Treatment With Pluvicto Soon After Radium-223 Is Safe, Effective for Prostate Cancer

Patients with metastatic castration-resistant prostate cancer treated with Pluvicto (177Lu-PSMA-617) within six months of receiving radium-223 tolerated the regimen and had similar outcomes to those who waited for its administration, recent research showed.

These findings may demonstrate that patients with metastatic castration-resistant prostate cancer may not have to wait months after receiving treatment with radium-223 before initiation therapy with Pluvicto.

“The question RALU set out to ask is whether it is safe to sequence two radionuclide therapies, an alpha and a beta emitter, in patients with (metastatic castration-resistant prostate cancer),” said Dr. Kambiz Rahbar, from the department of nuclear medicine at University Hospital of Münster in Germany, while presenting the findings at the 2023 ASCO GU Cancers Symposium.

Radionuclide therapies like radium-223 and Pluvicto work by using radioactive atoms to seek and destroy cancer cells.

The study analyzed outcomes from patients with metastatic castration-resistant prostate cancer who were divided into two groups:

• Group 1 involved 42 patients who were treated with Pluvicto within six months of radium-223 treatment.
• Group 2 involved 90 patients who started Pluvicto treatment six months or longer after radium-223.

Findings showed that 71% of patients in group 1 (those treated with Pluvicto with six months after radium-223) experienced side effects of any severity compared with 82% of patients in group 2. The most common side effects were fatigue (12% and 7% in groups 1 and 2, respectively), nausea (12% and 8%) and dry mouth (7% and 18%). Serious or severe side effects happened in 36% of patients in group 1 and 24% of those in group 2.

Additionally, survival outcomes were similar between the two groups. On average, patients in group 1 lived for 12 months after treatment, compared with 13.2 months in group 2. The researchers said that there was no statistically significant difference between these two survival averages — meaning that they could not conclude it was the timing of treatment that influenced survival. Instead, other factors, such as different patient characteristics among the two groups, could have played a role.

“In conclusion, we can say that these data can show that treating patients with lutetium within six months of completing radium was clinically feasible and well tolerated,” Rahbar said.

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