Real-World Experience of PD-1 Inhibitors for Relapsed and Refractory Hodgkin Lymphoma: A Multicenter Retrospective Analysis of Patients in China

INTRODUCTION

Despite the promising clinical trial data regarding programmed death 1 (PD-1) inhibitors in relapsed/refractory classical Hodgkin lymphoma (R/R cHL), there remains a paucity of studies describing the outcomes of patients in a real-world setting, especially for Asian cohort.

METHODS

We present a multicenter retrospective analysis of patients with R/R cHL who had failed ≥2 prior lines of therapies and received sintilimab or tislelizumab developed in China (sintilimab or tislelizumab monotherapy) at 3 medical centers from January 2019 to September 2021. Efficacy was evaluated with progression-free survival (PFS), overall survival, duration of response (DOR), best overall response (BOR) including objective response rate (ORR), complete response rate (CRR). Safety data were also recorded.

RESULTS

74 patients were reviewed. The median age was 38 years (range, 14-85 years). The ORR, CRR, and disease control rate were 78.3%, 52.7%, and 91.9%, respectively. The median duration of follow-up was 22 (4-36) months. Four patients (5.4%) died of disease progression. The median PFS and DOR was 22.1 and 23.5 months. BOR as a new emergent endpoint was found to be the only independent prognostic factor for PFS in our study (HR = 6.234, p = 0.005), suggesting this endpoint carries stronger prognostic value over traditional endpoints in the immunotherapy era. 66 (89.2%) patients reported adverse event (AE) with any grade, with the majority of AEs being grade 1 or 2.

CONCLUSION

We presented a unique real-life experience and conducted a relatively long follow-up of PD-1 antibodies developed in China for R/R HL patients which confirmed their promising effectiveness and manageable side effects given in real world in an Asian cohort. Even for those who would usually be excluded in most of clinical trials such as elderly or minor patients, anti-PD-1 monotherapy also showed a significant improvement of outcomes. Furthermore, the depth of response seemed to be a more powerful predictive tool in new era, which might serve as a basis for future immune risk-adapted strategies.

Treatment of classical Hodgkin lymphoma in the era of brentuximab vedotin and immune checkpoint inhibitors

The majority of Hodgkin lymphoma patients are now cured with conventional first-line therapy; however, 10-15% of early-stage disease and less than 30% of advanced-stage patients are refractory(rare) or relapsed. Salvage second-line therapy combined with high-dose therapy and autologous stem-cell transplantation can cure 40-50% of patients. Recently novel agents (Brentuximab Vedotin and Immune Checkpoint inhibitors) have demonstrated evidence of therapeutic activity and are potential bridge to an allogeneic stem-cell transplantation. The review is aimed to present not only salvage strategies; indeed, the paper contains paragraphs about therapy and new treatment options at diagnosis.

Where Do the New Drugs Fit in for Relapsed/Refractory Hodgkin Lymphoma?

The standard approach for relapsed or refractory (rel/ref) Hodgkin lymphoma (HL) following frontline treatment failure is salvage therapy followed by consolidation with high-dose therapy and autologous stem cell transplant (HDT/ASCT). While this overall treatment paradigm has been in place for several decades, recent studies have aimed to improve the efficacy and tolerability of salvage therapies by incorporating newer drugs, such as brentuximab vedotin (BV) and checkpoint inhibitors. Following HDT/ASCT, survival is improved due to the availability of BV and the checkpoint inhibitors, nivolumab and pembrolizumab; however, for patients responding to checkpoint inhibition, the appropriate length of treatment and the role of allogeneic stem cell transplant are unclear. In this review, we discuss our management of rel/ref HL, with particular focus on how BV, nivolumab, and pembrolizumab are currently incorporated into the treatment paradigms for rel/ref HL.

Real-world effectiveness of brentuximab vedotin versus physicians' choice chemotherapy in patients with relapsed/refractory Hodgkin lymphoma following autologous stem cell transplantation in the United Kingdom and Germany

This retrospective study compared effectiveness of (brentuximab vedotin) BV to other chemotherapies in patients with rrHL following an autologous stem cell transplant (ASCT). Data originated from a medical chart review of patients treated in real-world clinical settings at 50 sites in the United Kingdom and Germany. Inverse probability of treatment weights based on propensity scores were used to adjust for differences in baseline characteristics between treatment groups. Among 312 rrHL patients included, 196 received BV and 116 received physicians' choice chemotherapy. Median PFS was significantly longer (27.0 months vs. 13.4 months; p = .0144) and 12-month OS survival greater (78.1% vs. 65.9%; p = .0129) with BV compared to chemotherapy. Documented adverse events included leukopenia (12.8%) and peripheral neuropathy (8.7%) for BV and leukopenia (12.1%), anemia (5.2%) and diarrhea (5.2%) for chemotherapy. In this real-world study, rrHL patients treated for relapse after ASCT with BV had longer median PFS and 12-month OS than patients receiving chemotherapy.