A small Phase II trial tested a mix of radiation, a PD‑1 cancer drug, GM‑CSF, and the peptide thymosin‑alpha‑1 in people with advanced cancers. About a quarter of patients saw tumor shrinkage and many had disease stabilization, with some showing distant tumor shrinkage (abscopal effect). Side effects were mostly mild to moderate, with a few serious events. The results are promising for cancer treatment but don’t give clear guidance for healthy individuals looking to boost immunity or longevity.

This multicenter Phase II clinical study assessed the efficacy and safety of hypofractionated radiotherapy (HFRT) in combination with a PD-1 inhibitor, granulocyte macrophage-colony stimulating factor (GM-CSF), and thymosin-α1 in patients with heavily treated metastatic solid tumors. Patients were enrolled between September 2022 and May 2024. HFRT was administered to targeted tumors, and GM-CSF was administered for 14 days from day 1 of radiotherapy. Thymosin-α1 was injected concurrently twice weekly until disease progression. Immunotherapy with camrelizumab was started following HFRT and repeated every 3 weeks. GM-CSF was administered daily for 7 days before each cycle of immunotherapy. By June 15, 2024, there were 37 study participants. The median follow-up duration was 5.97 months (range 0.40-20.9). Median progression-free survival was 3.5 months (95% confidence interval 2.73-4.23) in the intention-to-treat population. The objective response rate was 23.08%, and the disease control rate was 65.38%. Overall survival data are not yet mature. Abscopal effects were observed in 6 patients (23.08%); four of whom achieved a partial response. Patients who achieved a partial response were significantly more likely to have an abscopal effect( P = 0.025). The group with a lower baseline neutrophil-lymphocyte ratio had a significantly lower risks of distant metastasis and death( P = 0.024). Seventeen adverse reactions were reported, including six grade 3 or 4 adverse events. There were no grade 5 adverse events. In conclusion, the trends in efficacy observed in our study are promising; however, well-designed protocols are essential to validate these findings.