Category: Hem/Onc Updates

FDA Approves SARCLISA® for Relapsed Refractory Multiple Myeloma

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SUMMARY: The FDA on March 2, 2020 approved SARCLISA® (Isatuximab-irfc) in combination with POMALYST® (Pomalidomide) and Dexamethasone for adult patients with multiple myeloma who have received at least two prior therapies including REVLIMID® (Lenalidomide) and a Proteasome Inhibitor. Multiple Myeloma is a clonal disorder of plasma cells in the bone marrow and the American Cancer Society estimates that in the United States, 32,270 new cases will be diagnosed in 2020 and 12,830 patients are expected to die of the disease. Multiple Myeloma (MM) in 2020 remains an incurable disease. The therapeutic goal therefore is to improve Progression Free Survival (PFS) and Overall Survival (OS). Multiple Myeloma is a disease of the elderly, with a median age at diagnosis of 69 years and characterized by intrinsic clonal heterogeneity. Almost all patients eventually will relapse, and patients with a high-risk cytogenetic profile or refractory disease have the worst outcomes. The median survival for patients with myeloma is over 10 years.

CD38, a transmembrane glycoprotein abundantly expressed on malignant plasma cells and with low levels of expression on normal lymphoid and myeloid cells. DARZALEX® (Daratumumab) is a human IgG1 antibody that targets CD38, and was approved for use in combination with POMALYST® (Pomalidomide) and Dexamethasone in 2017, for the treatment of patients with multiple myeloma, who have received at least two prior therapies including REVLIMID® and a Proteasome Inhibitor. DARZALEX® exerts its cytotoxic effect on myeloma cells by multiple mechanisms, including Antibody Dependent Cellular Cytotoxicity (ADCC), Complement Mediated Cytotoxicity and direct apoptosis. Additionally, DARZALEX® may have a role in immunomodulation by depleting CD38-positive regulator Immune suppressor cells, and thereby expanding T cells, in patients responding to therapy.

SARCLISA® (Isatuximab) is a CD38-targeting monoclonal antibody, similar to DARZALEX®, but unlike DARZALEX®, is not associated with complement activation, and can therefore be more readily given to patients with asthma or Chronic Obstructive Pulmonary Disease. Further, SARCLISA® targets a specific epitope on the CD38 receptor, and this distinction from DARZALEX® allows use of SARCLISA® in cases when DARZALEX® fails. Additionally, SARCLISA® infusions are less cumbersome.
The present FDA approval of SARCLISA® was based on ICARIA-MM trial, which is an open-label, randomized, multicentre Phase III study in which 307 adult patients with Relapsed and Refractory multiple myeloma who had received at least two previous lines of treatment, including REVLIMID® and a Proteasome Inhibitor were eligible. Patients were excluded if they were refractory to previous treatment with an anti-CD38 monoclonal antibody. Patients were randomly assigned 1:1 to receive either SARCLISA® along with POMALYST® and low-dose Dexamethasone (N =154) or POMALYST® and low-dose Dexamethasone alone (N = 153). Treatment consisted of 28-day cycles of SARCLISA® 10 mg/kg given IV on days 1, 8, 15, and 22 in the first cycle and days 1 and 15 in subsequent cycles. Both groups received POMALYST® 4 mg orally on days 1 to 21 of each cycle and Dexamethasone 40 mg (20 mg for patients aged 75 years or older) oral or IV on days 1, 8, 15, and 22 of each cycle. Treatment was continued until disease progression or unacceptable toxicity. The Primary endpoint was Progression Free Survival (PFS), determined by an Independent Response Committee, and assessed in the intent-to-treat population.

At a median follow up of 11.6 months, the median PFS was 11.5 months in the SARCLISA® group versus 6.5 months in the control group (HR= 0.596; P=0.001). This PFS improvement represented a 40% reduction in the risk of disease progression or death in the SARCLISA® group. In a prespecified subgroup analyses, which included patients with poor prognostic features, and those refractory to REVLIMID®, a Proteasome Inhibitor, or both, the Hazard Ratios were consistently in favor of SARCLISA®.(HR=0.58). The most common adverse events of any grade in the SARCLISA® vs control groups were infusion reactions (38% versus 0%, of which 3% were Grade 3 or 4), upper respiratory tract infection (28% versus 17%), and diarrhea (26% versus 20%).

It was concluded that the addition of SARCLISA® to POMALYST® and Dexamethasone significantly improves Progression Free Survival in patients with Relapsed and Refractory multiple myeloma, and is an important new treatment option for the management of patients who become refractory to REVLIMID® and a Proteasome Inhibitor. Multiple Myeloma patients will soon have the opportunity to choose between two equally effective treatment options with various modes of administration. Isatuximab plus pomalidomide and low-dose dexamethasone versus pomalidomide and low-dose dexamethasone in patients with relapsed and refractory multiple myeloma (ICARIA-MM): a randomised, multicentre, open-label, phase 3 study. Attal M, Richardson PG, Rajkumar SV, et al. The Lancet. November 14, 2019 DOI:https://doi.org/10.1016/S0140-6736(19)32556-5

Combination of MRI-Targeted and Systematic Biopsy Increases Detection of Clinically Significant Prostate Cancer 

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SUMMARY: Prostate cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 9 men will be diagnosed with prostate cancer during their lifetime. It is estimated that in the United States, about 191,930 new cases of prostate cancer will be diagnosed in 2020 and 33,330 men will die of the disease. TransRectal UltraSound (TRUS) guided biopsy has been the standard of care for diagnosing prostate cancer in men with a clinical suspicion of prostate cancer, based on an abnormal Digital Rectal Examination and/or an elevated Prostate Specific Antigen (PSA) level. TransRectal UltraSound (TRUS) guided biopsy is a blind biopsy of the lateral and posterior peripheral zone of the prostate using a template, and 10 to 12 cores of prostate tissue is obtained (Systematic Biopsy). Even though this may result in a higher rate of prostate cancer detection, many detected cancers are low grade tumors that do not benefit from treatment, and these patients are on active surveillance for their low risk disease. The major limitation of this biopsy procedure is the risk of under-sampling a more significant tumor that is located in a region of the prostate not usually targeted with a template. Further, in patients with a rising PSA with a prior negative biopsy, patients are often subjected to a repeat blind biopsy with the same limitations as the original biopsy. Since biopsy access is through the rectum and only specific zones of the prostate are sampled, large areas of the prostate, especially the anterior and central prostate, are not routinely sampled and clinically significant higher-grade cancers are sometimes missed.
Multiparametric MRI (mp-MRI) combines anatomic imaging in the form of T2-weighted imaging, with functional imaging and is being used to detect or rule out cancer in men who have persistent concern for prostate cancer. Previously published studies have shown that MRI-targeted biopsies alone have shown similar or higher rates of detection of clinically SIGNIFICANT cancer in the prostate gland (high grade cancers) and lower rates of detection of clinically INSIGNIFICANT cancer, when compared to systematic biopsy (standard TRUS guided biopsy). This interesting advantage appears to allow the use of mp-MRI as a triage test to avoid a biopsy if the results were negative, and if positive could be used for targeting abnormal areas in the prostate during biopsy. Despite this advantage, debate persists whether MRI-targeted biopsy should be used in place of systematic biopsy or in conjunction with it.
The Trio Study is a substudy of a larger clinical trial called, Use of Tracking Devices to Locate Abnormalities During Invasive Procedures. In this substudy, the authors assessed the use of MRI-targeted, systematic, or combined MRI-targeted and systematic prostate biopsy, in an attempt to define the most effective method for prostate cancer diagnosis.
In this study a total of 2732 men with abnormal PSA or Digital Rectal Exam underwent prostate MRI. Among these patients, 2103 men had MRI-visible lesions and subsequently underwent both MRI-targeted and systematic biopsies. Grade group 1 refers to clinically INSIGNIFICANT disease (Gleason score, 3+3=6), Grade group 2 or higher refers to cancer with favorable intermediate risk or worse (Gleason score, 3+4=7), and Grade group 3 or higher refers to clinically SIGNIFICANT cancer with unfavorable intermediate risk or worse (Gleason score, 4+3=7). The Primary outcome of this study was cancer detection rates according to Grade group (Clustering of Gleason grades) for each biopsy method, and in combination.
Among all 2103 patients who underwent the two biopsy methods, prostate cancer was diagnosed in 52.5% with systematic biopsy alone and in 51.5% with MRI-targeted biopsy alone. The addition of MRI-targeted biopsy to systematic biopsy led to 208 more prostate cancer diagnoses for a total prostate cancer diagnosis of 62.4%. MRI-targeted biopsy detected more clinically SIGNIFICANT Grade group 3 or higher cancers than systematic biopsy (P=0.004) and detected fewer cancers in Grade group 1 (P<0.001). Of the 404 patients who subsequently underwent radical prostatectomy, disease upgrading on histopathology occurred in 41.6% of patients when compared to findings on systematic biopsy alone, 30.9% when compared with findings on MRI-targeted biopsy alone and 14.4% when compared with findings on combined systematic and MRI-targeted biopsy.
The authors concluded that among patients with MRI-visible lesions, a combination of systematic and MRI-targeted biopsy increases the detection of clinically significant prostate cancers, compared to either strategy alone. MRI-Targeted, Systematic, and Combined Biopsy for Prostate Cancer Diagnosis. Ahdoot M, Wilbur AR, Reese SE, et al. N Engl J Med 2020; 382:917-928

FDA Approves AYVAKIT®, a Precision Therapy, for Gastrointestinal Stromal Tumors 

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SUMMARY: The FDA on January 9, 2020, approved AYVAKIT® (Avapritinib) for adults with unresectable or metastatic GastroIntestinal Stromal Tumor (GIST) harboring a Platelet-Derived Growth Factor Receptor Alpha (PDGFRA) Exon 18 mutation, including D842V mutations. The American Cancer Society estimates that in the US, about 4000-5000 cases of GastroIntestinal Stromal Tumors (GISTs) are diagnosed each year. GI Stromal Tumor (GIST) is one of the most common types of Soft Tissue Sarcoma and can develop anywhere along the GI tract, but are primarily found in the stomach (60%) and small intestine (30%). GISTs originate from the interstitial cells of Cajal or related stem cells and are associated with activating mutations in KIT-CD117 (80%) or PDGFRA (5-10%). These two mutations are mutually exclusive and are important in the molecular pathogenesis of these tumors. PDGFRA-mutated GISTs are mostly of gastric origin and display epithelioid morphology or mixed epithelioid and spindle histology. Gain-of-function mutations lead to constitutive, ligand independent activation of PDGFRA and its downstream pathways, subsequently resulting in cell proliferation and apotosis inhibition. Primary PDGFRA mutations are found mainly in Exons 12 and 18 and rarely in Exon 14. The most frequent mutation results in an Exon 18 D842V substitution, detected in up to 75% of all PDGFRA-mutated tumors Risk-of-GIST-Recurrence-After-Surgery
Most patients with GIST are diagnosed between 50 to 80 years of age, and patients may present with GI bleeding or as incidental findings during surgery or imaging, and occasionally with tumor rupture or bowel obstruction. Approximately two thirds of the patients with GISTs are cured with surgery but recurrences are frequent and this risk of relapse is dependent on the tumor size, mitotic rate and primary tumor site. The risk stratification of GISTs by Joensuu, unlike the NIH criteria, takes into account primary tumor site and tumor rupture as well, which can influence outcomes. Treatment of patients with advanced or metastatic GIST with Tyrosine Kinase Inhibitor GLEEVEC® (Imatinib) achieves high Objective Response and diseases stabilization rates. Patients with KIT Exon 9 mutation have a poor prognosis compared to those with KIT Exon 11 mutation (most common) and benefit from a higher dose of GLEEVEC® (800 mg daily). Following progression on GLEEVEC®, FDA approved therapies include SUTENT® (Sunitinib) and STIVARGA® (Regorafenib). Patients with PDGFRA D842V mutation are GLEEVEC® resistant.
AYVAKIT® is an oral, precision therapy, and is a potent and selective type 1 inhibitor of KIT and PDGFRA mutant kinases, and is also uniquely designed to selectively bind and inhibit D816V mutant KIT, the common driver of disease in approximately 95 percent of all Systemic Mastocytosis (SM) patients.
The present FDA approval was based on NAVIGATOR trial, designed to evaluate the safety, tolerability and clinical activity of AYVAKIT® in patients with unresectable or metastatic GIST. NAVIGATOR is a multicenter, single-arm, open-label trial, which enrolled 43 patients with GIST, harboring a PDGFRA Exon 18 mutation, including 38 patients with PDGFRA D842V mutations. Patients initially enrolled in this trial received AYVAKIT® at a starting dose of 400 mg orally once daily, which was later reduced to the recommended dose of 300 mg orally once daily due to toxicity. Treatment was continued until disease progression or unacceptable toxicity. The major efficacy endpoints were Overall Response Rate (ORR) and Duration of Response.
The ORR among patients harboring a PDGFRA Exon 18 mutation was 84%, with 7% Complete Responses and 77% Partial Responses. For the subgroup of patients with PDGFRA D842V mutations, the ORR was 89%, with 8% Complete Responses and 82% Partial Responses. The median Duration of Response was not reached with a median follow up for all patients of 10.6 months. Sixty one percent (61%) of the responding patients with Exon 18 mutations had a response lasting 6 months or longer. The most common Adverse Events across all grades included nausea, vomiting, decreased appetite, diarrhea, fatigue, anemia, cognitive effects, periorbital edema, increased lacrimation and peripheral edema.
It was concluded that AYVAKIT® shows unprecedented activity in D842V and other Exon 18 mutant PDGFRA GISTs, and is the first precision therapy approved to treat a genomically defined population of patients with GIST. Heinrich M, Jones RL, von Mehren M, et al. Clinical activity of avapritinib in ≥4th line (4L+) and PDGFRA exon 18 gastrointestinal stromal tumors (GIST). J Clin Oncol. 2019;37 (suppl; abstr 11022). DOI: 10.1200/JCO.2019.37.15_suppl.11022.

Adjuvant Therapy with Low Dose YERVOY® Improves Overall Survival in Resected High Risk Melanoma 

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SUMMARY: It is estimated that in the US, approximately 100,350 new cases of melanoma will be diagnosed in 2020 and approximately 6,850 patients are expected to die of the disease. The incidence of melanoma has been on the rise for the past three decades. Stage III malignant melanoma is a heterogeneous disease and the risk of recurrence is dependent on the number of positive nodes as well as presence of palpable versus microscopic nodal disease. Further, patients with a metastatic focus of more than 1 mm in greatest dimension in the affected lymph node, have a significantly higher risk of recurrence or death, than those with a metastasis of 1 mm or less. Patients with Stage IIIA disease have a disease-specific survival rate of 78%, whereas those with Stage IIIB and Stage IIIC disease have disease-specific survival rates of 59% and 40% respectively.
Immune checkpoints are cell surface inhibitory proteins/receptors that harness the immune system, prevent uncontrolled immune reactions and suppress antitumor immunity. Antibodies that target these membrane bound inhibitory Immune checkpoint proteins/receptors such as CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4), PD-1 (Programmed cell Death-1) and PD-L1 (Programmed cell Death-Ligand1) block the Immune checkpoint proteins and ligands, unleash T cells, resulting in T cell proliferation, activation and a therapeutic response. Several agents are presently approved by the FDA for the adjuvant treatment of high-risk Melanoma and they include YERVOY® (Ipilimumab), OPDIVO® (Nivolumab), KEYTRUDA® (Pembrolizumab), high-dose Interferon alfa-2b, as well as TAFINLAR® (Dabrafenib) and MEKINIST® (Trametinib) combination for BRAF-mutant Melanoma.Unleashing-T-Cell-Function-with-YERVOY-(Ipilimumab)
YERVOY® is a fully human immunoglobulin G1 monoclonal antibody that blocks Immune checkpoint protein/receptor CTLA-4. Overall Survival however has only been established for adjuvant high-dose Interferon alfa-2b or high dose YERVOY® given at 10 mg/kg. However, the use of YERVOY® at 10mg/kg as adjuvant therapy in clinical practice has been limited by the high incidence of severe toxicities. YERVOY® at 3 mg/kg was approved in 2011 for unresectable metastatic melanoma. To further address the relative efficacy and safety of YERVOY® at the 2 dose levels, the authors in the present study compared high-dose Interferon (HDI), a standard adjuvant treatment for high-risk melanoma available since 1996, with YERVOY® given at 3 mg/kg (Ipi3) and YERVOY® given at a dose of 10 mg/kg (Ipi10). Adjuvant high dose Interferon has been shown to improve Relapse Free Survival (RFS) and Overall Survival (OS) in ECOG and several intergroup trials. 
Intergroup trial E1609 is an open-label, multicenter, multinational, 3-arm, Phase III study in which 1,670 adult patients were randomly assigned 1:1:1 to receive Ipi3 (N = 523), HDI (N = 636), or Ipi10 (N = 511). Eligible patients had completely resected Stage IIIB, IIIC, or IV (M1a or M1b) cutaneous malignant melanoma, and patients with Stage IIIB or IIIC disease were required to have complete lymph node dissection. Both Ipi3 or Ipi10 were administered IV every 3 weeks for 4 doses (induction), followed by the same dose every 12 weeks for up to 4 additional doses (maintenance). HDI was administered IV at 20 million units/m2 daily, 5 days a week, for 4 weeks (induction), followed by 10 million units/m2 subcutaneously every other day, 3 days per week, for 48 weeks (maintenance). Treatment was continued for a maximum of 60 weeks with YERVOY® or 52 weeks with HDI, or until unacceptable toxicities or disease progression. The two Coprimary end points were Overall Survival (OS) and Relapse Free Survival (RFS) of patients in the Ipi3 or Ipi10 group, each compared with outcomes of those patients in the HDI group. Secondary end points were Safety and tolerability of adjuvant YERVOY® and Quality of Life assessments.
Patients in the Ipi3 (YERVOY® 3 mg/kg) group had superior Overall Survival compared with patients in the HDI (high dose Interferon) group (HR=0.78; P=0.044). The 5 year Overall Survival rate was 72% with ipi3 and 67% with HDI. For RFS, the HR was 0.85 (P=0.065), with a median RFS of 4.5 years for Ipi3 and 2.5 years for HDI, and these study outcomes were positive and favored Ipi3, based on the protocol criteria.
When Ipi10 (YERVOY® 10 mg/kg) was compared with HDI, there were trends toward improvement in OS and RFS in favor of Ipi10, but these findings were not statistically significant. More patients in the HDI group required salvage therapy with YERVOY® or YERVOY®/PD-1 combination, compared to the Ipi3 and Ipi10 groups (P<0.001).
It was concluded that adjuvant therapy with YERVOY®, given at a dose of 3 mg/kg, was significantly less toxic and demonstrated a significant improvement in OS against an active control regimen (high dose Interferon), among patients with high-risk resected melanoma. The authors added that the current approved adjuvant YERVOY® dose of 10 mg/kg was more toxic and not superior in efficacy to high dose Interferon. Phase III Study of Adjuvant Ipilimumab (3 or 10 mg/kg) Versus High-Dose Interferon Alfa-2b for Resected High-Risk Melanoma: North American Intergroup E1609. Tarhini AA, Lee SJ, Hodi FS, et al. DOI: 10.1200/JCO.19.01381 Journal of Clinical Oncology 38, no. 6 (February 20, 2020) 567-575.

FDA Approves NERLYNX® for Advanced HER2-Positive Breast Cancer 

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SUMMARY: The FDA on February 25, 2020, approved NERLYNX® (Neratinib) in combination with XELODA® (Capecitabine) for adult patients with advanced or metastatic HER2-positive breast cancer, who have received two or more prior anti-HER2 based regimens in the metastatic setting. Breast cancer is the most common cancer among women in the US and about 1 in 8 women (13%) will develop invasive breast cancer during their lifetime. Approximately 276,480 new cases of invasive female breast cancer will be diagnosed in 2020 and about 42,170 women will die of the disease. The HER or erbB family of receptors consist of HER1, HER2, HER3 and HER4. Approximately 15-20% of invasive breast cancers overexpress HER2/neu oncogene, which is a negative predictor of outcomes without systemic therapy. Patients with HER2-positive metastatic breast cancer are often treated with anti-HER2 targeted therapy along with chemotherapy, irrespective of hormone receptor status, and this has resulted in significantly improved treatment outcomes.HER2-Directed-Therapy
NERLYNX® (Neratinib) is a potent, irreversible, oral Tyrosine Kinase Inhibitor, of HER1, HER2 and HER4 (pan-HER inhibitor). NERLYNX® interacts with the catalytic domain of HER1, HER2, and HER4 and blocks their downstream signaling pathways, resulting in decreased cell proliferation and increased cell death. Clinical data has suggested that NERLYNX® has significant activity in suppressing HER-mediated tumor growth and is able to overcome tumor escape mechanisms experienced with current HER2-targeted and chemotherapeutic agents. It has been well known that hormone receptor positive breast cancer patients, who are also HER2-positive, have relative resistance to hormone therapy. Preclinical models had suggested that the addition of NERLYNX® could improve responses in ER positive, HER2-positive breast cancer patients. Further, NERLYNX® has clinical activity in patients with HER2-positive metastatic breast cancer. NERLYNX® is the first TKI approved by the FDA, shown to reduce the risk for disease recurrence, in patients with early stage HER2-positive breast cancer. NERLYNX® when given for 12 months after chemotherapy and HERCEPTIN®-based adjuvant therapy, to women with HER2-positive breast cancer, significantly reduced the proportion of clinically relevant breast cancer relapses that might lead to death, such as distant and locoregional recurrences outside the preserved breast.
TYKERB® (Lapatinib) is a Tyrosine Kinase Inhibitor of HER2 and EGFR, and in a previously published Phase III study, a combination of TYKERB® plus XELODA® (Capecitabine) was found to be superior to XELODA® alone in women with HER2-positive advanced breast cancer, that has progressed after treatment with regimens that included an Anthracycline, a Taxane, and HERCEPTIN®. (N Engl J Med 2006; 355:2733-2743)
NALA is a multinational, randomized, open-label, Phase III trial of NERLYNX® plus XELODA® in patients with heavily pretreated Stage IV HER2-positive metastatic breast cancer. In this study, 621 patients with metastatic HER2-positive breast cancer who received two or more prior anti-HER2 based regimens in the metastatic setting were randomly assigned in a 1:1 to receive NERLYNX® 240 mg given orally once daily on days 1-21 along with XELODA® 750 mg/m2 given orally twice daily on days 1-14 for each 21-day cycle (N=307) or TYKERB® 1250 mg given orally once daily on days 1-21 along with XELODA® 1000 mg/m2 given orally twice daily on days 1-14 for each 21-day cycle (N=314). Approximately 80% had visceral metastases, and about 30% had received at least three anti-HER2 therapies. Patients in the NERLYNX® group also received antidiarrheal prophylaxis with Loperamide. Patients were treated until disease progression or unacceptable toxicity. The Co-Primary endpoints were Progression Free Survival (PFS) and Overall Survival (OS). Secondary endpoints included Objective Response Rate (ORR) and Duration of Response, Clinical Benefit Rate (CBR), time to intervention for symptomatic metastatic Central Nervous System (CNS) disease and Safety.
It was noted that the median PFS was 5.6 months for patients who received NERLYNX® with XELODA® and 5.5 months for those receiving TYKERB® with XELODA® (HR=0.76; P=0.006). This represented a 24% reduction in the risk of disease progression or death for those receiving a combination of NERLYNX® and XELODA®. The PFS rate at 12 months was 29% versus 15% respectively. The median OS was 21 months for patients receiving NERLYNX® and XELODA® compared to 18.7 months for those receiving TYKERB® and XELODA® (HR=0.88; P=0.20). The ORR was numerically higher with NERLYNX® and XELODA® combination in patients with measurable disease (32.8% versus 26.7%), and there was a statistically significant improvement in the Clinical Benefit Rate (45% versus 36%; P=0.03). The median Duration of Response was 8.5 versus 5.6 months respectively (HR=0.50; P=0.0004), favoring the NERLYNX® combination. The time to intervention for symptomatic CNS disease was significantly delayed with NERLYNX® combination versus TYKERB® combination, with an overall cumulative incidence of 22.8% versus 29.2% respectively (P= 0.043). Treatment related toxicities were similar between arms, but there was a higher rate of Grade 3 diarrhea with the NERLYNX® combination (24.4% versus 12.5% respectively). Discontinuation due to treatment related toxicities were lower with NERLYNX® combination versus TYKERB® combination (10.9% versus 14.5%).
It was concluded from this study that a combination of NERLYNX® and XELODA® significantly improved Progression Free Survival, with a trend towards improved Overall Survival, and also resulted in a delayed time to intervention for symptomatic CNS disease, among patients with heavily pretreated advanced HER2-positive breast cancer. Neratinib + capecitabine versus lapatinib + capecitabine in patients with HER2+ metastatic breast cancer previously treated with ≥ 2 HER2-directed regimens: Findings from the multinational, randomized, phase III NALA trial. Saura C, Oliveira M, Feng Y-H, et al. J Clin Oncol. 2019;37 (suppl; abstr 1002).

LONSURF® Plus AVASTIN® Combination for Chemo-Refractory Metastatic Colorectal Cancer 

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SUMMARY: ColoRectal Cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 147,950 new cases of CRC will be diagnosed in the United States in 2020 and about 53,200 patients are expected to die of the disease. The lifetime risk of developing CRC is about 1 in 23. Approximately 15-25% of the patients with CRC present with metastatic disease at the time of diagnosis (synchronous metastases) and 50-60% of the patients with CRC will develop metastatic disease during the course of their illness. Patients with metastatic CRC, whose disease has progressed after treatment with standard therapies, have limited therapeutic options available, to treat their disease.
LONSURF® is a combination of two agents – a novel oral nucleoside, Trifluridine and a thymidine phosphorylase inhibitor, Tipiracil hydrochloride. This combination has a unique mechanism of action. Trifluridine, the active ingredient of LONSURF® incorporates into DNA resulting in DNA damage. Degradation of Trifluridine which occurs when taken orally is prevented by Tipiracil hydrochloride. In a pivotal, global, Phase III trial (RECOURSE), LONSURF® significantly improved Overall Survival (OS) compared to placebo, with a 32% reduction in the risk of death, among patients with chemo-refractory metastatic CRC. AVASTIN® (Bevacizumab) is a humanized anti-VEGF monoclonal IgG1 antibody that directly binds Vascular Endothelial Growth Factor (VEGF) to inhibit angiogenesis.
In a previously published multicenter Phase I/II study (C-TASK FORCE), the combination of LONSURF® in combination with AVASTIN® showed promising antitumor activity with acceptable toxicity among patients with metastatic CRC. Based on the encouraging results of this study, the authors conducted an open-label, randomized, Phase II study in which the efficacy of LONSURF® plus AVASTIN® was compared with LONSURF® monotherapy in patients with refractory metastatic CRC. This study enrolled and randomly assigned 93 patients in 1:1 ratio to LONSURF® plus AVASTIN® (N=46) or LONSURF® alone (N=47). The main inclusion criteria were histopathologically confirmed metastatic CRC, refractory or intolerant to a Fluoropyrimidine (5-FU), Irinotecan (CAMPTOSAR®), Oxaliplatin (ELOXATIN®), and Cetuximab (ERBITUX®) or Panitumumab (VECTIBIX®), with the latter two agents offered only for RAS wild-type tumors. Patients had a WHO performance status of 0 or 1 and previous therapy with AVASTIN®, ZALTRAP® (Aflibercept), CYRAMZA® (Ramucirumab), or STIVARGA® (Regorafenib) was allowed. Randomized patients received LONSURF® 35 mg/m2 orally twice daily on days 1-5 and 8-12 every 28 days alone, or in combination with AVASTIN® 5 mg/kg IV on days 1 and 15 of each treatment cycle, until disease progression or unacceptable toxicity. Patients were stratified by institution and RAS mutation status. The Primary endpoint was Progression Free Survival (PFS).
After a median follow up of 10.0 months, the median PFS was 4.6 months in the LONSURF® plus AVASTIN® group versus 2.6 months in the LONSURF® monotherapy group (HR=0.45; P=0.0015). This represented a 55% reduction in the risk of progression or death. This benefit remained significant when analysis was adjusted for the stratification factors of study center and RAS mutation status (HR = 0.47, P =0.0015). The median Overall Survival was 9.4 months versus 6.7 months (HR=0.55, P =0.03) and Disease Control Rates were 67% versus 51% (P=0.14), in favor of the combination therapy. The most common treatment-related Grade 3 or more adverse events in the combination group were neutropenia and diarrhea.
It was concluded that among patients with chemo-refractory metastatic CRC, a combination of LONSURF® and AVASTIN® was associated with a significant and clinically relevant improvement in Progression Free Survival with tolerable toxicity, compared with LONSURF® monotherapy. The authors added that this could be a new treatment option and practice-changing development for patients with refractory metastatic CRC. TAS-102 with or without bevacizumab in patients with chemorefractory metastatic colorectal cancer: an investigator-initiated, open-label, randomised, phase 2 trial. Pfeiffer P, Yilmaz M, Möller S, et al. THE LANCET Oncology. Published:January 27, 2020DOI:https://doi.org/10.1016/S1470-2045(19)30827-7

Neoadjuvant KEYTRUDA® Plus Chemotherapy Improves Pathological Complete Response in Triple Negative Breast Cancer

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SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (13%) will develop invasive breast cancer during their lifetime. Approximately 276,480 new cases of invasive female breast cancer will be diagnosed in 2020 and about 42,170 women will die of the disease.
Triple Negative Breast Cancer (TNBC) is a heterogeneous, molecularly diverse group of breast cancers and are ER (Estrogen Receptor), PR (Progesterone Receptor) and HER2 (Human Epidermal Growth Factor Receptor-2) negative. TNBC accounts for 15-20% of invasive breast cancers, with a higher incidence noted in young patients. It is usually aggressive, and tumors tend to be high grade and patients with TNBC are at a higher risk of both local and distant recurrence. Those with metastatic disease have one of the worst prognoses of all cancers with a median Overall Survival of 13 months. The majority of patients with TNBC who develop metastatic disease do so within the first 3 years after diagnosis, whereas those without recurrence during this period of time have survival rates similar to those with ER-positive breast cancers. The lack of known recurrent oncogenic drivers in patients with metastatic TNBC, presents a major therapeutic challenge. Nonetheless, patients with TNBC often receive chemotherapy in the neoadjuvant, adjuvant or metastatic settings and approximately 30-40% of patients achieve a pathological Complete Response (pCR) in the neoadjuvant setting. In addition to increasing the likelihood of tumor resectability and breast preservation, patients achieving a pCR following neoadjuvant chemotherapy have a longer Event Free Survival (EFS) and Overall Survival (OS). Those who do not achieve a pathological Complete Response tend to have a poor prognosis. For all these reasons, pCR is considered a valid endpoint for clinical testing of neoadjuvant therapy in patients with early stage TNBC. It appears that there are subsets of patients with TNBC who may be inherently insensitive to cytotoxic chemotherapy. Three treatment approaches appear to be promising and they include immune therapies, PARP inhibition and inhibition of PI3K pathway. Previously published studies have shown that presence of tumor-infiltrating lymphocytes was associated with clinical benefit, when treated with chemotherapy and immunotherapy, in patients with TNBC, and improved clinical benefit was observed in patients with immune-enriched molecular subtypes of metastatic TNBC.
KEYTRUDA® (Pembrolizumab) is a fully humanized, Immunoglobulin G4, anti-PD-1, monoclonal antibody, that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2. It thereby reverses the PD-1 pathway-mediated inhibition of the immune response and unleashes the tumor-specific effector T cells. Cytotoxic chemotherapy releases tumor-specific antigens and immune checkpoint inhibitors such as KEYTRUDA® when given along with chemotherapy can enhance endogenous anticancer immunity. Preliminary results from Phase I and II trials have shown that in patients with TNBC, KEYTRUDA® given along with chemotherapy in a neoadjuvant setting resulted in a high rate of pCR.
KEYNOTE-522 is an international, placebo controlled Phase III trial, conducted to evaluate the safety and efficacy of neoadjuvant KEYTRUDA® plus chemotherapy followed by adjuvant KEYTRUDA® or placebo, in patients with early stage TNBC. In this study, 1,174 patients were randomly assigned in a 2:1 ratio to receive neoadjuvant KEYTRUDA® 200 mg IV every 3 weeks (N=784) or placebo (N=390). All patients received 4 cycles of Carboplatin plus Paclitaxel, followed by 4 cycles of Doxorubicin or Epirubicin plus Cyclophosphamide, in the neoadjuvant setting. Following definitive surgery, adjuvant KEYTRUDA® or placebo was continued every 3 weeks for 9 cycles or until disease recurrence or unacceptable toxicity. Enrolled TNBC patients were newly diagnosed, treatment naïve, and included both node-negative and node-positive patients with nonmetastatic disease (Tumor Stage T1c, Nodal Stage N1-N2 or Tumor Stage T2-T4, Nodal Stage N0-N2, per AJCC criteria). Treatment groups were well balanced and patients were stratified according to nodal status, tumor size, and Carboplatin schedule (weekly versus every 3 weeks). The two Primary endpoints were pathological Complete Response (pCR) at the time of definitive surgery and Event Free Survival (EFS). The median follow up was 15.5 months.
At the first interim analysis, the pCR among the first 602 patients who underwent randomization was 64.8% in the KEYTRUDA® plus chemotherapy group, compared with 51.2% in the placebo plus chemotherapy group (P<0.001). This pCR benefit was consistent across subgroups including PD-L1 expresssion subgroups. In the PD-L1-positive population, the pCR was 68.9% in the KEYTRUDA® plus chemotherapy group compared with 54.9% in the placebo plus chemotherapy group. In the PD-L1 negative group, the pCR in the KEYTRUDA® plus chemotherapy group was 45.3% and 30.3% in the placebo plus chemotherapy group. Neoadjuvant KEYTRUDA® plus chemotherapy followed by adjuvant KEYTRUDA® showed a favorable trend for Event Free Survival compared with chemotherapy alone, although these data are still premature. Across all treatment phases, Grade 3 or higher treatment-related toxicities were 78.0% in the KEYTRUDA® plus chemotherapy group and 73.0% in the placebo plus chemotherapy group.
It was concluded that among patients with early stage Triple Negative Breast Cancer, the addition of KEYTRUDA® to neoadjuvant chemotherapy significantly increased the pathological Complete Response rate, compared to those who received placebo plus neoadjuvant chemotherapy, with a favorable trend in Event Free Survival. Pembrolizumab for Early Triple-Negative Breast Cancer. Schmid P, Cortés J, Pusztai L, et al. for the KEYNOTE-522 Investigators. N Engl J Med 2020;382:810-821

Improved Quality of Life and Efficacy with BRAFTOVI®, MEKTOVI® and ERBITUX® Triplet Therapy in Patients with BRAF V600E-Mutant Metastatic Colorectal Cancer

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SUMMARY: ColoRectal Cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 147,950 new cases of CRC will be diagnosed in the United States in 2020 and about 53,200 patients are expected to die of the disease. The lifetime risk of developing CRC is about 1 in 23. Advanced colon cancer is often incurable and standard chemotherapy when combined with anti EGFR (Epidermal Growth Factor Receptor) targeted monoclonal antibodies such as VECTIBIX® (Panitumumab) and ERBITUX® (Cetuximab), as well as anti VEGF agent AVASTIN® (Bevacizumab), have demonstrated improvement in Progression Free Survival (PFS) and Overall Survival (OS). The benefit with anti EGFR agents however is only demonstrable in patients with metastatic CRC (mCRC), whose tumors do not harbor KRAS mutations in codons 12 and 13 of exon 2 (KRAS Wild Type). It is now also clear that even among the KRAS Wild Type patient group about 15-20% have other rare mutations such as NRAS and BRAF mutations, which confer resistance to anti EGFR agents. Patients with Stage IV colorectal cancer are now routinely analyzed for extended RAS and BRAF mutations. KRAS mutations are predictive of resistance to EGFR targeted therapy. Approximately 5-20% of all metastatic CRC tumors present with BRAF V600E mutations and BRAF V600E is recognized as a marker of poor prognosis in this patient group. These patients tend to have aggressive disease with a higher rate of peritoneal metastasis and do not respond well to standard treatment intervention. Approximately 20% of the BRAF-mutated population in the metastatic setting has MSI-High tumors, but MSI-High status does not confer protection to this patient group.BRAF-and-MEK-Inhibition-in-MAPK-Pathway
The Mitogen-Activated Protein Kinase pathway (MAPK pathway) is an important signaling pathway which enables the cell to respond to external stimuli. This pathway plays a dual role, regulating cytokine production and participating in cytokine dependent signaling cascade. The MAPK pathway of interest is the RAS-RAF-MEK-ERK pathway. The RAF family of kinases includes ARAF, BRAF and CRAF signaling molecules. BRAF is a very important intermediary of the RAS-RAF-MEK-ERK pathway. The BRAF V600E mutations results in constitutive activation of the MAP kinase pathway. Inhibiting BRAF can transiently reduce MAP kinase signaling. However, this can result in feedback upregulation of EGFR signaling pathway, which can then reactivate the MAP kinase pathway. This aberrant signaling can be blocked by dual inhibition of both BRAF and EGFR. However, BRAF V600E-mutated CRC is inherently less sensitive to BRAF inhibition than melanoma. BRAFTOVI® (Encorafenib) is a BRAF inhibitor and has target binding characteristics that differ from other BRAF inhibitors such as ZELBORAF® (Vemurafenib) and TAFINLAR® (Dabrafenib), with a prolonged target dissociation half-life and higher potency. The combination of BRAFTOVI® along with anti-EGFR monoclonal antibody ERBITUX® (Cetuximab) showed promising activity in early-phase clinical trials. 
The BEACON CRC (Binimetinib, Encorafenib, and Cetuximab Combined to Treat BRAF-Mutant Colorectal Cancer) trial is an international, multicenter, randomized, open-label, Phase III study in which the efficacy and safety of BRAFTOVI® plus ERBITUX® with or without a MEK inhibitor MEKTOVI® (Binimetinib), was compared with the investigators’ choice of ERBITUX® combined with either Irinotecan or Fluorouracil, Folinic acid, and Irinotecan, in patients with BRAF V600E-mutant mCRC, whose disease has progressed after one or two prior regimens. In this trial, 665 patients were randomly assigned in a 1:1:1 ratio to receive either triplet therapy of BRAFTOVI® 300 mg orally daily, MEKTOVI® 45 mg orally twice daily, and ERBITUX® 400 mg/m2 IV as an initial dose, then 250 mg/m2 IV weekly (N=224), doublet-therapy of BRAFTOVI® and ERBITUX® administered in the same doses and on the same schedule as the triplet regimen (N=220) or investigators’ choice of ERBITUX® combined with either Irinotecan or Fluorouracil, Folinic acid, and Irinotecan (N=221). Patients were stratified according to previous Irinotecan use and treatment was administered in 28-day cycles until disease progression. The co-Primary end points were Overall Survival (OS) in the triplet-therapy group as compared with the control group and Secondary end points included OS in the doublet-therapy group as compared with the control group, as well as PFS, Duration of Response, and Safety in all groups. This study was not powered to compare the triplet-therapy group against the doublet-therapy group.
At the time of prespecified interim analysis, with a median duration of follow up for survival at 7.8 months across the three groups, the median OS was 9.0 months in the triplet-therapy group and 5.4 months in the control group (HR for death=0.52; P<0.001). This represented 48% reduction in the risk of death in the triplet-therapy group. The confirmed Response Rate was 26% in the triplet-therapy group and 2% in the control group (P<0.001). The median OS in the doublet-therapy group was 8.4 months (HR for death versus control=0.60; P<0.001).
The authors in this updated analysis focused on the patient-reported Quality of Life (QOL) assessments from this study. QOL assessments using 4 validated QOL measures were secondary endpoints in the trial. They included EORTC QOL Questionnaire (QLQ C30), Functional Assessment of Cancer Therapy Colon Cancer (FACT C), EuroQol 5D 5L, and Patient Global Impression of Change (PGIC). The risk of QOL deterioration was reduced by 45% (HR=0.55) and 44% (HR=0.56), using EORTC QLQ C30 and FACT C assessments respectively, in favor of the triplet regimen over control. Similar findings were observed when the doublet-therapy regimen was compared with the regimen in the control group, and when QOL assessments were made using the other two QOL measures (EuroQol 5D 5L and PGIC). There was however no significant differences in QOL when the triplet and doublet regimen groups were compared.
It was concluded based on this updated analysis of the BEACON CRC trial, that among patients with BRAF V600E-mutant metastatic Colorectal Cancer, a combination of BRAFTOVI® plus ERBITUX® with or without a MEK inhibitor MEKTOVI®, demonstrated longer maintenance of QOL on patient-reported assessments, compared to the current standard of care. Encorafenib plus cetuximab with or without binimetinib for BRAF V600E-mutant metastatic colorectal cancer: Quality-of-life results from a randomized, three-arm, phase III study versus the choice of either irinotecan or FOLFIRI plus cetuximab (BEACON CRC). Kopetz S, Grothey A, Van Cutsem E, et al. J Clin Oncol. 2020;38(suppl 4; abstr 8).

Blood-Based Screening Test Identifies Gastrointestinal Cancers

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SUMMARY: It is estimated that cancers of the esophagus, stomach, pancreas, gallbladder, liver, bile duct, colon and rectum account for approximately 17% of incident cancer diagnoses and 26% of cancer-related deaths in the US. There are currently no screening tests available for cancers of the gallbladder, bile duct, and pancreatic cancer. Although screening tests do exist for other types of GI malignancies such as colorectal and stomach cancer, many of them are invasive. Further, when GI malignancies are diagnosed, they are frequently at advanced stages and are more difficult to treat.
A noninvasive, liquid biopsy assay based on circulating tumor DNA (ctDNA) has the potential to detect cancer in early stages among asymptomatic individuals. ctDNA refers to DNA fragments that are shed into the bloodstream by cancer cells after apoptosis or necrosis. ctDNA can detect almost all molecular alterations present in cancer cells and genotyping circulating cell-free tumor DNA (cfDNA) in the plasma can potentially overcome the shortcomings of repeat biopsies and tissue genotyping, allowing the detection of many more targetable gene mutations, thus resulting in better evaluation of the tumor genome landscape. The proportion of cfDNA that originates from a tumor depends on the anatomic location, tumor burden and cell turnover. cfDNA also allows real-time monitoring for treatment response and resistance.
The Cancer Genome Atlas (TCGA), a landmark cancer genomics program, is a joint effort between the National Cancer Institute and the National Human Genome Research Institute. This program began in 2006 and has molecularly characterized over 20,000 primary cancers and matched normal samples, across 33 different cancer types. After 12 years and contributions from over 11,000 patients, TCGA has deepened our understanding of the molecular basis of cancer, changed the way cancer patients are managed in the clinic, established a rich genomics data resource for the research community, and helped advance health and science technologies.
The Circulating Cell-Free Genome Atlas (CCGA) is a prospective, multi-center, case-control, observational study with longitudinal follow up, and is the largest study ever initiated, to develop a noninvasive, liquid biopsy assay for early cancer detection based on cell-free DNA (cfDNA). This study completed enrollment of approximately 15,000 participants with and without cancer (56% with more than 20 tumor types and all clinical stages), across 142 sites in the US and Canada. The purpose of this study is to collect biological samples from patients with a new diagnosis of cancer (blood and tumor tissue) and from individuals who do not have a diagnosis of cancer (blood), in order to characterize the population heterogeneity in cancer and non-cancer participants, and to develop models for distinguishing cancer from non-cancer. The principal goal is to develop a noninvasive cancer detection assay and the CCGA was designed to characterize the landscape of genomic cancer signals in the blood and to detect and validate GRAIL, Inc.’s multi-cancer early detection blood test through three pre-planned sub-studies. 
GRAIL, Inc., is a healthcare company focused on the early detection of cancer by using the power of Next-Generation Sequencing, population-scale clinical studies, and state-of-the-art computer science and data science to enhance the scientific understanding of cancer biology, and to develop its multi-cancer early detection blood test. GRAIL’s high efficiency methylation technology preferentially targets the most informative regions of the genome, and is designed to use its proprietary database and machine-learning algorithms to both detect the presence of cancer and identify the tumor’s Tissue of Origin. GRAIL’s sequencing database of cancer and non-cancer methylation signatures is believed to be the largest of its kind, and covers approximately 30 million methylation sites across the genome, with more than 20 cancer types across stages represented within the database.
Previously reported data from the first sub-study of CCGA showed GRAIL’s prototype technology could detect the presence of multiple deadly cancer types with a low rate of false positive results (high specificity). In this analysis blood samples from 166 participants who had a cancer diagnosis at the time of enrollment were evaluated, and cancer was detected using the methylation technology. Results showed that GRAIL’s prototype technology correctly identified the tumor’s Tissue of Origin in 87% of the blood samples evaluated (N=144/166), including 96% of breast cancer cases (N=22/23), 88% of lung cancer cases (N=29/33), 90% of liver cancer cases (N=9/10) and 100% of pancreatic cancer cases (N=17/17).
GRAIL has since selected methylation as its preferred approach and evaluated its refined methylation blood test in the second pre-planned sub-study of CCGA. It was determined that whole-genome bisulfite sequencing for DNA methylation was the most effective approach for early cancer detection. DNA methylation is a natural epigenetic mechanism used by cells to regulate gene expression with some regions of hypermethylation and some regions of hypomethylation, and is a chemical modification to DNA, that can change how a gene’s function is carried out by the body without changing the order of the DNA bases. In cancer, abnormal methylation patterns and the resulting changes in gene expression can contribute to tumor growth (hypermethylation can cause tumor-suppressor genes to be inactivated). Methylation patterns or signatures, are unique to the tumor DNA, enabling tumor detection and localization, but are not of value when it comes to precision therapies. This is unlike mutations and copy number changes, which can be detected in white blood cells in individuals without cancer as well, leading to false-positives.
The researches in this second substudy reported the performance of methylation-based cfDNA early multi-cancer detection test, for GastroIntestinal (GI) tract cancers, and also provided data from individuals without known cancer (non-cancer controls). To test the current assay, the second substudy included approximately 4,500 individuals, both with and without cancer, who were split into a training cohort and a validation cohort. Of the 2,185 patients with newly-diagnosed cancer in the second substudy, 447 patients were diagnosed with GI malignancies. Plasma cfDNA was subjected to targeted methylation analysis to develop an algorithm that could identify the presence or absence of cancer, as well as the Tissue of Origin of the cancer. The GI malignancies included Esophagus/Stomach (N=67), Pancreas/Gallbladder/Extrahepatic bile duct (N=95), Liver/Intrahepatic bile duct (N=29), and Colon/Rectum (N=121). To minimize the likelihood of false-positives, the targeted methylation assay was pre-set to yield greater than 99% specificity.
The test showed a sensitivity level of approximately 82% for detecting GI cancers of all stages in the independent validation set. The predicted Tissue of Origin accuracy across all GI cancers was 92%.
It was concluded that this assay performed using a single noninvasive blood sample, has the potential to diagnose a variety of gastrointestinal cancers earlier, when they are more treatable, with good sensitivity and with a low rate of false positives. Performance of a blood-based test for the detection of multiple cancer types. Wolpin BM, Richards DA, Cohn AL, et al. J Clin Oncol. 2020;38(suppl 4; abstr 283).

Biomarkers May Predict Response to BRAF and MEK inhibitors in Malignant Melanoma

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Biomarkers May Predict Response to BRAF and MEK inhibitors in Malignant Melanoma 
SUMMARY: It is estimated that in the US, approximately 100,350 new cases of malignant melanoma will be diagnosed in 2020 and about 6850 patients are expected to die of the disease. The incidence of melanoma has been on the rise for the past three decades. Surgical resection with a curative intent is the standard of care for patients with early stage melanoma, with a 5-year survival rate of 98% for Stage I disease and 90% for Stage II disease. Patients with locally advanced or metastatic melanoma historically have had poor outcomes. With the development and availability of immune checkpoint inhibitors and BRAF and MEK inhibitors, this patient group now has significantly improved outcomes. In treatment naïve patients receiving anti-PD-1 therapies such as KEYTRUDA® (Pembrolizumab) or OPDIVO® (Nivolumab) in Phase III trials, the Progression Free Survival (PFS) rates have ranged from 27-31%, with an Overall Survival (OS) rate of 46% at 4 years. The 5-year OS among patients receiving KEYTRUDA® was 43%, and in those treated with a combination of OPDIVO® plus YERVOY® (Ipilimumab), 4-year PFS and OS rates were 37% and 53%, respectively.BRAF-MEK-Inhibition-in-MAPK-Pathway
The Mitogen-Activated Protein Kinase pathway (MAPK pathway) is an important signaling pathway which enables the cell to respond to external stimuli. This pathway plays a dual role, regulating cytokine production and participating in cytokine dependent signaling cascade. The MAPK pathway of interest is the RAS-RAF-MEK-ERK pathway. The RAF family of kinases includes ARAF, BRAF and CRAF signaling molecules. BRAF is a very important intermediary of the RAS-RAF-MEK-ERK pathway. BRAF mutations have been detected in 6-8% of all malignancies. The most common BRAF mutation in melanoma is at the V600E/K site and is detected in approximately 50% of melanomas, and result in constitutive activation of the MAPK pathway.
TAFINLAR® (Dabrafenib), is a selective oral BRAF inhibitor and MEKINIST® (Trametinib) is a potent and selective inhibitor of MEK gene, which is downstream from RAF in the MAPK pathway. Long term survival data pooled from two randomized Phase III COMBI-d and COMBI-v trials, which involved previously untreated, unresectable or metastatic melanoma patients, with BRAFV600E or V600K mutation who had received TAFINLAR® along with MEKINIST® showed PFS rates of 21% at 4 years and 19% at 5 years. The OS rates were 37% at 4 years and 34% at 5 years. The 5-year OS rate was 71% among patients who had a Complete Response and 55% among those who had a normal LDH level plus fewer than three metastatic organ sites at baseline.
With the approval of multiple therapeutic options for the management of patients with BRAF-mutant melanoma, treatment decisions have become increasingly complex. In patients with limited disease burden, immunotherapy with checkpoint inhibitors is favored by most clinicians based on the long term data supporting the durability of responses with immunotherapies. On the contrary, BRAF-targeted agents are utilized in patients with extensive, symptomatic disease and active brain metastases. The optimal sequence of these therapeutic strategies in order to improve long-term patient outcome, has remained unclear. 
COMBI-AD is an international, multi-center, randomized, double-blind, placebo-controlled, Phase III trial, in which 870 patients with completely resected, Stage III melanoma and with BRAF V600E or V600K mutations were enrolled. Patients were randomly assigned in a 1:1 to receive TAFINLAR® 150 mg orally twice daily in combination with MEKINIST® 2 mg orally once daily (N=438) or two matched placebos (N=432). Treatment was given for 12 months. At a median follow up of 2.8 years, the estimated 3-year Relapse Free Survival (RFS) rate was 58% with a combination of TAFINLAR® and MEKINIST® and 39% in the placebo group (HR=0.47; P<0.001), and this represented a 53% lower risk of relapse. The risk of distant metastases or death was reduced by 49% with the combination therapy versus placebo (HR=0.51; P<0.001). A prespecified exploratory outcome of this trial was assessment of biomarkers. The authors assessed intrinsic tumor genomic features in 368 patients using Next-Generation DNA sequencing, and tumor microenvironment characteristics were assessed in 507 patients by use of a NanoString RNA assay, in an attempt to provide prognostic and predictive information. Median follow up at data cutoff was 44 months in the TAFINLAR® plus MEKINIST® group and 42 months in the placebo group.
Baseline MAPK pathway genomic alterations did not affect treatment benefit or outcomes in either treatment groups. An Interferon Gamma gene expression signature higher than the median was prognostic for prolonged RFS in both treatment groups. Tumor Mutational Burden (TMB) was independently associated with better RFS in the placebo group (HR for top third versus bottom third of TMB values=0.56; P=0.0056), but this benefit was not seen in the TAFINLAR® plus MEKINIST® group (HR= 0.83; P=0.44). However, patients with TMB in the lower two terciles who received TAFINLAR® plus MEKINIST® combination had improved RFS compared to those who received placebo (HR=0.49: P<0.0001). Patients with high TMB appeared to have a less pronounced benefit with TAFINLAR® plus MEKINIST® targeted therapy, compared to placebo, especially if they had an Interferon Gamma gene expression signature lower than the median. 
It was concluded from this biomarker analysis that high Tumor Mutational Burden was independently associated with better Relapse Free Survival in the placebo group but not in the TAFINLAR® plus MEKINIST® combination group, and an Interferon Gamma gene expression signature higher than the median was prognostic for prolonged RFS in both treatment groups. Adjuvant dabrafenib plus trametinib versus placebo in patients with resected, BRAFV600-mutant, stage III melanoma (COMBI-AD): exploratory biomarker analyses from a randomised, phase 3 trial. Dummer R, Brase JC, Garrett J, et al. The Lancet Oncology. Published:January 30, 2020DOI:https://doi.org/10.1016/S1470-2045(20)30062-0