Background: Primary refractory disease (PRD) and early relapse (ER) are predictors of poor prognosis in classic Hodgkin lymphoma (cHL). In this multicenter retrospective study, we describe outcomes of PRD and ER in pts with relapsed/refractory (R/R) cHL treated with salvage therapy (ST) and autologous stem cell transplant (ASCT). Methods: Of 14 sites, adult patients with R/R cHL who received ST and underwent ASCT were enrolled. PRD was defined as progression on frontline chemoimmunotherapy or within 6 months of diagnosis. ER was defined as relapse from 6 months-1 yr of diagnosis. Pts who relapsed >1 yr of diagnosis were called late relapses (LR). Study objectives were Overall response rates (ORR), CR rates, PFS, and OS. Results: Of 986 total pts, 160 had PRD, 365 had ER and 461 had LR. Significantly higher number of pts with PRD, but not ER, had bulky disease (41% vs 27%, p<0.01) and B symptoms (53% vs 38%, p<0.001) than LR. Higher proportions of pts with PRD and ER required >1 line of ST (44% vs 30% vs 23%, p<0.001) before ASCT and received BV maintenance (25% vs 24% vs 16%, p<0.05). When adjusted for B symptoms and Bulky disease, PRD and ER had significantly lower ORR (65% vs 76% vs 84%, p<0.001) and CR (37% vs 46% vs 57%, p<0.001) to first ST than LR. Pts with PRD and ER had significantly lower PFS (56.3%, 61.4%, vs 77.6%, p<.0001) and OS (93% vs 89% vs 94%, p=0.01) than LR. In pts with ER, Brentuximab/bendamustine (BBV) and brentuximab vedotin/nivolumab (BV/nivo) had a trend towards higher ORR (92% vs 92% vs 75%) but significantly higher CR (79.2% vs 76% vs 42%, p<0.01) than platinum based chemotherapy (PBC). In pts with PRD, BBV and BV/Nivo had a statistically insignificant trend towards higher ORR and CR than PBC. The table shows 2 yr PFS by type of ST in PRD, ER, LR. There was no difference in PFS by time to relapse in BV/nivo, CPI and miscellaneous agents. BV/Nivo had a significantly higher PFS than PBC in PRD (88% vs 48%, p<0.05) and ER (95% vs 57%, p<0.05). There was no difference in PFS of PBC and other ST in PRD, ER or LR. OS was not significantly associated with type of ST in either group. Conclusions: PRD and ER are associated with lower response to ST and survival after ASCT compared to late relapse. In pts with PRD and ER, BV/Nivo has high ORR and CR and leads to significantly higher PFS comparable to pts with late relapse and may be preferable ST regardless of time to relapse.

BV; brentuximab vedotin, CPI; checkpoint inhibitors, Gem; gemcitabine-based therapy, NS; not significant, P; p value, CI₉₅; 95% confidence interval.