TY - JOUR
T1 - A Phase Ib/II Study of Sabizabulin, a Novel Oral Cytoskeleton Disruptor, in Men with Metastatic Castration-resistant Prostate Cancer with Progression on an Androgen Receptor–targeting Agent
AU - Markowski, Mark C.
AU - Tutrone, Ronald
AU - Pieczonka, Christopher
AU - Barnette, K. Gary
AU - Getzenberg, Robert H.
AU - Rodriguez, Domingo
AU - Steiner, Mitchell S.
AU - Saltzstein, Daniel R.
AU - Eisenberger, Mario A.
AU - Antonarakis, Emmanuel S.
N1 - Publisher Copyright:
©2022 American Association for Cancer Research
PY - 2022/7/1
Y1 - 2022/7/1
N2 - Purpose: Sabizabulin, an oral cytoskeleton disruptor, was tested in a phase Ib/II clinical study in men with metastatic castration-resistant prostate cancer (mCRPC). Patients and Methods: The phase Ib portion utilized a 3þ3 design with escalating daily oral doses of 4.5–81 mg and increasing schedule in 39 patients with mCRPC treated with one or more androgen receptor–targeting agents. Prior taxane chemotherapy was allowed. The phase II portion tested a daily dose of 63 mg in 41 patients with no prior chemotherapy. Efficacy was assessed using PCWG3 and RECIST 1.1 criteria. Results: The MTD was not defined in the phase Ib and the recommended phase II dose was set at 63 mg/day. The most common adverse events (>10% frequency) at the 63 mg oral daily dosing (combined phase Ib/II data) were predominantly grade 1–2 events. Grade ≥3 events included diarrhea (7.4%), fatigue (5.6%), and alanine aminotransferase/aspartate aminotransferase elevations (5.6% and 3.7%, respectively). Neurotoxicity and neutropenia were not observed. Preliminary efficacy data in patients treated with ≥1 continuous cycle of 63 mg or higher included objective response rate in 6 of 29 (20.7%) patients with measurable disease (1 complete, 5 partial) and 14 of 48 (29.2%) patients had PSA declines. The Kaplan–Meier median radiographic progression-free survival was estimated to be 11.4 months (n ¼ 55). Durable responses lasting >2.75 years were observed. Conclusions: This clinical trial demonstrated that chronic oral daily dosing of sabizabulin has a favorable safety profile with preliminary antitumor activity. These data support the ongoing phase III VERACITY trial of sabizabulin in men with mCRPC.
AB - Purpose: Sabizabulin, an oral cytoskeleton disruptor, was tested in a phase Ib/II clinical study in men with metastatic castration-resistant prostate cancer (mCRPC). Patients and Methods: The phase Ib portion utilized a 3þ3 design with escalating daily oral doses of 4.5–81 mg and increasing schedule in 39 patients with mCRPC treated with one or more androgen receptor–targeting agents. Prior taxane chemotherapy was allowed. The phase II portion tested a daily dose of 63 mg in 41 patients with no prior chemotherapy. Efficacy was assessed using PCWG3 and RECIST 1.1 criteria. Results: The MTD was not defined in the phase Ib and the recommended phase II dose was set at 63 mg/day. The most common adverse events (>10% frequency) at the 63 mg oral daily dosing (combined phase Ib/II data) were predominantly grade 1–2 events. Grade ≥3 events included diarrhea (7.4%), fatigue (5.6%), and alanine aminotransferase/aspartate aminotransferase elevations (5.6% and 3.7%, respectively). Neurotoxicity and neutropenia were not observed. Preliminary efficacy data in patients treated with ≥1 continuous cycle of 63 mg or higher included objective response rate in 6 of 29 (20.7%) patients with measurable disease (1 complete, 5 partial) and 14 of 48 (29.2%) patients had PSA declines. The Kaplan–Meier median radiographic progression-free survival was estimated to be 11.4 months (n ¼ 55). Durable responses lasting >2.75 years were observed. Conclusions: This clinical trial demonstrated that chronic oral daily dosing of sabizabulin has a favorable safety profile with preliminary antitumor activity. These data support the ongoing phase III VERACITY trial of sabizabulin in men with mCRPC.
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U2 - 10.1158/1078-0432.CCR-22-0162
DO - 10.1158/1078-0432.CCR-22-0162
M3 - Article
C2 - 35416959
AN - SCOPUS:85133980629
SN - 1078-0432
VL - 28
SP - 2789
EP - 2795
JO - Clinical Cancer Research
JF - Clinical Cancer Research
IS - 13
ER -