A Phase II Redifferentiation Trial with Dabrafenib-Trametinib and 131I in Metastatic Radioactive Iodine Refractory BRAF p.V600E Mutated Differentiated thyroid Cancer

PURPOSE

To evaluate the efficacy and safety of dabrafenib-trametinib-131I for the treatment of radioactive iodine refractory metastatic differentiated thyroid cancer (DTC) with a BRAFp.V600E mutation.

EXPERIMENTAL DESIGN

A prospective phase II trial including patients with RECIST progression within 18 months and no lesion >3 cm. Following a baseline recombinant human (rh)TSH-stimulated diagnostic whole-body scan (dc1-WBS), dabrafenib and trametinib were given for 42 days. A second rhTSH-stimulated dc WBS (dc2-WBS) was done at day 28 and 131I (5.5 GBq-150mCi after rhTSH) was administered at day 35. Primary endpoint was the 6-months RECIST objective response rate. In case of partial response (PR) at 6 or 12 months, a second treatment course could be given. Among 24 enrolled patients, 21 were evaluable at 6 months.

RESULTS

Abnormal 131I uptake was present on 5%, 65% and 95% of the dc1-WBS, dc2-WBS and post-therapy scan, respectively. At 6 months, PR was achieved in 38%, stable disease in 52% and progressive disease (PD) in 10%. Ten patients received a second treatment course: one complete response and 6 PR were observed at 6 months. The median progression free survival (PFS) was not reached. The 12 and 24-months PFS were 82% and 68%, respectively. One death due to PD occurred at 24 months. Adverse events (AEs) occurred in 96% of the patients with 10 grade 3-4 AEs in 7 patients.

CONCLUSION

Dabrafenib-trametinib is effective in BRAFp.V600E mutated DTC patients for restoring 131I uptake with partial response observed 6 months after 131I administration in 38% of the patients.

Postoperative radiotherapy versus no postoperative radiotherapy in patients with completely resected non-small-cell lung cancer and proven mediastinal N2 involvement (Lung ART): an open-label, randomised, phase 3 trial

BACKGROUND

In patients with non-small-cell lung cancer (NSCLC), the use of postoperative radiotherapy (PORT) has been controversial since 1998, because of one meta-analysis showing a deleterious effect on survival in patients with pN0 and pN1, but with an unclear effect in patients with pN2 NSCLC. Because many changes have occurred in the management of patients with NSCLC, the role of three-dimensional (3D) conformal PORT warrants further investigation in patients with stage IIIAN2 NSCLC. The aim of this study was to establish whether PORT should be part of their standard treatment.

METHODS

Lung ART is an open-label, randomised, phase 3, superiority trial comparing mediastinal PORT to no PORT in patients with NSCLC with complete resection, nodal exploration, and cytologically or histologically proven N2 involvement. Previous neoadjuvant or adjuvant chemotherapy was allowed. Patients aged 18 years or older, with an WHO performance status of 0-2, were recruited from 64 hospitals and cancer centres in five countries (France, UK, Germany, Switzerland, and Belgium). Patients were randomly assigned (1:1) to either the PORT or no PORT (control) groups via a web randomisation system, and minimisation factors were the institution, administration of chemotherapy, number of mediastinal lymph node stations involved, histology, and use of pre-treatment PET scan. Patients received PORT at a dose of 54 Gy in 27 or 30 daily fractions, on five consecutive days a week. Three dimensional conformal radiotherapy was mandatory, and intensity-modulated radiotherapy was permitted in centres with expertise. The primary endpoint was disease-free survival, analysed by intention to treat at 3 years; patients from the PORT group who did not receive radiotherapy and patients from the control group with no follow-up were excluded from the safety analyses. This trial is now closed. This trial is registered with ClinicalTrials.gov number, NCT00410683.

FINDINGS

Between Aug 7, 2007, and July 17, 2018, 501 patients, predominantly staged with 18F-fluorodeoxyglucose (18F-FDG) PET (456 [91%]; 232 (92%) in the PORT group and 224 (90%) in the control group), were enrolled and randomly assigned to receive PORT (252 patients) or no PORT (249 patients). At the cutoff date of May 31, 2019, median follow-up was 4·8 years (IQR 2·9-7·0). 3-year disease-free survival was 47% (95% CI 40-54) with PORT versus 44% (37-51) without PORT, and the median disease-free survival was 30·5 months (95% CI 24-49) in the PORT group and 22·8 months (17-37) in the control group (hazard ratio 0·86; 95% CI 0·68-1·08; p=0·18). The most common grade 3-4 adverse events were pneumonitis (13 [5%] of 241 patients in the PORT group vs one [<1%] of 246 in the control group), lymphopenia (nine [4%] vs 0), and fatigue (six [3%] vs one [<1%]). Late-grade 3-4 cardiopulmonary toxicity was reported in 26 patients (11%) in the PORT group versus 12 (5%) in the control group. Two patients died from pneumonitis, partly related to radiotherapy and infection, and one patient died due to chemotherapy toxicity (sepsis) that was deemed to be treatment-related, all of whom were in the PORT group.

INTERPRETATION

Lung ART evaluated 3D conformal PORT after complete resection in patients who predominantly had been staged using (18F-FDG PET-CT and received neoadjuvant or adjuvant chemotherapy. 3-year disease-free survival was higher than expected in both groups, but PORT was not associated with an increased disease-free survival compared with no PORT. Conformal PORT cannot be recommended as the standard of care in patients with stage IIIAN2 NSCLC.

FUNDING

French National Cancer Institute, Programme Hospitalier de Recherche Clinique from the French Health Ministry, Gustave Roussy, Cancer Research UK, Swiss State Secretary for Education, Research, and Innovation, Swiss Cancer Research Foundation, Swiss Cancer League.