Evaluating low-dose pembrolizumab and nivolumab for relapsed or refractory classical Hodgkin lymphoma.

This trial was carried out to examine the effectiveness and safety profile of pembrolizumab (Keytruda) and nivolumab (Opdivo) for the treatment of classical Hodgkin lymphoma (cHL) that has relapsed and is refractory (resistant to drug treatment). The authors found that low-dose pembrolizumab and nivolumab were highly effective and safe in these patients.

cHL may be treated with a combination of chemotherapy, radiation therapy, and stem cell transplant. Despite existing treatment options cHL that is relapsing or refractory remains difficult to treat. 

Nivolumab and pembrolizumab are anti-PD1 antibodies (immune proteins) that have been approved to treat this form of cHL. PD1 is a protein that is found in high numbers on cancer cells and can stop the immune system from killing cancerous cells. Currently, the effectiveness and safety profile for nivolumab and pembrolizumab has not been assessed in patients with relapsed and refractory cHL

There were 17 patients in this trial. 11 patients were treated with pembrolizumab every 3 weeks and 6 patients were treated with nivolumab every 2 weeks. Patients had previously received an average of 3 treatment lines. 

Pembrolizumab showed a complete response in 73% of patients and a partial response in 27% of patients. There was an overall response rate (ORR) of 100% in the pembrolizumab group. Of the 8 patients who achieved complete responses on pembrolizumab, 2 relapsed. Of 287 pembrolizumab cycles, 3 patients had side effects. The most common side effects were diarrhea, skin reactions and low thyroid function.

Nivolumab resulted in a complete response in 4 patients (67%) and a partial response in 1 patient (17%). 1 patient was found to have complete resolution of their cHL. One patient suffered a relapse with nivolumab treatment and was retreated with nivolumab. Side effects occurred in 4 patients after 195 cycles of drug therapy. These included skin reactions, low cortisol (stress hormone) and platelet (blood cells involved in cotting) levels.

The authors concluded that low-dose pembrolizumab and nivolumab were highly effective and safe in relapsed/refractory cHL.

This study had a very small number of participants and was based on medical records. Further larger, controlled studies are needed to confirm these results.