Advances in the treatment of Hodgkin lymphoma: Current and future approaches

New England Journal of Medicine, 372(4), 311-319

Classical Hodgkin lymphoma (cHL) and mediastinal large B-cell lymphoma (MLBCL) are lymphoid malignancies with certain shared clinical, histologic, and molecular features. Primary cHLs and MLBCLs include variable numbers of malignant cells within an inflammatory infiltrate, suggesting that these tumors escape immune surveillance. Herein, we integrate high-resolution copy number data with transcriptional profiles and identify the immunoregulatory genes, PD-L1 and PD-L2, as key targets at the 9p24.1 amplification peak in HL and MLBCL cell lines. We extend these findings to laser-capture microdissected primary Hodgkin Reed-Sternberg cells and primary MLBCLs and find that programmed cell death-1 (PD-1) ligand/9p24.1 amplification is restricted to nodular sclerosing HL, the cHL subtype most closely related to MLBCL. Using quantitative immunohistochemical methods, we document the association between 9p24.1 copy number and PD-1 ligand expression in primary tumors. In cHL and MLBCL, the extended 9p24.1 amplification region also included the Janus kinase 2 (JAK2) locus. Of note, JAK2 amplification increased protein expression and activity, specifically induced PD-1 ligand transcription and enhanced sensitivity to JAK2 inhibition. Therefore, 9p24.1 amplification is a disease-specific structural alteration that increases both the gene dosage of PD-1 ligands and their induction by JAK2, defining the PD-1 pathway and JAK2 as complementary rational therapeutic targets.

Background Malignant cells of classical Hodgkin lymphoma (cHL) are characterised by genetic alterations at the 9p24·1 locus. This leads to overexpression of the programmed death 1 (PD-1) ligands and enables tumour cells to evade immune surveillance. A phase 1b study showed that nivolumab, a PD-1-blocking antibody, produced a high response rate in patients with relapsed and refractory cHL, with an acceptable safety profile. This phase 2 study assessed the clinical benefit of nivolumab monotherapy in patients with cHL after autologous stem-cell transplantation and brentuximab vedotin failure. Methods This ongoing phase 2 study (NCT02181738) assessed the efficacy and safety of nivolumab, administered intravenously over 60 minutes at 3 mg/kg every 2 weeks, in adult patients with cHL who had failed both autologous stem-cell transplantation and brentuximab vedotin. The primary endpoint was objective response rate by independent radiologic review committee (IRRC) assessment. Secondary and other endpoints included duration of response, safety, and assessment of PD-L1 and PD-L2 loci and PD-L1 and PD-L2 protein expression. Findings Among 80 treated patients, the median number of prior therapies was four (range 3–15). With a mean (SD) follow-up of 8·6 months (2·02), objective response rate per IRRC was 66·3% (53/80). The most common drug-related adverse events (≥15%) included fatigue, infusion-related reaction, and rash. The most common drug-related grade 3–4 adverse events were neutropenia and increased lipase levels (both n=4). The most common serious adverse event (any grade) was pyrexia (n=3). Interpretation Nivolumab demonstrated a high response rate and an acceptable safety profile in patients with cHL who progressed following autologous stem-cell transplantation and brentuximab vedotin. Nivolumab may therefore provide a novel treatment option for a patient population with a high unmet need. Ongoing follow-up will help to assess the durability of response. Funding Bristol-Myers Squibb.