Phase I Study of Acalabrutinib Plus Danvatirsen (AZD9150) in Relapsed/Refractory Diffuse Large B-Cell Lymphoma Including Circulating Tumor DNA Biomarker Assessment.

PURPOSE: Novel targeted and immunotherapies have improved outcomes in relapsed/refractory (R/R) diffuse large B-cell lymphoma (DLBCL), but toxicities limit widespread use. The selective Bruton tyrosine kinase (BTK) inhibitor acalabrutinib has activity in patients with R/R DLBCL but durable responses are uncommon. STAT3 inhibition has demonstrated clinical activity in DLBCL. PATIENTS AND METHODS: Final results of the phase I study of acalabrutinib plus STAT3 inhibitor (danvatirsen; AZD9150) in patients with R/R DLBCL are reported. Danvatirsen 200 mg intravenous infusion [Days 1, 3, 5 (Cycle 1); weekly infusions starting Day 8, Cycle 1] was administered in combination with oral acalabrutinib 100 mg twice daily until progressive disease (PD) or unacceptable toxicity. Primary endpoints were safety and tolerability. Secondary endpoints included efficacy, pharmacokinetics, and immunogenicity. RESULTS: Seventeen patients received combination treatment. One dose-limiting toxicity (Grade 3 liver transaminase) occurred in 1 patient. The most common reason for treatment discontinuation was PD (65%). In evaluable patients (n = 17), objective response rate was 24%; median duration of response was 1.9 months. All responders with available DLBCL cell-of-origin data were either activated B-cell or nongerminal center B-cell like subtype. Genetic subtype did not correlate with response. Baseline and longitudinal plasma cell-free DNA (cfDNA) concentrations were mostly higher in nonresponding patients. cfDNA changes were generally concordant with imaging. Pretreatment circulating B-cell levels were higher in responders versus nonresponders. CONCLUSIONS: Targeting both STAT3 and BTK in combination is safe and tolerable but efficacy is limited in R/R DLBCL. Results support evaluation of circulating tumor DNA as a biomarker for clinical response.

Assessment of the drug interaction potential and single- and repeat-dose pharmacokinetics of the BRAF inhibitor dabrafenib.

The induction of CYP2C9 by dabrafenib using S-warfarin as a probe and the effects of a CYP3A inhibitor (ketoconazole) and a CYP2C8 inhibitor (gemfibrozil) on dabrafenib pharmacokinetics were evaluated in patients with BRAF V600 mutation-positive tumors. Dabrafenib single- and repeat-dose pharmacokinetics were also evaluated. S-warfarin AUC(0- ∞) decreased 37% and Cmax increased 18% with dabrafenib. Dabrafenib AUC(0- τ) and C(max) increased 71% and 33%, respectively, with ketoconazole. Hydroxy- and desmethyl-dabrafenib AUC(0-τ) increased 82% and 68%, respectively, and AUC for carboxy-dabrafenib decreased 16%. Dabrafenib AUC(0-τ) increased 47%, with no change in C(max), after gemfibrozil co-administration. Gemfibrozil did not affect systemic exposure to dabrafenib metabolites. Single- and repeat-dose dabrafenib pharmacokinetics were consistent with previous reports. All cohorts used the commercial capsules. More-frequent monitoring of international normalized ratios is recommended in patients receiving warfarin during initiation or discontinuation of dabrafenib. Substitution of strong inhibitors or strong inducers of CYP3A or CYP2C8 is recommended during treatment with dabrafenib.

Prospective validation of a prognostic score to improve patient selection for oncology phase I trials.

PURPOSE: With the aim of improving patient selection for phase I trials, we previously performed a retrospective analysis of 212 phase I oncology patients where we were able to develop a prognostic score predicting overall survival (OS). This prospective study was performed to test the validity of the prognostic score. PATIENTS AND METHODS: On the basis of our retrospective multivariate analysis, three factors were associated with poor survival (albumin < 35 g/L, lactate dehydrogenase [LDH] > upper limit of normal [ULN], and > two sites of metastases). We integrated these into a prognostic score ranging from 0 to 3 and analyzed this score in a prospectively selected cohort of 78 patients enrolled onto phase I trials. RESULTS: All patients had progressive disease before study entry. The median age was 56 years (range, 18 to 79 years). After a median follow-up time of 27.3 weeks, patients with a prognostic score of 0 to 1 (n = 43) had superior OS (33.0 weeks; 95% CI, 24 to 42 weeks) compared with patients with a score of 2 to 3 (n = 35; 15.7 weeks; 95% CI, 11 to 21 weeks). Our multivariate analysis confirmed that our prognostic score was an independent marker for OS, with a hazard ratio of 1.4 (95% CI, 1.02 to 1.9; P = .036). CONCLUSION: This is the first prospective analysis confirming that a prognostic score based on objective markers, including albumin less than 35 g/L, LDH more than ULN, and more than two sites of metastasis, is a helpful tool in the process of patient selection for phase I trial entry.