the microenvironment. Patients at risk for CNS spread should undergo staging CSF evaluation by flow cytometry.

Progress on new vaccine strategies for the immunotherapy and prevention of cancer

In recent years, great strides in understanding and regulating the immune system have led to new hope for harnessing its exquisite specificity to destroy cancer cells without affecting normal tissues. This review examines the fundamental immunologic advances and the novel vaccine strategies arising from these advances, as well as the early clinical trials studying new approaches to treat or prevent cancer.

Elevated serum-soluble interleukin-2 receptor levels in patients with anaplastic large cell lymphoma

Levels of serum soluble interleukin 2 receptor (sIL-2R) provide a reliable marker of disease activity in patients with hairy cell leukemia and adult T-cell leukemia/lymphoma. The malignant cells in patients with anaplastic large cell lymphoma (ALCL) express CD30 and are usually positive for expression of CD25. We measured serum sIL-2R and soluble CD30 (sCD30) levels in patients with ALCL treated with EPOCH (etoposide, prednisone, Oncovin, Cytoxan, hydroxydaunorubicin) infusional chemotherapy. Serum sCD30 levels were elevated and decreased in response to therapy as previously reported. Serum sIL-2R levels were elevated in 7 of 9 patients with ALCL and decreased in response to treatment. Baseline serum sIL-2R levels varied but correlated well with serum sCD30 levels (r = 0.97). Patients positive for the anaplastic lymphoma kinase (ALK) gene showed elevated sIL-2R levels, whereas those negative for ALK had normal serum sIL-2R levels and their tumors lacked CD25 expression. Serum sIL-2R levels were elevated in both patients with recurrent disease.

Short-stay open appendectomy

PURPOSE

This report describes a minimally invasive short-stay open appendectomy technique which improves the length of stay in comparison to traditional open appendectomy and improves the cost of hospitalization in comparison to laparoscopic appendectomy.

STUDY DESIGN

This retrospective analysis reviewed 100 consecutive children treated with traditional open appendectomy and 100 consecutive children treated with a minimally invasive short-stay open technique with local infiltration of bupivacaine hydrochloride. Data collected for each child included age, sex, diagnosis, operative time, return to activity time, complications, length of stay, and hospital charge.

RESULTS

The mean length of stay (LOS) was reduced from 2.7 days for traditional open appendectomy patients to 1.0 day for minimally invasive short-stay open appendectomy. The mean hospital charge (HC) for this short-stay open appendectomy, US dollars 6795, was significantly less than the mean HC for traditional open appendectomy (US dollars 8162), and for laparoscopic appendectomy (US dollars 7668).

CONCLUSION

This short-stay open appendectomy technique offers an efficacious alternative to both traditional open appendectomy and laparoscopic appendectomy.

Common expression of an unusual CD45 isoform on T cells from patients with large granular lymphocyte leukaemia and autoimmune lymphoproliferative syndrome

Patients with T-cell large granular lymphocyte (T-LGL) leukaemia and autoimmune lymphoproliferative syndrome (ALPS) share many features, including autoimmunity and an expansion of (cytotoxic) T cells, which in ALPS patients express an unusual (B220) isoform of CD45, corresponding to an altered O-glycosylation profile. Here we showed that T-LGL leukaemia cells also expressed this B220 isoform. We hypothesize that B220+ T cells constitute proliferating T cells that have become competent to undergo apoptosis, but that constitutive (ALPS) or functional (T-LGL) defects prevent this process. Altered O-glycosylation of the extracellular domains of CD45 may have consequences for this tyrosine phosphatase as a regulator of cell proliferation and survival.