Novel small-molecule therapy of Hodgkin lymphoma

Clinical Options in Relapsed or Refractory Hodgkin Lymphoma: An Updated Review

Hodgkin lymphoma (HL) is a potentially curable lymphoma, and modern therapy is expected to successfully cure more than 80% of the patients. Second-line salvage high-dose chemotherapy and autologous stem cell transplantation (auto-SCT) have an established role in the management of refractory and relapsed HL, leading to long-lasting responses in approximately 50% of relapsed patients and a minority of refractory patients. Patients progressing after intensive treatments, such as auto-SCT, have a very poor outcome. Allogeneic SCT represents the only strategy with a curative potential for these patients; however, its role is controversial. Based on recent knowledge of HL pathology, biology, and immunology, antibody-drug conjugates targeting CD30, small molecule inhibitors of cell signaling, and antibodies that inhibit immune checkpoints are currently explored. This review will discuss the clinical results regarding auto-SCT and allo-SCT as well as the current role of emerging new treatment strategies.

Radioimmunotherapy with Tenarad, a 131I-labelled antibody fragment targeting the extra-domain A1 of tenascin-C, in patients with refractory Hodgkin's lymphoma

PURPOSE

The extra-domain A1 of tenascin-C (TC-A1) is highly expressed in the extracellular matrix of tumours and on newly formed blood vessels and is thus a valuable target for radionuclide therapy. Tenarad is a fully human miniantibody or small immunoprotein (SIP, molecular weight 80 kDa) labelled with (131)I that is derived from a TC-A1-binding antibody. Previous phase I/II studies with a similar compound ((131)I-L19SIP) used for radioimmunotherapy (RIT) have shown preliminary efficacy in a variety of cancer types. In this ongoing phase I/II trial, Tenarad was administered to patients with recurrent Hodgkin's lymphoma (HL) refractory to conventional treatments.

METHODS

Eight patients (four men, four women; age range 19 - 41) were enrolled between April 2010 and March 2011. All patients had received a median of three previous lines of chemotherapy (range three to six) and seven had also undergone autologous stem cell transplantation (ASCT) or bone marrow transplantation. In addition, seven patients received external beam radiation. All patients had nodal disease, constitutional B symptoms and some showed extranodal disease in skeletal bone (four patients), lung (three), liver (two) and spleen (one). Baseline assessments included whole-body FDG PET with contrast-enhanced CT and diagnostic Tenarad planar and SPECT studies. Patients were considered eligible to receive a therapeutic dose of Tenarad (2.05 GBq/m(2)) if tumour uptake was more than four times higher than that of muscle.

RESULTS

All patients were eligible and received the therapeutic dose of Tenarad. Only one patient developed grade 4 thrombocytopenia and leucocytopenia, requiring hospitalization and therapeutic intervention. All other patients had haematological toxicity of grade 3 or lower, which resolved spontaneously. At the first response assessment (4 - 6 weeks after therapy), one patient showed a complete response, one showed a partial response (PR) and five had disease stabilization (SD). Five patients were given up to three repeated Tenarad treatments. One patient showed SD which then improved to a PR, three showed clinical benefit while maintaining SD and one patient showed disease progression.

CONCLUSION

Tenarad RIT is effective in chemorefractory HL and resulted in objective responses or clinical benefit in the majority of patients. Toxicity was acceptable despite the high load of prior treatments, previous ASCT and multiple Tenarad administrations. Further studies are planned to define the most effective schedule for this type of RIT in HL patients.

Lestaurtinib inhibition of the Jak/STAT signaling pathway in hodgkin lymphoma inhibits proliferation and induces apoptosis

Standard cytotoxic chemotherapy for Hodgkin Lymphoma (HL) has changed little in 30 years; the treatment for patients with relapsed or refractory disease remains challenging and novel agents are under development. JAK/STAT constitutive activation plays an important role in the pathogenesis of HL. Lestaurtinib is an orally bioavailable multikinase inhibitor that has recently been shown to inhibit JAK2 in myeloproliferative disorders. The potential role of Lestaurtinib in HL therapy is unknown. We have analyzed the effect of Lestaurtinib treatment in five HL cell lines from refractory patients, L-428, L-1236, L-540, HDML-2 and HD-MY-Z. At 48 h, a dose-dependent cell growth inhibition (23%–66% at 300 nM) and apoptotic increment (10%–64% at 300 nM) were observed. Moreover, Lestaurtinib inhibited JAK2, STAT5 and STAT3 phosphorylation and reduced the mRNA expression of its downstream antiapoptotic target Bcl-xL. In addition, we have analyzed the effect of Lestaurtinib treatment in lymph nodes from four classic HL patients. We observed a decrease in cell viability at 24 hours of treatment in three patients (mean decrease of 27% at 300 nM). Our findings provide, for the first time, a molecular rationale for testing JAK2 inhibitors, specifically Lestaurtinib, in HL patients.

Novel treatment strategies for patients with relapsed classical Hodgkin lymphoma

The treatment of patients with relapsed and refractory Hodgkin lymphoma (HL), especially those who relapse after autologous stem cell transplantation, remains challenging. Patients with HL whose disease relapses after stem cell transplantation are rarely cured with current treatment modalities, and have a median survival of less than 3 years. Since no new drugs have been approved by the FDA for HL in more than three decades, there is a clear unmet medical need for drug development for this patient population. New treatment strategies that are based on targeting oncogenic signaling pathways are currently explored. This review will focus on emerging new treatment modalities that are currently under investigation for patients with relapsed classical HL.

Molecular biology of Hodgkin lymphoma

Hodgkin lymphoma (HL) is derived from mature B cells and subdivided into classical HL and nodular lymphocyte predominant HL (NLPHL). HL is unique among human B cell lymphomas because of the rarity of the lymphoma cells, the Hodgkin and Reed-Sternberg (HRS) cells in classical HL and the lymphocyte-predominant (LP) cells in NLPHL, which usually account for 0.1% to 10% of the cells in the affected tissues. Moreover, HRS cells are unique in the extent to which they have lost their B cell-typical gene expression pattern. Deregulation of transcription factor networks plays a key role in this reprogramming process. HRS cells show strong constitutive activity of the transcription factor NF-kappaB. Multiple mechanisms likely contribute to this deregulated activation, including signaling through particular receptors and genetic lesions. Inactivating mutations in the TNFAIP3 tumor suppressor gene, encoding a negative regulator of NF-kappaB activity, were recently identified in about 40% of patients with classical HL. HRS cells are latently infected by Epstein-Barr virus in about 40% of patients, and an important role of this virus in HL pathogenesis-in particular for cases in which HRS cells had lost the capacity to express a B-cell receptor due to destructive somatic mutation-was recently substantiated.

Novel treatment strategies for patients with relapsed classical Hodgkin lymphoma

Although classical Hodgkin lymphoma (HL) is considered one of the most curable human cancers, the treatment of patients with relapsed and refractory disease, especially those who relapse after autologous stem cell transplantation, remains challenging. Furthermore, because the median age of the patients is in the mid-30s, the impact of early mortality on the number of years lost from productive life is remarkable. Patients with HL whose disease relapses after stem cell transplantation are rarely cured with current treatment modalities. New drugs and novel treatment strategies that are based on our understanding of the disease biology and signaling pathways are needed to improve treatment outcome for these patients. This review will focus on emerging new treatment modalities that are currently under investigation for patients with relapsed classical HL.