Binimetinib in combination with nivolumab or nivolumab and ipilimumab in patients with previously treated microsatellite-stable metastatic colorectal cancer with RAS mutations in an open-label phase 1b/2 study.

BACKGROUND: In patients with previously treated RAS-mutated microsatellite-stable (MSS) metastatic colorectal cancer (mCRC), a multicenter open-label phase 1b/2 trial was conducted to define the safety and efficacy of the MEK1/MEK2 inhibitor binimetinib in combination with the immune checkpoint inhibitor (ICI) nivolumab (anti-PD-1) or nivolumab and another ICI, ipilimumab (anti-CTLA4). METHODS: In phase 1b, participants were randomly assigned to Arm 1A (binimetinib 45 mg twice daily [BID] plus nivolumab 480 mg once every 4 weeks [Q4W]) or Arm 1B (binimetinib 45 mg BID plus nivolumab 480 mg Q4W and ipilimumab 1 mg/kg once every 8 weeks [Q8W]) to determine the maximum tolerable dose (MTD) and recommended phase 2 dose (RP2D) of binimetinib. The MTD/RP2D was defined as the highest dosage combination that did not cause medically unacceptable dose-limiting toxicities in more than 35% of treated participants in Cycle 1. During phase 2, participants were randomly assigned to Arm 2A (binimetinib MTD/RP2D plus nivolumab) or Arm 2B (binimetinib MTD/RP2D plus nivolumab and ipilimumab) to assess the safety and clinical activity of these combinations. RESULTS: In phase 1b, 21 participants were randomized to Arm 1A or Arm 1B; during phase 2, 54 participants were randomized to Arm 2A or Arm 2B. The binimetinib MTD/RP2D was determined to be 45 mg BID. In phase 2, no participants receiving binimetinib plus nivolumab achieved a response. Of the 27 participants receiving binimetinib, nivolumab, and ipilimumab, the overall response rate was 7.4% (90% CI: 1.3, 21.5). Out of 75 participants overall, 74 (98.7%) reported treatment-related adverse events (AEs), of whom 17 (22.7%) reported treatment-related serious AEs. CONCLUSIONS: The RP2D binimetinib regimen had a safety profile similar to previous binimetinib studies or nivolumab and ipilimumab combination studies. There was a lack of clinical benefit with either drug combination. Therefore, these data do not support further development of binimetinib in combination with nivolumab or nivolumab and ipilimumab in RAS-mutated MSS mCRC. TRIAL REGISTRATION: NCT03271047 (09/01/2017).

A plain language summary of the PHAROS study: the combination of encorafenib and binimetinib for people with BRAF V600E-mutant metastatic non-small cell lung cancer.

WHAT IS THIS SUMMARY ABOUT?: This is a summary of the results of a study called PHAROS. This study looked at combination treatment with encorafenib (BRAFTOVI®) and binimetinib (MEKTOVI®). This combination of medicines was studied in people with metastatic non-small-cell lung cancer (NSCLC). NSCLC is the most common type of lung cancer. Metastatic means that the cancer has spread to other parts of the body. All people in this study had a type of NSCLC that has a change in a gene called BRAF termed a BRAF V600E mutation. A gene is a part of the DNA that has instructions for making things that your body needs to work, and the BRAF V600E mutation contributes to the growth of the lung cancer. WHAT WERE THE RESULTS?: In this study, 98 people with BRAF V600E-mutant metastatic NSCLC were treated with the combination of encorafenib and binimetinib (called encorafenib plus binimetinib in this summary). Before starting the study, 59 people had not received any treatment for their metastatic NSCLC, and 39 people had received previous anticancer treatment. At the time of this analysis, 44 (75%) out of 59 people who did not receive any treatment before taking encorafenib plus binimetinib had their tumors shrink or disappear. Eighteen (46%) out of 39 people who had received treatment before starting encorafenib plus binimetinib also had their tumors shrink or disappear. The most common side effects of encorafenib plus binimetinib were nausea, diarrhea, fatigue, and vomiting. WHAT DO THE RESULTS MEAN?: These results support the use of encorafenib plus binimetinib combination treatment as a new treatment option in people with BRAF V600E-mutant metastatic NSCLC. The side effects of encorafenib plus binimetinib in this study were similar to the side effects seen with encorafenib plus binimetinib in people with a type of skin cancer called metastatic melanoma.

Phase II, Open-Label Study of Encorafenib Plus Binimetinib in Patients With BRAFV600-Mutant Metastatic Non-Small-Cell Lung Cancer.

PURPOSE: The combination of encorafenib (BRAF inhibitor) plus binimetinib (MEK inhibitor) has demonstrated clinical efficacy with an acceptable safety profile in patients with BRAFV600E/K-mutant metastatic melanoma. We evaluated the efficacy and safety of encorafenib plus binimetinib in patients with BRAFV600E-mutant metastatic non-small-cell lung cancer (NSCLC). METHODS: In this ongoing, open-label, single-arm, phase II study, patients with BRAFV600E-mutant metastatic NSCLC received oral encorafenib 450 mg once daily plus binimetinib 45 mg twice daily in 28-day cycles. The primary end point was confirmed objective response rate (ORR) by independent radiology review (IRR). Secondary end points included duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), overall survival, time to response, and safety. RESULTS: At data cutoff, 98 patients (59 treatment-naïve and 39 previously treated) with BRAFV600E-mutant metastatic NSCLC received encorafenib plus binimetinib. Median duration of treatment was 9.2 months with encorafenib and 8.4 months with binimetinib. ORR by IRR was 75% (95% CI, 62 to 85) in treatment-naïve and 46% (95% CI, 30 to 63) in previously treated patients; median DOR was not estimable (NE; 95% CI, 23.1 to NE) and 16.7 months (95% CI, 7.4 to NE), respectively. DCR after 24 weeks was 64% in treatment-naïve and 41% in previously treated patients. Median PFS was NE (95% CI, 15.7 to NE) in treatment-naïve and 9.3 months (95% CI, 6.2 to NE) in previously treated patients. The most frequent treatment-related adverse events (TRAEs) were nausea (50%), diarrhea (43%), and fatigue (32%). TRAEs led to dose reductions in 24 (24%) and permanent discontinuation of encorafenib plus binimetinib in 15 (15%) patients. One grade 5 TRAE of intracranial hemorrhage was reported. Interactive visualization of the data presented in this article is available at the PHAROS dashboard (https://clinical-trials.dimensions.ai/pharos/). CONCLUSION: For patients with treatment-naïve and previously treated BRAFV600E-mutant metastatic NSCLC, encorafenib plus binimetinib showed a meaningful clinical benefit with a safety profile consistent with that observed in the approved indication in melanoma.

Encorafenib plus binimetinib in patients with BRAFV600-mutant non-small cell lung cancer: phase II PHAROS study design.

BRAFV600 oncogenic driver mutations occur in 1-2% of non-small-cell lung cancers (NSCLCs) and have been shown to be a clinically relevant target. Preclinical/clinical evidence support the efficacy and safety of BRAF and MEK inhibitor combinations in patients with NSCLC with these mutations. We describe the design of PHAROS, an ongoing, open-label, single-arm, phase II trial evaluating the BRAF inhibitor encorafenib plus the MEK inhibitor binimetinib in patients with metastatic BRAFV600-mutant NSCLC, as first- or second-line treatment. The primary end point is objective response rate, based on independent radiologic review (per RECIST v1.1); secondary objectives evaluated additional efficacy end points and safety. Results from PHAROS will describe the antitumor activity/safety of encorafenib plus binimetinib in patients with metastatic BRAFV600-mutant NSCLC.

Plain language summary Some people with non-small-cell lung cancer (NSCLC) have changes in a gene called BRAF (known as 'gene mutations'). One common BRAF mutation is called 'V600'. Combinations of medicines that block proteins encoded by mutant BRAF and another gene called MEK can shrink tumors and slow their progression. We describe the design of PHAROS, a clinical trial investigating encorafenib (mutant BRAF inhibitor) combined with binimetinib (MEK inhibitor) in people with BRAF^V600-mutant NSCLC that had spread to other parts of the body ('metastatic disease'). People are monitored for side effects and to see if their tumor shrunk. PHAROS includes people treated with encorafenib plus binimetinib as their first treatment for metastatic disease, and people whose cancer progressed after previous anticancer therapy. Clinical trial registration: Clinicaltrials.gov (NCT03915951) and EudraCT (2019-000417-37).

Factors Influencing Infusion-Related Reactions Following Dosing of Reference Rituximab and PF-05280586, a Rituximab Biosimilar.

BACKGROUND: Infusion-related reactions (IRRs) are the most common adverse event (AE) associated with infusion of rituximab, an anti-CD20 monoclonal antibody. OBJECTIVE: Our objective was to evaluate the impact of dosing/infusion patterns and certain baseline characteristics on IRR occurrence during the first rituximab infusion administered as the biosimilar PF-05280586 (RTX-PF) or reference rituximab sourced from the EU (RTX-EU, MabThera®) in patients with CD20+ low-tumor-burden follicular lymphoma. PATIENTS AND METHODS: Rituximab (RTX-PF, n=196; RTX-EU, n=198) was administered (375 mg/m2) on days 1, 8, 15, and 22 (one cycle), with a follow-up period through 52 weeks. The relationships between infusion rate, drug exposure, and IRR incidence were assessed by logistic regression analysis and pharmacokinetic modeling and simulation. Baseline CD20 level, antidrug antibody (ADA) status, and tumor burden according to IRR occurrence (yes/no) were compared descriptively. RESULTS: Median rituximab infusion duration on day 1 was 3.50 h for each of the two groups. There was a positive correlation between infusion rate and all-grade IRRs occurring within 24 h after infusion (p < 0.0001). Patients who developed IRRs had a higher median baseline CD20+ level. IRR incidence was unaffected by baseline ADA status. Drug exposure did not predict IRR incidence. Baseline tumor burden was similar between patients with and without IRRs. CONCLUSIONS: Results of this analysis provide a better understanding of IRRs after the first rituximab (RTX-PF or RTX-EU) infusion and demonstrate a potential correlation of infusion rate and other factors with IRR at the individual and population levels. Infusion-rate escalation steps continue to be needed to manage IRRs. TRIAL REGISTRATION (DATE OF REGISTRATION): ClinicalTrials.gov Identifier: NCT02213263 (11 August 2014); and EudraCT: 2014-000132-41 (10 October 2014).

A Randomized, Double-Blind, Efficacy and Safety Study of PF-05280586 (a Rituximab Biosimilar) Compared with Rituximab Reference Product (MabThera®) in Subjects with Previously Untreated CD20-Positive, Low-Tumor-Burden Follicular Lymphoma (LTB-FL).

BACKGROUND: Biosimilars are highly similar to the licensed biologic ("reference product"), with no clinically meaningful differences in safety, purity, or potency between the two products. OBJECTIVE: This comparative 52-week clinical study evaluated the efficacy, safety, immunogenicity, pharmacokinetics (PK), and pharmacodynamics (PD) of PF-05280586 (Ruxience™ [a rituximab biosimilar]) versus rituximab reference product sourced from the EU (MabThera®; rituximab-EU). PATIENTS AND METHODS: Subjects with CD20-positive, low-tumor-burden follicular lymphoma (LTB-FL) and an Eastern Cooperative Oncology Group performance status 0-1 were randomized (1:1) to PF-05280586 or rituximab-EU (375 mg/m2 intravenously [once weekly for 4 weeks at days 1, 8, 15, and 22]), stratified using the Follicular Lymphoma International Prognostic Index 2 classification. The primary endpoint was overall response rate (ORR) at week 26 (percentage of subjects achieving complete response [CR] or partial response [PR]). Therapeutic equivalence was concluded if the two-sided 95% confidence interval (CI) for the difference in ORR between groups was within the prespecified margin (± 16%). Secondary endpoints included progression-free survival (PFS), CR rate, safety, immunogenicity, PK, and PD. RESULTS: A total of 394 subjects were randomized: PF-05280586 (n = 196) or rituximab-EU (n = 198). ORR at week 26 was 75.5% (PF-05280586) versus 70.7% (rituximab-EU), for a difference of 4.66%; 95% CI (- 4.16 to 13.47), which was entirely within the prespecified equivalence margin. Rates of CR were 29.3% (PF-05280586) versus 31.0% (rituximab-EU). Estimated 1-year PFS rates were 78.2% (95% CI 70.2-84.2) and 83.0% (95% CI 75.0-88.6) for PF-05280586 and rituximab-EU, respectively. Safety, immunogenicity, and mean serum concentrations were similar between groups. CONCLUSIONS: The efficacy, safety, immunogenicity, PK, and PD of PF-05280586 and rituximab-EU were similar up to week 52 in subjects with previously untreated CD20-positive LTB-FL. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02213263 and EudraCT (2014-000132-41).