Current Selection Patterns, Toxicities and Outcomes of Pre-Transplant Salvage Treatment Regimens in Patients with Relapsed/Refractory Hodgkin Lymphoma: Results of a Multicenter Retrospective Analysis
Authors: Svoboda Jakub , Ballard Hatcher J. , Bair Steven M. , Banerjee Rahul , Andreadis Charalambos , Feldman Tatyana A. , McCarthy Elizabeth L. , Khan Niloufer , Moskowitz Alison J. , Orellana-Noia Victor M. , Portell Craig A. , Nagle Sarah J. , Dwivedy Nasta Sunita , Landsburg Daniel J. , Barta Stefan K. , Chong Elise A. , Schuster Stephen J 
Published: November 2019

Background: Treatment strategies for patients (pts) with relapsed/refractory (RR) classical Hodgkin lymphoma (cHL) continue to evolve as brentuximab vedotin (BV) and immune checkpoint inhibitors are utilized in pre-transplant salvage regimens. These new approaches are based on promising results of non-randomized trials, but it is not clear how they perform outside of clinical studies. We aimed to investigate selection patterns, toxicities, and outcomes of salvage regimens prior stem cell transplant (SCT) used currently in the United States for pts with RR cHL in the non-trial setting.
Methods: We conducted a multisite, retrospective study of pts with RR cHL who were treated with a first salvage regimen (salvage 1) with intent to proceed to SCT within the past 5 years. Only pts who were treated outside of a clinical trial with salvage 1 were included. Responses were based on treating physician assessment using Revised Response Criteria for Malignant Lymphoma (Cheson et al, JCO 2014). Kaplan Meier survival curves were generated using STATA 15.0 software.
Results: We identified 160 pts with diagnosis of RR cHL from 6 U.S. centers who received salvage 1 in the non-trial setting between January 2013 and January 2018. The pts' characteristics are described in Table 1. Both primary refractory pts (41%) and those with relapsed disease (59%) were included. The most common salvage 1 regimen for RR cHL was ifosfamide, carboplatin, etoposide (ICE) in 68% followed by BV monotherapy (14%) and BV+bendamustine (9%). Only 1 pt (1%) received immune checkpoint inhibitor. There were no statistically significant factors that would increase likelihood of receiving BV-containing salvage 1 including primary refractory status, age, and advanced stage. In the cohort of 59 pts who required more than one line of salvage therapy, the most common second salvage regimen (salvage 2) was BV monotherapy (42%), followed by various BV-containing combinations (22%), and ICE (19%). Only 14% of pts received 3 or more lines of salvage therapy prior to SCT. Out of 107 pts who received ICE as salvage 1, 33% were administered second salvage while out of 35 pts who received BV-containing regimen as salvage 1, 53% required salvage 2 (X2=4.7, p=0.03). Of 148 pts who ultimately underwent SCT, 52% were exposed to BV and 12% to an immune checkpoint inhibitor as part of any salvage regimen at some point prior to SCT.
Response assessment to salvage 1 were available for 154 pts; 47% pts achieved complete response (CR), 30% partial response (PR), and 19% had progressive disease (PD). The responses to specific salvage 1 regimens are summarized in Table 2. For those pts undergoing salvage 2, 48% achieved CR, 19% PR and 30% had PD. Radiation was administered to 11% of pts at any point of salvage treatment prior SCT.
In terms of toxicities, there were no deaths attributed to complications from any of the salvage therapies. When compared to ICE, pts undergoing BV or BV+bendamustine as salvage 1 had lower risk of neutropenic fever (0% vs 7%) and GI toxicities (10% vs 18%), but had higher risk of experiencing peripheral neuropathy (5% vs 15%).
Out of 148 pts who ultimately underwent SCT, the majority had autologous (96%) and 6 (4%) pts had allogeneic SCT. The majority (73%) of patients were in CR immediately prior SCT. Four pts (3%) died due to SCT-related toxicities. BV maintenance was used in 35% of pts. Exposure to BV during salvage 1 prior SCT did not affect the likelihood of receiving BV maintenance.
While there was no statistically significant difference in progression free survival (PFS) between chemotherapy only and BV-containing salvage 1, there was a trend toward improved PFS with BV-containing salvage 1 as shown in Figure 1. The 2-year PFS for chemotherapy only salvage 1 was 71% (95% CI: 60-79%) vs. 80% (95% CI: 60-91%) for BV-containing salvage treatments.
Conclusion: Growing number of salvage regimens are used in RR cHL. In the current practice outside of clinical trials, 23% of RR cHL pts received BV during salvage 1. In total, 37% received more than one salvage treatment and 52% received BV as part of salvage therapy prior SCT. It is unlikely that a prospective randomized trial will be conducted to compare various salvage treatment options. However, further analysis of sub-populations who may benefit from a particular regimen or optimal treatment sequences may lead to more effective and less toxic treatment strategies for pts with RR cHL.

Disclosures
Svoboda: Seattle Genetics: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Merck: Research Funding; Incyte: Research Funding; Pharmacyclics: Consultancy, Research Funding; AstraZeneca: Consultancy; Celgene: Research Funding; Kyowa: Consultancy; Kite: Consultancy. Andreadis:Genentech: Equity Ownership, Other: Spouse is Employee; Novartis: Honoraria, Research Funding; Amgen: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Gilead: Consultancy; Jazz Pharmaceuticals: Consultancy; Bayer: Consultancy. Feldman:Portola Pharma: Research Funding; Eisai: Research Funding; Kyowa Hakko Kirin: Research Funding; Janssen: Honoraria, Speakers Bureau; Pharmacyclics: Honoraria, Other: Travel expenses, Speakers Bureau; AbbVie: Honoraria, Other: Travel expenses, Speakers Bureau; Roche: Research Funding; Viracta: Research Funding; Trillium: Research Funding; Pfizer: Research Funding; Seattle Genetics: Consultancy, Honoraria, Other: Travel expenses, Speakers Bureau; Kite Pharma: Honoraria, Other: Travel expenses, Speakers Bureau; Bayer: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Amgen: Research Funding; Corvus: Research Funding; Roche: Research Funding; Cell Medica: Research Funding; Takeda: Honoraria, Speakers Bureau; Celgene: Honoraria, Research Funding, Speakers Bureau. Khan:Back Bay Life Science Advisors: Honoraria; ASCO/Conquer Cancer Foundation sponsored by Gilead Sciences: Research Funding. Moskowitz:ADC Therapeutics: Consultancy; Cell Medica: Consultancy; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Takeda Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Takeda Pharmaceuticals: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Cell Medica: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Incyte: Research Funding; Cell Medica: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Merck: Research Funding; Merck: Research Funding; ADC Therapeutics: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Cell Medica: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; ADC Therapeutics: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; Merck: Research Funding; Merck: Research Funding; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; ADC Therapeutics: Consultancy; Incyte: Research Funding; Cell Medica: Consultancy; Takeda Pharmaceuticals: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Incyte: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Cell Medica: Consultancy; miRagen Therapeutics Inc: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Incyte: Research Funding; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; ADC Therapeutics: Consultancy; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; Erytech Pharma: Consultancy; Merck: Research Funding; Incyte: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Cell Medica: Consultancy; Takeda Pharmaceuticals: Consultancy; Takeda Pharmaceuticals: Consultancy; Cell Medica: Consultancy; Incyte: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Takeda Pharmaceuticals: Consultancy; Merck: Research Funding; Merck: Research Funding; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Erytech Pharma: Consultancy; Seattle Genetics: Consultancy, Honoraria, Research Funding; Merck: Research Funding; Merck: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Cell Medica: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Erytech Pharma: Consultancy; Takeda Pharmaceuticals: Consultancy; Bristol-Myers Squibb: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Cell Medica: Consultancy; Cell Medica: Consultancy; Incyte: Research Funding; Incyte: Research Funding; Cell Medica: Consultancy; ADC Therapeutics: Consultancy; Incyte: Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Merck: Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; miRagen Therapeutics Inc: Consultancy, Research Funding; Takeda Pharmaceuticals: Consultancy; Kyowa Hakko Kirin Pharma: Consultancy, Research Funding; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; ADC Therapeutics: Consultancy; Incyte: Research Funding; Takeda Pharmaceuticals: Consultancy; Incyte: Research Funding; Incyte: Research Funding; Seattle Genetics: Consultancy, Honoraria, Research Funding. Portell:Roche/Genentech: Research Funding; Xencor: Research Funding; TG Therapeutics: Research Funding; Acerta/AstraZeneca: Research Funding; Kite: Consultancy, Research Funding; BeiGene: Consultancy, Research Funding; Bayer: Consultancy; Amgen: Consultancy; Genentech: Consultancy, Research Funding; Janssen: Consultancy; Pharmacyclics: Consultancy; AbbVie: Research Funding; Infinity: Research Funding. Dwivedy Nasta:Merck: Consultancy, Other: data safety monitorin; 47 (Forty Seven): Research Funding; Roche: Research Funding; Rafael: Research Funding; Debiopharm: Research Funding; Aileron: Research Funding; ATARA: Research Funding; Pharmacyclics: Research Funding; Celgene: Honoraria; Millenium/takeda: Research Funding. Landsburg:Takeda: Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Curis, INC: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Curis, INC: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Seattle Genetics: Speakers Bureau; Seattle Genetics: Speakers Bureau; Takeda: Research Funding; Triphase: Research Funding; Triphase: Research Funding. Barta:Mundipharma: Honoraria; Seattle Genetics: Honoraria, Research Funding; Takeda: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding; Mundipharma: Honoraria; Bayer: Consultancy, Research Funding; Merck: Research Funding; Celgene: Research Funding; Janssen: Membership on an entity's Board of Directors or advisory committees. Chong:Tessa: Consultancy; Merck: Research Funding; Novartis: Consultancy. Schuster:Acerta: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria; Nordic Nanovector: Consultancy, Honoraria; Genentech: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding; Gilead: Consultancy, Honoraria, Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Loxo Oncology: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Celgene: Consultancy, Honoraria, Research Funding; Novartis: Honoraria, Patents & Royalties: Combination CAR-T and PD-1 Inhibitors, Research Funding.

OffLabel Disclosure:
Brentaximab vedotin containing salvage in Hodgkin lymphoma