Comparison of Novel Salvage Regimens and Traditional salvage Chemotherapy in Relapsed and Refractory Classic Hodgkin Lymphoma
Novel agents such as brentuximab vedotin (BV) and check-point inhibitors (CPIs) have high response rates in patients with relapsed/refractory (r/r) classical Hodgkin Lymphoma (cHL) and have recently been used as salvage regimens to induce remissions before autologous stem cell transplant (ASCT). Our aim was to compare the outcomes of pts receiving salvage chemotherapy (CT) as opposed to novel treatments (NT) for their first salvage regimen for r/r cHL since limiting data exists regarding their efficacy.
Adult pts with r/r cHL who received their first salvage regimen (SR1) between January 2018 and June 2020 were retrospectively identified. Endpoints were to compare complete response (CR), overall response rate (ORR), and event free survival (EFS) between the CT and NT cohorts.
120 pts were identified with a median age of 33 years (range 18-85). 68% had advanced disease and 13% were early stage unfavorable at diagnosis. Many pts had poor prognostic characteristics including 43% with primary refractory disease, 52% with relapse <12 months from diagnosis, 38% with extranodal disease, and 26% with B-symptoms at time of relapse (Table 1).
65% of pts (n=78) received CT and 35% (n=42) received NT for SR1. 90% of CT pts received Ifosfamide, Carboplatin, and Etoposide (ICE) as SR1. Regimens used for NT treated pts included BV + Bendamustine (43%), BV alone (36%), BV + CPI (12%), BV + CT (5%), and other CPI (4%). No significant difference was found in the ORR and CR rates according to pts treated with CT vs. NT of 67% vs. 69% and 47% vs. 55%, respectively. 88% of those who received CT for SR1 and 83% of those who received NT for SR1, eventually had ASCT. At a median follow-up of 32 months, 1-year EFS was 57% vs 69% and 2-year EFS was 56% vs 66% between CT and NT cohorts (p=0.25) (Figure 1).
All pts who progressed after CT for SR1 (n=31) received NT for SR2; whereas 73% (n=11) of those progressing after NT for SR1 received CT for SR2. ORR for CT in SR2 was 91% vs 70% for NT (p=.48). 79% vs 89% remained progression-free post-ASCT at their last follow-up after receiving CT vs. NT at last salvage before ASCT respectively (p=0.15).
There was a numerical trend towards better CR and EFS for novel therapy compared to traditional chemotherapy for first salvage, however the outcomes were not statistically significant, demonstrating that chemotherapy is still a valid option for salvage before ASCT.