Where does brentuximab vedotin fit into the management of patients with Hodgkin lymphoma?

A new TROP2-targeting antibody-drug conjugate shows potent antitumor efficacy in breast and lung cancers

Trophoblast cell surface antigen 2 (Trop2) is considered to be an attractive therapeutic target in cancer treatments. We previously generated a new humanized anti-Trop2 antibody named hIMB1636, and designated it as an ideal targeting carrier for cancer therapy. Lidamycin (LDM) is a new antitumor antibiotic, containing an active enediyne chromophore (AE) and a noncovalently bound apoprotein (LDP). AE and LDP can be separated and reassembled, and the reassembled LDM possesses cytotoxicity similar to that of native LDM; this has made LDM attractive in the preparation of gene-engineering drugs. We herein firstly prepared a new fusion protein hIMB1636-LDP composed of hIMB1636 and LDP by genetic engineering. This construct showed potent binding activities to recombinant antigen with a KD value of 4.57 nM, exhibited binding to Trop2-positive cancer cells and internalization and transport to lysosomes, and demonstrated powerful tumor-targeting ability in vivo. We then obtained the antibody-drug conjugate (ADC) hIMB1636-LDP-AE by molecular reconstitution. In vitro, hIMB1636-LDP-AE inhibited the proliferation, migration, and tumorsphere formation of tumor cells with half-maximal inhibitory concentration (IC50) values at the sub-nanomolar level. Mechanistically, hIMB1636-LDP-AE induced apoptosis and cell-cycle arrest. In vivo, hIMB1636-LDP-AE also inhibited the growth of breast and lung cancers in xenograft models. Moreover, compared to sacituzumab govitecan, hIMB1636-LDP-AE showed more potent antitumor activity and significantly lower myelotoxicity in tumors with moderate Trop2 expression. This study fully revealed the potent antitumor efficacy of hIMB1636-LDP-AE, and also provided a new preparation method for LDM-based ADC, as well as a promising candidate for breast cancer and lung cancer therapeutics.

Brentuximab vedotin in association with bendamustine in refractory or multiple relapsed Hodgkin lymphoma. A retrospective real-world study

OBJECTIVE AND METHODS

In order to assess the efficacy of brentuximab vedotin (Bv) in combination with bendamustine (B) in multiple relapsed or refractory (RR) classic Hodgkin lymphoma (cHL), medical records of 47 patients treated with BvB in second relapse or beyond were reviewed.

RESULTS

The median number of previous treatments was 2 (1-4). Bv was given at 1.8 mg/kg on day 1 and bendamustine at 90 mg/m² on days 1 and 2 of a 21-day cycle. The median number of BvB cycles was 4 (2-7), and all patients were evaluable for efficacy. The CR and OR rates were 49% and 79%, respectively; 67% of responding patients and 2 in stable disease proceeded to a SCT procedure. After a median follow-up of 19 months (5-47), median PFS was 18 months (95%CI: 23-29), and the 2-year OS was 72%. Significantly longer PFS and OS were observed in patients attaining a major clinical response to treatment and in those who received consolidation with SCT. Fifteen (32%) patients experienced severe (G > 2) toxicity. The main toxicities were neutropenia (23%), gastrointestinal (10%), peripheral sensory neuropathy (11%), and infection (4%).

CONCLUSION

Our real-world results suggest that BvB is an effective third-line rescue and bridge-to-transplant regimen for RR-cHL patients.

Treatment and outcomes in classic Hodgkin lymphoma post-transplant lymphoproliferative disorder in children

Classic Hodgkin lymphoma post-transplant lymphoproliferative disorder (HL-PTLD) has been rarely reported in children, with limited data available to guide treatment decisions. We report a retrospective review of five children diagnosed with classic HL-PTLD following solid organ transplant between 2007 and 2013 at Stanford University. Patients were treated with Stanford V chemotherapy and involved field radiation therapy. With a median follow-up of 7.2 years (range, 4.7-10.5 years) since diagnosis, all patients remain in remission from HL-PTLD and free from graft failure. In this series, combined modality therapy with risk-adapted chemotherapy and radiation therapy was a successful strategy for the treatment of classic HL-PTLD.

Immune off-target effects of Brentuximab Vedotin in relapsed/refractory Hodgkin Lymphoma

Hodgkin Lymphoma (HL) is associated with deep microenvironment re-shaping and myeloid dysfunction. Given that only limited data are available regarding the role of Brentuximab Vedotin (BV) as single agent in transplant-naive relapsed/refractory (R/R) patients and its off-target effects on immune system, we evaluated the amount of regulatory T-cells (T-regs), myeloid-derived suppressor cells (MDSC) subpopulations, and their functional marker, serum arginase-1 (s-Arg-1), in peripheral blood of 15 consecutive R/R HL patients. After a median of four BV cycles, the overall response rate (complete response + partial response) was 47%, with 4 (27%) complete metabolic remissions. BV reduced the absolute number of three MDSC subtypes and s-Arg-1 levels. Patients with baseline s-Arg-1 ≥200 ng/ml had inferior progression-free survival at 36 months compared to those with low s-Arg-1. T-regs dysfunction was recovered by BV: absolute T-regs count was increased after treatment with BV, independently of metabolic response achieved, with a significant reduction of CD30⁺ T-regs. Our data disclose off-target effects of BV in the microenvironment that could explain its deep and durable clinical efficacy.

Classical Hodgkin's lymphoma: the Lymphoma Study Association guidelines for relapsed and refractory adult patients eligible for transplant

The Hodgkin's Lymphoma Committee of the Lymphoma Study Association (LYSA) gathered in 2012 to prepare guidelines on the management of transplant-eligible patients with relapsing or refractory Hodgkin's lymphoma. The working group is made up of a multidisciplinary panel of experts with a significant background in Hodgkin's lymphoma. Each member of the panel of experts provided an interpretation of the evidence and a systematic approach to obtain consensus was used. Grades of recommendation were not required since levels of evidence are mainly based on phase II trials or standard practice. Data arising from randomized trials are emphasized. The final version was endorsed by the scientific council of the LYSA. The expert panel recommends a risk-adapted strategy (conventional treatment, or single/double transplantation and/or radiotherapy) based on three risk factors at progression (primary refractory disease, remission duration < 1 year, stage III/IV), and an early evaluation of salvage chemosensitivity, including (18)fluorodeoxy glucose-positron emission tomography interpreted according to the Deauville scoring system. Most relapsed or refractory Hodgkin's lymphoma patients chemosensitive to salvage should receive high-dose therapy and autologous stem-cell transplantation as standard. Efforts should be made to increase the proportion of chemosensitive patients by alternating non-cross-resistant chemotherapy lines or exploring the role of novel drugs.

Role of brentuximab vedotin in the treatment of relapsed or refractory Hodgkin lymphoma

Brentuximab vedotin (BV) is an antibody-drug conjugate that targets CD30-positive malignancies via an anti-CD30 monoclonal antibody linked to monomethyl auristatin E, a microtubule-disrupting agent, by a protease-cleavable linker. BV has received accelerated approval from the US Food and Drug Administration for the treatment of classical Hodgkin lymphoma that has relapsed either after autologous stem cell transplantation (ASCT) or after two lines of combination chemotherapy in patients ineligible for ASCT, and in systemic anaplastic large cell lymphoma after failure of at least one line of multiagent chemotherapy. Phase I studies in CD30-positive lymphomas have determined the maximum tolerated dose to be 1.8 mg/kg intravenously every 21 days. In relapsed/refractory Hodgkin lymphoma, a pivotal Phase II study of single-agent BV showed an overall response rate of 75%, with 34% complete responses and a median remission duration of 20 months for complete responders. BV has a modest toxicity profile, with peripheral neuropathy as one of the most clinically significant side effects, and this is largely reversible. Therefore, BV is the treatment of choice for patients with relapsed/refractory Hodgkin lymphoma after ASCT or two standard regimens. Ongoing trials are evaluating the role of BV as salvage therapy prior to ASCT and for maintenance after ASCT for patients with relapsed/refractory disease.