Evaluating pembrolizumab for patients with reoccurring classical Hodgkin’s lymphoma

This study evaluated the safety and effectiveness of pembrolizumab (Keytruda) for patients with classical Hodgkin’s lymphoma (cHL) that came back after initial treatment. This study concluded that pembrolizumab was effective for these patients, with manageable side effects.

First-line chemotherapy is highly effective in treating 70 – 80% of patients with cHL. Stem cell transplantation (SCT) is usually the next step for patients whose cancer returns or stops responding to treatment. Another 10% of patients respond to SCT. However, patients whose disease does not respond to SCT have limited treatment options.

PD-1 inhibitors are a new treatment option for these patients. Pembrolizumab (Keytruda) is a PD-1 inhibitor. It is a type of targeted immunotherapy that binds to cancer cells to help the body’s immune system attack the cancer. This leads to cancer cell death. Whether pembrolizumab is safe and effective for patients with cHL that came back after initial treatment is unclear.

This study had 210 patients who experienced tumor growth or spread (disease progression) after initial treatment. Patients were divided into three groups based on previous treatment. 69 patients had SCT, followed by brentuximab vedotin (Adcetris) treatment. 81 patients received chemotherapy and brentuximab vedotin. 60 patients had SCT only. Patients were followed-up for an average of 27.6 months.

Overall, 71.9% of all patients responded to treatment. 44.3% of patients had tumor shrinkage. 27.6% of patients had no signs of cancer after treatment (complete response). Of these, 84.5% had a complete response after at least 6 months of treatment.

On average, 100% of patients who had a complete response were still alive two years later. 91.1% of patients who had tumor shrinkage were still alive two years later. Patients who had tumor shrinkage survived for an average of 13.8 months after treatment without disease progression.

Overall, 72.9% of all patients had side effects. Most side effects (60.9%) were mild. 12.0% of patients reported serious side effects. The most common ones were seriously low white blood cell count (5 patients, 2.4%) and diarrhea (3 patients, 1.4%). 6.7% of all patients stopped treatment due to side effects.

This study concluded that pembrolizumab was effective for patients with cHL that has come back after initial treatment, with manageable side effects.

This study had a short follow-up time. Larger studies with a longer follow-up are needed to confirm these results.