Preliminary findings from part 1 of COMBI-i: A phase III study of anti–PD-1 antibody PDR001 combined with dabrafenib (D) and trametinib (T) in previously untreated patients (pts) with advanced BRAF V600-mutant melanoma

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Background: Checkpoint inhibitors and targeted therapies have improved outcomes in pts with advanced BRAF V600–mutant melanoma; however, many still progress and die from this disease. Thus, new treatment strategies are needed. BRAF and MEK inhibitor combinations (eg, D+T) may reverse immunosuppressive phenotypes induced by oncogenic BRAF and improve sensitivity to checkpoint inhibitors by enhancing HLA and melanocytic antigen expression and tumor antigen–specific T-lymphocyte recognition. Methods: The phase 3 COMBI-i study (NCT02967692) is evaluating the anti–PD-1 antibody PDR001 in combination with D+T in treatment-naive pts with BRAF V600–mutant unresectable or metastatic melanoma in 3 parts: 1, safety run-in; 2, biomarker cohort; and 3, randomized, double-blind, placebo-controlled part. Here we report preliminary findings for 9 pts in part 1 dosed with PDR001 400 mg Q4W + D 150 mg BID + T 2 mg QD. Response was assessed at wk 12 and Q8W thereafter. Results: At data cutoff (16 Jul 2017; median follow-up, 2.7 mo), all 9 pts completed the 8-wk dose-limiting toxicity (DLT) period, during which 1 DLT (transaminitis [AST and ALT > 8 × ULN]; n = 1) occurred. Adverse events (AEs) of any grade occurring in > 3 pts included pyrexia (n = 9), headache (n = 6), chills (n = 4), and vomiting (n = 4). Grade 3/4 AEs reported in > 1 pt included hepatitis (n = 3), increased lipase (n = 2), and increased transaminases (n = 2). AEs leading to discontinuation occurred in 2 pts (22%; transaminitis, n = 1; grade 3 hepatitis, n = 1) who permanently discontinued PDR001 but were still receiving D+T at the data cutoff. All 9 pts responded: 3 (33%) achieved a complete response (confirmed, n = 1), and 6 (67%) had partial responses (confirmed, n = 1). Additional safety and efficacy results for these 9 pts, all ongoing at the data cutoff, will be presented. Conclusions: These preliminary results indicate that PDR001 can be combined with D+T with a manageable safety profile and demonstrate promising activity in pts with BRAF V600–mutant melanoma. Clinical trial information: NCT02967692.

Dabrafenib plus trametinib in patients with previously treated BRAF(V600E)-mutant metastatic non-small cell lung cancer: an open-label, multicentre phase 2 trial

BACKGROUND

BRAF mutations act as an oncogenic driver via the mitogen-activated protein kinase (MAPK) pathway in non-small cell lung cancer (NSCLC). BRAF inhibition has shown antitumour activity in patients with BRAF(V600E)-mutant NSCLC. Dual MAPK pathway inhibition with BRAF and MEK inhibitors in BRAF(V600E)-mutant NSCLC might improve efficacy over BRAF inhibitor monotherapy based on observations in BRAF(V600)-mutant melanoma. We aimed to assess the antitumour activity and safety of dabrafenib plus trametinib in patients with BRAF(V600E)-mutant NSCLC.

METHODS

In this phase 2, multicentre, non-randomised, open-label study, we enrolled adult patients (aged ≥18 years) with pretreated metastatic stage IV BRAF(V600E)-mutant NSCLC who had documented tumour progression after at least one previous platinum-based chemotherapy and had had no more than three previous systemic anticancer therapies. Patients with previous BRAF or MEK inhibitor treatment were ineligible. Patients with brain metastases were allowed to enrol only if the lesions were asymptomatic, untreated (or stable more than 3 weeks after local therapy if treated), and measured less than 1 cm. Enrolled patients received oral dabrafenib (150 mg twice daily) plus oral trametinib (2 mg once daily) in continuous 21-day cycles until disease progression, unacceptable adverse events, withdrawal of consent, or death. The primary endpoint was investigator-assessed overall response, which was assessed by intention to treat in the protocol-defined population (patients who received second-line or later treatment); safety was also assessed in this population and was assessed at least once every 3 weeks, with adverse events, laboratory values, and vital signs graded according to the Common Terminology Criteria for Adverse Events version 4.0. The study is ongoing but no longer recruiting patients. This trial is registered with ClinicalTrials.gov, number NCT01336634.

FINDINGS

Between Dec 20, 2013, and Jan 14, 2015, 59 patients from 30 centres in nine countries across North America, Europe, and Asia met eligibility criteria. Two patients who had previously been untreated due to protocol deviation were excluded; thus, 57 eligible patients were enrolled. 36 patients (63·2% [95% CI 49·3-75·6]) achieved an investigator-assessed overall response. Serious adverse events were reported in 32 (56%) of 57 patients and included pyrexia in nine (16%), anaemia in three (5%), confusional state in two (4%), decreased appetite in two (4%), haemoptysis in two (4%), hypercalcaemia in two (4%), nausea in two (4%), and cutaneous squamous cell carcinoma in two (4%). The most common grade 3-4 adverse events were neutropenia in five patients (9%), hyponatraemia in four (7%), and anaemia in three (5%). Four patients died during the study from fatal adverse events judged to be unrelated to treatment (one retroperitoneal haemorrhage, one subarachnoid haemorrhage, one respiratory distress, and one from disease progression that was more severe than typical progression, as assessed by the investigator).

INTERPRETATION

Dabrafenib plus trametinib could represent a new targeted therapy with robust antitumour activity and a manageable safety profile in patients with BRAF(V600E)-mutant NSCLC.

FUNDING

GlaxoSmithKline.

Second-line dovitinib (TKI258) in patients with FGFR2-mutated or FGFR2-non-mutated advanced or metastatic endometrial cancer: a non-randomised, open-label, two-group, two-stage, phase 2 study

BACKGROUND

Activating FGFR2 mutations are found in 10-16% of primary endometrial cancers and provide an opportunity for targeted therapy. We assessed the safety and activity of dovitinib, a potent tyrosine-kinase inhibitor of fibroblast growth factor receptors, VEGF receptors, PDGFR-β, and c-KIT, as second-line therapy both in patients with FGFR2-mutated (FGFR2(mut)) endometrial cancer and in those with FGFR2-non-mutated (FGFR2(non-mut)) endometrial cancer.

METHODS

In this phase 2, non-randomised, two-group, two-stage study, we enrolled adult women who had progressive disease after first-line chemotherapy for advanced or metastatic endometrial cancer from 46 clinical sites in seven countries. We grouped women according to FGFR2 mutation status and gave all women dovitinib (500 mg per day, orally, on a 5-days-on and 2-days-off schedule) until disease progression, unacceptable toxicity, death, or study discontinuation for any other reason. The primary endpoint was proportion of patients in each group who were progression-free at 18 weeks. For each group, the second stage of the trial (enrolment of 20 additional patients) could proceed if at least eight of the first 20 treated patients were progression free at 18 weeks. Activity was assessed in all enrolled patients and safety was assessed in all patients who received at least one dose of dovitinib. The completed study is registered with ClinicalTrials.gov, number NCT01379534.

FINDINGS

Of 248 patients with FGFR2 prescreening results, 27 (11%) had FGFR2(mut) endometrial cancer. Between Feb 17, 2012, and Dec 13, 2013, we enrolled 22 patients in the FGFR2(mut) group and 31 patients in the FGFR2(non-mut) group. Seven (31·8%, 95% CI 13·9-54·9) patients in the FGFR2(mut) group and nine (29·0%, 14·2-48·0) in the FGFR2(non-mut) group were progression-free at 18 weeks. On the basis of predefined criteria, neither group continued to stage two: seven (35%) of the first 20 patients in the FGFR2(mut) group were progression free at 18 weeks, as were five (25%) of the first 20 in the FGFR2(mut) population. Rates of treatment-emergent adverse events were similar between groups and events were most frequently gastrointestinal. Overall, the most common grade 3 or 4 adverse events suspected to be related to the study drug were hypertension (nine patients; 17%) and diarrhoea (five; 9%). The most frequently reported serious adverse events suspected to be related to study drug were pulmonary embolism (four patients; 8%), vomiting (four; 8%), dehydration (three; 6%), and diarrhoea (three; 6%). Only one death was deemed to be treatment-related: one patient in the FGFR2(non-mut) group died from cardiac arrest with contributing reason of pulmonary embolism (grade 4, suspected to be study drug related) 4 days previously.

INTERPRETATION

Second-line dovitinib in FGFR2(mut) and FGFR2(non-mut) advanced or metastatic endometrial cancer had single-agent activity, although it did not reach the prespecified study criteria. Observed treatment effects seemed independent of FGFR2 mutation status. These data should be considered exploratory and additional studies are needed.

FUNDING

Novartis Pharmaceuticals.

Dovitinib as second-line therapy in patients with fibroblast growth factor receptor 2 (FGFR2)-mutated or non-mutated advanced and/or metastatic endometrial cancer (EC): A single-arm, multicenter, phase II study

TPS5616

Background: Despite the use of combination chemotherapy and introduction of novel targeted agents, the prognosis for advanced and/or metastatic EC is challenging. The occurrence of somatic activating FGFR2 mutations in EC suggests an opportunity for testing FGFR inhibitors. Dovitnib (DOV) is a potent receptor tyrosine kinase inhibitor of vascular endothelial growth factor receptor, platelet-derived growth factor receptor and FGFR. The objective of the study is to investigate the efficacy and safety of DOV as second-line therapy in patients (pts) with advanced and/or metastatic EC. Methods: This multicenter, non-randomized, open label, single-arm, phase II study (NCT01379534) will enroll adult female pts (N~80) with either FGFR2 mutated (group 1) or non-mutated (group 2) histologically confirmed advanced and/or metastatic EC, who have documented radiological evidence of progressive disease (RECISTv1.1) after 1 prior line of chemotherapy, excluding adjuvant therapy. Eligible pts also need to have ≥1 measurable lesion (RECISTv1.1) and ECOG performance status ≤ 2. Pts will receive oral DOV of 500 mg/day, on a 5-days-on / 2-days-off dosing schedule until disease progression, unacceptable toxicity, death, or discontinuation due to any other reason. Primary endpoint is 18-week progression-free survival (PFS) rate (local review; RECIST v1.1) and secondary endpoints include overall response rate, disease control rate, duration of response, PFS, overall survival, safety, tolerability, pharmacokinetics, and pharmacodynamic effect of DOV on soluble plasma biomarker expression level. A 2-stage design with Bayesian interim monitoring (interim for futility analyses) will be used in each group. For stage 1, 20 pts will be enrolled into each group. If ≥ 8 of the first 20 pts with measurable disease at baseline in either group are progression-free after 18 weeks of treatment, 20 additional pts will be enrolled into that group in stage 2. Preliminary results for each group will be evaluated in the interim analysis. As of 20 January 2013, 43 pts have been enrolled (12 with and 31 without FGFR2 mutations). Clinical trial information: NCT01379534.