RSR 13 Plus Cranial Radiation Therapy Improves Survival in Patients With Brain Metastases Compared to RTOG Recursive Partitioning Analysis Brain Metastases Database

William Levin, MD
OncoLink Assistant Editor
Last Modified: October 25, 2000

Presenter: E. Shaw
Affiliation: Wake Forest University School of Medicine

Background:

RSR 13 is a potential enhancer of ionizing radiation by decreasing hemoglobin-O2 binding affinity and increasing tumor oxygenation.
This is a Phase II open label study design to assess the efficacy/safety of RSR 13 plus external beam radiation therapy (RT) in patients with brain metastases.
The primary endpoint was survival compared to the Radiation Therapy Oncology Group Recursive Partitioning Analysis Brain Metastases Database (RTOG RPA BMD).

Materials and Methods:

Eligibility: Age > 18, KPS > 70, brain metastases.
57 patients were enrolled and evaluated, the majority of these patients had metastatic disease from either a primary lung or breast cancer.
Patients received cranial RT, 30 Gy in 10 fractions of 3 Gy each, proceeded by RSR 13, 75- 100 mg/kg IV over 30 minute infusion.

Results:

80% of pts. Completed over 90% of RSR 13 doses.
40% of patients required dose reduction of RSR 13
30% of patients had severe adverse effects which included: hypoxemia, hypotension, acute renal failure, altered mental status, and allergic reaction.
There were no treatment related deaths.
The pts. treated with RSR 13 had a median survival of 6.4 months versus 4.1 months for the RTOG RPA BMD group (p < 0.02).
At 6 month follow-up, survival rates were 51% versus 35% in favor of the RSR 13 group.
Death due to brain metastases was decreased with the use of RSR 13, 11% versus 37% for the RTOG RPA BMD group.

Authors' Conclusions

RSR 13 plus cranial RT resulted in significant improvement in survival as well as a reduction in death due to brain metastases compared to the RTOG RPA BMD group.

Clinical/Scientific Implications:

The use of hemoglobin-oxygen modifiers such as RSR 13 may increase tumor oxygenation in patients with metastatic brain disease.
Combined with cranial irradiation, RSR 13 may offer a survival benefit for these patients, who generally have poor prognosis.