Real-world comparison of lutetium-177 vipivotide tetraxetan in advanced castration resistant metastatic prostate cancer patients in Appalachia.

Abstract

e17026 Background: Patients (pts) with advanced metastatic castration resistant prostate cancer (mCRPC) have undergone multiple modalities of therapy limiting treatment options for these pts. Lutetium-177 vipivotide tetraxetan (Lu-177) shown in studies (VISION and EAP) to improve overall survival (OS) in mCRPC pts. We present our experiences with Lu-177 in mCRPC pts in Appalachia (WVU) and compare them to those from VISION and EAP. Methods: Adult (age ≥ 18) pts who received Lu-177 at a rural academic center in West Virginia and had a baseline prostate specific membrane antigen PET/CT scan prior to starting Lu-177 were included in the study. Pts received androgen deprivation therapy and Lu-177 every 6 weeks for up to 6 cycles until disease progression, adverse events, or pt withdrawal from treatment. Pts received Lu-177 from 7/28/2022 to 9/17/2024. Cumulative incidence and descriptive statistics of laboratory values, evaluation for OS, objective/mixed response, or progression of disease were of interest. Results were compared to those reported from VISION and EAP. Results: 51 pts were analyzed. Majority (94%) of pts were Caucasian with a median age of 76 years old at the first treatment of Lu-177. Median OS was 14 months (9.4-25 months) and 49% remain alive 29 months after starting on Lu-177. Comparing WVU data to those of VISION and EAP, the WVU data showed slightly inferior OS. WVCI data had older pts, shorter time from diagnosis to treatment, and worse Gleason scores at the time of diagnosis. Conclusions: WVU results call to action the need for improving patient selection or applying different selection criteria for using Lu-177. Other considerations include the using Lu-177 earlier in prostate cancer treatment, targeted radiation, and using novel isotopes or new PSMA linker molecules. Summary of Lu-177 trials and WVU data. VISION EAP WVU Δ WVU to VISION Result Δ WVU to EAP Result Total # of Pts 551 117 51 - - Caucasian, # Pts (%) 486 (88%) 89 (79%) 48 (94%) +6% +15% Average Age (range) 70 (48-94) 71 (52-86) 76 (49-94) +6 yrs +5 yrs Years Since Diagnosis Prior to Lu-177, Average (range) 7.4 (0.9-28.9) 8.8 (0.9-32.2) 5.6 (0.9-30.6) -1.8 yrs -3.2 yrs Gleason Score of 8-10 at Diagnosis, # (%) 324 (59%) 66 (56%) 31 (79%) +20% +23% Average # of Lu-177 Cycles 5 4 4.2 -0.8 +0.2 Months Follow Up 20.9 19.1 29 +8.1 mo +9.9 mo Median OS, Months (range) 15.3 (14.2-16.9) 15.1 (11.7-18.5) 14.0 (9.4-25) -1.3 mo -1.1 mo # of Pts Alive (%) 36 (7%) 72 (62%) 25 (49%) +42% -13%