In a nutshell
This study looked at the effect of pembrolizumab (Keytruda) to treat classical Hodgkin lymphoma (cHL) which had relapsed after previous treatments including brentuximab vedotin (Adcetris). It found that pembrolizumab was effective for these patients.
Some background
cHL is typically treated with chemotherapy, and sometimes with radiation therapy. If the cHL relapses (returns) after this initial treatment, the next treatment is stem cell transplant (SCT). For patients who cannot use this treatment or whose cancer relapses after SCT, brentuximab vedotin (BV) is an option. BV uses an antibody to deliver chemotherapy directly to cHL cancer cells. Antibodies are molecules used by the immune system which can target a specific compound, much like a key fits a specific lock. It can be more difficult to treat patients whose cHL relapses after BV.
Pembrolizumab is used to treat patients whose cHL has relapsed after BV. Pembrolizumab is also an antibody therapy, which blocks the PD-1 protein. This protein causes white blood cells to become less active. However, cancers including cHL can use the PD-1 protein to evade the immune system. Pembrolizumab helps the immune system to correctly attack cancer cells. It is unclear what the long-term outcomes of pembrolizumab are for relapsed cHL.
Methods & findings
This study included 31 patients with relapsed cHL. Patients had received five previous treatments on average, and all had previously received BV. Patients were not fit for a SCT were refused this treatment. The patients were treated with pembrolizumab and followed for 52.8 months on average.
58% of the patients responded to pembrolizumab. Six patients (19%) had a complete remission, meaning the cancer could no longer be detected. Patients went an average of 11.4 months before the cHL progressed (worsened). Among patients who responded to treatment, 70% responded for at least 12 months and 50% responded for more than 36 months. 9 patients who responded to treatment went on to have a stem cell transplant. Overall survival at 3 years was 81%.
The most common side effects were diarrhea (23%), low thyroid functioning (13%), and nausea (13%). 19% of patients had a serious side effect.
The bottom line
This study found that a majority of patients with relapsed cHL responded to pembrolizumab.
The fine print
This study was not able to determine how stem cell transplant affected outcomes for patients who responded to pembrolizumab. This study was supported by Merck, the manufacturer of pembrolizumab.
Published By :
Blood advances
Date :
Jun 23, 2020