Development of immunotherapies that can alter the activity of T cells by targeting checkpoint pathways and determining their level of activity is well under way.

Tumor cells include evolved mechanisms to evade attack by the immune system, and one such tactic is high cell-surface expression of the programmed death receptor-ligand 1 (PD-L1).

The PD-1 receptor is expressed on the surface of tumor-invading T cells, and when activated by the ligand, sends a signal leading to decreased T-cell proliferation and reduction of cytokine synthesis, inducing a degree of immunosuppression within the tumor.

Under normal circumstances, this inhibitory checkpoint pathway is thought to protect healthy tissue from T-cell attack and the induction of autoimmunity,

but when tumor-invading T cells interact with PD-L1, they are inactivated, permitting tumor cell replication and tumor growth. The microenvironment within a tumor may also stimulate invading T cells to increase expression of PD-1 versus T cells in normal tissue and peripheral blood.

Additionally, PD-L1 is a ligand for B7-1 (CD 80), which also inhibits T-cell proliferation and cytokine synthesis.

&ldquo;Early data from multiple studies suggest to us that PD- L1 expression can predict for a higher response (particularly to an anti-PD-L1 therapy),&rdquo; said David R. Spigel, MD, director of the lung cancer research program at the Sarah Cannon Research Institute in Nashville, Tennessee. &ldquo;However, these same studies show that patients without PD-L1 overexpression can still benefit from these agents, so it remains unclear that their PD-L1 expression by immunohistochemistry is going to be the optimal biomarker and a way to select patients for immunotherapy treatment.&rdquo;

The high levels of expression of PD-L1 in lung cancer tumor cells has led to the development of monoclonal antibodies that prevent the ligand from binding to its receptors, including PD-1 and B7.1, thereby facilitating a vigorous T-cell immune response against the tumor.

Two agents are in the advanced stages of development: MPDL3280A, an antibody that has been modified to remove its antibody-dependent cell-mediated cytotoxicity function, and MEDI4736, a human IgG1 monoclonal antibody.

A phase I study of MPDL3280A (NCT01375842) in patients with locally advanced or metastatic solid tumors demonstrated Response Evaluation Criteria In Solid Tumors (RECIST) responses in patients with NSCLC and other tumor types, and the treatment was well tolerated. Patients with PD-L1positive tumors showed an overall response rate (ORR) of 39%, and a progressive disease (PD) rate of 12%. Patients with PD-L1&ndash;negative tumors had an ORR of 13% with a PD rate of 59%. The results suggested a correlation between response to the agent and PD-L1 status.

In an ongoing multicenter dose-escalation study of MEDI4736 (NCT01693562) in patients with advanced solid tumors (13 NSCLC, 8 melanoma, 5 other), treatment resulted in a disease control rate of 46% and 4 partial responses (3 NSCLC, 1 melanoma). The safety profile was acceptable and tumor shrinkage occurred at all doses tested, was durable, and was seen as early as 6 weeks.

Currently recruiting, the ATLANTIC (NCT02087423) is a single-arm, phase II global study of efficacy and safety of MEDI4736 in patients with locally advanced or metastatic NSCLC who have received at least 2 prior chemotherapies, one of which had to be platinum-based. The primary outcome measure is ORR. The estimated primary completion date is April 2015.

In May 2014, AstraZeneca announced the start of a phase III study

for its anti-PD-L1 monoclonal antibody, MEDI4736, versus placebo, in concert with the global double-blind PACIFIC trial (NCT02125461). The primary outcome measures are PFS and OS. It is expected that 880 patients will be randomized, and the trial will use more than 100 sites. It will recruit patients with locally advanced, unresectable NSCLC, with no evidence of progression after completion of treatment with a course of chemoradiotherapy. Estimated primary completion date is May 2017.

A phase III trial of MPDL3280A (NCT02008227) is recruiting patients. This open-label, multicenter, global trial expects to enroll 850 patients and is designed to evaluate the efficacy and safety of MPDL3280A (1200 mg IV on day 1 of each 21-day cycle) versus an active comparator, docetaxel (75mg/m

IV on day 1 of each 21-day cycle) in patients with locally advanced or metastatic NSCLC following failure on a platinum-containing chemotherapy. The primary outcome measure is OS. The estimated primary completion date is June 2018.

&ldquo;To date, the efficacy and safety profiles are very encouraging for the anti-PD-1 and PD-L1 therapies. In terms of efficacy, so far there appear to be higher response rates in heavily pretreated patients than we would expect with single-agent systemic therapy,&rdquo; said Spigel.

In terms of safety, results have been encouraging, according to Spigel. &ldquo;The agents appear to be well tolerated across the board, although there have been rare serious events, including pneumonitis (with nivolumab in the initial phase I experience, leading to 2 fatalities). However, so far, this does not appear to be a general problem for any one agent or for the class. Immune-related toxicities have occurred, including thyroid abnormalities, but most of the toxicities have been mild and reversible.&rdquo;

Inducing a robust T-cell response against NSCLC tumors using antibodies directed at PD-L1 is a promising approach to improving outcomes, and clinical data clarifying the benefits of this approach are expected from active clinical trials over the next 4 to 5 years.

Forde PM, Ettinger DS. Targeted therapy for non-small-cell lung cancer: past, present and future.

Pardoll DM. The blockade of immune checkpoints in cancer immunotherapy.

Sznol M, Chen L. Antagonist antibodies to PD-1 and B7-H1 (PD-L1) in the treatment of advanced human cancer.

Ahmadzadeh M, Johnson LA, Heemskerk B, et al. Tumor antigen-specific CD8 T cells infiltrating the tumor express high levels of PD-1 and are functionally impaired.

Butte MJ, Keir ME, Phamduy TB, Sharpe AH, Freeman GJ. Programmed death-1 ligand 1 interacts specifically with the B7-1 costimulatory molecule to inhibit T cell responses.

Spigel DR, Gettinger SN, Horm L, et al. Clinical activity, safety, and biomarkers of MPDL3280A, an engineered PD-L1 antibody in patients with locally advanced or metastatic non- small cell lung cancer (NSCLC)

Herbst RS, Gordon MS, Fine GD, et al. A study of MP- DL3280A, an engineered PD-L1 antibody in patients with locally advanced or metastatic tumors.

Jose Lutzky J, Antonia SJ, Blake-Haskins A, et al. A phase 1 study of MEDI4736 an anti-PD-L1 antibody in patients with advanced solid tumors.

AstraZeneca. AstraZeneca initiates phase III immunother- apy study for MEDI4736 in patients with lung cancer. http:// www.astrazeneca.com/Media/Press-releases/Article/20140508- -astrazeneca-initiates-phase-iii-immunotherapy-study-ME- DI4736. Accessed July 18, 2014.

Articles

Clinical Articles

Anti-PD-L1 Agents May Improve Outcomes in NSCLC

LKB1 is a gene located on the short arm of chromosome 19 that is absent in approximately 30% of cases of non-small cell lung cancer (NSCLC). Deletions of LKB1 are the third- most common type of mutation associated with NSCLC, after

mutations. Despite the fact that LKB1 is deleted in nearly one-third of cases of NSCLC, no therapeutic strategies are available to target LKB1.

LKB1 has an important role in the growth and survival of cells. Mice that were genetically engineered to lack the LKB1 gene die during in utero development, often as a result of hepatocellular carcinoma.

LKB1 also functions in energy use pathways, and is involved in the activity of a protein, adenosine monophosphate (AMP)-activated protein kinase (AMPK), which regulates energy use by sensing when levels of AMP are high intracellularly. High levels of AMP indicate overuse of energy within a cell, and AMPK may act to slow energy use and increase delivery of adenosine triphosphate to the cell. Without LKB1, cells apparently lose the important energy regulation activities of AMPK.

Deletions of LKB1 have been implicated in a familial syndrome (Peutz-Jeghers syndrome) that increases the risk of developing cancers of epithelial tissues, including lung tissue. LKB1 deficiency is associated with a greater incidence of metastasis, especially in patients with LKB1 deletion and

Identifying LKB1 deficiency may be useful in establishing the prognosis of tumors. Scientists have developed a rabbit monoclonal antibody that may be used in analyzing human formalin-fixed, paraffin-embedded lung cancer tissues for the presence or absence of LKB1, which may lead to a test for clinical use in establishing the prognosis of patients whose cancers harbor the LKB1 mutation.

The results of genome-wide studies of mice with a silenced

gene led investigators to identify high levels of expression of deoxythymidylate kinase (DTMYK) in association with the pathophysiology of lung cancer. DTMYK may be a future therapeutic target of novel therapies.

Other recent evidence suggests a therapeutic effect of antibodies working against the oncogene NEDD9, which is associated with LKB1 deletions.

In the near future, LKB1 may become a useful biomarker in assessing the prognosis of patients with NSCLC.

Subsequently, LKB1 deletions may become a therapeutic target of NSCLC in much the same way that HER2 was initially a negative prognostic indicator in breast cancer, and later became the target of novel therapeutic agents.

Similarly, inhibition of DTMYK and NEDD9, which are associated with LKB1 deletions, are potential future therapeutic targets in NSCLC.

Sanchez-Cespedes M. The role of LKB1 in lung cancer.

Marcus AI, Khuri FR. Energizing the search to target LKB1- mutant tumors.

Ji H, Ramsey MR, Hayes DN, et al. LKB1 modulates lung cancer differentiation and metastasis.

Nakada Y, Stewart TG, Pe&ntilde;a CG, et al. The LKB1 tumor suppressor as a biomarker in mouse and human tissues.

Liu Y, Marks K, Cowley GS, et al. Metabolic and functional genomic studies identify deoxythymidylate kinase as a target in LKB1-mutant lung cancer.

Feng Y, Wang Y, Wang Z, et al. The CRTC1-NEDD9 signaling axis mediates lung cancer progression caused by LKB1 loss.

Ferretti G, Felici A, Papaldo P, Fabi A, Cognetti F. HER2/neu role in breast cancer: from a prognostic foe to a predictive friend.

Despite the fact that LKB1 is deleted in nearly one-third of cases of NSCLC, no therapeutic strategies are available to target LKB1.

LKB1: Cancer Biomarker and Potential Therapeutic Target in NSCLC

A key to improved outcomes for patients with non-small cell lung cancer (NSCLC) is the ability to identify the wide spectrum of genetic changes present in tumors. Doing so will guide treatment decisions and influence the development of much-needed additional targeted therapies.

Since 2004, development of sophisticated next- generation sequencing (NGS) technology has allowed for the comprehensive sequencing of entire cancer genomes, exomes, and transcriptomes.

&ldquo;With NGS, our diagnostic capability has outpaced what we have in the therapeutic armamentarium, but this may change,&rdquo; said Benjamin P. Levy MD, director of thoracic medical oncology at the Mount Sinai Beth Israel Hospital in New York, regarding the significance of this testing.

Aside from the sheer volume of data generated by NGS analysis, evidence is emerging that targeted NGS may be more accurate than some other currently used techniques. At the American Society of Clinical Oncology (ASCO) 2014 Annual Meeting, Ali and colleagues presented retrospective data comparing the efficacy of fluorescent in situ hybridization (FISH) with targeted NGS for the detection of

rearrangements in 1070 lung carcinomas. They concluded that targeted NGS may be more sensitive in detecting

rearrangements than FISH in lung cancer, and proposed fur- ther analysis in a prospective study.

Several NGS platforms are now available for clinicians, and Levy pointed out that, &ldquo;Given the rapid development of competing NGS platforms, I think clinicians remain confused regarding which platform is optimal in clinical practice.&rdquo;

Commonly used NGS technologies are those produced by Illumina (High Seq Analyser),

Illumina High Seq Analyser and SOLID use optical detection of fluorescence-labeled nucleotides and fluorescence-labeled nucleotide octamers, respectively. The Roche 454 GS FLX uses optical detection of fluorescence evoked by pyrophosphate release during base incorporation, while Ion Torrent employs semiconductor detection of hydrogen ions released as a consequence of nucleotide incorporation.

OmniSeq Target has been approved by the New York State Department of Health for genomic testing of patients with cancer. OmniSeq Target uses both Ion Torrent and Illumina sequencing plat- forms. It specifically analyzes 23 cancer-associated genes (eg,

) to identify mutations for which there are approved therapeutic agents.

&ldquo;Focus on actionable mutations is what makes our approach unique and what makes this test such an important tool in therapeutic decision making,&rdquo; said Carl D. Morrison, MD, DVM, execu- tive director of the center for personalized medi- cine at Roswell Park Cancer Institute in Buffalo, New York, where the test was developed.

&ldquo;At the moment, I order molecular testing for

by FISH for all my advanced-stage lung adenocarci- noma patients,&rdquo; Levy said. &ldquo;If the tests are negative and the patient has the appropriate clinical pheno- type (never-smoker), I will consider ordering NGS with the goal of finding a genetic alteration that may guide me in finding the right clinical trial for a patient,&rdquo; he stated.

The cost of NGS testing has also been a consideration, but, Levy said, &ldquo;As costs reduce, it may be that people will perform NGS routinely for all patients in anticipation of new drugs being available.&rdquo;

A major player in the quest to analyze cancer genomes using NGS technology is The Cancer Genome Atlas (TCGA), a coordinated effort to accelerate understanding of the molecular basis of cancer through the application of genome analysis technologies, including large-scale genome sequencing.

reported that TCGA has developed a comprehensive molecular profiling of lung adenocarcinoma using samples of tumor and matched normal material from 230 previously untreated patients. Among the samples studied, 76% had somatic evidence of RTK/RAS/RAF activation. The results also suggested there remain unknown mechanisms by which the pathway is activated, opening the door to investigating inhibition of other possible target alterations, including MET and ERB2/HER2. The authors stressed the importance of their discovery of inactivating mutations of MGA, a global positive gene regulator, highlighting a role for the MYC pathway.

Clearly, data from NGS will identify more targets for clinical trials, and, referring to NSCLC, Levy said. &ldquo;One such trial in lung cancer, is the Lung-MAP study launched by the National Cancer Institute, which is utilizing Foundation One&rsquo;s next generation platform to help select targeted thera- pies for patients with squamous cell carcinoma.&rdquo;

The data acquired by NGS will increase understanding of the genomic alterations in NSCLC, lead to more efficacious personalized treatments, and avoid prescription of inappropriate therapeutic agents. It may also help assess an individual&rsquo;s risk of developing cancer and lead to development of risk reduction.

Ross JS, Cronin M. Whole cancer genome sequencing by next-generation methods.

rearrangements that are not detected by FISH with targeted next-gen- eration sequencing of lung carcinoma.

Illumina. http://www.illumina.com/systems.ilmn. Accessed August 9, 2014.

454 Sequencing Roche. http://454.com. Accessed August 9, 2014.

Life Technologies. Applied Biosystems. http://www.applied- biosystems.com.au. Accessed August 9, 2014.

Life Technologies. Ion Community. http://www.iontorrent .com. Accessed August 9, 2014.

Daniels M, Goh F, Wright CM, et al. Whole genome seq- uencing for lung cancer.

Roswell Park Cancer Institute. https://www.roswellpark .org/media/news/roswell-park-cancer-institute-genomic- sequencing-test-wins-new-york-state-approval. Accessed August 5, 2014.

The Cancer Genome Atlas. http://cancergenome.nih.gov/ abouttcga/overview. Accessed July 19, 2014.

The Cancer Genome Research Atlas. Comprehensive molecular profiling of lung adenocarcinoma Nature. 2014;511;543-550.

Daniels M, Goh F, Wright CM, et al. Whole genome se- quencing for lung cancer.

Next-Generation Sequencing Tests in NSCLC

Patients with non-small cell lung cancer (NSCLC) with

rearrangements account for a small minority (4%) of patients with NSCLC. NSCLC with

rearrangement occurs more often in patients with lung cancer who are nonsmokers and in patients with a history of smoking of 10 pack-years or fewer.

acts to regulate cell signaling, including signaling to downstream signaling pathways, such as the RASmitogen-activated protein kinase pathway, the

gene through translocation and formation of fusion proteins may lead to formation of cancerous cells that demonstrate uncontrolled proliferation and survival.

Early retrospective studies indicated a survival benefit with use of crizotinib in patients with

In one retrospective study, Berge et al analyzed records of patients with

rearrangements treated with pemetrexed followed by crizotinib, and reported improved outcomes compared with patients receiving crizotinib followed by pemetrexed. Median progression-free survival

was 4.5 months with pemetrexed following crizotinib versus 8.5 months with crizotinib following pemetrexed. The risk of progression was significantly greater with pemetrexed than with crizotinib as secondary therapy (hazard ratio [HR] 2.59;

In another retrospective study, Shaw et al analyzed data indicating an advantage in overall survival (OS) in patients with NSCLC and the

rearrangement treated with crizotinib. Investigators analyzed data from 67 patients with the

rearrangements. Patients were well matched based on age, sex, smoking history, and ethnicity. Compared with patients with the

rearrangement who received standard chemotherapy instead of crizotinib, patients who received crizotinib had a significantly lower risk of progression (HR, 0.36;

= .004) and a longer OS after 1 year (70% vs 44%) and 2 years (55% vs 12%).

Early retrospective studies indicated a survival benefit with use of crizotinib in patients with ALK rearrangements.

rearrangements treated with pemetrexed followed by crizotinib, and reported improved outcomes compared with patients receiving crizotinib followed by pemetrexed. Median progression-free survival (PFS) was 4.5 months with pemetrexed following crizotinib versus 8.5 months with crizotinib following pemetrexed. The risk of progression was significantly greater with pemetrexed than with crizotinib as secondary therapy (hazard ratio [HR] 2.59;

Studies confirm crizotinib&rsquo;s superior efficacy compared with standard chemotherapy in patients with lung cancer who have

In June 2013, investigators published results of a prospective study of crizotinib in the

In a press release, lead investigator Alice T. Shaw, MD, PhD, who is affiliated with the Massachusetts General Hospital Cancer Center in Boston, stated, &ldquo;This is the first randomized study to compare crizotinib with standard chemotherapy in advanced

-positive lung cancer.&rdquo; The trial involved 347 patients who had experienced a progression of NSCLC after receiving earlier treatments. Patients received either crizotinib orally twice daily or standard treatment with every-3-week intravenous infusions of docetaxel or pemetrexed.

Among patients receiving crizotinib, nearly two- thirds (65%) of patients responded to therapy versus one-fifth (20%) of patients receiving standard chemotherapy (P <.001). Overall PFS averaged 7.7 months in patients receiving crizotinib versus 3 months in patients receiving standard chemotherapy. According to Shaw, &ldquo;This study shows that patients with advanced

-positive lung cancer respond better to crizotinib and for longer periods of time.&rdquo;

Investigators speculated that an OS was not found between groups because of patient crossover from the standard chemotherapy group to the crizotinib group.

These results confirm the efficacy of crizotinib and support its use as a standard-of-care treatment for cases of advanced NSCLC with evidence of

rearrangements. This recommendation is supported by the latest guidelines from the National Clinical Cancer Network (NCCN).

In addition to its efficacy against tumors with the

rearrangement, crizotinib has separate effects on 2 other mutations: the

rearrangement. According to the NCCN guidelines, crizotinib is the only known agent to act against these 2 cancer mutations.6-8 Early cell line studies indicate that NSCLC with both

rearrangements may be more sensitive to crizotinib than NSCLC with

In addition, in a case report, a patient with NSCLC with a MET amplification and without an

rearrangementresponded to treatment with crizotinib.

Future trials will evaluate the role of crizotinib patients with these mutations.

Crizotinib improves PFS in patients with advanced NSCLC and

rearrangements. However, the developing understanding of the spectrum of activity of crizotinib may lead to its use in select patients with ROS1 mutations and MET amplifications.

Understanding the full spectrum of activity of crizotinib could lead to an expanded use of crizotinib that may benefit more patients with NSCLC.

in lung cancer: past, present, and future.

Berge EM, Lu X, Maxson D, et al. Clinical benefit from pemetrexed before and after crizotinib exposure and from crizotinib before and after pemetrexed exposure in patients with anaplastic lymphoma kinase-positive non-small-cell lung cancer.

Shaw AT, Yeap BY, Solomon BJ, et al. Effect of crizotinib on overall survival in patients with advanced non-small-cell lung cancer harbouring

gene rearrangement: a retro- spective analysis.

Marquedant K. Massachusetts General Hospital. MGH-led studies shed new light on targeted lung cancer therapy [press release]. http://www.eurekalert.org/pub_releases/2013-06/ mgh-mss053013.php. Published June 1, 2013. Accessed August 2014.

Shaw AT, Kim DW, Nakagawa K, et al. Crizotinib versus chemotherapy in advanced

National Comprehensive Cancer Network. NCCN Clinical Practice Guidelines in Oncology. Non-Small Cell Lung Cancer. Version 4.2014. www.nccn.org. Accessed August 2014.

rearrangements define a unique molecular class of lung cancers.

Ou SH, Kwak EL, Siwak-Tapp C, et al. Activity of crizotinib (PF02341066), a dual mesenchymal-epithelial transition (MET) and anaplastic lymphoma kinase (

) inhibitor, in a non- small cell lung cancer patient with de novo

In one retrospective study, Berge et al analyzed records of patients with ALK rearrangements treated with pemetrexed followed by crizotinib, and reported improved outcomes compared with patients receiving crizotinib followed by pemetrexed.

Lung Cancer (Sept 2014) | Targeted Therapies: Lung Cancer

Anti-PD-L1 Agents May Improve Outcomes in NSCLC

LKB1: Cancer Biomarker and Potential Therapeutic Target in NSCLC

Next-Generation Sequencing Tests in NSCLC

Treatment Focus: What New Research Means for Crizotinib