Author: RR

Long Term Data Confirms Durable Efficacy and Safety of JAKAFI® in Myelofibrosis

RR

SUMMARY: MyeloFibrosis (MF) is a MyeloProliferative Neoplasm (MPN) characterized by a ineffective hematopoiesis, progressive fibrosis of the bone marrow and potential for leukemic transformation. This stem cell disorder is Philadelphia Chromosome negative and manifestations include anemia, splenomegaly and related symptoms such as abdominal distension and discomfort with early satiety. Cytokine driven debilitating symptoms such as fatigue, fever, night sweats, weight loss, pruritus and bone or muscle pain can further impact an individual’s quality of life. Myelofibrosis can be primary (PMF) or secondary to Polycythemia Vera (PV) or Essential Thrombocythemia (ET). The JAK-STAT signaling pathway has been implicated in the pathogenesis of Myelofibrosis. This pathway normally is responsible for passing information from outside the cell through the cell membrane to the DNA in the nucleus for gene transcription. Janus Kinase (JAK) family of tyrosine kinases are cytoplasmic proteins and include JAK1, JAK2, JAK3 and TYK2. JAK1 helps propagate the signaling of inflammatory cytokines whereas JAK2 is essential for growth and differentiation of hematopoietic stem cells. These tyrosine kinases mediate cell signaling by recruiting STAT’s (Signal Transducer and Activator of Transcription), with resulting modulation of gene expression. In patients with MPN, the aberrant myeloproliferation is the result of dysregulated JAK2-STAT signaling as well as excess production of inflammatory cytokines associated with this abnormal signaling. These cytokines contribute to the symptoms often reported by patients with MF. JAK2 mutations such as JAK2 V617F are seen in approximately 60% of the patients with PMF and ET and 95% of patients with PV. Unlike CML where the BCR-ABL fusion gene triggers the disease, JAK2 mutations are not initiators of the disease and are not specific for MPN. Further, several other genetic events may contribute to the abnormal JAK2-STAT signaling.

JAKAFI® (Ruxolitinib) is a potent JAK1 and JAK2 inhibitor and exerts its mechanism of action by targeting and inhibiting the dysregulated JAK2-STAT signaling pathway. The FDA approval of JAKAFI® for the treatment of Intermediate and high risk Myelofibrosis was based on two phase III trials – COMFORT (Controlled Myelofibrosis Study with Oral JAK1/JAK2 Inhibitor Treatment)-I and COMFORT-II studies. JAKAFI® in patients with Myelofibrosis, demonstrated rapid and durable improvements in splenomegaly and symptoms as well as improved survival in both phase III COMFORT studies. The authors now reported the final long term efficacy and safety results after 5 years of treatment with JAKAFI® in the COMFORT-I study. In COMFORT-I study, 309 intermediate or high risk patients were randomized to receive either JAKAFI® (N=155) or Placebo (N=154). The Primary end point was a 35% or more reduction in spleen size at 24 weeks. The preplanned 5- year analysis occurred when all patients reached the 5-year visit or discontinued treatment. Patients in the placebo group could crossover to the JAKAFI® group after the primary analysis (when all patients completed week 24) or at any time if they had pre-specified worsening of splenomegaly. Of the 154 patients randomized to placebo, 111 patients crossed over to the JAKAFI® group and the median time to crossover was 41 weeks.

It was noted that at week 24, patients in the JAKAFI® arm had a mean Spleen Volume reduction of 32% from baseline and this response was durable for patients who continued treatment, with a mean Spleen Volume reduction of 38% at week 264 (5 years). At 5 years, 18.5% of patients on JAKAFI® had a 35% or more, reduction in Spleen Volume from baseline. Median duration of this spleen response (35% or more reduction in Spleen Volume) in the JAKAFI® group was 168 weeks. Overall Survival was significantly better for patients originally randomized to JAKAFI® compared to placebo (HR=0.69; P=0.025). The mean hemoglobin and platelet count remained stable through 5 years, after week 24. Adverse events included anemia, thrombocytopenia, Herpes Zoster and Basal Cell Carcinomas

The authors concluded that after a median follow up of over 5 years, patients with Myelofibrosis randomized to receive JAKAFI® in the COMFORT-I study, had a superior Overall Survival compared to placebo, as well as durable spleen response, while on long term therapy with JAKAFI®. Long-Term Outcomes of Ruxolitinib(RUX) Therapy in Patients(PTS) with Myelofibrosis(MF): 5-Year Final Efficacy and Safety Analysis from COMFORT-I. Verstovsek S, Mesa RA, Gotlib JR, et al. Presented at 2016 European Hematology Association Congress; June 9-12, 2016; Copenhagen, Denmark. Abstract:S452

GAZYVA® in Combination with TREANDA® for RITUXAN® Refractory Indolent Lymphoma

RR

SUMMARY: The American Cancer Society estimates that in 2016, about 72,580 people will be diagnosed with Non Hodgkin Lymphoma (NHL) in the United States and about 20,150 individuals will die of this disease. Indolent Non Hodgkin Lymphomas are mature B cell lymphoproliferative disorders and include Follicular Lymphoma, Nodal Marginal Zone Lymphoma (NMZL), Extranodal Marginal Zone Lymphoma (ENMZL) of Mucosa-Associated Lymphoid Tissue (MALT) lymphoma, Splenic Marginal Zone Lymphoma (SMZL), LymphoPlasmacytic Lymphoma (LPL) and Small Lymphocytic Lymphoma (SLL). Follicular Lymphoma is the most indolent form and second most common form of all NHLs and they are a heterogeneous group of lymphoproliferative malignancies. Approximately 20% of all NHLs are Follicular Lymphomas. Advanced stage indolent NHL are not curable and as such, prolonging Progression Free Survival (PFS) and Overall Survival (OS), while maintaining Quality of Life (QoL), has been the goals of treatment intervention. Asymptomatic patients with indolent NHL are generally considered candidates for “watch and wait” approach, whereas those with B symptoms (fever, night sweats, and weight loss), painful lymphadenopathy/splenomegaly, organ compromise and cytopenias are generally considered candidates for therapy.

GAZYVA® (Obinutuzumab) is glycoengineered, fully humanized, third generation, type II anti-CD20 antibody (IgG1 monoclonal antibody) that selectivity binds to the extracellular domain of the CD20 antigen on malignant human B cells. By virtue of binding affinity of the glycoengineered Fc portion of GAZYVA® to Fcγ receptor III on innate immune effector cells such as natural killer cells, macrophages and neutrophils, Antibody-Dependent Cell-mediated Cytotoxicity (ADCC) and Antibody-Dependent Cellular phagocytosis is significantly enhanced, whereas it induces very little Complement-Dependent Cytotoxicity. This is in contrast to RITUXAN® (Rituximab), which is a first generation type I, chimeric anti-CD20 targeted monoclonal antibody that kills lymphoma cells primarily by Complement-Dependent Cytotoxicity and also ADCC.

GADOLIN is a pivotal multicenter, open-label, phase III study in which TREANDA® (Bendamustine) alone was compared with TREANDA® plus GAZYVA® followed by GAZYVA® maintenance, in patients with indolent NHL (iNHL), refractory to RITUXAN®. Patients with RITUXAN® refractory iNHL (N=396) were randomly assigned to receive either TREANDA® 120 mg/m2 IV on days 1 and 2 every 28 days for a total of 6 cycles (N=202) or TREANDA® 90 mg/m2 IV on days 1 and 2 every 28 days for 6 cycles and GAZYVA® 1000mg IV days 1, 8 and 15 every 28 days of cycle 1 and on day 1 of cycles 2-6 (N=194). In patients with non-progressive disease in the combination arm, GAZYVA® was continued (maintenance) every 2 months for up to 2 years. Both treatment groups were well balanced and the median age was 63 years, with a median of two prior lines of therapy. More than 90% of patients in each treatment group were refractory to their previous therapy and between 76% and 81% were double-refractory to both RITUXAN® and an alkylating agent. The Primary end point was Progression Free Survival (PFS) and Secondary end points included Overall Survival and Response Rate.

The study was unblinded at the time of planned interim analysis and had to be halted early, upon recommendations from the Independent Data Monitoring Committee, as the primary end point was reached. After a median follow up of 21 months, the Progression Free Survival with GAZYVA® and TREANDA® combination was superior (median not reached) compared to a PFS of 14.9 months with TREANDA® monotherapy (HR=0.55; P<0.0001). This meant a 45% reduction in the rate of disease progression. There was however no difference in the Response Rates between the treatment groups and the best Overall Response Rate up to 12 months from start of treatment, was 77% in the TREANDA® alone group and 79% in the TREANDA® plus GAZYVA® group. Median Overall Survival has not yet been reached in either arm and longer follow up is needed. The combination experimental group experienced more grade 3 adverse events such as infusion related reactions and neutropenia whereas the TREANDA® alone group experienced more thrombocytopenia and anemia.

The authors concluded that GAZYVA® in combination with TREANDA® is superior to TREANDA® alone, in patients with RITUXAN® refractory indolent Non Hodgkin Lymphoma, with a significant improvement in Progression Free survival. The lack of difference in the Response Rate between the two treatment groups begs the question if the improvement in PFS benefit in the combination treatment group was derived from the quality of remission related to improved minimal residual disease negativity versus continuous maintenance treatment with GAZYVA® or both. Obinutuzumab plus bendamustine versus bendamustine monotherapy in patients with rituximab-refractory indolent non-Hodgkin lymphoma (GADOLIN): a randomised, controlled, open-label, multicentre, phase 3 trial. Sehn LH, Chua N, Mayer J, et al. Lancet Oncol 2016;17:1081-1093

FDA Approves SUSTOL® for the Prevention of Chemotherapy-Induced Nausea and Vomiting

RR

SUMMARY: The FDA on August 10, 2016 approved SUSTOL® (Granisetron) extended- release injection, for use in combination with other antiemetics in adults, for the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of Moderately Emetogenic Chemotherapy (MEC) or Anthracycline and Cyclophosphamide (AC) combination chemotherapy regimen. 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. 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, with the chemotherapeutic agents stimulating the release of Serotonin from the enterochromaffin cells of the small intestine. 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 also located centrally in the Chemoreceptor Trigger Zone of the area Postrema. 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.

Granisetron is a first-generation serotonin-3 (5-HT3) receptor antagonist commonly used to treat CINV, but has a short half-life of approximately 8 hours. SUSTOL® is a novel formulation of 2 % Granisetron and a bioerodible tri(ethylene glycol) polymer, designed to provide slow, controlled hydrolysis, resulting in slow and sustained release of Granisetron, thereby preventing both acute and delayed CINV associated with MEC and Highly Emetogenic Chemotherapy (HEC). With a plasma half-life of 24-34 hours, this novel preparation formulation can maintain therapeutic levels of Granisetron for 5 or more days.

The FDA approval of SUSTOL® was based on the efficacy data from a multicenter double-blind trial which included 733 patients who received MEC or AC combination chemotherapy. Patients were randomized to receive either SUSTOL® 10 mg Subcutaneous injection (N=371) or ALOXI® 0.25 mg IV (N=362). This study was structured to compared SUSTOL® with ALOXI® (Palonosetron), which is also a serotonin-3 (5-HT3) receptor antagonist because, ALOXI® is not approved by the FDA to prevent delayed-onset CINV in patients who receive HEC. The trial was designed to allow for the evaluation of non-inferiority of SUSTOL® to ALOXI® in the acute and delayed phases. Antiemetics were administered 30 minutes before chemotherapy on Day 1. Dexamethasone was also administered IV at 8 or 20 mg on Day 1, depending on the chemotherapy regimen administered and those who received Dexamethasone 20 mg IV, were also given an 8 mg oral dose of the drug twice daily on Days 2, 3, and 4. The mean age was 57 years and 79% the patients were female. Approximately 55% of the patients received MEC regimen and 45% of the patients received AC combination chemotherapy. The most frequently used MEC regimen was Carboplatin and Paclitaxel combination (31%). The primary endpoint of the study was Complete Response (CR), which was defined as no emetic episodes or rescue medication during the acute phase (0-24 hours) and the delayed phase (more than 24 to 120 hours) after chemotherapy administration in cycle 1.

The results demonstrated that SUSTOL® was noninferior to ALOXI® . It was noted that among patients receiving MEC (N=406) the CR rate in the acute phase was 83% in the SUSTOL® group compared with 89% in the ALOXI® group. The CR rates in the delayed phase were 69% and 70% respectively. For those patients who received AC chemotherapy (N=327), the CR rate in the acute phase for the SUSTOL® group was 70% compared with 64% in the ALOXI® group. The CR rates in the delayed phase were 50% and 47% respectively. The safety of the FDA recommended dose of SUSTOL® (10 mg Subcutaneous dose), was evaluated in 924 patients across two double-blind, randomized active-controlled studies and it was noted that SUSTOL® was associated with a higher incidence of injection site reactions and constipation.

The authors concluded that SUSTOL® by virtue of its Biochronomer polymer-based drug delivery technology, represents a novel and convenient alternative to intravenous ALOXI® for the prevention of acute and delayed Chemotherapy Induced Nausea and Vomiting. Randomized phase III trial of APF530 versus palonosetron in the prevention of chemotherapy-induced nausea and vomiting in a subset of patients with breast cancer receiving moderately or highly emetogenic chemotherapy. Boccia R, O’Boyle E, Cooper W. BMC Cancer. 2016;16:166. doi:10.1186/s12885-016-2186-4.

Late Breaking Abstract – ASCO 2016 Biosimilar of HERCEPTIN® Equally Effective and Safe

RR

SUMMARY: A Biosimilar product is a biological product that is approved based on its high similarity to an already approved biological product (also known as reference product). Biological products are made from living organisms including humans, animals and microorganisms such as bacteria or yeast and are manufactured through biotechnology, derived from natural sources or produced synthetically. Biological products have larger molecules with a complex structure than conventional drugs (also known as small molecule drugs). Unlike biological products, conventional drugs are made of pure chemical substances and their structures can be identified. A generic drug is a copy of brand name drug and has the same active ingredient and is the same as brand name drug in dosage form, safety and strength, route of administration, quality, performance characteristics and intended use. Therefore, brand name and the generic drugs are bioequivalent. The Affordable Care Act in 2010 created an abbreviated licensure pathway for biological products that are demonstrated to be “Biosimilar” to, or “interchangeable” with an FDA-licensed (FDA approved) biological product (reference product). The Biosimilar must show that it has no clinically meaningful differences in terms of safety and effectiveness from the reference product. A Biosimilar product can only be approved by the FDA if it has the same mechanism of action, route of administration, dosage form and strength as the reference product, and only for the indications and conditions of use that have been approved for the reference product. Biosimilars are not as easy to manufacture as generics (copies of brand name drugs) because of the complexity of the structure of the biologic product and the process used to make a biologic product. The facilities where Biosimilars are manufactured must also meet the FDA’s standards.

Heritage is a double-blind, randomized phase III trial in which the efficacy and safety of Myl-1401O, a Biosimilar, was compared with HERCEPTIN®. The randomization included 500 patients treated at 95 sites worldwide, with centrally confirmed, measurable HER2 positive metastatic breast cancer, who had not received prior chemotherapy or HERCEPTIN® for their metastatic disease. Patients received either Myl-1401O or HERCEPTIN® along with TAXOTERE® (Docetaxel) or TAXOL® (Paclitaxel) administered every 3 weeks for a minimum of 8 cycles (24 weeks), with the antibody therapy continued, until disease progression. Both antibodies were administered with a loading dose of 8 mg/kg and a maintenance dose of 6 mg/kg every 3 weeks. Approximately 44% of the enrolled patients had hormone receptor positive disease and 84% received TAXOTERE®. The final analysis included 458 patients of whom 230 were in the Myl-1401O group and 228 were in the HERCEPTIN® group. The Primary endpoint was Overall Response Rate (ORR) at 24 weeks and Secondary endpoints include Progression Free Survival (PFS), Overall Survival (OS) and Safety.

The ORR after 24 weeks of treatment was 69.6% for the Myl-1401O group and 64% for the HERCEPTIN® group and this was not statistically significant. The median PFS had not yet been reached. Safety data in both treatment groups were comparable and there was no significant change in cardiac function from baseline to Week 24 in either group. The dose-normalized maximum concentration and Area Under the Curve, were similar for both antibodies.

The authors concluded that this study is one of the first trials of Biosimilars in oncology to demonstrate similar results and they added that MYL-1401O is equivalent to HERCEPTIN®, when given in combination with a Taxane, as first line therapy, for patients with HER2 positive metastatic breast cancer. Heritage: A phase III safety and efficacy trial of the proposed trastuzumab biosimilar Myl-1401O versus Herceptin. Rugo HS, Barve A, Waller CF, et al. J Clin Oncol 34, 2016 (suppl; abstr LBA503)

TASIGNA® Maintains Durable Deep Molecular Responses Even after Treatment Discontinuation in Chronic Phase CML

RR

SUMMARY: Chronic Myeloid Leukemia (CML) constitutes a little over 10% of all new cases of leukemia. The American Cancer Society estimates that about 8,220 new CML cases will be diagnosed in the United States in 2016 and about 1,070 patients will die of the disease. The hallmark of CML, the Philadelphia Chromosome (Chromosome 22), is a result of a reciprocal translocation between chromosomes 9 and 22, wherein the ABL gene from chromosome 9 fuses with the BCR gene on chromosome 22. As a result, the auto inhibitory function of the ABL gene is lost and the BCR-ABL fusion gene is activated resulting in cell proliferation and leukemic transformation of hematopoietic stem cells. The presently available Tyrosine Kinase Inhibitors (TKI’s) approved in the United States including GLEEVEC®, share the same therapeutic target, which is BCR-ABL kinase. Resistance to TKI’s can occur as a result of mutations in the BCR-ABL kinase domain or amplification of the BCR-ABL gene. With the availability of newer therapies for CML, monitoring response to treatment is important. This is best accomplished by measuring the amount of residual disease using Reverse Transcription-Polymerase Chain Reaction (RT-PCR). Molecular response in CML is expressed using the International Scale (IS) as BCR-ABL%, which is the ratio between BCR-ABL and a control gene. BCR-ABL kinase domain point mutations are detected, using the mutational analysis by Sanger sequencing. Majority of the patients receiving a TKI following diagnosis of CML achieve a Complete Cytogenetic Response (CCyR) within 12 months following commencement of therapy and these patients have a life expectancy similar to that of their healthy counterparts. Previously published studies have shown that deep molecular response (MR4.5) is a new molecular predictor of long term survival in CML patients and was achieved in a majority of patients treated with optimized dose of GLEEVEC®. It has been hypothesized based on previous observations, that a subgroup of CML patients experiencing deeper responses (MR3, MR4, and MR4.5), may stay in unmaintained remission even after treatment discontinuation. Despite this observation, stopping CML therapy is currently not a clinical recommendation and should only be considered in the context of a clinical trial.

ENESTfreedom (Evaluating Nilotinib Efficacy and Safety in Clinical Trial – Following REsponsE in De nOvo CML-CP Patients) is a single arm, open-label, international, multicenter phase II study, which evaluated Treatment-Free Remission (TFR) of patients with CML-Chronic Phase, after stopping TASIGNA® (Nilotinib), following frontline treatment with this agent. This analysis included 215 patients Philadelphia Chromosome positive (Ph+) CML patients in the Chronic Phase, who received at least 2 years of frontline treatment with TASIGNA® and had achieved a Molecular Response 4.5 (BCR-ABL International Scale 0.0032%). Patients then continued TASIGNA® for an additional year (Consolidation Phase) with close monitoring for sustained deep molecular response using real-time quantitative PCR assessments at 12-week intervals. Patients who had a molecular response no worse than MR4 (0.01% or less) in the last assessment of the Consolidation phase (N=190), were then eligible to stop treatment (TFR phase). The median age of these patients was 55 years. The median time from study entry to first MR4.5 was 18 months. The median duration of treatment on TASIGNA® prior to TFR was 43 months.

After 48 weeks without treatment, 51.6% of the 190 patients in the TFR phase remained in MMR and did not require re-initiation of treatment. Of the 86 patients who restarted treatment with TASIGNA® due to loss of MMR, 99% were able to regain MMR and 88% were able to regain MR4.5. The median time to MMR for these patients was 7.9 weeks and for MR4.5 was 13.1 weeks. About 25% of the patients experienced musculoskeletal pain during the first year of the TFR phase, which is an expected adverse event from TKI withdrawal.

The authors concluded that TFR is clinically meaningful and a high rate of sustained MR4.5 leads to stable disease. TASIGNA® is the first Tyrosine Kinase Inhibitor to demonstrate successful TFR in a large proportion of eligible patients after relatively short duration of treatment of 3.6 years. Over 50% of patients who stopped therapy were able to remain treatment free at 48 weeks. The authors recommended that frequent patient monitoring during Treatment-Free Remission (TFR) period, allows timely determination of loss of MR4.0 and MMR and the need for treatment re-initiation. Treatment-free remission (TFR) in patients (pts) with chronic myeloid leukemia in chronic phase (CML-CP) treated with frontline nilotinib: Results from the ENESTFreedom study. Hochhaus A, Masszi T, Giles FJ, et al. J Clin Oncol 34, 2016 (suppl; abstr 7001)

Influence of MSI on Prognostic Effect of BRAF and KRAS Mutations in Patients with Stage III Colon Cancer

RR

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 135,000 new cases of ColoRectal Cancer will be diagnosed in the United States in 2016 and over 49,000 patients are expected to die of the disease. The role of adjuvant chemotherapy in patients with Stage III ColoRectalCancer (CRC) has been well established, with improvement in Disease Free Survival (DFS) and Overall Survival (OS). However, not all patients equally benefit from this therapy. Patients with MSI (Micro Satellite Instability) tumor phenotype have better survival when cancer is at an earlier stage although this beneficial effect in Stage III colon cancer remains unclear.

The DNA MisMatchRepair (MMR) system is responsible for molecular surveillance and works as an editing tool that identifies errors within the microsatellite regions of DNA and removes them. Defective MMR system leads to MSI (Micro Satellite Instability) and hypermutation, triggering an enhanced antitumor immune response. MSI (Micro Satellite Instability) is therefore a hallmark of defective/deficient DNA MisMatchRepair (MMR) system and occurs in 15% of all colorectal cancers. Defective MisMatchRepair can be a sporadic or heritable event. Approximately 65% of the MSI tumors are sporadic and when sporadic, the DNA MisMatchRepair gene is MLH1. Defective MisMatchRepair can also manifest as a germline mutation occurring in 1 of the 4 MisMatchRepair genes which include MLH1, MSH2, MSH6, PMS2. This produces Lynch Syndrome (Hereditary Nonpolyposis Colorectal Carcinoma – HNPCC), an autosomal dominant disorder and is the most common form of hereditary colon cancer, accounting for 35% of the MSI colorectal cancers. MSI tumors tend to have better outcomes and this has been attributed to the abundance of tumor infiltrating lymphocytes in these tumors from increase immunogenicity. MSI (Micro Satellite Instability) testing is performed using a PCR based assay and MSI-High refers to instability at 2 or more of the 5 mononucleotide repeat markers and MSI-Low refers to instability at 1 of the 5 markers. Patients are considered Micro Satellite Stable (MSS) if no instability occurs. MSI-L and MSS are grouped together because MSI-L tumors are uncommon and behave similar to MSS tumors. Tumors considered MSI-H have deficiency of one or more of the DNA MisMatchRepair genes. MMR gene deficiency can be detected by ImmunoHistoChemistry (IHC). MLH1 gene is often lost in association with PMS2.

Patients with stage IV colorectal cancer are now routinely analyzed for extended RAS and BRAF mutations because KRAS mutations are predictive of resistance to EGFR targeted therapy and BRAF V600E is recognized as a marker of poor prognosis in this patient group. BRAF mutations occur in approximately 45% of patients with sporadic colorectal cancer with MSI but not seen in patients with Lynch syndrome. The prognostic effect of these mutations in early stage disease has however remained controversial. This is a Post Hoc Analysis of the PETACC-8 study, a randomized phase III trial, in which patients with resected Stage III colon cancer received treatment with adjuvant FOLFOX with or without Cetuximab. The authors in this publication examined the prognostic effect of BRAF and KRAS mutations in this patient population, as it relates to MSI of the tumor.

The PETACC-8 trial enrolled 2559 patients with surgically resected colon cancer, treated with adjuvant FOLFOX chemotherapy regimen. The median age was 60 years. MisMatch Repair, BRAF V600E, and KRAS exon 2 mutational status, were determined on tumor blocks that were collected prospectively from the enrolled patients. MSI phenotype was noted in 9.9% (N=177), KRAS mutations in 33.1% (N=588) and BRAF V600E mutations in 9% (N=148) of the patients. The primary end point was Disease Free Survival (DFS) and Overall Survival (OS), as it relates to these mutations.

In multivariate analysis, MSI and BRAF V600E mutations for DFS were not prognostic, whereas KRAS mutation was associated with significantly shorter DFS (P<0.001) and OS (P=0.008). The subgroup analysis showed that in patients with Micro Satellite Stable (MSS) tumors, DFS and OS was inferior among those with KRAS and BRAF V600E mutation and were independently associated with worse clinical outcomes. In patients with MSI tumors, KRAS status was not prognostic, whereas BRAF V600E mutation was associated with significantly longer DFS (P=0.04), but not OS (P=0.08).

The authors based on this large analysis of patients with Stage III colon cancer receiving FOFOX adjuvant chemotherapy, concluded that BRAF V600E and KRAS mutations were significantly associated with shorter DFS and OS in patients with Micro Satellite Stable (MSS) tumors, but not in patients with MSI tumors. Prognostic Effect of BRAF and KRAS Mutations in Patients With Stage III Colon Cancer Treated With Leucovorin, Fluorouracil, and Oxaliplatin With or Without Cetuximab. A Post Hoc Analysis of the PETACC-8 Trial. Taieb J, Zaanan A, Le Malicot, et al. JAMA Oncol. 2016;2:643-653.

SOMATULINE® – Tumor Growth Rate (TGR) a Better Indicator of Therapeutic Activity than RECIST in NeuroEndocrine Tumors

RR

SUMMARY: NeuroEndocrine Tumors (NETs) arise from cells of the endocrine and nervous systems and produce biogenic amines and polypeptide hormones. NETs can be clinically symptomatic (functioning) or silent (nonfunctioning). The incidence is higher in African-Americans and is most frequently diagnosed in the small intestine, appendix, rectum, lungs and bronchi. NETs may be sporadic or may be a component of inherited genetic syndromes such as Multiple Endocrine Neoplasia (MEN) types 1 and 2. Majority of the NETs are nonfunctioning and are diagnosed incidentally but are clinically symptomatic following spread to the liver. Most NETs are classified based on tumor differentiation into 1) Well-differentiated, Low-grade (G1) 2) Well-differentiated, Intermediate-grade (G2) and 3) Poorly differentiated, High-grade (G3). Tumor differentiation and tumor grade often correlate with mitotic count and Ki-67 proliferation index. Even though surgery is curative when the tumor is detected early, this is often not the case, as most patients present with metastatic disease at the time of diagnosis.

SOMATULINE® (Lanreotide) is a synthetic analogue of Somatostatin, a naturally occurring inhibitory hormone, which blocks the release of other hormones, including Insulin, Glucagon, Growth hormone, Thyroid Stimulating Hormone, etc. The approval of SOMATULINE® by the FDA for the treatment of patients with unresectable, well or moderately differentiated, locally advanced or metastatic GastroEnteroPancreatic NeuroEndocrine Tumors (GEP-NETs), was based on the demonstration of improved Progression Free Survival (PFS) in the CLARINET trial, a multicenter, international, randomized placebo-controlled study. This study enrolled 204 patients of whom 55% (113/204) had NeuroEndocrine Tumors arising outside the pancreas. Patients were randomized to receive either SOMATULINE® 120 mg or placebo, subcutaneously every 28 days. This trial demonstrated a significant prolongation of PFS for the SOMATULINE® group compared to the placebo group (HR 0.47; P<0.001).

The authors now report an exploratory analysis of Tumor Growth Rate (TGR) with SOMATULINE® in patients with NeuroEndocrine Tumors from the CLARINET study. TGR has been proposed as a novel measure of tumor response. Target lesions were assessed by central radiologic review based on RECIST criteria. TGR was defined as the percentage of variation of tumor volume per month. This was calculated from sum-of-longest-diameters (SLD) of original target lesions (excluding new ones) on 2 CT scans during defined periods, which was 12-24 weeks prior to randomization versus baseline (pretreatment) and baseline versus each visit or between consecutive visits. TGR pre- and post-treatment were compared between treatment groups.

It was noted that even though all patients were classified as stable based on RECIST, a significant proportion of patients treated with SOMATULINE® showed changes in the TGR, following 12 weeks of treatment. This benefit was not seen in those on placebo. The TGR benefit with SOMATULINE® was significant compared to placebo and was maintained at subsequent study visits.

The authors concluded that in patients with NeuroEndocrine Tumors, Tumor Growth Rate provides an early and more precise characterization of therapeutic activity than RECIST and requires validation in prospective studies. Exploratory analysis of tumor growth rate (TGR) with lanreotide depot/autogel (LAN) in patients (pts) with neuroendocrine tumors (NETs) from the CLARINET study. Caplin ME, Pavel ME, Ruszniewski P, et al. J Clin Oncol 34, 2016 (suppl; abstr 4096)

FDA Approves KEYTRUDA® for Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

RR

SUMMARY: The FDA on August 5, 2016, granted accelerated approval to KEYTRUDA® (Pembrolizumab) for the treatment of patients with recurrent or metastatic Head and Neck Squamous Cell Carcinoma (HNSCC), with disease progression on or after Platinum containing chemotherapy. The American Cancer Society estimates that 61,760 people will be diagnosed with Head and Neck cancer in 2016 and 13,190 patients will die of the disease. Patients with recurrent/metastatic Squamous Cell Carcinoma of the Head and Neck have a poor prognosis with a median Overall Survival (OS) of about 13 months with first line therapy and about 6 months or less with later lines of therapy. The treatment paradigm for solid tumors has been rapidly evolving with a better understanding of the Immune checkpoints or gate keepers. 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.

KEYTRUDA® is a fully humanized, Immunoglobulin G4, 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. The accelerated approval of KEYTRUDA® was based on a multicenter, nonrandomized, open-label, multi-cohort phase Ib study (KEYNOTE-012), which included 192 patients with recurrent or metastatic HNSCC. Approximately 33% of the patients were HPV positive and patients have a median of two prior lines of therapy. Almost all enrolled patients (95%) had prior radiation therapy. Median patient age was 60 years. Treatment consisted of KEYTRUDA® 10 mg/kg IV every 2 weeks or 200 mg IV every 3 weeks and continued until disease progression or unacceptable toxicities. Patients without disease progression were treated for up to 24 months. The primary end point was Objective Response Rate (ORR) and Duration of Response. Secondary endpoints included response by HPV status, Progression Free Survival (PFS), and safety. Efficacy was evaluated in 174 of the enrolled patients. The ORR was 16% with a Complete Response Rate of 5%. The median response duration had not been reached at the time of analysis. Among the responding patients, 82% had responses of 6 months or longer. The ORR and Duration of Response were similar irrespective of dosage regimen or HPV status. In a pooled analyses after long term follow up, responses were ongoing in 76% of the patients with a median follow up duration in responders of 12.5 months. Median Overall Survival was 8.5 months and 6 month PFS rate was 24.9%. The most common adverse reactions ((20% or greater) were fatigue, decreased appetite, and dyspnea and these were similar to those occurring in patients with Melanoma or Non Small Cell Lung Cancer, with the exception of an increased incidence of facial edema and new or worsening hypothyroidism.

It was concluded that KEYTRUDA® has significant antitumor activity in recurrent/metastatic Head and Neck Squamous Cell Carcinoma and PD-L1 testing is not needed prior to use of KEYTRUDA® for this indication. As a condition of the accelerated approval, a multicenter, randomized trial is to be conducted for continued approval, establishing the superiority of KEYTRUDA® over standard therapy. Efficacy and safety of pembrolizumab in recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC): Pooled analyses after long-term follow-up in KEYNOTE-012. Mehra R, Seiwert TY, Mahipal A, et al. J Clin Oncol 34, 2016 (suppl; abstr 6012)

Ovarian Suppression in Premenopausal Women with ER Positive Breast Cancer – ASCO Clinical Practice Guideline Update

RR

SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. Approximately, 246,660 new cases of invasive breast cancer will be diagnosed in 2016 and 40,450 women will die of the disease. Approximately 75% of patients with breast cancer are hormone receptor positive (Estrogen Receptor/Progesterone Receptor positive) and this is a predictor of response to endocrine therapy. These patients are often treated with anti-estrogen therapy as first line treatment. In premenopausal woman, the ovary is the main source of estrogen production, whereas in postmenopausal women, the primary source of estrogen is the Aromatase enzyme mediated conversion of androstenedione and testosterone to estrone and estradiol, in extragonadal/peripheral tissues. NOLVADEX® (Tamoxifen) is a nonsteroidal Selective Estrogen Receptor Modulator (SERM) and works mainly by binding to the Estrogen Receptor and thus blocks the proliferative actions of estrogen on the mammary tissue. ARIMIDEX® (Anastrozole), FEMARA® (Letrozole) and AROMASIN® (Exemestane) are Aromatase Inhibitors (AIs) that binds to the Aromatase enzyme and inhibit the conversion of androgens to estrogens in the extra-gonadal tissues.

An Update Panel of the ASCO conducted a systematic review of randomized clinical trials investigating ovarian suppression and published this update. This information is an update of the ASCO adjuvant endocrine therapy guideline, regarding the risks and benefits of ovarian suppression in addition to standard adjuvant therapy, in premenopausal women with Estrogen Receptor positive breast cancer. The ASCO Update Panel addressed the following questions with regard to premenopausal women with stage I-III hormone receptor-positive Breast Cancer:

1) Should premenopausal women with ER positive tumors receive adjuvant ovarian suppression in addition to standard adjuvant therapy, and, if so, in which subsets of patients?

2) If ovarian suppression is recommended, should ovarian suppression be administered in combination with Tamoxifen or an Aromatase Inhibitor?

Recommendation 1

1.1 The panel recommends that higher risk patients should receive ovarian suppression in addition to adjuvant endocrine therapy, whereas lower-risk patients should not. (For women with higher risk cancers who receive chemotherapy but remain premenopausal, ovarian suppression added to Tamoxifen reduces the risk of breast cancer recurrence).

1.2 Women with stage II or III Breast Cancers who would ordinarily be advised to receive adjuvant chemotherapy should receive ovarian suppression in addition to endocrine therapy.

1.3 Women with stage I or II breast cancers at higher risk of recurrence, who might consider chemotherapy, may also be offered ovarian suppression in addition to endocrine therapy.

1.4 Women with stage I breast cancers not warranting chemotherapy should receive endocrine therapy but not ovarian suppression.

1.5 Women with node-negative cancers 1 cm or less (T1a, T1b) should receive endocrine therapy but not ovarian suppression.

Qualifying Statements

• The standard duration of ovarian suppression in the included trials was 5 years. The panel therefore supports ovarian suppression for 5 years as there is no comparative data available on alternative durations.

• To date, there is no adequate evidence for assessing the benefit of adjuvant ovarian suppression in women at sufficient risk to warrant chemotherapy compared with 10 years of Tamoxifen.

• There is no current role for ovarian suppression as adjuvant therapy in ER negative breast cancers.

• There are substantial adverse effects related to ovarian suppression. Clinicians and patients should take this into consideration when choosing ovarian suppression.

• The long-term effects of ovarian suppression on breast cancer risk and survival are not yet established.

Recommendation 2

Ovarian suppression may be administered with either Tamoxifen or an Aromatase Inhibitor.

Qualifying Statements

• Tamoxifen and Aromatase Inhibitor therapy differ in their side effect profiles, which may affect patient preferences.

• Clinicians should be alert to the possibility of incomplete ovarian suppression with Gonadotropin-Releasing Hormone agonist therapy and evaluate patients for whom there is concern about residual ovarian function.

Burstein HJ, Lacchetti C, Anderson H, et al: Adjuvant endocrine therapy for women with hormone receptor-positive breast cancer: American Society of Clinical Oncology clinical practice guideline update on ovarian suppression. J Clin Oncol 2016;34:1689-1701

KEYTRUDA® (Pembrolizumab)

RR

The FDA on August 5, 2016 granted accelerated approval to KEYTRUDA® injection for the treatment of patients with recurrent or metastatic Head and Neck Squamous Cell Carcinoma (HNSCC) with disease progression on or after platinum-containing chemotherapy. KEYTRUDA® is a product of Merck Sharp & Dohme Corp.