SUMMARY: The FDA granted accelerated approval to KEYTRUDA® (Pembrolizumab), for the treatment of patients with metastatic Non Small Cell Lung Cancer (NSCLC), whose tumors express Programmed Death Ligand 1 (PD-L1), as determined by an FDA-approved test, following disease progression on or after platinum-containing chemotherapy. Lung cancer is the second most common cancer in both men and women and accounts for about 13% of all new cancers and 27% of all cancer deaths. It is the leading cause of cancer death among both men and women. The American Cancer Society estimates that over 221,200 new cases of lung cancer will be diagnosed in the United States in 2015 and over 158,000 patients will die of the disease. Non Small Cell Lung Cancer (NSCLC) accounts for approximately 85% of all lung cancers.
The treatment paradigm for solid tumors has been rapidly evolving with a better understanding of the Immune checkpoints. Immune checkpoints are cell surface inhibitory proteins/receptors that are expressed on activated T cells. They harness the immune system and prevent uncontrolled immune reactions. Survival of cancer cells in the human body may be to a significant extent, related to their ability to escape immune surveillance, by inhibiting T lymphocyte activation. The T cells of the immune system therefore play a very important role in modulating the immune system. Under normal circumstances, Immune checkpoints or gate keepers, switch off the T cells of the immune system and thereby inhibit an intense immune response. With the recognition of Immune checkpoint proteins and their role in suppressing antitumor immunity, antibodies have been developed, that target the membrane bound inhibitory Immune checkpoint proteins/receptors such as CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4), also known as CD152, PD-1(Programmed cell Death-1), etc. Targeting Immune checkpoints unleashes the T cells, resulting in T cell proliferation, activation and a therapeutic response. KEYTRUDA® 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, thereby undoing PD-1 pathway-mediated inhibition of the immune response and unleashing the tumor-specific effector T cells.
In this publication, the authors assessed the efficacy and safety of KEYTRUDA® in patients with advanced NSCLC enrolled in the KEYNOTE-001 phase I trial. Four Hundred and Ninety five (N=495) patients were assigned to either a training group (N=182) or a validation group (N=313) and KEYTRUDA® was administered at three dosages: 2 mg/kg IV every 3 weeks, 10 mg/kg IV every 3 weeks, or 10 mg/kg IV every 2 weeks. Patient responses were assessed every 9 weeks.
The Objective Response Rate (ORR) in the entire study population was 19.4%, the median Duration of Response was 12.5 months, the median Progression Free Survival was 3.7 months and the median Overall Survival was 12.0 months. The PD-L1 (Programmed Death-Ligand 1) expression was evaluated in 204 patients in the validation group by ImmunoHisto Chemistry (IHC) and membrane PD-L1 expression of 50% or more, in tumor cells, was selected as the cutoff. It was noted that among patients with PD-L1 expression in at least 50% of tumor cells, the Objective Response Rate was 45.2%, median Progression Free Survival was 6.3 months and median Overall Survival has not been reached. Responses were not as robust in those patients with tumors demonstrating less than 50% PD-L1 expression, but in those who did respond, the duration of responses were comparable to those with 50% or more PD-L1 expression. KEYTRUDA® was well tolerated overall and the common immune mediated adverse events were infusion reactions, hypothyroidism and pneumonitis.
The authors concluded that KEYTRUDA® showed significant antitumor activity in patients with advanced Non Small Cell Lung Cancer, whose tumor PD-L1expression was 50% or more. Further, the median duration of response exceeded 12 months among responders, regardless of the degree of PD-L1 expression. This study validated that PD-L1 expression in tumors is clearly a marker of response to KEYTRUDA®. Pembrolizumab for the Treatment of Non–Small-Cell Lung Cancer. Garon EB, Rizvi NA, Hui R, et al. N Engl J Med 2015; 372:2018-2028



Non Small Cell Lung Cancer patients with squamous cell histology have been a traditionally hard- to-treat patient group, with less than 5% of patients with advanced SCC, surviving for five years or longer. Some of the advanced NSCLC tumors are dependent on the Epidermal Growth Factor Receptor (EGFR) for cell proliferation and survival, regardless of EGFR mutation status. TARCEVA® (Erlotinib) is a reversible EGFR Tyrosine Kinase Inhibitor and is presently approved by the FDA for the treatment of locally advanced or metastatic NSCLC, after failure of at least one prior chemotherapy regimen. GILOTRIF® (Afatinib) is an oral, irreversible blocker of the ErbB family which includes EGFR (ErbB1), HER2 (ErbB2), ErbB3 and ErbB4. This kinase inhibitor is indicated for the first line treatment of patients with metastatic NSCLC, whose tumors have Epidermal Growth Factor Receptor (EGFR) exon 19 deletions or exon 21 (L858R) substitution mutations.
Under normal circumstances, inhibition of an intense immune response and switching off the T cells of the immune system, is an evolutionary mechanism and is accomplished by Immune checkpoints or gate keepers. With the recognition of Immune checkpoint proteins and their role in suppressing antitumor immunity, antibodies are being developed that target the membrane bound inhibitory Immune checkpoint proteins/receptors such as CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4), also known as CD152, PD-1(Programmed cell Death-1), etc. By doing so, one would expect to unleash the T cells, resulting in T cell proliferation, activation and a therapeutic response. The first Immune checkpoint protein to be clinically targeted was CTLA-4. YERVOY® (Ipilimumab) , an antibody that blocks Immune checkpoint protein/receptor CTLA- 4, has been shown to prolong overall survival in patients with previously treated, unresectable or metastatic melanoma. OPDIVO® (Nivolumab) is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, thereby undoing PD-1 pathway-mediated inhibition of the immune response and unleashing the T cells. The U. S. Food and Drug Administration granted approval to OPDIVO®, for the treatment of patients with metastatic Squamous Non-Small Cell Lung Cancer (NSCLC), with progression on or after platinum based chemotherapy. CheckMate 057 is a randomized, international, phase 3 study designed to evaluate the benefit of OPDIVO® for patients with Non-Squamous (NSQ) NSCLC who had progressed after platinum-based doublet chemotherapy. A total of 582 patients were randomized to receive OPDIVO® 3 mg/kg IV every 2 weeks (n=292) or TAXOTERE® 75 mg/m2 IV every 3 weeks (n=290). Eligible patients included those with advanced Non-Squamous NSCLC who had progressed after platinum-based doublet chemotherapy and a Tyrosine Kinase Inhibitor (TKI), if deemed eligible for a TKI. Treatment was continued until disease progression or unacceptable toxicity. The primary clinical endpoint was Overall Survival (OS). Secondary endpoints included Objective Response Rate (ORR), Progression Free Survival (PFS), Efficacy based on PD-L1 expression, Quality of Life, and Safety. The study was stopped earlier than expected following assessment by the independent Data Monitoring Committee (DMC) which concluded that the study met its endpoint, demonstrating superior overall survival, in patients receiving OPDIVO®, compared to the control group. Patients in the OPDIVO®, group had a significantly higher median OS compared to those in the TAXOTERE® group (12.2 months versus 9.4 months, Hazard Ratio [HR] 0.73, P=0.0015). This meant a 27% reduction in the risk of death in the OPDIVO® group and this survival benefit was seen in all predefined subgroup of patients. The Objective Response Rate (ORR) was also significantly higher for patients receiving OPDIVO® compared to TAXOTERE® (19% versus 12%, P=0.0246) and the median duration of response (DOR) was significantly higher for the OPDIVO® group (17.2 months) vs the TAXOTERE® group (5.6 months). More importantly, when tumor PD-L1 expression was correlated with Overall Survival, the median OS for OPDIVO® was 17.2 months, 18.2 months, and 19.4 months for patients with tumors having 1% or higher, 5% or higher, and 10% or higher of cells staining positive for PD-L1, respectively, compared with 9.0 months, 8.1 months, and 8.0 months with TAXOTERE® treatment. Even though this study showed significant survival outcomes for patients expressing any level of PD-L1, the magnitude of benefit was even more so, in patients with tumors expressing higher levels of PD-L1. PD-L1 expression may therefore be a predictor of response, although this should not yet be used for patient selection. Grade 3-5 adverse events occurred more often in the TAXOTERE® group compared to the OPDIVO® group (54% vs 10%). Based on this compelling data, the authors concluded that OPDIVO® significantly improves Overall Survival when compared to TAXOTERE®, in patients with advanced non-Squamous NSCLC, after failure of platinum based doublet therapy. Phase III, randomized trial (CheckMate 057) of nivolumab (NIVO) versus docetaxel (DOC) in advanced non-squamous cell (non-SQ) non-small cell lung cancer (NSCLC). Paz-Ares L, Horn L, Borghaei H, et al. J Clin Oncol 33, 2015 (suppl; abstr LBA109)</s
Approximately 1% – 2% of lung adenocarcinomas harbor ROS1 gene rearrangements. ROS1 gene is located on chromosome 6q22 (long arm of chromosome 6) and plays an important role in cell growth and development. ROS1 gene fusion with another gene results in a mutated DNA sequence which then produces an abnormal protein responsible for unregulated cell growth and cancer. ROS1 gene rearrangement has been identified as a driver mutation in Non Small cell Lung Cancer with adenocarcinoma histology. This is more common in nonsmokers or in light smokers (<10 pack years) who are relatively young (average age of 50 years) and thus share similar characteristics with ALK-positive patients. The ROS protein and the ALK protein have similar structure and function and are sensitive to Tyrosine Kinase Inhibitors such as XALKORI® (Crizotinib) and ZYKADIA® (Ceritinib). ROS1 mutations have been also been associated with Cholangiocarcinoma (Bile duct cancer) and Glioblastoma multiforme. ROS1 rearrangements are mutually exclusive with other oncogenic mutations found in NSCLC such as EGFR mutations, KRAS mutations and ALK rearrangement. The presence of a ROS1 rearrangement can be detected by Fluorescence In Situ Hybridization (FISH), ImmunoHistoChemistry (IHC), Reverse Transcriptase– Polymerase Chain Reaction (RT-PCR) and Next Generation-Sequencing. XALKORI® is a small molecule Tyrosine Kinase Inhibitor that targets ALK, MET and ROS1 tyrosine kinases. In a previously published expansion cohort of the phase 1 study by Shaw and colleagues ( NEJM 2014; 371:1963-1971), XALKORI® showed significant activity in patients with in patients with advanced ROS1rearranged NSCLC. The authors in this publication provided additional evidence that ROS1 gene rearrangement is an actionable target in NSCLC, by conducting a retrospective study in centers that tested for ROS1 rearrangement and evaluated the outcomes of ROS1-positive NSCLC patients, who had been treated with XALKORI®. They included 32 patients with NSCLC whose tumors showed ROS1 rearrangement and who had received off-label treatment with XALKORI®. The median age was 50.5 years. They noted an overall response rate of 80% and a disease control rate, 86.7%. The median Progression Free Survival (PFS) was 9.1 months, and the PFS rate at 12 months was 44%. This impressive efficacy data again validates that similar to EGFR mutations and ALK rearrangements, ROS1 gene rearrangements are molecular drivers and patients with NSCLC with adenocarcinoma histology should be tested for ROS1. Crizotinib Therapy for Advanced Lung Adenocarcinoma and a ROS1 Rearrangement: Results From the EUROS1 Cohort. Mazières J, Zalcman G, Crinò L, J Clin Oncol. 2015;33:992-999
Although there is sufficient evidence for postoperative chemotherapy in patients with stage II or stage IIIA NSCLC, its usefulness in patients with stage IB NSCLC remains unclear. The value of adjuvant Post Operative Radiation Therapy (PORT) has been evaluated and has not been found to improve the outcome of patients with completely resected stage I NSCLC. The risk of locoregional recurrence (LRR) is 20-40% in patients with resected node-positive disease and this in turn may independently contribute to worsened Overall Survival in patients with NSCLC. Nonetheless, a large meta-analysis from trials conducted mainly in the 1960’s and 1970’s showed that adjuvant Post Operative Radiation Therapy (PORT) in stages IIA NSCLC and IIB NSCLC was associated with an 18% relative increase in the risk of death compared with surgery alone. This decrease in Overall Survival has been attributed to outmoded RT techniques and doses resulting in cardiac and pulmonary toxicity. This study was conducted to evaluate the impact of modern (Computed Tomography simulation and at least Linear accelerator- Linac based, three-dimensional, conformal RT) Post Operative Radiation Therapy (PORT) on Overall Survival (OS) in a large population-based registry of patients with completely resected stage IIIA (N2) NSCLC, when compared with adjuvant chemotherapy alone. The authors identified 4,483 patients in the National Cancer Data Base from 2006 to 2010 with pathologic N2, NSCLC, who underwent complete resection and adjuvant chemotherapy. This large patient population was representative of typical patients treated throughout the United States. Of these large cohort of patients, 1,850 had received PORT (45 Gy or more) and 2,633 patients did not. The authors evaluated the impact of patient and treatment variables on OS. The median follow-up time was 22 months. The use of PORT was associated with an increase in median and 5-year OS compared with no PORT (median OS, 45.2 vs 40.7 months, respectively; 5-year OS, 39.3% vs 34.8% respectively; P= 0.014). The improved OS remained, independently predicted by younger age, female sex, urban population, fewer comorbidities, smaller tumor size, multiagent chemotherapy, resection with at least a lobectomy, and PORT. The authors concluded that modern Post Operative Radiotherapy Therapy confers an additional OS advantage beyond that achieved with adjuvant chemotherapy alone, for patients with N2, NSCLC after complete resection and adjuvant chemotherapy. Postoperative Radiotherapy for Pathologic N2 Non–Small-Cell Lung Cancer Treated With Adjuvant Chemotherapy: A Review of the National Cancer Data Base. Robinson CG, Patel AP, Bradley JD, et al. J Clin Oncol. 2015; 33:870-876
The development a novel immunotherapeutic approaches, with a better understanding of the Immune checkpoints has however changed the treatment paradigm. Immune checkpoints are cell surface inhibitory proteins/receptors that are expressed on activated T cells. They harness the immune system and prevent uncontrolled immune reactions. Survival of cancer cells in the human body may be to a significant extent, related to their ability to escape immune surveillance, by inhibiting T lymphocyte activation. The T cells of the immune system therefore play a very important role in modulating the immune system. Under normal circumstances, inhibition of an intense immune response and switching off the T cells of the immune system, is an evolutionary mechanism and is accomplished by Immune checkpoints or gate keepers. With the recognition of Immune checkpoint proteins and their role in suppressing antitumor immunity, antibodies are being developed that target the membrane bound inhibitory Immune checkpoint proteins/receptors such as CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4), also known as CD152, PD-1(Programmed cell Death-1), etc. By doing so, one would expect to unleash the T cells, resulting in T cell proliferation, activation and a therapeutic response. The first Immune checkpoint protein to be clinically targeted was CTLA-4. YERVOY® (Ipilimumab), an antibody that blocks Immune checkpoint protein/receptor CTLA- 4, has been shown to prolong overall survival in patients with previously treated, unresectable or metastatic melanoma. OPDIVO® (Nivolumab) is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, thereby undoing PD-1 pathway-mediated inhibition of the immune response and unleashing the T cells. The approval of OPDIVO® was based on CheckMate-017, an open label, multicenter, multinational randomized phase III trial in which 272 patients with metastatic squamous NSCLC who had experienced disease progression during or after one prior platinum-based chemotherapy regimen were randomized to receive OPDIVO® (Nivolumab) 3 mg/kg IV every 2 weeks (N=135) or TAXOTERE® (Docetaxel) 75 mg/m2 IV every 3 weeks (N=137). The primary endpoint was Overall Survival (OS) and secondary endpoints included Progression Free Survival (PFS) and Objective Response Rate (ORR). This study was stopped early at the protocol pre-specified interim analysis after an independent monitoring panel determined that the primary endpoint of improved Overall Survival (OS) with OPDIVO® had been reached. The median OS was 9.2 months for patients assigned to OPDIVO® and 6 months for those in the TAXOTERE® group (HR=0.59; P=0.00025). This suggested a 41% improvement in the OS with OPDIVO® compared to TAXOTERE®. This FDA approval was further supported by a single arm, multinational, multicenter trial in patients with metastatic squamous NSCLC (N=117) who had progressed after receiving a platinum-based therapy and at least one additional systemic regimen. OPDIVO® in this study, was administered as a single agent at 3mg/kg IV every two weeks until disease progression or treatment discontinuation. The primary endpoint was Objective Response Rate (ORR) and exploratory endpoints were Overall Survival (OS), Progression Free Survival (PFS) and efficacy, based on PD-L1 expression status. With 11 months of minimum follow up, the Objective Response Rate (ORR) was 15% independent of PD-L1 status. The estimated one-year survival rate was 41% and median Overall Survival was 8.2 months. The authors noted that an additional 26% of patients had stable disease for a median duration of 6 months, resulting in a disease control rate (ORR+stable disease) of 41%. The most frequent grade 3-4 adverse events noted in at least 5% of the patients were fatigue, dyspnea and musculoskeletal pain. OPDIVO® will now be a new treatment option, with survival advantage, for patients with advanced relapsed and refractory metastatic squamous NSCLC. Phase II study of nivolumab (Anti-PD-1, BMS-936558, ONO-4538) in patients with advanced, refractory squamous non-small cell lung cancer. Ramalingam SS, Mazieres J, Planchard D, et al. Presented at: 2014 Multidisciplinary Symposium in Thoracic Oncology; Chicago, IL. LBA#3462