Prostate cancer is a common malignancy of elderly, and with aging of the population the need is growing for therapies suitable for this age group. Lutetium-177-PSMA (Lu-PSMA), a radiolabelled small molecule, binds with high affinity to prostate-specific membrane antigen (PSMA), enabling beta particle therapy targeted to metastatic castration-resistant prostate cancer (mCRPC). In a recent single-arm phase II trial and a subsequent expansion cohort, a PSA decline of ≥50% was observed in about 60% of patients receiving Lu-PSMA. Taking into account the specific challenges and potential toxicities of Lu-PSMA administration in elderly men, we sought out to retrospectively analyze the safety and activity of Lu-PSMA in men over 75 with mCRPC.
The electronic medical records of 24 patients over 75 years treated with Lu-PSMA 'off-trial' were reviewed and clinical data was extracted. Clinical endpoints were toxicity and activity, defined as a PSA decline≥ 50%. Descriptive statistics were performed using Excel.
The median age at treatment start was 81.7 years (range 75.1-91.9). The median number of previous treatment lines was 4. The number of treatment cycles ranged from 1 to 4; the mean administered radioactivity was 6 GBq per cycle. Treatment was generally tolerable; side effects included fatigue (n=8, 33%), anemia (n=7, 29%), thrombocytopenia (n=5, 21%) and anorexia/nausea (n=3, 13%). Clinical benefit was observed in 12 of 22 patients (54%), PSA decline above 50% was observed in 11 patients (48%) and was associated with significantly longer overall survival (OS).
Our results indicate that Lu-PSMA is safe and active in elderly patients with mCRPC.
Lutetium-177-PSMA (Lu-PSMA), a radiolabelled small molecule, binds with high affinity to prostate-specific membrane antigen (PSMA), enabling beta particle therapy targeted to metastatic castration-resistant prostate cancer (mCRPC). The recently published single-arm phase II trial with LU-PSMA, describing its safety and activity, did not include patients over 75. We retrospectively analyzed Lu-PSMA activity in patients over 75 and found that treatment was tolerable and similarly active in this age group, with no new emerging safety signals. Albeit our small cohort size, our analysis suggests that Lu-PSMA can serve as an advanced palliative treatment line in mCRPC in elderly patients.
The oncologist. 2020 May 19 [Epub ahead of print]
Raya Leibowitz, Tima Davidson, Moran Gadot, Margalit Aharon, Avraham Malki, Meital Levartovsky, Cecilie Oedegaard, Akram Saad, Israel Sandler, Simona Ben-Haim, Liran Domachevsky, Raanan Berger
Oncology institute, Sheba medical center, Tel-Hashomer, Israel., Sackler faculty of medicine, Tel-Aviv university, Tel-Aviv, Israel., Department of nuclear medicine, Sheba medical center, Tel-Hashomer, Israel., Department of Biophysics and Nuclear Medicine, Hadassah University Hospital, Jerusalem, Israel, 9112001.