Safety, tolerability, and pharmacokinetic profile of dabrafenib in Japanese patients with BRAF V600 mutation-positive solid tumors: a phase 1 study.

Background Dabrafenib is a BRAF inhibitor that has demonstrated clinical activity with a good tolerability profile in patients with BRAF V600E mutated metastatic melanoma. This study evaluated the safety and tolerability, pharmacokinetics and preliminary efficacy of dabrafenib in Japanese patients. Methods This phase I, open-label, dose escalation study was conducted in 12 Japanese patients with BRAF V600 mutation positive solid tumours. Primary endpoint was safety, assessed by monitoring and recording of all adverse events (AEs), serious AEs, drug-related AEs; secondary endpoints were pharmacokinetic profiles and efficacy measured by tumour response. This study is registered with ClinicalTrials.gov, number NCT01582997. Results Of the 12 patients enrolled, 3 each received 75 mg and 100 mg dabrafenib while 6 received 150 mg dabrafenib twice daily orally. Melanoma and thyroid cancer were the primary tumours reported in 11 (92%) and 1 (8%) patients respectively. Most AEs were grade 1 or 2 and considered related to study treatment. Most common AEs reported in the 12 patients were alopecia in 7 (58%); pyrexia, arthralgia and leukopenia in 6 (50%) each, hyperkeratosis and nausea in 4 (33%) each. Partial response as best overall response was reported in 7 of 12 (58%) patients and in 6 (55%) with malignant melanoma. No dose-limiting toxicity (DLTs) were reported during the DLT evaluation periods. Conclusions Dabrafenib was well tolerated and rapidly absorbed administered as single- or multiple dose. Comparable safety and pharmacokinetic profiles were observed compared with non-Japanese patients. Dabrafenib has promising clinical activity in Japanese patients with BRAF mutated malignant melanoma.

A phase I/Ib study of trametinib (GSK1120212) alone and in combination with gemcitabine in Japanese patients with advanced solid tumors.

BACKGROUND: Trametinib is an inhibitor of MEK1/MEK2 activation and kinase activity. In order to evaluate the safety, tolerability, pharmacokinetics, and preliminary efficacy of single-agent trametinib (part 1) and trametinib in combination with gemcitabine (part 2), we undertook the first clinical study of this combination in Japanese patients with cancer and herein report our results. METHODS: In part 1, 13 patients with advanced solid tumors were enrolled into 3 dose cohorts, receiving trametinib once daily at a dose of 1.0, 2.0, or 3.0 mg. In part 2, 5 patients with pancreatic cancer received trametinib (2.0 mg once daily) in combination with gemcitabine (1000 mg/m(2)). RESULTS: In part 1, a dose-limiting toxicity was observed in a patient in the 2.0-mg dose cohort, but the maximum tolerated dose was not reached at doses up to 3.0 mg daily. The best overall response was a PR in 1 patient, and 6 patients had SD. In part 2, the combination of trametinib and gemcitabine was tolerated for a short period of time. However, serious interstitial lung disease (ILD) was observed in 3 of 5 patients 4 weeks or more after the start of the treatment, including 1 fatal case. Three patients achieved a PR, and 2 patients had SD. The most common adverse event was rash (85 % in part 1 and 100 % in part 2). CONCLUSIONS: Trametinib monotherapy was tolerable in Japanese patients with cancer. However, the combination of trametinib plus gemcitabine carried a higher risk as compared with monotherapy, during which no ILD was observed. (ClinicalTrials.gov number, NCT01324258.).

Phase I dose-escalation and pharmacokinetic trial of lapatinib (GW572016), a selective oral dual inhibitor of ErbB-1 and -2 tyrosine kinases, in Japanese patients with solid tumors.

OBJECTIVE: The Phase I dose-escalation study was conducted to evaluate the safety and pharmacokinetics of lapatinib (GW572016), a dual ErbB-1 and -2 inhibitor, in Japanese patients with solid tumors that generally express ErbB-1 and/or overexpress ErbB-2. METHODS: Patients received oral lapatinib once daily until disease progression or in an event of unacceptable toxicity. RESULTS: Twenty-four patients received lapatinib at dose levels of 900, 1200, 1600 and 1800 mg/day; six subjects enrolled to each dose level. The majority of drug-related adverse events was mild (Grade 1-2); the most common events were diarrhea (16 of 24; 67%), rash (13 of 24; 54%) and dry skin (8 of 24; 33%). No Grade 4 adverse event was observed. There were four Grade 3 drug-related adverse events in three patients (i.e. two events of diarrhea at 1600 and 1800 mg/day each and gamma-glutamyl transpeptidase increase at 1800 mg/day). The maximum tolerated dose was 1800 mg/day. The pharmacokinetic profile of lapatinib in Japanese patients was comparable to that of western subjects. CONCLUSIONS: Lapatinib was well tolerated at doses of 900-1600 mg/day in Japanese solid tumor patients. Overall, our findings were similar to those of overseas studies.

Phase 1/2 study assessing the safety and efficacy of dabrafenib and trametinib combination therapy in Japanese patients with BRAF V600 mutation-positive advanced cutaneous melanoma.

The combination of dabrafenib and trametinib demonstrated encouraging antitumor activity and tolerability, at initial analysis, in Japanese patients with BRAF V600 mutant advanced melanoma warranting further investigation. This study evaluated the safety and tolerability, pharmacokinetics (PK) and preliminary efficacy of dabrafenib 150 mg b.i.d. plus trametinib 2 mg q.d. in Japanese patients with BRAF V600E/K mutant solid tumors (phase 1) and melanoma (phase 2). Phase 1 was primarily intended to assess safety and tolerability as assessed by adverse events (AE), and the primary end-point in phase 2 was to assess confirmed overall response rate (ORR). The secondary end-points in phase 1 included PK, confirmed/unconfirmed ORR and duration of response (DOR). The secondary end-points in phase 2 were PK, unconfirmed ORR, DOR, safety and tolerability. A total of 12 cutaneous melanoma patients were enrolled in the study (six in phase 1 and six in phase 2) and received the combination therapy of dabrafenib and trametinib. Common AE (≥50.0%) included pyrexia (75%), increased aspartate aminotransferase (67%), peripheral edema (50%) and nasopharyngitis (50%). The investigator-assessed ORR was reported in five patients (83%) in phase 1 and was also reported in five patients (83%; 95% confidence interval, 35.9-99.6; P < 0.0001) in phase 2. Plasma concentrations of both dabrafenib and trametinib seemed to a reach steady state by week 3. Overall, efficacy and PK properties for the dabrafenib plus trametinib combination in Japanese patients were comparable with those seen in global studies.

Lapatinib plus paclitaxel versus paclitaxel alone in the second-line treatment of HER2-amplified advanced gastric cancer in Asian populations: TyTAN--a randomized, phase III study.

PURPOSE: In Asian countries, paclitaxel once per week is used as second-line treatment in advanced gastric cancer, including human epidermal growth factor receptor 2 (HER2) -positive tumors. The role of anti-HER2 agents, including lapatinib, in this setting and population is unclear. PATIENTS AND METHODS: TyTAN was a two-part, parallel-group, phase III study in Asian patients. An open-label, dose-optimization phase (n = 12) was followed by a randomized phase (n = 261), in which patients who were HER2 positive by fluorescence in situ hybridization (FISH) received lapatinib 1,500 mg once per day plus once-per-week paclitaxel 80 mg/m(2) or paclitaxel alone. The primary end point was overall survival (OS). Secondary end points included progression-free survival (PFS), time to progression (TTP), overall response rate (ORR), time to response, response duration, and safety. Analyses were based on immunohistochemistry (IHC) and gastrectomy status, prior trastuzumab therapy, and regional subpopulations. RESULTS: Median OS was 11.0 months with lapatinib plus paclitaxel versus 8.9 months with paclitaxel alone (P = .1044), with no significant difference in median PFS (5.4 v 4.4 months) or TTP (5.5 v 4.4 months). ORR was higher with lapatinib plus paclitaxel versus paclitaxel alone (odds ratio, 3.85; P < .001). Better efficacy with lapatinib plus paclitaxel was demonstrated in IHC3+ compared with IHC0/1+ and 2+ patients and in Chinese compared with Japanese patients. A similar proportion of patients experienced adverse events with each treatment (lapatinib plus paclitaxel, 100% v paclitaxel alone, 98%). CONCLUSION: Lapatinib plus paclitaxel demonstrated activity in the second-line treatment of patients with HER2 FISH-positive IHC3+ advanced gastric cancer but did not significantly improve OS in the intent-to-treat population.

Phase I and pharmacologic study of weekly bolus topotecan for advanced non-small-cell lung cancer.

PURPOSE: We conducted a phase I trial of the topoisomerase I inhibitor topotecan for the purpose of determining the maximum tolerated dose (MTD) and the dose-limiting toxicities (DLTs) of topotecan when administered weekly to patients with advanced non-small-cell lung cancer. PATIENTS AND METHODS: Twelve patients with stage IIIB or IV disease were treated with topotecan by 30-minute intravenous infusion on days 1, 8, and 15 every 4 weeks. The dose was escalated in 2-mg/m2 increments from the starting dose of 4 mg/m2 until the MTD was reached. After the MTD had been reached in previously treated patients, chemotherapy-naive patients were enrolled for treatment at that dose, and the dose was escalated to estimate the MTD in the treatment-naive group. RESULTS: The MTD of topotecan was determined to be 6 mg/m2 in the previously treated group and 8 mg/m2 in the chemotherapy-naive group. All 3 previously treated patients experienced DLT at the 6-mg/m2 dose level. Although only 1 of the 3 previously treated patients experienced DLT (grade 4 neutropenia for > or = 3 days) at the 8-mg/m2 dose level, skipping the topotecan dose on day 15 because of neutropenia was reported in 2 patients. Anorexia and general fatigue were the common nonhematologic toxicities. CONCLUSION: The recommended dose of topotecan for phase II studies in previously untreated patients is 6 mg/m2 on days 1, 8, and 15, every 28 days, and 4 mg/m2 appears to be a suitable dose for use in previously treated patients with this schedule.