Maarten van der Doelen

Actinium-225 labeled PSMA radioligand therapy in mCRPC patients

Follow-up imaging with CT scans was available in nine patients. Due to absence of extra skeletal disease at baseline in three patients, six patients were evaluable according to RECIST. Partial response was observed in three (50%) patients, and one (17%) patient had stable disease (Supplementary table 2). Follow-up 68 Ga-PSMA-11 PET/CT scans were available in seven patients, of which six (86%) showed partial responses according to PERCIST. All seven patients demonstrated >90% total tumor volume reduction as determined by the whole body tumor volume measurements. 68 Ga-PSMA-11 PET/CT overviews are presented in Figure 3.

2

A

150

100

50

0

-50

-100

Maximal decline from baseline (%)

12 05 09 04 02 13 08 10 03 01 11 07 06

Study ID

B

100

50

0

-50

-100

Maximal decline from baseline (%)

04 02 05 13 12 08 09 10 07 03 01 06 11

Study ID

Figure 2. Waterfall plots of maximal biochemical changes among patients treated with 225 Ac-PSMA-617 targeted alpha-radiation therapy. A . Maximum prostate-specific antigen decline from baseline. B . Maximum alkaline phosphatase decline from baseline. Blue bars indicate patients previously treated with 177 Lu PSMA-617 radioligand therapy. Yellow bars indicate patients with pathogenic DNA damage repair alterations.

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