Targeted treatment and new agents in peripheral T-cell lymphoma

Humanized CD7 nanobody-based immunotoxins exhibit promising anti-T-cell acute lymphoblastic leukemia potential

BACKGROUND

Nanobodies, named as VHHs (variable domain of heavy chain of HCAb [heavy-chain antibodies]), are derived from heavy-chain-only antibodies that circulate in sera of camelids. Their exceptional physicochemical properties, possibility of humanization, and unique antigen recognition properties make them excellent candidates for targeted delivery of biologically active components, including immunotoxins. In our previous efforts, we have successfully generated the monovalent and bivalent CD7 nanobody-based immunotoxins, which can effectively trigger the apoptosis of CD7-positive malignant cells. To pursue the possibility of translating those immunotoxins into clinics, we humanized the nanobody sequences (designated as dhuVHH6) as well as further truncated the Pseudomonas exotoxin A (PE)-derived PE38 toxin to produce a more protease-resistant form, which is named as PE-LR, by deleting majority of PE domain II.

METHODS AND RESULTS

Three new types of immunotoxins, dhuVHH6-PE38, dVHH6-PE-LR, and dhuVHH6-PE-LR, were successfully constructed. These recombinant immunotoxins were expressed in Escherichia coli and showed that nanobody immunotoxins have the benefits of easy soluble expression in a prokaryotic expression system. Flow cytometry results revealed that all immunotoxins still maintained the ability to bind specifically to CD7-positive T lymphocyte strains without binding to CD7-negative control cells. Laser scanning confocal microscopy revealed that these proteins can be endocytosed into the cytoplasm after binding with CD7-positive cells and that this phenomenon was not observed in CD7-negative cells. WST-8 experiments showed that all immunotoxins retained the highly effective and specific growth inhibition activity in CD7-positive cell lines and primary T-cell acute lymphoblastic leukemia (T-ALL) cells. Further in vivo animal model experiments showed that humanized dhuVHH6-PE38 immunotoxin can tolerate higher doses and extend the survival of NOD-Prkdcem26Il2rgem26Nju (NCG) mice transplanted with CEM cells without any obvious decrease in body weight. Further studies on NCG mice model with patient-derived T-ALL cells, dhuVHH6-PE38 treatment, significantly prolonged mice survival with ~40% survival improvement. However, it was also noticed that although dhuVHH6-PE-LR showed strong antitumor effect in vitro, its in vivo antitumor efficacy was disappointing.

CONCLUSION

We have successfully constructed a targeted CD7 molecule-modified nanobody (CD7 molecule-improved nanobody) immunotoxin dhuVHH6-PE38 and demonstrated its potential for treating CD7-positive malignant tumors, especially T-cell acute lymphoblastic leukemia.

Gemcitabine, dexamethasone, and cisplatin (GDP) as salvage chemotherapy for patients with relapsed or refractory peripheral T cell lymphoma-not otherwise specified

Standard therapeutic options for patients with relapsed or refractory peripheral T cell lymphoma-not otherwise specified (PTCL-NOS) remain unclear. There are few large cohort studies specifically focused on gemcitabine-based chemotherapy for PTCL-NOS. We retrospectively reviewed patients with relapsed or refractory PTCL-NOS who received salvage GDP (gemcitabine, dexamethasone, and cisplatin) chemotherapy at the Cancer Hospital, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing, China, from May 2008 to August 2014. Twenty-five patients were enrolled and analyzed. The median number of cycles of GDP chemotherapy per patient was four (range, 2-8 cycles). Overall response rate was 64.0% (16/25) with five achieved complete remission or complete remission unconfirmed. After a median follow-up of 9 months, median overall survival (OS) and progression-free survival after relapse or progression (second-PFS) were 9.3 and 5.4 months. One-year PFS rate and 1-year OS rate were 27.4% and 43.9%, respectively. Median second-PFS was significantly longer in patients sensitive to GDP than the ones resistant to the treatment (10.3 vs. 2.8 months, p < .01). In addition, the low International Prognostic Index, low Prognostic Index for T cell lymphoma, or normal level of LDH in serum was associated with favorable prognosis. Grade 3/4 adverse effect was observed in 10 of 25 patients treated with GDP including neutropenia (8/25), thrombocytopenia (5/25), and anemia (4/25). Taken together, our study suggests that GDP is an effective and optional salvage regimen for relapsed or refractory PTCL-NOS.

Histone deacetylase inhibitors and epigenetic regulation in lymphoid malignancies

A vast majority of lymphomas and leukaemias are results of translocations. These translocations produce various genetic and epigenetic changes that lead to oncogenesis. This opens an opportunity to use a relatively new class of anti-cancer agents, inhibitors of histone deacetylases (HDACi) to target lymphoid malignancies. Surprisingly, the rational basis for treatment of lymphomas with HDACi is far from clear, although some positive results have been obtained. Here we analyze the effect of histone deacetylase (HDAC) inhibitors on lymphoid malignancies.

Belinostat in patients with refractory or relapsed peripheral T-cell lymphoma: a perspective review

Peripheral T-cell lymphoma (PTCL) is a disease with poor prognosis and limited treatment options. Recent advances in cancer biology suggest that PTCL may be characterized by gross epigenetic dysregulation, which may help explain its sensitivity to histone deacetylase (HDAC) inhibitors. HDAC inhibitors have demonstrated significant activity in T-cell neoplasms and recently, the BELIEF trial evaluated belinostat leading to its approval in the US. This review discusses the development of belinostat, its mechanism of action, pivotal clinical trials, drug toxicity and its recent approval for patients with relapsed or refractory PTCL. Key clinical trials covered include phase I/II evaluation of belinostat in hematologic malignancies, cutaneous T-cell lymphoma (CTCL) and PTCL. In addition, the BELIEF trial in PTCL leading to FDA approval of belinostat is reviewed in detail.

The combination of hypomethylating agents and histone deacetylase inhibitors produce marked synergy in preclinical models of T-cell lymphoma

T-cell lymphomas (TCL) are aggressive lymphomas usually treated with CHOP (cyclophsophamide, doxorubicin, vincristine, prednisolone)-like regimens upfront. Recent data suggest that TCL are driven by epigenetic defects, potentially rendering them sensitive to epigenetic therapies. We explored the therapeutic merits of a combined epigenetic platform using histone deacetylase inhibitors (HDACIs) and DNA methyltransferase inhibitors (DNMT) in in vitro and in vivo models of TCL. The 50% inhibitory concentration (IC50 ) values revealed romidepsin was the most potent HDACI, with an IC50 in the low nanomolar range. The combination with a hypomethylating agent produced synergy across all cell lines, which was confirmed in cytotoxicity and apoptosis assays. An in vivo xenograft study demonstrated inhibition of tumour growth in the combination cohort compared to the single agent. Gene expression array and global methylation profiling revealed differentially expressed genes and modulated pathways for each of the single treatment conditions and the combination. Most of the effects induced by the single agent treatment were maintained in the combination group. In total, 944 unique genes were modulated by the combination treatment, supporting the hypothesis of molecular synergism. These data suggest combinations of hypomethylating agents and HDACIs are synergistic in models of TCL, which is supported at the molecular level.

Mogamulizumab and the treatment of CCR4-positive T-cell lymphomas

Glyco-engineering has been developed to enhance the pharmacological properties of monoclonal antibodies (mAbs) resulting in superior immune effector function. Mogamulizumab is the first approved glyco-engineered therapeutic antibody and first approved mAb to target the CC chemokine receptor 4 (CCR4). CCR4 is principally expressed on Tregs and helper T cells (Th) where it functions to induce homing of these leukocytes to sites of inflammation. Tregs play an essential role in maintaining immune balance; however, in malignancy, Tregs impair host antitumor immunity and provide a favorable environment for tumors to grow. CCR4 is highly expressed by aggressive peripheral T-cell lymphomas (PTCLs), particularly adult T-cell leukemia/lymphoma (ATL) and cutaneous T-cell lymphomas (CTCLs). Mogamulizumab is a humanized anti-CCR4 mAb with a defucosylated Fc region that enhances antibody-dependent cellular cytotoxicity (ADCC). In addition, mogamulizumab depletes CCR4+ Tregs, potentially evoking antitumor immune responses by autologous effector cells. This ability is highly pertinent as subsets of malignant T cells are believed to function as CD4+ Tregs, overexpressing CCR4. Clinical trials with mogamulizumab have demonstrated clinical efficacy and tolerability for the treatment of relapsed/refractory aggressive T-cell lymphomas, previously associated with very poor outcomes.

Correlation of BAG-3 and heat shock protein 70 with CD30 expression in T-cell lymphomas

T-cell lymphomas are aggressive lymphomas with decreased prognosis and resistance to therapy. BAG-3 and heat shock protein 70 (HSP70) function in chemotherapeutic resistance and cellular survival. Expression of BAG-3 has not been investigated in T cell lymphomas. We investigated fifty cases including benign, systemic and cutaneous T cell lymphomas. Benign T cells were negative for BAG-3 and HSP70 immunohistochemical staining. BAG-3 expression correlated with increased HSP70 expression in a subset of systemic T cell lymphoma cases co-expressing the CD30 antigen. Correlation between BAG-3, HSP70 and CD30 expression was not seen in cutaneous T cell lymphoma cases. However, these cases showed a significant increase in BAG-3 staining when compared to CD30 negative systemic T cell lymphoma cases. The differential protein expression profile of BAG-3 and HSP70 may indicate a specific role for these proteins and the ubiquitin-proteasome system/autophagy in T cell lymphomas which may help guide future targeted therapy.

Noninvasive phosphorus magnetic resonance spectroscopic imaging predicts outcome to first-line chemotherapy in newly diagnosed patients with diffuse large B-cell lymphoma

RATIONALE AND OBJECTIVES

Based on their association with malignant proliferation, using noninvasive phosphorus MR spectroscopic imaging ((31)P MRSI), we measured the tumor content of the phospholipid-related phosphomonoesters (PME), phosphoethanolamine and phospholcholine, and its correlation with treatment outcome in newly diagnosed patients with diffuse large B-cell lymphoma (DLBCL) receiving standard first-line chemotherapy.

EXPERIMENTAL DESIGN

The PME value normalized to nucleoside triphosphates (PME/NTP) was measured using (31)P MRSI in tumor masses of 20 patients with DLBCL before receiving standard first-line chemotherapy. Response at 6 months was complete in 13 patients and partial in seven. Time to treatment failure (TTF) was ≤11 months in eight patients, from 18 to 30 months in three, and ≥60 months in nine.

RESULTS

On a t test, the pretreatment tumor PME/NTP mean value (SD, n) of patients with a complete response at 6 months was 1.42 (0.41, 13), which was significantly different from the value of 2.46 (0.40, 7) in patients with partial response (P < .00001). A Fisher test significantly correlated the PME/NTP values with response at 6 months (sensitivity and specificity at 0.85, P < .004) while a Cox proportional hazards regression significantly correlated the PME/NTP values with TTF (hazard ratio = 5.21, P < .02). A Kaplan-Meier test set apart a group entirely composed of patients with TTF ≤ 11 months (hazard ratio = 8.66, P < .00001).

CONCLUSIONS

The pretreatment tumor PME/NTP values correlated with response to treatment at 6 months and time to treatment failure in newly diagnosed patients with DLBCL treated with first-line chemotherapy, and therefore they could be used to predict treatment outcome in these patients.

Allogeneic stem cell transplantation with BEAM and alemtuzumab conditioning immediately after remission induction has curative potential in advanced T-cell non-Hodgkin's lymphoma

Patients with relapsed or refractory advanced T cell non-Hodgkin lymphoma have a dismal prognosis and may not even reach allogeneic hematopoietic stem cell transplantation (HSCT) in adequate condition. We present the outcome of 24 consecutive patients (age range 11 to 65 years) treated at a single institution in Kiel within a recent 5.5-year time frame with allogeneic HSCT in a rather uniform approach. Relapsed and refractory T and natural killer cell lymphomas of various subtypes were included. All patients except 1 were in progression or relapse before start of pretransplantation salvage therapy. Five patients had relapsed after autologous HSCT. With intensive remission induction therapy, usually the CLAEG (cladribine, cytosine arabinoside, and etoposide with granulocyte colony-stimulating factor support) protocol, attempts were made to improve disease control and proceed immediately to conditioning with carmustine, etoposide, cytosine arabinoside, melphalan (BEAM), and medium-dose alemtuzumab. Twenty of 21 patients who received CLAEG induction therapy benefited from this protocol and 1 patient appeared to be therapy-resistant. At the time of allogeneic HSCT, 9 patients were in complete remission (CR) (2 in CR1, 5 in CR2, and 2 in CR >2), whereas 50% had never achieved CR. Nineteen transplants were obtained from matched or partially matched unrelated donors and only 5 from siblings. With a median follow-up of 321 days (1252 days for surviving patients), 20 of 22 assessable patients reached CR. Five of these patients had hematologic or molecular relapse. With donor lymphocyte infusions, 1 patient became minimal residual disease MRD negative again and has maintained CR for more than 4 years. The frequency of grades II to IV acute graft-versus-host disease was 25% and chronic graft-versus-host disease, 30%. Intense reinduction therapy followed by reduced-intensity BEAM-alemtuzumab conditioning and allogeneic HSCT is effective and offers curative potential for patients with advanced T cell lymphomas, even for those not in remission.

Very long-lasting remission of refractory T-large granular lymphocytes leukemia and myeloma by lenalidomide treatment

BACKGROUND

Large granular lymphocyte leukemias (LGLLs) represent a spectrum of biologically distinct lymphoproliferative diseases originating from either mature T cells (CD3+) or natural killer (NK) cells (CD3-). Both T-cell and NK-cell LGL leukemia can manifest as indolent or aggressive neoplasia. These rare lymphoproliferative disorders are often associated with autoimmune diseases and impaired hematopoiesis. Symptomatic patients are treated with immunosuppressive drugs. The co-association of T-LGLL with clonal B-cell disorders is reported in more than 10% of patients.

CASE PRESENTATION

We describe the case of a 57-yr-old white male patient with no history of autoimmune disorders, with refractory T-LGLL and myeloma who was treated with bortezomib and subsequently with lenalidomide. After 30 months of on-going lenalidomide therapy, the patient is in partial remission from myeloma and in continuous complete hematological remission from T-LGLL.

CONCLUSIONS

As far as we know, this is the first report of a patient with refractory T-LGLL treated with bortezomib and lenalidomide. As refractory T-LGLL is a challenging condition, we think that lenalidomide and bortezomib deserve further investigation.

Gemcitabine, oxaliplatin and dexamethasone as salvage treatment for elderly patients with refractory and relapsed peripheral T-cell lymphoma

The development of a more effective and less toxic salvage regimen remains a major challenge in elderly patients with relapsed and/or refractory peripheral T-cell lymphoma (PTCL). From April 2004 to May 2010, we used a new salvage regimen combining gemcitabine, oxaliplatin and dexamethasone (GemOD) in 24 elderly patients with relapsed (n = 11) or refractory (n = 13) PTCL unsuitable for high dose therapy. GemOD consisted of gemcitabine (1000 mg/m(2) on day 1), oxaliplatin (100 mg/m(2) on day 1) and dexamethasone (20 mg/day from day 1 to day 4), which was given every 3 weeks. Patients were scheduled to receive up to six courses of GemOD therapy unless there was evidence of progressive disease. The median number of GemOD courses delivered was four (range 3-6). After three courses of GemOD, the overall response rate (ORR) was 38%, with two complete responses (CRs) and seven partial responses (PRs). Among 11 patients who received three additional planned courses of therapy, there were three CRs and three PRs, for an ORR of 25% after complete treatment as per the study protocol. With a median follow-up of 18 months, the median overall survival (OS) and event-free survival (EFS) reached 14 and 10 months, respectively. Hematologic and non-hematologic toxicities were moderate in all patients. We conclude that the GemOD regimen can be administered safely and effectively in elderly patients with relapsed and refractory PTCL who are ineligible for high dose chemotherapy with stem cell transplant.

Antitumor activities of valproic acid on Epstein-Barr virus-associated T and natural killer lymphoma cells

Epstein-Barr virus (EBV), which infects B cells, T cells, and natural killer (NK) cells, is associated with multiple lymphoid malignancies. Recently, histone deacetylase (HDAC) inhibitors have been reported to have anticancer effects against various tumor cells. In the present study, we evaluated the killing effect of valproic acid (VPA), which acts as an HDAC inhibitor, on EBV-positive and -negative T and NK lymphoma cells. Treatment of multiple T and NK cell lines (SNT13, SNT16, Jurkat, SNK6, KAI3 and KHYG1) with 0.1-5 mM of VPA inhibited HDAC, increased acetylated histone levels and reduced cell viability. No significant differences were seen between EBV-positive and -negative cell lines. Although VPA induced apoptosis in some T and NK cell lines (SNT16, Jurkat and KHYG1) and cell cycle arrest, it did not induce lytic infection in EBV-positive T or NK cell lines. Because the killing effect of VPA was modest (1 mM VPA reduced cell viability by between 22% and 56%), we tested the effects of the combination of 1 mM of VPA and 0.01 μM of the proteasome inhibitor bortezomib. The combined treated of cells with VPA and bortezomib had an additive killing effect. Finally, we administered VPA to peripheral blood mononuclear cells from three patients with EBV-associated T or NK lymphoproliferative diseases. In these studies, VPA had a greater killing effect against EBV-infected cells than uninfected cells, and the effect was increased when VPA was combined with bortezomib. These results indicate that VPA has antitumor effects on T and NK lymphoma cells and that VPA and bortezomib may have synergistic effects, irrespective of the presence of EBV.

Peripheral T-cell lymphoma, not otherwise specified: a report of 340 cases from the International Peripheral T-cell Lymphoma Project

The International Peripheral T-cell Lymphoma Project is a collaborative effort to better understand peripheral T-cell lymphoma (PTCL). A total of 22 institutions submitted clinical and pathologic material on 1314 cases. One objective was to analyze the clinical and pathologic features of 340 cases of PTCL, not otherwise specified. The median age of the patients was 60 years, and the majority (69%) presented with advanced stage disease. Most patients (87%) presented with nodal disease, but extranodal disease was present in 62%. The 5-year overall survival was 32%, and the 5-year failure-free survival was only 20%. The majority of patients (80%) were treated with combination chemotherapy that included an anthracycline, but there was no survival advantage. The International Prognostic Index (IPI) was predictive of both overall survival and failure-free survival (P < .001). Multivariate analysis of clinical and pathologic prognostic factors, respectively, when controlling for the IPI, identified bulky disease (≥ 10 cm), thrombocytopenia (< 150 × 109/L), and a high number of transformed tumor cells (> 70%) as adverse predictors of survival, but only the latter was significant in final analysis. Thus, the IPI and a single pathologic feature could be used to stratify patients with PTCL-not otherwise specified for novel and risk-adapted therapies.