by Dr. C.H. Weaver M.D. Medical Editor, updated 11/2019
Individuals who fail initial treatment for Hodgkin's lymphoma (HL) remain curable using high dose chemotherapy (HDC) and autologous stem cell transplantation (ASCT), CAR T cells, and precision cancer medicines. The current dilemma is how best to use these therapies?
Patients with relapsed or recurrent HL can be divided into two broad categories. Patients who fail to achieve an initial complete disappearance or remission of their cancer following a complete course of chemotherapy treatment are referred to as “induction failures.” Other patients achieve a complete remission to initial treatment and later experience a cancer recurrence. These patients are said to have relapsed or recurrent HL. Relapse of HL may occur several months to years after the initial remission; however, the majority of relapses occur within 2 years of initial treatment. (1)
Historically, patients with recurrent HL were treated with additional chemotherapy using drugs to which the patient had not been previously exposed and or radiation therapy. Treatment of relapsed patients with several cycles of “salvage” chemotherapy produces a complete disappearance or remission of cancer in 30%-40% of patients and as many as 20% survive without an additional cancer relapse. (1)
In the 1990’s it was demonstrated that HDC and ASCT cured more patients with recurrent HL compared to conventional “salvage” chemotherapy and HDC became the standard treatment for the majority of patients with relapsed HL. (2,3,4)
The basic strategy uses higher doses of chemotherapy, which kills more cancer cells than lower doses. Unfortunately, the higher doses of therapy used to destroy cancer cells also damages normal cells. The body’s normal cells that are most sensitive to destruction by HDC are the blood-producing “stem: cells in the bone marrow. To “rescue” the bone marrow and hasten blood cell production and immune system recovery, HDC is followed by an infusion of autologous stem cells collected from the patient prior to administering the HDC.
The ASCT process was developed more than 40 years ago and the individuals responsible for its advancement were awarded the Nobel Prize for Medicine in 1990. Over the last few decades the hospital length of stay has been reduced to one to two weeks and the risk associated with the HDC and ASCT and not that much different than those from standard chemotherapy. (4,5)
Researchers from the Royal Marsden Hospital have reported long-term data including 195 patients with recurrent HL who received an ASCT between 1985 and 2005. (6)
- 61% of patients achieved a complete disappearance of cancer.
- The median survival was nine years.
- Median progression-free survival was three years.
- Five- and 10-year overall survivals were 55% and 49%, respectively.
- 10% of patients developed a second cancer, the most of which were acute myeloid leukemia or myelodysplastic syndromes.
Adcetris (brentuximab vedotin)
Adcetris is a precision cancer medicine that targets a protein known as CD30, which is present on HL cells. Adcetris attaches to and enters CD30-positive cells where it releases the potent chemotherapy drug monomethyl auristatin E. Adcetris when combined with chemotherapy has become the standard initial treatment for advanced HL and appears to improve the outcome of HDC and ASCT as well. (7,8,9)
Adcetris and PET-Adapted Salvage Therapy in Relapsed/Refractory HL
Patients with relapsed/refractory HL are typically treated with a few cycles of chemotherapy prior to ASCT. This is often achieved with a regimen called ICE (ifosfamide, carboplatin, etoposide), which is highly toxic. Pre-transplant positron-emission tomography (PET) normalization is one of the strongest predictors of outcome following ASCT.
Researchers sought to avoid pretransplant ICE by utilizing Adcetris with the goal of normalizing the PET. In a small trial 46 patients with relapsed/refractory HL received two cycles of weekly Adcetris followed by PET imaging. Patients who achieved normalization of their PET proceeded directly to ASCT while those who did not received two cycles of augmented ICE. The complete response rate was 80% after Adcetris with or without ICE, and 30% of patients were able to avoid ICE salvage therapy altogether and proceed straight to ASCT. (9)
Radiation Treatment of Relapsed Hodgkin’s Lymphoma
Radiation therapy can be used with curative or palliative intent for recurrences. If the recurrences are localized and can be encompassed within a tolerable field of radiation, good results can be achieved. More often, patients with recurrent HL receive radiation for palliation of local symptoms.
Strategies to Improve Treatment
The progress that has been made in the treatment of relapsed Hodgkin’s lymphoma has resulted from the development of high-dose chemotherapy regimens, new treatment strategies and their evaluation in clinical trials. Currently, there are several areas of active exploration aimed at improving the treatment of Hodgkin’s lymphoma.
Post-ASCT Adcetris®: The use of post ASCT maintenance therapy with Adcetris® significantly delays cancer progression and prolongs survival according to the results of the AETHERA clinical trial.
Doctors performing ASCT had long theorized that administration of targeted therapy following ASCT that could be helpful by eradicating any residual lymphoma cells and might improve cure rates achieved with HDC and ASCT alone.
The AETHERA clinical trial was designed to evaluate whether Adcetris® could improve the outcome of HL patients undergoing ASCT. In this trial 329 patients who had either achieved remission or had stable disease at time of ASCT were treated with either Adcetris® or placebo for up to 1 year after ASCT and directly compared.
Post ASCT Adcetris® delayed the time to cancer progression; at 2 years 63% of HL patients who were treated with the drug survived without lymphoma progression compared to only 51% of patients who received placebo. The average time to cancer progression was 43 months for Adcetris® treated patients compared to 24 months for those on placebo resulting in a 43% reduction in risk of disease progression.
Overall survival was similar in both groups at 2 years based on interim analysis, and this was most likely because patients treated with placebo were allowed to cross over and receive Adcetris® when their HL progressed. (8)
CAR T Cells: The use of a patient’s own immune cells to fight cancer through a technique called CART therapy, is proving to be a promising therapeutic approach in the treatment of some lymphomas. Learn about CAR T here:
Immunotherapy: Keytruda® is a monoclonal antibody that helps to restore the body’s immune system in fighting cancer. It creates its anti-cancer effects by blocking a specific protein used by cancer cells called PD-L1, to escape an attack by the immune system. Once PD-L1 is blocked, cells of the immune system are able to identify cancer cells as a threat and initiate an attack to destroy the cancer. Keytruda® was approved for the treatment of recurrent HL based on data in 210 patients from the KEYNOTE-087 trial, which demonstrated an overall response rate of 69 percent with a complete remission rate of 22 percent and a partial remission rate of 47 percent. The median follow-up time was 9.4 months. Among the 145 responding patients, the median duration of response was 11.1 months. (2)
New Chemotherapy Regimens: Development of new multi-drug chemotherapy treatment regimens that incorporate new or additional anti-cancer therapies for use as treatment is an active area of clinical research carried out in phase II clinical trials in patients with relapsed or recurrent lymphoma.
- Arella C, Cuttica A, Vitolo U, et al.: High-dose sequential chemotherapy and peripheral blood progenitor cell autografting in patients with refractory and/or recurrent Hodgkin lymphoma: a multicenter study of the intergruppo Italiano Linfomi showing prolonged disease free survival in patients treated at first recurrence. Cancer 97 (11): 2748-59, 2003.
- Schmitz N, Pfistner B, Sextro M, et al.: Aggressive conventional chemotherapy compared with high-dose chemotherapy with autologous haemopoietic stem-cell transplantation for relapsed chemosensitive Hodgkin's disease: a randomised trial. Lancet 359 (9323): 2065-71, 2002.
- Rancea M, Monsef I, von Tresckow B, et al.: High-dose chemotherapy followed by autologous stem cell transplantation for patients with relapsed/refractory Hodgkin lymphoma. Cochrane Database Syst Rev 6: CD009411, 2013.
- Sirohi B, Cunningham D, Powles R, et al. Long-term outcome of autologous stem-cell transplantation in relapsed or refractory Hodgkin’s lymphoma. Annals of Oncology. 2008;19:1312-1319.
- Moskowitz C, Nadamanee A, Masszi T, et al. The Aethera Trial: Results of a Randomized, Double-Blind, Placebo-Controlled Phase 3 Study of Brentuximab Vedotin in the Treatment of Patients at Risk of Progression Following Autologous Stem Cell Transplant for Hodgkin Lymphoma. Presented at the 56th Annual Meeting of the American Society of Hematology, December 6-9, 2014. Abstract 673.
- Moskowitz CH, Nademanee A, Masszi T, et al. Brentuximab vedotin as consolidation therapy after autologous stem-cell transplantation in patients with Hodgkin’s lymphoma at risk of relapse or progression (AETHERA): a randomised, double-blind, placebo-controlled, phase 3 trial. The Lancet [online publication]. March 18, 2015.
- Moskowitz AJ, Schoder H, Gerecitano J, et al: PET adapted sequential salvage therapy with brentuximab vedotin and augmented ICE for transplant eligible patients with relapsed and refractory Hodgkin lymphoma. 9th International Symposium on Hodgkin Lymphoma. Abstract T128. Presented October 15, 2013.