In:
Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 24, No. 1 ( 2018-01-01), p. 22-32
Kurzfassung:
Purpose: The objectives of the study were to evaluate the safety of daily oral PX-866 in combination with twice daily vemurafenib and to identify potential predictive biomarkers for this novel combination. Experimental Design: We conducted a phase I, open-label, dose-escalation study in patients with advanced BRAF V600–mutant solid tumors. PX-866 was administered on a continuous schedule in combination with vemurafenib. Patients underwent a baseline and on-treatment biopsy after 1-week of PX-866 monotherapy for biomarker assessment. Results: Twenty-four patients were enrolled. The most common treatment-related adverse events were gastrointestinal side effects. One dose-limiting toxicity (DLT) of grade 3 rash and one DLT of grade 3 pancreatitis were observed in cohort 2 (PX-866 6 mg daily; vemurafenib 960 mg twice daily) and cohort 3 (PX-866 8 mg daily; vemurafenib 960 mg twice daily), respectively. Of 23 response-evaluable patients, seven had confirmed partial responses (PR), 10 had stable disease, and six had disease progression. Decreases in intratumoral pAKT expression were observed following treatment with PX-866. Patients who achieved PRs had higher rates of PTEN loss by IHC (80% vs. 58%) and pathogenic PTEN mutations and/or deletions (57% vs. 25%). Two patients with durable PRs had an increase in intratumoral CD8+ T-cell infiltration following treatment with PX-866. Conclusions: PX-866 was well tolerated at its maximum tolerated single-agent dose when given in combination with a modified dose of vemurafenib (720 mg twice daily). Response to treatment appeared to be associated with PTEN loss and treatment with PX-866 seemed to increase CD8+ T-cell infiltration in some patients. Clin Cancer Res; 24(1); 22–32. ©2017 AACR.
Materialart:
Online-Ressource
ISSN:
1078-0432
,
1557-3265
DOI:
10.1158/1078-0432.CCR-17-1807
Sprache:
Englisch
Verlag:
American Association for Cancer Research (AACR)
Publikationsdatum:
2018
ZDB Id:
1225457-5
ZDB Id:
2036787-9