KEY TAKEAWAYS
- The study aimed to analyze how BM respond to pembro and link characteristics such as size and location to treatment outcomes in patients with untreated BM.
- The findings indicated pembro’s effectiveness against BM from NSCLC and melanoma, necessitating careful radiographic monitoring for treatment decisions.
Brain cancer metastases from lung cancers and melanoma significantly impact health outcomes, despite progress in local therapies. Effective systemic treatments, such as pembrolizumab (pembro), a PD-1 inhibitor, show promise for untreated brain cancer metastases from melanoma and non-small cell lung cancer (NSCLC).
Amit Mahajan and the team aimed to analyze brain metastasis (BM) response to pembro and link characteristics such as size and location to treatment outcomes.
This retrospective study utilized imaging data from a phase II trial of pembro in patients with untreated BM from melanoma or NSCLC. MRI evaluations were conducted (at 2-month intervals), treating each BM (as a distinct tumor) for response assessment, based on modified RECIST criteria (up to 5 lesions, with 5 mm target lesions).
The results showed that among 130 individual target metastases (>5 mm) in 65 patients with NSCLC (90 metastases) and melanoma (40 metastases), 24.6% achieved complete resolution (CR), 18.5% had partial resolution (PR), 24.6% remained stable, and 32.3% progressed.
Metastases smaller than 10 mm were more likely to completely resolve (P= 0.0218), while those ≥10 mm were more likely to show partial resolution. There was no significant association between size, number, or location (supratentorial vs. infratentorial) and lesion progression. The median time to progression of BM was 5.7-7 weeks.
The study concluded that pembro demonstrates effectiveness against BM from NSCLC and melanoma, with a 43% response rate (CR + PR) and 32% progression rate (PD). Given the median time to CNS progression of 5.7-7 weeks, diligent radiographic monitoring is crucial for guiding timely decisions on local treatment strategies.
Authors have not disclosed any funding.
Source: https://link.springer.com/article/10.1007/s11060-024-04754-8
Mahajan, A., Goldberg, S.L., Weiss, S.A. et al. (2024). “Patterns of brain metastases response to immunotherapy with pembrolizumab.” J Neurooncol (2024). https://doi.org/10.1007/s11060-024-04754-8
