A combination of the immunotherapy drugs galinpepimut-S and Opdivo may give mesothelioma patients a few extra months, according to newly-released data.
The clinical data is part of an ongoing study of galinpepimut-S and Opdivo. SELLAS Life Sciences Group, the makers of galinpepimut-S, released the latest findings this week.
Although the early data is based on just four mesothelioma cases, it appears to be promising. All of the study subjects had either relapsed after chemotherapy or failed to respond at all.
These patients had a median overall survival of 35.4 weeks on the combination of galinpepimut-S and Opdivo. Typical overall survival in relapsed patients with standard care is just 7 months.
Immunotherapy with Galinpepimut-S and Opdivo
Galinpepimut-S and Opdivo are both types of immunotherapy. Scientists at Memorial Sloan Kettering Cancer Center developed galinpepimut-S and licensed it to SELLAS Life Sciences.
Galinpepimut-S works by activating the immune system to help fight cancer. Specifically, this drug targets WT-1 or the Wilms Tumor protein found on the surface of mesothelioma cells.
According to a Phase 2 study of 40 malignant pleural mesothelioma patients, those on galinpepimut-S lived for a median of more than 2 years. Those in the control group had a median survival of just 16.6 months.
WT-1 is the target of galinpepimut-S and Opdivo (nivolumab) targets PD-1. Like WT-1, PD-1 is also a protein that helps mesothelioma cells hide from the immune system. Together, these two immunotherapy drugs stimulate an even more powerful immune response than either one alone.
New Hope for Pleural Mesothelioma?
The new study focused on four men with pleural mesothelioma. The men had an average age of 67. All had standard chemotherapy with Alimta and all got worse in spite of it. Two patients had stage II mesothelioma and the other two had stage IV.
The men received galinpepimut-S and Opdivo together for at least a month. The median overall survival was 35.4 weeks. The median progression-free survival period was 7 weeks.
“Patients treated with GPS plus nivolumab combination therapy appear to be surviving significantly longer than expected,” SELLAS CEO Angelos Stergiou, MD, said in a statement. Dr. Stergiou says the data suggest patients could get “meaningful clinical benefit” from the treatment.
One of the biggest surprises from the study was the survival of the only patient with sarcomatoid mesothelioma. Normally, patients with the sarcomatoid mesothelioma subtype do not respond as well to treatment. But the sarcomatoid patient on galinpepimut-S and Opdivo survived for 25 months and is still alive.
“Studying additional patients along with longer follow-up of existing patients will hopefully provide further clarity on these data, which we expect to review over the next six months as the study progresses,” says Dr. Stergiou.
The incidence of mesothelioma is slowly declining in the US but rising in poorer countries where asbestos use is common. About 2,500 Americans receive a mesothelioma diagnosis every year. Chemotherapy with Alimta is the primary treatment. There is no standard second-line treatment.
“SELLAS Reports Encouraging Updated Clinical Data from Ongoing Mesothelioma Study of Galinpepimut-S (GPS) Combined with Opdivo”, June 24, 2021, News RElease, SELLAS Life Sciences Group, https://www.globenewswire.com/en/news-release/2021/06/24/2252603/0/en/