A Study Comparing Trametinib and Dabrafenib Combination Therapy to Dabrafenib Monotherapy in Subjects With BRAF-mutant Melanoma

Novartis Pharmaceuticals423 enrolled

Overview

This was a two-arm, double-blinded, randomized, Phase III study comparing dabrafenib and trametinib combination therapy to dabrafenib administered with a placebo (dabrafenib monotherapy). Subjects with histologically confirmed cutaneous melanoma that is either Stage IIIC (unresectable) or Stage IV, and BRAF V600E/K mutation positive were screened for eligibility. Subjects who had prior systemic anti-cancer treatment in the advanced or metastatic setting were not eligible although prior systemic treatment in the adjuvant setting was allowed. Subjects were stratified according to the baseline lactate dehydrogenase level and BRAF genotype.

Dabrafenib and trametinib was administered orally at their recommended monotherapy doses of 150 mg b.i.d and 2 mg q.d., respectively. Subjects in the combination therapy arm received both agents; subjects in the dabrafenib monotherapy arm received dabrafenib and placebo. Treatment was continued in both arms until disease progression, death, unacceptable toxicity, or withdrawal of consent. After treatment discontinuation, subjects were followed for survival and disease progression as applicable to collect data for the secondary objective of overall survival (OS). Crossover to the combination therapy arm was allowed for subjects still receiving study treatment on the dabrafenib monotherapy arm after the positive result for the final OS analysis.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

QUADRUPLE

Enrollment

423

Conditions

Melanoma

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Histologically confirmed cutaneous melanoma that is either Stage IIIC (unresectable) or Stage IV (metastatic), and determined to be BRAF V600E/K mutation-positive using the bioMerieux (bMx) investigational use only (IUO) THxID BRAF Assay (IDE: G120011). The assay will be conducted by a central reference laboratory. Subjects with ocular or mucosal melanoma are not eligible. * The subject must have a radiologically measurable tumor * The subject is able to carry out daily life activities without significant difficulty (ECOG performance status score of 0 or 1). * Able to swallow and retain oral medication * Sexually active subjects must use acceptable methods of contraception during the course of the study * Adequate organ system function and blood counts Exclusion Criteria: * Prior treatment with a BRAF or a MEK inhibitor * Prior systemic anti-cancer treatment for Stage IIIC (unresectable) or Stage IV (metastatic) melanoma. Prior systemic treatment in the adjuvant setting is allowed. (Note: Ipilimumab treatment must end at least 8 weeks prior to randomization.) * The subject has received major surgery or certain tyes of cancer therapy with 21 days of starting treatment * Current use of prohibited medication listed in the protocol * Left ventricular ejection fraction less than the lower limit of normal * Uncontrolled blood pressurl * History or current evidence of retinal vein occlusion or central serous retinopathy * Brain metastases unless previously treated with surgery or stereotactic radiosurgery and the disease has been stable for at least 12 weeks * The subject is pregnant or nursing

Outcomes

Primary Outcomes

Progression-Free Survival (PFS) as Assessed by the Investigator

PFS is defined as the interval between the date of randomization and the earliest date of PD or death due to any cause. PD was based on radiographic or photographic evidence, and assessments were made by the investigator according to RECIST, version 1.1. PD is defined as at least a 20% increase in the sum of the diameters of target lesions, taking as a reference, the smallest sum of diameters recorded since the treatment started. In addition, the sum must have an absolute increase from nadir of 5 mm. The appearance of one or more new lesions, or the worsening of non-target lesions significant enough to require study treatment discontinuation, was also included as PD. Participants who received anti-cancer therapy prior to the date of documented events, were censored at the last adequate assessment prior to the initiation of therapy. If the participant did not have documented progression or death, PFS was censored at the date of the last adequate assessment.

Time frame: From randomization until the earliest date of disease progression (PD) or death due to any cause (up to approximately 6 years)

Secondary Outcomes

Overall Survival (OS)

OS is defined as the interval of time between the date of randomization and the date of death due to any cause. For the participants who did not die, overall survival was censored at the date of last contact.

Time frame: From the date of randomization until date of death due to any cause (up to approximately 6 years)

Objective Response Rate (ORR) as Assessed by the Investigator

ORR is defined as the percentage of participants with a confirmed complete response (CR) or partial response (PR). A participant was defined as a responder if he/she sustained a complete response (CR: the disappearance of all target lesions and any pathological lymph nodes must have a short axis of \<10 mm and the disappearance of all non-target lesions) or partial response (PR: at least a 30% decrease in the sum of the diameters of target lesions, taking as a reference, the Baseline sum of the diameters or the persistence of 1 or more non-target lesions or lymph nodes identified as a site of disease at Baseline with a short axis of ≥10mm). Only descriptive analysis performed.

Time frame: From randomization until the first documented complete response or partial response (up to approximately 6 years)

Duration of Response (DoR)

Duration of response is defined as the time from the first documented complete response (CR: the disappearance of all target lesions and any pathological lymph nodes must have a short axis of \<10 mm and the disappearance of all non-target lesions) or partial response (PR: at least a 30% decrease in the sum of the diameters of target lesions, taking as a reference, the Baseline sum of the diameters or the persistence of 1 or more non-target lesions or lymph nodes identified as a site of disease at Baseline with a short axis of ≥10mm) until disease progression (PD) or death due to any cause. PD is defined as at least a 20% increase in the sum of the diameters of target lesions with an absolute increase of at least 5mm or the appearance of one or more new lesions, or the worsening of non target lesions significant enough to require study treatment discontinuation. PD was based on the radiological evidence by investigator. Only descriptive analysis performed.

Time frame: From the time of the first documented response (CR or PR) until disease progression (up to approximately 6 years)

Trametinib Pharmacokinetic Concentrations

Blood samples were collected for Pharmacokinetic (PK) analysis in all participants. Three blood samples were collected at Week 8: pre-dose, 1-3 hours post dose, and 4-6 hours post dose. One pre-dose blood sample was obtained at Weeks 16 and 24. Only descriptive analysis performed.

Time frame: Week 8 (0, 1-3, 4-6 hours post dose), Weeks 16 and 24 (0 hour pre-dose)

Dabrafenib and Dabrafenib Metabolites (Hydroxy-, Carboxy- and Desmethyl-Dabrafenib) Concentrations

Blood samples were collected for PK analysis in all participants. Three blood samples were collected at Week 8: pre-dose, 1-3 hours post dose, and 4-6 hours post dose. One pre-dose blood sample was obtained at Weeks 16 and 24. Plasma concentrations of Dabrafenib (GSK2118436) and its metabolites (Hydroxy-Dabrafenib (GSK2285403), Carboxy-Dabrafenib (GSK2298683), and Desmethyl-Dabrafenib (GSK2167542)) were determined using the currently approved analytical methodology. Only descriptive analysis performed.

Time frame: Week 8 (0, 1-3, 4-6 hours post dose), Weeks 16 and 24 (0 hour pre-dose)

Number of Participants With Adverse Events and Serious Adverse Events

Analysis of absolute and relative frequencies for Adverse Event (AE) and Serious Adverse Event (SAE) by primary System Organ Class (SOC) to characterize the safety of dabrafenib and trametinib combination therapy through the monitoring of relevant clinical and laboratory safety parameters. In addition, new malignancies and AEs possibly related to study treatment were collected even if they occurred more than 30 days post-treatment. Only descriptive analysis performed.

Time frame: From the time the first dose of study treatment administered until 30 days after discontinuation of study treatment (up to approximately 6 years).