Dabrafenib plus trametinib versus dabrafenib monotherapy in patients with metastatic BRAF V600E/K-mutant melanoma: long-term survival and safety analysis of a phase 3 study

Background

Previous analysis of COMBI-d (NCT01584648) demonstrated improved progression-free survival (PFS) and overall survival (OS) with combination dabrafenib and trametinib versus dabrafenib monotherapy in BRAF V600E/K-mutant metastatic melanoma. This study was continued to assess 3-year landmark efficacy and safety after ≥36-month follow-up for all living patients.

Patients and methods

This double-blind, phase 3 study enrolled previously untreated patients with BRAF V600E/K-mutant unresectable stage IIIC or stage IV melanoma. Patients were randomized to receive dabrafenib (150 mg twice daily) plus trametinib (2 mg once daily) or dabrafenib plus placebo. The primary endpoint was PFS; secondary endpoints were OS, overall response, duration of response, safety, and pharmacokinetics.

Results

Between 4 May and 30 November 2012, a total of 423 of 947 screened patients were randomly assigned to receive dabrafenib plus trametinib (n = 211) or dabrafenib monotherapy (n = 212). At data cut-off (15 February 2016), outcomes remained superior with the combination: 3-year PFS was 22% with dabrafenib plus trametinib versus 12% with monotherapy, and 3-year OS was 44% versus 32%, respectively. Twenty-five patients receiving monotherapy crossed over to combination therapy, with continued follow-up under the monotherapy arm (per intent-to-treat principle). Of combination-arm patients alive at 3 years, 58% remained on dabrafenib plus trametinib. Three-year OS with the combination reached 62% in the most favourable subgroup (normal lactate dehydrogenase and <3 organ sites with metastasis) versus only 25% in the unfavourable subgroup (elevated lactate dehydrogenase). The dabrafenib plus trametinib safety profile was consistent with previous clinical trial observations, and no new safety signals were detected with long-term use.

Conclusions

These data demonstrate that durable (≥3 years) survival is achievable with dabrafenib plus trametinib in patients with BRAF V600-mutant metastatic melanoma and support long-term first-line use of the combination in this setting.

Phase II randomized trial of vinorelbine and gemcitabine versus carboplatin and paclitaxel in advanced non-small-cell lung cancer

BACKGROUND

The purpose of this study was to compare quality of life and overall toxicity in patients with advanced non-small-cell lung cancer (NSCLC) treated with vinorelbine-gemcitabine (VG) or carboplatin-paclitaxel (Taxol) (CP).

PATIENTS AND METHODS

A total of 165 previously untreated patients were randomized to the two regimens. Quality of life was assessed by the Lung Cancer Symptom Scale (LCSS). Overall toxicity and secondary efficacy end points were evaluated by standard WHO criteria.

RESULTS

There was no significant difference in overall quality of life between the two treatments. Neutropenia, thrombocytopenia, peripheral neuropathy, and alopecia, were more common in the CP arm, whereas constipation was more frequent in the VG arm. Response rates were 14.6% in the VG arm and 16.9% in the CP arm. Median survival times were 7.8 and 8.6 months, and 1 year survival rates were 38.4% and 31.9%, respectively.

CONCLUSIONS

Patients treated with VG experienced lower toxicity, but overall quality of life was similar in both arms. Efficacy seemed comparable between VG and CP. Our study shows that VG is a viable alternative to platinum-based chemotherapy in patients with advanced NSCLC.

Long-term survival in a phase III, randomised study of topotecan versus paclitaxel in advanced epithelial ovarian carcinoma

BACKGROUND

We have continued to monitor the survival of patients randomised in a previously reported multicentre phase III study of topotecan versus paclitaxel in patients with advanced epithelial ovarian cancer who had failed one prior platinum-based regimen.

PATIENTS AND METHODS

Patients with bidimensionally measurable disease were randomised to topotecan (1.5 mg/m(2)/day for 5 days) or paclitaxel (175 mg/m(2)/day as a 3-h infusion) every 21 days. Patients were eligible for treatment with the alternate therapy at third line. The European Organisation for Research and Treatment of Cancer Quality of Life (EORTC QOL)-C30 questionnaire was also used to measure eight symptoms at baseline and during each course (pain, anorexia, diarrhoea, fatigue, nausea and vomiting, dyspnea, constipation and insomnia).

RESULTS

A total of 226 patients were evaluable for response. Demographic characteristics were similar in both treatment groups, as were results of the EORTC QOL-30 questionnaire. For the topotecan group, median time to progression was 18.9 weeks (range <1 to 92.6+ weeks; 25% censored), and, for paclitaxel, 14.7 weeks (range <1 to 137.3+ weeks; 12.3% censored); P = 0.076. At 4 years post-randomisation, median survival in the topotecan group was 63.0 weeks (range <1 to 238.4+ weeks; 20.5% censored) and, for paclitaxel, 53.0 weeks (range <1 to 226.3+ weeks; 12.3% censored); P = 0.44.

CONCLUSION

Topotecan continues to demonstrate comparable efficacy and survival to paclitaxel with manageable and non-cumulative haematological toxicity. Non-haematological toxicity was generally mild for both groups. The long-term survival rate indicates substantial therapeutic benefit for this group of patients receiving topotecan at relapse of ovarian cancer.

Oral topotecan as single-agent second-line chemotherapy in patients with advanced ovarian cancer

PURPOSE

To evaluate oral topotecan as single-agent, second-line therapy in patients with ovarian cancer previously treated with a platinum-based regimen.

PATIENTS AND METHODS

Patients (N = 116) received oral topotecan 2.3 mg/m2 daily for 5 days every 21 days. Eligibility criteria included histologic diagnosis of International Federation of Gynecology and Obstetrics stage III or IV epithelial ovarian cancer, bidimensionally measurable disease, prior platinum-containing chemotherapy, age > or = 18 years, performance status < or = 2, and life expectancy > or = 12 weeks.

RESULTS

Overall response rate was 21.6% (25 of 116 patients). Median duration of response was 25.0 weeks; median time to response was 8.4 weeks. Median time to progression was 14.1 weeks; median survival was 62.2 weeks. Grade 4 neutropenia was experienced by 50.4% of patients in 13.4% of courses administered. Grade 4 thrombocytopenia was experienced by 22.1% of patients in 5.1% of courses. Grade 3 or 4 anemia was experienced by 29.2% of patients in 8.5% of courses. Most frequent nonhematologic toxicities were predominantly (> 90%) grade 1 or 2 and included nausea, alopecia, diarrhea, and vomiting.

CONCLUSION

Second-line oral topotecan administered at 2.3 mg/m2 for 5 days every 21 days demonstrated activity in patients with progressive or recurrent ovarian cancer after first-line platinum-based chemotherapy. This activity was comparable to that seen in previous studies with intravenous topotecan. Grade 4 neutropenia was less frequent with oral topotecan than previously reported for intravenous topotecan. Oral topotecan is an active, tolerable, and convenient formulation of an established agent for the second-line treatment of advanced epithelial ovarian cancer and may also facilitate exploring prolonged treatment schedules.

Topotecan given as a 21-day infusion in the treatment of advanced ovarian cancer

A phase II programme was carried out in both Europe and North America to evaluate the activity of topotecan administered as a 21-day continuous intravenous infusion to patients with recurrent ovarian cancer. The European results are reported here. Patients who had failed first line therapy with a platinum-based regimen received topotecan 0.4 mg/m(2)/day, as a 21-day infusion every 28 days. Patients were only permitted one prior regimen. 35 patients were enrolled and evaluable for response. 3 patients (8.6%) had a partial response to treatment (95% CI 1.8%, 23.1%) with a median time to response of 8.1 weeks and a median duration of response of 17.6 weeks. Response was also evaluated by CA125 and was also found to be 8%. For all 35 patients, median time to progression was 16.1 weeks and median survival was 43.6 weeks. The principal toxicity was myelosuppression although grade 4 neutropenia occurred in only 8.8% of patients (2.1% of courses) and infectious complications were relatively infrequent. Non-haematological toxicity was generally mild and mainly consisted of gastrointestinal events, alopecia and fatigue. A prolonged infusion of topotecan was well tolerated with a low incidence of severe neutropenia. Responses were seen in both North American and European patients. Response rates varied between the 2 studies possibly due to differences in patient demographics.

Stabilization of disease as an indicator of clinical benefit associated with chemotherapy in non-small cell lung cancer patients

In Phase II oncology studies, response rate has traditionally been used to assess activity. However stabilization of disease (SD) may also provide patient benefit. To assess the value of SD (stabilization of measurable disease for at least 8 weeks) as a predictor of survival following chemotherapy in patients with non-small cell lung cancer (NSCLC), we have analyzed data from 198 NSCLC patients receiving topotecan i.v. or orally as first-line therapy either as single agent or in combination. Proportional hazards (Cox) regression models showed that responders [complete response (CR) + partial response (PR), 1.5% and 11.6% respectively] had an estimated risk of death that was 9.8% (95% CI: 4.2% to 22.7%) of that for progressive disease (PD) (60.1% of the patient population). Similarly, patients with SD (26.8% of the patient population) showed a potential benefit with a risk of death that was 27.7% of the one of patients with PD (95% CI: 17.8% to 43.1%). In conclusion SD may be a useful indicator of patient benefit from chemotherapy for NSCLC.

Stabilization of disease as a useful predictor of survival following second-line chemotherapy in small cell lung cancer and ovarian cancer patients

To assess the value of disease stabilization (SD) as a predictor of survival following chemotherapy, data were analyzed from multicenter clinical trials in small cell lung cancer (SCLC) and ovarian cancer (OC) patients receiving various second-line chemotherapy regimens. In both patient populations, SD (lasting >8 weeks) and partial responses (PR) were associated with a survival benefit versus progressive disease (PD); interestingly, the survival benefit was similar between the two groups (PR and SD). These results suggest that, at least in these populations, SD may represent a potential benefit of chemotherapy and therefore the distinction between SD and PR may not be useful.

Topotecan versus cyclophosphamide, doxorubicin, and vincristine for the treatment of recurrent small-cell lung cancer

PURPOSE

Topotecan and cyclophosphamide, doxorubicin, and vincristine (CAV) were evaluated in a randomized, multicenter study of patients with small-cell lung cancer (SCLC) who had relapsed at least 60 days after completion of first-line therapy.

PATIENTS AND METHODS

Patients received either topotecan (1.5 mg/m2) as a 30-minute infusion daily for 5 days every 21 days (n = 107) or CAV (cyclophosphamide 1,000 mg/m2, doxorubicin 45 mg/m2, and vincristine 2 mg) infused on day 1 every 21 days (n = 104). Eligibility included the following: bidimensionally measurable disease, Eastern Cooperative Oncology Group performance status of less than or equal to 2, and adequate marrow, liver, and renal function. Response was confirmed by blinded independent radiologic review.

RESULTS

Response rate was 26 of 107 patients (24.3%) treated with topotecan and 19 of 104 patients (18.3%) treated with CAV (P = .285). Median times to progression were 13.3 weeks (topotecan) and 12.3 weeks (CAV) (P = .552). Median survival was 25.0 weeks for topotecan and 24.7 weeks for CAV (P = .795). The proportion of patients who experienced symptom improvement was greater in the topotecan group than in the CAV group for four of eight symptoms evaluated, including dyspnea, anorexia, hoarseness, and fatigue, as well as interference with daily activity (P< or =.043). Grade 4 neutropenia occurred in 37.8% of topotecan courses versus 51.4% of CAV courses (P<.001). Grade 4 thrombocytopenia and grade 3/4 anemia occurred more frequently with topotecan, occurring in 9.8% and 17.7% of topotecan courses versus 1.4% and 7.2% of CAV courses, respectively (P<.001 for both). Nonhematologic toxicities were generally grade 1 to 2 for both regimens.

CONCLUSION

Topotecan was at least as effective as CAV in the treatment of patients with recurrent SCLC and resulted in improved control of several symptoms.

Characterization of the palmitoylation domain of SNAP-25

SNAP-25 (synaptosomal associated protein of 25 kDa) is a neural specific protein that has been implicated in the synaptic vesicle docking and fusion process. It is tightly associated with membranes, and it is one of the major palmitoylated proteins found in neurons. The functional role of palmitoylation for SNAP-25 is unclear. In this report, we show that the palmitate of SNAP-25 is rapidly turned over in PC12 cells, with a half-life of approximately 3 h, and the half-life for the protein is 8 h. Mutation of Cys to Ser at positions 85, 88, 90, and 92 reduced the palmitoylation to 9, 21, 42, and 35% of the wild-type protein, respectively. Additional mutations of either Cys(85,88) or Cys(90,92) nearly abolished palmitoylation of the protein. A similar effect on membrane binding for the mutant SNAP-25 was observed, which correlated with the degree of palmitoylation. These results suggest that all four Cys residues are involved in palmitoylation and that membrane association of SNAP-25 may be regulated through dynamic palmitoylation.

Acoustic analysis of gradient-coil noise in MR imaging

A survey was conducted of acoustic noise levels in magnetic resonance (MR) imaging systems. Static magnetic flux and radio-frequency pulses did not affect the function of shielded sound-pressure detection equipment. Noise levels were measured at bore isocenter during a variety of imaging sequences in six MR imaging systems with magnetic fields of 0.35-1.5 T. Measured noise ranged from 82 to 93 dB on the A-weighted scale and from 84 to 103 dB on the linear scale. Noise levels increased during sequences employing thinner section thickness and shorter repetition and echo times and were independent of field strength. Gradient-coil noise in MR imaging is an annoyance but is well within safety guidelines.

A clinical and pathologic study of chronic sinusitis: the role of the eosinophil

Evidence exists that the eosinophil plays an important role in mediating injury to bronchial epithelium in chronic asthma. Here, the role of the eosinophil in chronic inflammatory disease of the paranasal sinuses was studied with tissue from patients who underwent surgery for chronic sinusitis. Paranasal tissue from patients with chronic asthma and/or allergic rhinitis was extensively infiltrated with eosinophils. Immunofluorescent studies demonstrated a striking association between the presence of extracellular deposition of major basic protein and damage to sinus mucosa. The histopathology of paranasal respiratory epithelium appeared similar to that described in bronchial asthma. These findings suggest that the eosinophil acts as an effector cell in chronic inflammatory disease of paranasal respiratory epithelium. Thus, sinus disease in patients with asthma may be due to the same mechanisms that cause damage to bronchial epithelium.