Open label phase I trial using SPL-108 in combination with weekly paclitaxel final report with molecular correlates

Autor: June YiJuan Hou, Mihae Song, Eugenia Girda, David M Nelson, Ruth Stephenson, Malcolm Finlayson, Lorna Rodriguez-Rodriguez, Alexandre Buckley de Meritens, Aliza L. Leiser
Rok vydání: 2020
Předmět:
Zdroj: Journal of Clinical Oncology. 38:e18040-e18040
ISSN: 1527-7755
0732-183X
Popis: e18040 Background: Therapeutic options for patients with recurrent platinum resistant ovarian cancer are scarce and represent an unmet need in ovarian cancer. Chemotherapy resistance has been linked to many CD44 pathways including P-glycoprotein mediated efflux of chemotherapeutic agents. Our working hypothesis was that chemotherapy resistant ovarian tumors that expressed CD44 would revert drug resistance by using a CD44 inhibitor SPL-108, that had proven safe as a single agent. Methods: Patients with platinum refractory or resistant CD44+ ovarian tumors were eligible. We used a standard 3+3 phase I design, open-label, 2-arm trial of the combination of SPL-108 and IV paclitaxel (PTX): Arm 1 (2 cohorts) Safety Phase: Cohort 1: SPL-108 150 mg SQ Daily +80 mg PTX weekly Cohort 2: SPL-108 300mg daily +80 mg PTX weekly Arm 2 (1 cohort) Exploratory Phase: Cohort 3: SPL-108 daily dose 300 mg +80 mg PTX weekly Days 1-15 in 28 day cycles Primary end points were safety and tolerability. Secondary endpoints included determining molecular signatures of response using NGS. Tumors were sequenced at the time of recurrence or initial diagnosis. Results: Fourteen patients were enrolled in the study. Prior number of treatments ranged from 2-6, except for one patient with platinum refractory disease that progressed during first line of therapy. There was no DLT and all cohorts were completed as designed. The treatment was well tolerated. There was one instance of a bowel micro-perforation that was treated medically. This patient had platinum refractory disease and eventually underwent an interval cytoreduction. There was one patient with grade 3 neurotoxicity. Sixty-two% of the patients had clinical benefit with 36% having a PR. Forty-three % of patient had a PFS of more than 6 months. Two patients enjoyed a PR of 12 months. Molecular profiling of the tumors revealed that all tumors had TP53 alterations and the 4 patients that did not have a response had tumors with TP53 truncations or a lack of function alteration. Conclusions: Daily SPL-108 300mg SQ in combination with weekly PTX is safe and feasible. The promising clinical activity on drug resistant ovarian tumors warrants further investigation. Resistance to SPL-108 are characterized by lack of function of TP53, mostly early truncations. It is possible that SPL-108 may be reactivating TP53 by promoting its active conformation. Once TP53 is active CD44 expression is abrogated at the promoter. Therefore SPL-108 is effectively acting on CD44 through 2 different mechanisms to promote chemotherapy sensitivity. Clinical trial information: NCT03078400.
Databáze: OpenAIRE