Chimeric Antigen Receptor T Cells for Sustained Remissions in Leukemia

SUMMARY: The FDA has granted Breakthrough Therapy Designation to immunotherapy with CTL019, which are genetically engineered T-cells. Chimeric Antigen Receptor (CAR) T-cell therapy is a type of immunotherapy in which T cells collected from the patient’s own blood and are genetically engineered to produce special receptors on their surface called chimeric antigen receptors (CAR’s). The cytotoxic T cells with these chimeric antigen receptors on their surface are now able to recognize a specific antigen on tumor cells. These engineered CAR T-cells which are grown in the lab are then infused into the patient and they in turn proliferate in the patient’s body and the engineered receptor on their surface help recognize and kill cancer cells that expresses that specific antigen. CTL019 are genetically engineered T-cells using CAR technology that seeks out cancer cells expressing the antigen CD19, which is found uniquely on B cells and destroy them. Patients, following treatment with CAR T-cells, develop B-cell aplasia (absence of CD19 positive cells) due to B-cell destruction and may need immunoglobin replacement. Hence, B-cell aplasia can be a useful therapeutic marker, as continued B-cell aplasia has been seen in all patients who had sustained remission, following CAR T-cell therapy. Cytokine Release Syndrome, an inflammatory process is the most common and serious side effect of CAR T-cell therapy and is associated with marked elevation of Interleukin-6. Cytokine release is important for T-cell activation and can result in high fevers and myalgias. This is usually self limiting although if severe can be associated with hypotension and respiratory insufficiency. Tocilizumab, an Interleukin-6 receptor blocking antibody produces a rapid improvement in symptoms. This is however not recommended unless the symptoms are severe and life threatening, as blunting the cytokine response can in turn negate T-cell proliferation. Elevated serum Ferritin and C-reactive protein levels are surrogate markers for severe Cytokine Release Syndrome. The CAR T-cells have been shown to also access sanctuary sites such as the central nervous system and eradicate cancer cells. CD19 antigen is expressed by majority of the B cell malignancies and therefore most studies using CAR T-cell therapy have focused on the treatment of advanced B-cell malignancies such as Chronic Lymphocytic Leukemia (CLL), Acute Lymphoblastic Leukemia (ALL) and Non Hodgkin lymphoma (NHL), such as Diffuse Large B-Cell Lymphoma (DLBCL). Previously published studies have shown significant responses with CAR T-cell therapy in patients with relapsed and refractory B-cell ALL. But the durability of remission has remained unclear.

The authors in this study, treated a total of 30 patients with relapsed or refractory ALL ( included those who had relapsed after allogeneic stem cell transplantation and those refractory to CD19 directed bispecific antibody Blinatumomab), with autologous Chimeric Antigen Receptor (CAR) T-cells (CTL019 T-cells) and monitored response rates, toxicities as well as proliferation and persistence of circulating CTL019 T-cells in the patient’s body. The first assessment was performed 1 month after infusion of CTL019 and 90% of the patients were in complete remission and sustained remissions were noted for up to 2 years. At a median follow up of 6 months, the event free survival was 67% and overall survival was 78%. The authors compared this efficacy data with the FDA approved agents for relapsed ALL such as Clofarabine, Nelarabine and Liposomal encapsulated Vincristine, which have a complete remission of less than 25% with a median duration of response of 4-9 weeks. Persisting CTL019 T-cells in the body is a marker of therapeutic efficacy. CTL019 T-cells proliferated in the patient’s body and was detectable in the blood bone marrow, and cerebrospinal fluid of patients who had a response. At 6 months, the probability that a patient would have persistence of CTL019 T-cells was 68% and the probability that a patient would have relapse free B-cell aplasia was 73%. Severe Cytokine Release Syndrome was noted in 27% of the patients and these patients had a higher disease burden before CTL019 infusion. All of these patients were effectively treated with the Interleukin-6 receptor blocking antibody Tocilizumab. The authors concluded that Chimeric Antigen Receptor modified T-cell therapy against CD19 positive cells (CTL019) was highly efficacious, in patients with relapsed and refractory ALL and was associated with a high and durable remission rate. This technology may be applied to other malignancies, as new antigen targets are identified. Maude SL, Frey N, Shaw PA, et al. N Engl J Med 2014; 371:1507-1517

Bevacizumab Combined With Chemotherapy for Platinum-Resistant Recurrent Ovarian Cancer The AURELIA Open-Label Randomized Phase III Trial

SUMMARY:The FDA recently approved AVASTIN® (Bevacizumab) in combination with chemotherapy for the treatment of patients with platinum-resistant, recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer. It is estimated that in the United States, approximately 22,000 women will be diagnosed with ovarian cancer in 2014 and a little over 14,000 women will die of the disease. In spite of significantly improved median survival following aggressive surgical debulking and platinum plus taxane based therapy, long term cure rate is approximately 20-30%. Majority of the patients relapse in 18-24 months and 25% of these patients are Platinum Resistant. These platinum resistant patients are usually treated with single agent chemotherapy drugs such as DOXIL® (Pegylated Liposomal Doxorubicin-PLD), TAXOL® (Paclitaxel) and HYCAMTIN® (Topotecan), with an expected response rate of 10-15%, median response duration of about 3-4 months and median Overall Survival of approximately 12 months. AURELIA (Avastin Use in Platinum-Resistant Epithelial Ovarian Cancer) is a multicenter, randomized, open-label, Phase III study in which 361 women with platinum resistant recurrent epithelial ovarian, primary peritoneal or fallopian tube cancer were enrolled. These patients had disease progression within six months of their platinum based chemotherapy (Platinum Resistant) and were randomly assigned to receive AVASTIN® (Bevacizumab) 10 mg/kg every 2 weeks or 15 mg/kg every 3 weeks in combination with investigators choice of single agent chemotherapy agent (N=179) or single agent chemotherapy alone (N=182). Chemotherapy included one of the following agents – TAXOL® 80 mg/m2 on days 1, 8, 15 and 22 every 4 weeks, DOXIL® 40 mg/m2 on day 1 every 4 weeks or HYCAMTIN® either 4 mg/m2 on days 1, 8 and 15 every 4 weeks or 1.25 mg/m2 on days 1-5 every 3 weeks. Patients with refractory disease, history of bowel obstruction, or those who had received two or more prior anticancer regimens were excluded. Treatment was given until disease progression. Patients who had progressed on single agent chemotherapy were allowed to cross over to AVASTIN® group. The primary end point was Progression Free Survival (PFS) and secondary end points included Objective Response Rate (ORR), Overall Survival (OS), safety, and patient reported outcomes. The combination of AVASTIN® plus chemotherapy resulted in a 62% reduction in the risk of progression compared to those who received chemotherapy alone, with a median PFS of 6.8 months for the AVASTIN® plus chemotherapy group versus 3.4 months for the single agent chemotherapy group (HR=0.38, P<0.0001) and thus met the primary endpoint of this clinical trial. This PFS benefit was seen consistently across all subgroups including the subgroup of patients with ascites. The ORR was 27.3% with the AVASTIN® combination versus 11.8% with single agent chemotherapy (P =0.001). The median OS was 16.6 months for the AVASTIN® combination versus 13.3 months for the single agent chemotherapy group (HR=0.85; P < .17). The lack of statistical significance in the OS has been attributed to cross over of 40% of patients, initially randomized to the chemotherapy alone group, who upon progression received AVASTIN®. There was a 15% improvement in abdominal and GI symptoms as reported by patients, with the AVASTIN® combination, compared to chemotherapy alone. On exploratory analyses it was noted that the addition of AVASTIN® to TAXOL® resulted in the most benefit, with a 5.7 month improvement in median PFS (9.6 versus 3.9 months), a 23% improvement in the overall response rate (53% versus 30%) and a 9.2 month improvement in median OS (22.4 versus 13.2 months) compared to single agent TAXOL®. This benefit was seen in spite of the fact that 97% of the patients in the TAXOL® group had received this agent with previous chemotherapy regimens. These findings suggest that patients who have received prior treatment with TAXOL® may benefit from AVASTIN® plus weekly TAXOL®. The most common adverse reactions (greater than or equal to 15%) in patients treated with AVASTIN® plus chemotherapy were neutropenia, peripheral neuropathy, hypertension and GI perforation occurred in 1.7% of these patients. This low perforation rate has been attributed to the exclusion of patients with rectosigmoid involvement by pelvic examination or bowel involvement on CT scan as well as those with clinical symptoms of bowel obstruction. The authors concluded that AVASTIN® in combination with chemotherapy significantly improved Progression Free Survival and Objective Response Rates in patients with Platinum Resistant Recurrent Ovarian Cancer. Pujade-Lauraine E, Hilpert F, Weber B, et al. J Clin Oncol 2014;32:1302-1308

Ipilimumab Plus Sargramostim vs Ipilimumab Alone for Treatment of Metastatic Melanoma – A Randomized Clinical Trial

SUMMARY: It is estimated that in the US, approximately 76,000 new cases of melanoma will be diagnosed and close to 8000 individuals will die of the disease in 2014. The incidence of melanoma has been on the rise for the past three decades. Unlike other malignancies, the role of chemotherapy for the treatment of melanoma has been limited. Treatment of advanced melanoma with immunotherapy using a cytokine, Interleukin-2 (IL-2) produced by T cells during an immune response, was first explored in the mid 1970’s. Durable responses were noted in a very small percentage of patients but this was associated with significant toxicities. This however opened the doors for the development a novel immunotherapeutic approaches, 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, 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 authors in this randomized study, compared the efficacy of YERVOY® (Ipilimumab) plus Sargramostim with YERVOY® alone, for treatment of metastatic melanoma. The rationale for this study was based on the synergy that was noted between YERVOY® and GM-CSF in preclinical models. The first immune checkpoint protein to be clinically targeted was CTLA-4. YERVOY® is a fully human IgG1monoclonal antibody that blocks Immune checkpoint protein/receptor CTLA- 4 and counteracts immune regulatory cells. YERVOY® has been shown to prolong overall survival in patients with previously treated, unresectable or metastatic melanoma. GM-CSF is a cytokine that enhances the antitumor activity of T and B lymphocytes by activating the antigen presenting dendritic cells and recruiting macrophages. It however can induce negative regulatory immune responses. In this phase II randomized clinical trial conducted by the Eastern Cooperative Oncology Group (ECOG), patients with unresectable stage III or IV melanoma (N = 245), who had received at least 1 prior therapy and with no central nervous system metastases were randomized to receive either YERVOY® along with Sargramostim (N=123) or YERVOY® alone (N=122). Patients in the combination group (Group A) received YERVOY®10 mg/kg, IV on day 1 along with Sargramostim 250 μg given subcutaneously, on days 1 thru 14 of a 21day cycle, every 3 weeks for four cycles followed by YERVOY® maintenance every 12 weeks. Patients in Group B received YERVOY® alone. Treatment was continued until disease progression or uncontrolled toxicities. The primary endpoint was comparison of length of Overall Survival (OS). Secondary end points included Progression Free Survival (PFS), response rate, safety, and tolerability. With a median follow up of 13.3 months, the median OS for the combination of YERVOY® plus Sargramostim was 17.5 months vs 12.7 months for YERVOY® alone. The one year survival rate for YERVOY® plus Sargramostim was 68.9% compared to 52.9% for YERVOY® alone (HR=0.64; P=0.01). The median PFS was similar and was 3.1 months in both study groups. The explanation for similar PFS in both treatment groups may be due to both YERVOY® and Sargramostim bringing about inflammatory changes at the tumor sites, which in turn could be misinterpreted as disease progression, on radiological studies. The authors commented that PFS may not be an appropriate endpoint in immunotherapy trials. Grade 3 to 5 adverse events were less in the combination group (44.9%) compared to 58% for single agent YERVOY® (P=0.04). The authors concluded that treatment of unresectable stage III or IV melanoma patients with YERVOY® plus Sargramostim resulted in significantly longer overall survival with lower toxicities, compared to YERVOY® alone. Hodi SF, Lee S, McDermott DF, et al. JAMA 2014;312:1744-1753

RAINBOW A global, phase III, randomized, double-blind study of ramucirumab plus paclitaxel versus placebo plus paclitaxel in the treatment of metastatic gastroesophageal junction (GEJ) and gastric adenocarcinoma following disease progression on first-line platinum- and fluoropyrimidine-containing combination therapy rainbow IMCL CP12-0922 (I4T-IE-JVBE)

SUMMARY: The FDA on November 5, 2014 approved CYRAMZA® (Ramucirumab) for use in combination with TAXOL® (Paclitaxel) for the treatment of patients with advanced gastric or GastroEsophageal Junction (GEJ) adenocarcinoma. CYRAMZA® was approved by the FDA in April, 2014 as a single agent for the treatment of patients with advanced gastric or GEJ adenocarcinoma, refractory to or progressive, following first-line therapy with platinum or fluoropyrimidine chemotherapy. It is estimated that there were approximately 21,600 new cases and 10,990 deaths from gastric cancer in the United States in 2013. The biology of gastric cancer appears to be different in different parts of the globe. Following progression after first line treatment for metastatic disease, the median survival is approximately 3 months. CYRAMZA® is a human IgG1 monoclonal antibody that inhibits VEGF-receptor 2, unlike AVASTIN® (Bevacizumab) which inhibits VEGF-A. The RAINBOW study is an international, placebo-controlled, double-blind, phase III trial in which 665 patients with metastatic gastroesophageal junction or gastric adenocarcinoma, who had disease progression on or within 4 months after first-line platinum and fluoropyrimidine-based combination therapy, were included. Patients were randomly assigned to receive TAXOL® (Paclitaxel) 80 mg/m2 given on D1, 8, 15 along with Placebo (N=335) or the same dose and schedule of TAXOL® given along with CYRAMZA® at 8 mg/kg IV every 2 weeks (N=330), of a 28 day cycle. Treatment was continued until disease progression or unacceptable toxicities were noted. The primary endpoint was Overall Survival (OS). Secondary endpoints included Progression Free Survival (PFS), Objective Response Rate (ORR) and Time To Progression (TTP). The median OS for the combination of CYRAMZA® and TAXOL® was 9.6 months compared to 7.4 months for Placebo and TAXOL® (HR=0.81; P=0.017), resulting in a 19% reduction in the risk of death with the CYRAMZA® and TAXOL® combination. The secondary endpoints favored the CYRAMZA® and TAXOL® combination as well. The median PFS was 4.4 months and 2.9 months (HR=0.64; P<0.001), ORR was 28% and 16% (P<0.0001) and median TTP was 5.5 months and 3 months with the CYRAMZA® and TAXOL® combination vs Placebo and TAXOL® combination respectively. As one would expect, treatment related adverse events were seen more frequently in the CYRAMZA® and TAXOL® combination group. Significant were neutropenia, hypertension, fatigue and asthenia, diarrhea and epistaxis. The incidence of febrile neutropenia in the two treatment groups was however comparable (3.1% vs 2.4%). The authors concluded that the combination of CYRAMZA® and TAXOL® combination significantly improved both Progression Free and Overall Survival and also resulted in significantly improved disease control rates, in patients with metastatic gastroesophageal junction or gastric adenocarcinoma. Wilke H, Van Cutsem E, Oh SC, et al. J Clin Oncol 32, 2014 (suppl 3; abstr LBA7)

Promise and Pitfalls of Heavy-Particle Therapy

SUMMARY: Radiation Therapy involves the use of X-Rays, gamma rays and charged particles for cancer treatment. External-beam radiation therapy is most often delivered using a linear accelerator in the form of Photon beams (either x-rays or gamma rays). Photons have no mass and are packets of energy of an electromagnetic wave. Electrons and Protons are charged particles and Electrons are considered light particles whereas Protons are considered heavy particles. Electron beams are used to irradiate skin and superficial tumors, as they are unable to penetrate deep into the tissues. The different types of external beam radiation treatments include 3-Dimensional Conformal Radiation Therapy (3D-CRT) meant to deliver radiation to very precisely shaped target areas, IMRT or Intensity Modulated Radiation Therapy which allows different areas of a tumor or nearby tissues to receive different doses of radiation, Image Guided Radiation Therapy (IGRT) which allows reduction in the planned volume of tissue to be treated as changes in a tumor size are noted during treatment, Stereotactic RadioSurgery (SRS) which can deliver one or more high doses of radiation to a small tumor, Stereotactic Body Radiation Therapy (SBRT) or CYBERKNIFE® which is similar to SRS but also takes the normal motion of the body into account while treating malignancies involving the lung and liver and Proton Beam therapy. Proton beams unlike Photons, enter the skin and travel through the tissues and deposit much of their energy at the end of their path (known as the Bragg peak) and deposit less energy along the way. This is unlike Photons which deposit energy all along the path through the tissues and the deposited dose decreases with increasing depth. As a result, with Proton beam therapy, normal tissues are exposed to less radiation compared with Photons. Despite this advantage, tissue heterogeneity such as organ motion, tumor volume changes during treatment can have a significant negative impact on target coverage for Proton beam therapy and can result in damage to the surrounding tissues and potential complications. The authors in this review discussed the clinical applications of Proton therapy in Adult and Pediatric malignancies. Pediatric patients with malignancies have greater benefit with Proton beam therapy, with a statistically significant lower risk of secondary malignancies and less damage to the developing tissues and organs, compared to Photon therapy (External Beam Radiation Therapy). This clinical benefit may be less so in adult malignancies in spite of superior dosimetry, compared to external beam radiation, as adults are less prone to secondary malignancies compared to children.

ADULT MALIGNANCIES

Prostate Cancer: Majority of the patients receiving Proton beam treatment in the United States have prostate cancer. Several randomized trials have concluded that higher radiation dose to the prostate gland leads to better tumor control. Proton beam therapy may deliver this promise, but with associated toxicities, in particular rectal bleeding. This is by virtue of the anatomy of the prostate gland which is deep in the pelvis. Outcomes and patient reported side effects were similar when men with prostate cancer were treated with similar doses of radiation using either Proton beam therapy or External beam radiation therapy. The American Society of Therapeutic Radiology and Oncology (ASTRO) has recommended that Proton beam therapy for patients with prostate cancer should be offered in the context of a clinical trial or registry, as there is not enough evidence suggesting clinical benefit in this patient population.

Breast Cancer: Proton beam therapy may be of value in select situations, such as patients with bilateral implants after mastectomy and in clinical scenarios where cardiac or pulmonary risks with Photon therapy are not acceptable. This is because of a significant reduction in the radiation doses to the heart, lung and contralateral breast with Proton therapy compared to Photon therapy.

Lung Cancer: Proton beam therapy for NSCLC (Non Small Cell Lung Cancer) is in the early stages of evaluation and has the advantage of reduced radiation to the normal lung and heart. This may be relevant in patients with inoperable early stage NSCLC with poor lung function, prior chest irradiation or in those with multifocal lung cancers requiring more than one treatment course. Proton therapy can be of significant value in patients with Stage IIIA NSCLC who in addition to chemoradiation may be candidates for pneumonectomy, thus sparing the contralateral lung from radiation related toxicities.

Head and Neck Cancers: Proton therapy may be of value in nasopharyngeal carcinoma and malignancies involving the oropharynx and paranasal sinuses. Proton therapy limits the radiation dose to the brain stem, optic structures, mandible and salivary glands, decreasing the risk of xerostomia and osteoradionecrosis of the mandible.

GI Malignancies: Proton beam therapy is the preferable treatment for hepatocellular carcinoma in patients with Child-Pugh class B and class C cirrhosis, as it is able to spare more liver tissue from radiation.

Brain Tumors: Meningiomas are ideal tumors for Proton beam therapy, with less cerebral adverse events and therefore has a positive impact on quality of life of patients. Clinical trials are underway to test this hypothesis.

PEDIATRIC TUMORS

Medulloblastoma- CranioSpinal Irradiation: There is a significant long term advantage with Proton CranioSpinal Irradiation compared to conventional or IMRT photon CSI. There is a 6-12 times lower risk of secondary malignancies due to lower radiation doses to normal tissues. This is more relevant because craniospinal axis irradiation results in the most exposure of a childs tissue to radiation.

Rhabdomyosarcoma: This is the most common soft tissue sarcoma in children arising in the head and neck region and Proton therapy can significantly reduce the mean doses to the retina, optic nerve, parotid and cochlea.

Ependymoma, Craniopharyngioma, Retinoblastoma and Glioma: Proton therapy for these tumors has been associated with lower acute and long term toxicities as well lower risk of secondary malignancies.

The authors concluded that the most benefit for Proton beam therapy is in pediatric malignancies, no significant benefit in skin cancer and marginal benefit in adult lung and prostate cancer. With ongoing advances in the delivery of Proton therapy such as Intensity Modulated Proton Therapy (IMPT) and other expensive therapeutic interventions, economics will take precedence, until and unless a clear clinical benefit is proven. Mitin T and Zietman AL. J Clin Oncol 2014;32:2855-2863

Phase II study of nivolumab (Anti-PD-1, BMS-936558, ONO-4538) in patients with advanced, refractory squamous non-small cell lung cancer

SUMMARY: 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 224,000 new cases of lung cancer will be diagnosed in the United States in 2014 and over 159,000 will die of the disease. Of the three main subtypes of Non Small Cell Lung Cancer (NSCLC), 25% are Squamous cell carcinomas, 40% are Adenocarcinomas and 10% are Large cell carcinomas. With a better understanding of the Immune checkpoints, the gates are now wide open for the development of various immunotherapies. 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. Checkmate -063 is a Phase II single arm, open label study designed to evaluate the efficacy of OPDIVO® (Nivolumab) in patients with advanced NSCLC with squamous histology, who had progressed on platinum based therapy as well as at least one additional systemic therapy. OPDIVO® is an immune checkpoint PD-1 (Programmed cell Death 1) targeted, fully human, immunoglobulin G4 monoclonal antibody, which demonstrated an objective response in 20% – 25% of patients with advanced Non Small Cell Lung Cancer, Melanoma and Renal Cell Carcinoma, with favorable toxicities, in previously published studies. This study enrolled 117 patients and two thirds of the patients had previously failed 3 or more treatments and three fourths of patients were within 3 months of completion of their most recent therapy. OPDIVO® was administered as a single agent at 3mg/kg by intravenous infusion 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% as assessed by an independent review committee and the median duration of response was not reached. These responses were independent of PD-L1 status for patients with quantifiable PD-L1 expression. 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%. Approximately 17% of the patients experienced grade 3-4 adverse events which included fatigue, pneumonitis and diarrhea. The authors concluded that the high response rates, median duration of response and disease control rates for Squamous NSCLC, is very promising in this difficult to treat group of patients and phase III trials are underway evaluating OPDIVO® monotherapy in frontline and previously treated patients with Non Small Cell Lung cancer. Ramalingam SS, Mazieres J, Planchard D, et al. Presented at: 2014 Multidisciplinary Symposium in Thoracic Oncology; October 30-November 1, 2014; Chicago, IL. LBA#3462

Statin Use After Colorectal Cancer Diagnosis and Survival A Population-Based Cohort Study

SUMMARY: Approximately 32 million Americans take a statin in the United States. Statins (3-Hydroxy-3-MethylGlutaryl coenzyme A reductase inhibitors) are usually prescribed to lower LDL cholesterol. Cholesterol is a structural component of cell membranes and a reduction in the availability of cholesterol can result in decreased proliferation and migration of cancer cells. The six statin drugs available in the United States include LIPITOR® (Atorvastatin), ZOCOR® (Simvastatin), CRESTOR® (Rosuvastatin), MEVACOR® (Lovastatin), PRAVACHOL® (Pravastatin) and LESCOL® (Fluvastatin). Statin use in cancer patients has been associated with a reduction in cancer related mortality in several clinical studies. This benefit has been attributed to the inhibition of HMG-CoA reductase, which is a rate limiting enzyme in the mevalonate and cholesterol synthesis pathway. The mevalonate pathway is upregulated by mutated p53 (tumor suppressor gene) which is often expressed in cancer cells. By inhibiting the mevalonate pathway, statins can reduce isoprenoid levels such as farnesylpyrophosphate (F-PP) and geranylgeranylpyrophosphate (GG-PP). These isoprenoids are essential for the posttranslational modification of several proteins involved in important intracellular signaling pathways and therefore play a crucial role in cell growth, proliferation, survival and migration. Statins also inhibit angiogenic pathways and proteasomes, thereby negatively impacting cell proliferation and survival. Survival benefit with statin use after colorectal cancer diagnosis has been unclear. To answer this question, the authors identified a cohort of patients (N=7657) diagnosed with stage I to III colorectal cancer from 1998 to 2009, in the National Cancer Data Repository (English Cancer Registry). Information on statin use was obtained from medical records of patients and in this cohort of patients 35% were identified to have used statin drugs following diagnosis of colorectal cancer. Twenty percent of these patients had stage I disease, 43% had stage II disease and 37% had stage III disease. Patients were followed up for 14 years following their diagnosis of colorectal cancer. Statin use after a diagnosis of colorectal cancer was associated with a 29% reduction in colorectal cancer-specific mortality (HR= 0.71). There was a dose-response association with a 36% reduction in colorectal cancer-specific mortality with statin use for more than 1 year (HR=0.64). Statin users after colorectal cancer diagnosis also had a 25% reduction in all-cause mortality (HR=0.75). The authors concluded that based on this large population based colorectal cancer cohort, statin use following diagnosis of colorectal cancer was associated with longer rates of survival. Cardwell CR, Hicks BM, Hughes C, et al. J Clin Oncol 2014;32:3177-3183

Cancer of Unknown Primary Site

SUMMARY:Carcinoma of Unknown Primary Site (CUPS) is a heterogeneous clinical pathologic syndrome for which the anatomical site of origin of the primary tumor is clinically undetectable. CUPS accounts for approximately 2% of all advanced malignances annually. The American Cancer Society estimates that about 31,430 cases of Cancer of Unknown Primary site will be diagnosed in 2014 in the United States. The pathobiology of tumors from unknown primary sites is similar to those with detectable primary tumors and therefore may respond to therapies similar to those with easily detectable primary tumors. Historically, the treatment approach for patients with CUPS included broad spectrum empiric chemotherapy. Histological evaluation of the biopsy tissue alone has been the standard practice for decades. With the availability of gene expression profiling assays and advances in ImmunoHistoChemistry staining as well as imaging technology, predicting the tissue of origin of the primary tumor and tailoring therapy accordingly, has improved overall survival in this patient population. Evaluation of a patient with CUPS starts with gathering and incorporating medical information which includes the patient’s gender, medical history, clinical findings and sites of metastases. A CT scan of the chest, abdomen and pelvis with IV and oral contrast is recommended, although PET (Positron Emission Tomography) or an MRI can be performed in those with renal insufficiency or iodine allergy. PET scan is recommended for those with cervical lymphadenopathy with squamous histology, to help determine the extent of the disease and treatment planning for radiation. PET imaging is also helpful for patients with solitary metastases before locoregional therapies are planned, as well as assessing response in patients with predominantly bone only disease. In women presenting with isolated axillary lymphadenopathy, adenocarcinoma histology, negative mammograms and ultrasound, MRI of the breasts is indicated. With the exception of those patients with CUPS who present with cervical lymphadenopathy, diagnostic procedures such as bronchoscopy, EGD and colonoscopy are not recommended in asymptomatic patients. Tumor markers in general do not have diagnostic value in patients with CUPS although they could be utilized to monitor response to treatment. However, PSA when elevated in a male with adenocarcinoma and osteoblastic metastases, is suggestive of a prostate primary. Similarly an elevated Beta HCG and AFP in a patient with undifferentiated or poorly differentiated carcinoma, is suggestive of an extragonadal germ cell tumor and an elevated AFP is also helpful in making a diagnosis of Hepatoma. Approximately 60% of the patients with CUPS have well or moderately differentiated adenocarcinoma on light microscopy, 30% have poorly differentiated carcinoma or adenocarcinoma, 5% have poorly differentiated or undifferentiated malignancy and 5% have squamous cell carcinoma. Following histological evaluation on light microscopy, the biopsy specimen is further tested using ImmunoHistoChemical stains, using peroxidase labeled antibodies against tumor specific antigens, taking advantage of the similarities in the tumor profiles of primary and metastatic malignancies. After delineating a tumor as carcinoma, lymphoma, sarcoma or melanoma, additional IHC testing can help identify tumors such as a lung primary (postive Thyroid Transcription Factor 1-TTF1and positive CytoKeratin 7- CK7), lower gastrointestinal cancers (positive CK20, positive CDX2 and negative CK7) or a breast primary (positive CK7 and positive Mammaglobin). Tissue-of-Origin molecular profiling is based on the principle that in patients with CUPS, molecular signatures of metastatic tumors are similar to their primary tumor. Tissue-of-Origin molecular profiling is performed using tools such as DNA microarray, quantitative real time polymerase chain reaction assay (rt-PCR) or assays based on messenger RNA (mRNA) or microRNA. These tests are cost-effective and 70% – 90% accurate. This study can be performed on formalin-fixed samples as well as samples from fine needle aspiration. Even though platinum based chemotherapy has been the default regimen for patients with CUPS, histological evaluation of biopsy tissue by light microscopy, IHC testing and molecular profiling assay may complement each other and help guide the Health Care Provider to select site specific therapy. The survival outcomes of CUPS patients with a Tissue-of-Origin molecularly diagnosed profile are comparable to those with similar type advanced cancer with a known primary. The authors concluded that with additional molecular insights into tumor biology and availability of newer therapeutic agents, patients with CUPS and known primary tumors may eventually be treated alike. Varadhachary, GR and Raber, MN. N Engl J Med 2014; 371:757-765

Clinical and Safety Outcomes Associated With Treatment of Acute Venous Thromboembolism A Systematic Review and Meta-analysis

SUMMARY: The Center for Disease Control and Prevention (CDC) estimates that approximately 1-2 per 1000 individuals develop Deep Vein Thrombosis/Pulmonary Embolism (PE) each year in the United States, resulting in 60,000 – 100,000 deaths. VTE is the third leading cause of cardiovascular mortality with a mortality rate of up to 25% in those with untreated acute pulmonary embolism. For decades, Unfractionated Heparin (UFH) also known as standard heparin along with Vitamin K antagonist (Warfarin) has been the established standard, for the treatment of Acute Venous ThromboEmbolism. Even though Low Molecular Weight Heparin (LMWH) preparations as well as new oral anticoagulants have been available for the treatment Venous ThromboEmbolism, there has been very little guidance for Health Care Providers on the use of these newer agents. The authors in this analysis compared the efficacy and safety outcomes associated with different anticoagulation regimens for treatment of Venous ThromboEmbolism (VTE). These anticoagulant regimens included Unfractionated Heparin (UFH), Low Molecular Weight Heparin (LMWH) or Fondaparinux in combination with Vitamin K antagonists, LMWH with Dabigatran (PRADAXA®), Rivaroxaban (XARELTO®), Apixaban (ELIQUIS®) or Edoxaban and LMWH alone. This meta analysis included 44,989 patients from 45 randomized trials which reported rates of recurrent VTE and major bleeding in patients with acute VTE. In these Acute Deep Vein Thrombosis and Pulmonary Embolism trials, Rivaroxaban and Apixaban were evaluated without the use of initial LMWH whereas both Dabigatran or Edoxaban were assessed following an initial 5 day treatment with LMWH. This analysis was therefore able to assess clinical and safety outcomes associated with different anticoagulation regimens. The followings findings were noted:

1) Standard Heparin–Vitamin K antagonist combination was associated with an increased risk of recurrent VTE compared with the LMWH–Vitamin K antagonist combination

2) Both new oral anticoagulants and LMWH–vitamin K antagonist combination had similar clinical outcomes. However, the newer oral anticoagulants were associated with a lower risk of major bleeding and this benefit was more pronounced with Rivaroxaban and Apixaban. Compared with LMWH-Dabigatran and LMWH-Edoxaban combinations, Apixaban was associated with a lower risk of bleeding.

This comprehensive analysis lead the authors to conclude that Unfractionated Heparin (Standard Heparin)–Vitamin K antagonist combination is the least effective strategy for the treatment of Acute Venous ThromboEmbolism and Rivaroxaban and Apixaban are associated with the lowest risk for bleeding. Castellucci LA, Cameron C, Le Gal G, et al. JAMA 2014;312:1122-1135

Phase 3 study of NEPA, a fixed-dose combination of netupitant and palonosetron, for prevention of chemotherapy-induced nausea and vomiting during repeated moderately emetogenic chemotherapy (MEC) cycles

SUMMARY: Chemotherapy Induced Nausea and Vomiting (CINV) is one of the most common adverse effects of chemotherapy and is experienced by about 80% of patients receiving chemotherapy. The development of effective antiemetic agents has facilitated the administration of majority of the chemotherapy agents in an outpatient setting avoiding hospitalization. Acute CINV begins within the first 24 hours following chemotherapy administration, with most patients experiencing symptoms within the first four hours of treatment whereas delayed nausea and vomiting occurs more than 24 hours after chemotherapy administration and can persist for several days. Delayed CINV is often underestimated and a third of the patients receiving chemotherapy may experience delayed nausea and vomiting without prior acute nausea or vomiting. Acute nausea and vomiting is dependent on serotonin (5-hydroxytryptamine-5HT3) and its receptors. 5-HT3 receptors are located on vagal afferent pathway, which in turn activates the vomiting center to initiate the vomiting reflex. 5-HT3 receptors are located peripherally on the nerve endings of the vagus and centrally in the Chemoreceptor Trigger Zone of the area Postrema. Chemotherapeutic agents produce nausea and vomiting by stimulating the release of serotonin from the enterochromaffin cells of the small intestine. Delayed nausea and vomiting is associated with the activation of Neurokinin 1 (NK1) receptors by substance P. NK1 receptors are broadly distributed in the central and peripheral nervous systems. Netupitant inhibits substance P mediated responses. ALOXI® (Palonosetron) is a second generation 5-HT3 antagonist and has a 100 fold higher binding affinity to 5-HT3 receptor than other 5-HT3 receptor antagonists. AKYNZEO® (300 mg Netupitant/0.5 mg Palonosetron) is an oral, fixed combination product of Netupitant, a substance P/Neurokinin 1 (NK1) receptor antagonist, and ALOXI®, a serotonin (5- HT3) receptor antagonist. Taking advantage of the different mechanisms of action and synergy between these two agents, a randomized, double-blind, multinational study was conducted, comparing AKYNZEO® with ALOXI® in chemotherapy naive patients receiving anthracycline based chemotherapy regimens. One thousand four hundred and fifty five (N=1455) were randomized to receive either AKYNZEO® or ALOXI® and both groups received oral Dexamethasone as a part of their antiemetic regimen. The primary endpoint was complete response (CR) defined as no emesis, no rescue medication needed and no significant nausea. AKYNZEO® maintained superiority over ALOXI® for overall (0-120 hours) complete response and also maintained superiority over multiple chemotherapy cycles (P < 0.0001). The most common side effects for AKYNZEO® were headache, fatigue and constipation. The authors concluded that AKYNZEO®, by targeting dual antiemetic pathways, significantly improved chemotherapy induced nausea and vomiting compared to ALOXI® alone and this benefit was maintained over multiple cycles of moderately emetogenic chemotherapy. AKYNZEO® capsule can be administered as a single dose, one hour prior to the start of chemotherapy. Aapro MS, Karthaus M, Schwartzberg LS, et al. J Clin Oncol 32:5s, 2014 (suppl; abstr 9502)</s