Medication-Related Osteonecrosis of the Jaw: MASCC/ISOO/ASCO Clinical Practice Guideline Summary

SUMMARY: Medication-Related OsteoNecrosis of the Jaw (MRONJ) is defined as progressive bone destruction in the maxillofacial region resulting in exposed bone, or bone that can be probed through an intraoral or extraoral fistula (or fistulae) in the maxillofacial region and that does not heal within 8 weeks, occurring in a patient who has received a Bone-Modifying Agent (BMA) or an angiogenic inhibitor agent and with no history of head and neck radiation. The condition may involve the mandible or the maxilla and can be challenging to treat and can cause significant pain, impacting patients quality of life.
BMAs that have been linked with MRONJ principally include bisphosphonates such as Zoledronic acid and Pamidronate and Rank Ligand inhibitor, Denosumab. BMAs are an integral part of cancer management and have essential roles in supportive oncology for the treatment of hypercalcemia of malignancy and bone metastases, and prevention of skeletal-related events such as pathologic fractures and reduce the need for radiation or surgical intervention. BMAs disrupt the bone remodeling cycle by reducing osteoclast survival and function.
The incidence of MRONJ in the osteoporosis patient population is very low and majority of the MRONJ cases occur in the oncology patient population receiving high doses of BMAs and prevalence has been estimated to be as high as 18.6%. The incidence in cancer patients appears to be related to dose and duration of exposure to BMAs. Bisphosphonates-related ONJ occurs after a mean IV administration of 33 months in cancer patients, whereas Denosumab-related ONJ occurs early after treatment, independent of the number of previous administrations. Risk factors for ONJ while on BMAs include smoking, poor oral hygiene, ill-fitting dentures, invasive dental procedures, and uncontrolled diabetes. Chemotherapeutic agents such as angiogenesis inhibitors, Tyrosine Kinase Inhibitors, mTOR inhibitors and immunotherapeutic agents have also been implicated.
The expert panel including representatives from ASCO, the Multinational Association of Supportive Care in Cancer, and the International Society of Oral Oncology outlined best practice recommendations for the prevention and management of MRONJ in patients with cancer who receive BMAs for oncologic indications, following a systematic review of the medical literature. Given the paucity of high-quality evidence, a majority of the recommendations are based on consensus using ASCO’s formal consensus process. The guideline does not address BMAs used for osteoporosis, which are administered at a lower dose and carry a lower risk for MRONJ.
Medication-Related Osteonecrosis of the Jaw: MASCC/ISOO/ASCO Clinical Practice Guideline Summary
Guideline Question: What are the recommended best practices for preventing and managing medication-related osteonecrosis of the jaw (MRONJ) in patients with cancer?
Target Population: Adult patients with cancer who are receiving Bone-Modifying Agents (BMAs) for any oncologic indication.
Target Audience: Oncologists and other physicians, dentists, dental specialists, oncology nurses, clinical researchers, oncology pharmacists, advanced practitioners, and patients with cancer.
Clinical Question 1. What is the preferred terminology and definition for OsteoNecrosis of the Jaw (maxilla and mandible) associated with pharmacologic therapies in oncology patients?
Recommendation 1.1. It is recommended that the term Medication-Related OsteoNecrosis of the Jaw (MRONJ) be used when referring to bone necrosis associated with pharmacologic therapies.
Recommendation 1.2. Clinicians should confirm the presence of all three of the following criteria to establish a diagnosis of MRONJ – a) Current or previous treatment with a BMA or angiogenic inhibitor b) Exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region and that has persisted for longer than 8 weeks c) No history of radiation therapy to the jaws or metastatic disease to the jaws
Clinical Question 2. What steps should be taken to reduce the risk of MRONJ?
Recommendation 2.1. (Coordination of care.) For patients with cancer who are scheduled to receive a BMA in a non-urgent setting, oral care assessment (including a comprehensive dental, periodontal, and oral radiographic exam when feasible to do so) should be undertaken before initiating therapy. On the basis of the assessment, a dental care plan should be developed and implemented. The care plan should be coordinated between the dentist and the oncologist to ensure that medically necessary dental procedures are undertaken before initiation of the BMA. Follow-up by the dentist should then be performed on a routine schedule (eg, every 6 months) once therapy with a BMA has commenced.
Recommendation 2.2. (Modifiable risk factors.) Members of the multidisciplinary team should address modifiable risk factors for MRONJ with the patient as early as possible. These risk factors include poor oral health, invasive dental procedures, ill-fitting dentures, uncontrolled diabetes mellitus, and tobacco use.
Recommendation 2.3. (Elective dentoalveolar surgery.) Elective dentoalveolar surgical procedures (eg, non–medically necessary extractions, alveoloplasties, and implants) should not be performed during active therapy with a BMA at an oncologic dose. Exceptions may be considered when a dental specialist with expertise in prevention and treatment of MRONJ has reviewed the benefits and risks of the proposed invasive procedure with the patient and the oncology team.
Recommendation 2.4. (Dentoalveolar surgery follow-up.) If dentoalveolar surgery is performed, patients should be evaluated by the dental specialist on a systematic and frequently scheduled basis (eg, every 6 to 8 weeks) until full mucosal coverage of the surgical site has occurred. Communication with the oncologist regarding status of healing is encouraged, particularly when considering future use of BMA.
Recommendation 2.5. (Temporary discontinuation of BMAs before dentoalveolar surgery.) For patients with cancer who are receiving a BMA at an oncologic dose, there is insufficient evidence to support or refute the need for discontinuation of the BMA before dentoalveolar surgery. Administration of the BMA may be deferred at the discretion of the treating physician, in conjunction with discussion with the patient and the oral health provider.
Clinical Question 3. How should MRONJ be staged?
Recommendation 3.1. A well-established staging system should be used to quantify the severity and extent of MRONJ and to guide management decisions. Options include the 2014 American Association of Oral and Maxillofacial Surgeons staging system, the Common Terminology Criteria for Adverse Events version 5.0, and the 2017 International Task Force on Osteonecrosis of the Jaw staging system for MRONJ. The same system should be used throughout the patient’s MRONJ course of care. Diagnostic imaging may be used as an adjunct to these staging systems.
Recommendation 3.2. Optimally, staging should be performed by a clinician experienced with the management of MRONJ
Clinical Question 4. How should MRONJ be managed?
Recommendation 4.1. (Initial treatment of MRONJ.) Conservative measures compose the initial approach to treatment of MRONJ. Conservative measures may include antimicrobial mouth rinses, antibiotics if clinically indicated, effective oral hygiene, and conservative surgical interventions (eg, removal of a superficial bone spicule).
Recommendation 4.2. (Treatment of refractory MRONJ.) Aggressive surgical interventions (eg, mucosal flap elevation, block resection of necrotic bone, soft tissue closure) may be used if MRONJ results in persistent symptoms or affects function despite initial conservative treatment. Aggressive surgical intervention is not recommended for asymptomatic bone exposure. In advance of the aggressive surgical intervention, the multidisciplinary care team and the patient should thoroughly discuss the risks and benefits of the proposed intervention.
Clinical Question 5. Should BMAs be temporarily discontinued after a diagnosis of MRONJ has been established?
Recommendation 5. For patients diagnosed with MRONJ while being treated with BMAs, there is insufficient evidence to support or refute the discontinuation of the BMAs. Administration of the BMA may be deferred at the discretion of the treating physician, in conjunction with discussion with the patient and the oral health provider.
Clinical Question 6. What outcome measures should be used in clinical practice to describe the response of the MRONJ lesion to treatment?
Recommendation 6. During the course of MRONJ treatment, the dentist or dental specialist should communicate with the medical oncologist the objective and subjective status of the lesion (ie, resolved, improving, stable, or progressive). The clinical course of MRONJ may impact local and/or systemic treatment decisions with respect to cessation or recommencement of BMAs.
The Multinational Association of Supportive Care in Cancer, International Society of Oral Oncology, and ASCO believe that cancer clinical trials are vital to inform medical decisions and improve cancer care, and that all patients should have the opportunity to participate.
Medication-Related Osteonecrosis of the Jaw: MASCC/ISOO/ASCO Clinical Practice Guideline Summary. Shapiro CL, Yarom N, Peterson DE, et al. J Oncol Practice 2019;15: 603-606.

CDK4/6 Inhibitors May Replace Chemotherapy in HR-Positive, HER2-Negative Metastatic Breast Cancer

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 279,100 new cases of invasive breast cancer will be diagnosed in 2020 and about 42,690 individuals will die of the disease. Approximately 70% of breast tumors express Estrogen Receptors and/or Progesterone Receptors and the most common subtype of metastatic breast cancer is Hormone Receptor-positive (HR-positive), HER2-negative breast cancer (65% of all metastatic breast tumors), and these patients are often treated with anti-estrogen therapy as first line treatment. However, resistance to hormonal therapy occurs in a majority of the patients with a median Overall Survival (OS) of 36 months. Cyclin Dependent Kinases (CDK) play a very important role to facilitate orderly and controlled progression of the cell cycle. Genetic alterations in these kinases and their regulatory proteins have been implicated in various malignancies.Cell-Cycle-Inhibition-by-CDK4/6-Inhibitors
Cyclin Dependent Kinases 4 and 6 (CDK4 and CDK6) phosphorylate RetinoBlastoma protein (RB), and initiate transition from the G1 phase to the S phase of the cell cycle. RetinoBlastoma protein has antiproliferative and tumor-suppressor activity and phosphorylation of RB protein nullifies its beneficial activities. CDK4 and CDK6 are activated in hormone receptor positive breast cancer, promoting breast cancer cell proliferation. Further, there is evidence to suggest that endocrine resistant breast cancer cell lines depend on CDK4 for cell proliferation. The understanding of the role of Cyclin Dependent Kinases in the cell cycle, has paved the way for the development of CDK inhibitors.
Even though major international oncology treatment guidelines recommend a sequence of endocrine based therapies with or without targeted therapies in postmenopausal women with HR-positive, HER2-negative metastatic breast cancer, Real-World Data suggests that upfront use of chemotherapy remains common even in the absence of visceral crisis. This treatment approach may partly be due to paucity of data directly comparing hormonal therapies with chemotherapy regimens, in this patient group. To provide guidance with additional evidence, the authors conducted a comprehensive systematic review and network meta-analysis to evaluate the efficacy and activity of several first or second line hormonal therapy and chemotherapy regimens that have been investigated in randomized controlled trials, and the researchers aimed to compare these two different approaches.
This analysis included all Phase II and III randomized controlled trials investigating chemotherapy with or without targeted therapies and hormone therapies with or without targeted therapies as first-line or second-line treatments, or both, in postmenopausal women with HR-positive, HER2-negative metastatic breast cancer. Relevant examples of new targeted therapies are mTOR inhibitor Everolimus (AFINITOR®), CDK4/6 inhibitors Palbociclib (IBRANCE®), Ribociclib (KISQALI®) and Abemaciclib (VERZENIO®), and PI3K inhibitor Alpelisib (PIQRAY®), which are used in combination with endocrine therapy. Following a literature search on PubMed, Embase, Cochrane Central Register of Clinical Trials, Web of Science, and online archives of the most relevant international oncology conferences published between Jan 1, 2000 and Dec 31, 2017, 140 studies were selected, comprising of 50,029 patients. Studies exclusively enrolling premenopausal patients and those with HER2-positive or triple-negative breast cancer were excluded from this analysis. The median age was 58 yrs and median follow up was 20 months. All treatments were compared to Anastrozole (ARIMIDEX®) and to CDK4/6 inhibitor Palbociclib (IBRANCE®) plus Letrozole (FEMARA®). The Primary outcome was Progression Free Survival (PFS) and the Secondary outcome was Overall Response Rate.
In this analysis, it was noted that CDK4/6 inhibitors and PIK3K inhibitor (in patients with PIK3CA mutation) along with endocrine therapy was superior to standard endocrine therapy such as Anastrozole alone or Fulvestrant (FASLODEX®) alone, with significantly better PFS. Chemotherapy regimens with or without targeted agents were not significantly better than CDK4/6 inhibitors plus endocrine therapy. Further, the combination of CDK4/6 inhibitors plus endocrine therapy was associated with a favorable toxicity profile compared to chemotherapy. There were no significant differences noted in PFS among the three CDK4/6 inhibitors in combination with an Aromatase Inhibitor or Fulvestrant.
The authors concluded that in the first and second line setting, CDK4/6 inhibitors plus endocrine therapies are superior to standard single agent endocrine therapies in terms of Progression Free Survival. Moreover, no chemotherapy regimen with or without targeted therapy is significantly better than CDK4/6 inhibitors plus endocrine therapies in terms of Progression Free Survival. The researchers added that this is the first study to directly compare all three CDK4/6 inhibitors combined with an Aromatase Inhibitor or Fulvestrant. Endocrine treatment versus chemotherapy in postmenopausal women with hormone receptor-positive, HER2-negative, metastatic breast cancer: a systematic review and network meta-analysis. Giuliano M, Schettini F, Rognoni C, et al. Lancet Oncol. 2019;20:1360-1369.

Circulating Tumor DNA in the Peripheral Blood Predicts Recurrence Risk After Surgery and Adjuvant Chemotherapy in Stage III Colon Cancer

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 145,600 new cases of CRC were diagnosed in the United States in 2019 and about 51,020 patients died of the disease. The lifetime risk of developing CRC is about 1 in 23. Adjuvant chemotherapy for patients with resected, locally advanced, node-positive (Stage III) colon cancer has been the standard of care since the 1990s. Adjuvant treatment with an ELOXATIN® (Oxaliplatin) based chemotherapy regimen has been considered standard intervention since 2004, for patients with Stage III colon cancer, following surgical resection, and has been proven to decrease the chance of recurrent disease. Chemotherapy regimens have included (FOLFOX – Leucovorin, 5-FluoroUracil, ELOXATIN®) or CAPOX/XELOX (XELODA®/Capecitabine and ELOXATIN®), given over a period of 6 months. In spite of these advancements, defining patient subsets at high risk of recurrence following standard adjuvant therapy remains challenging and treatment failure can only be acknowledged when clinical recurrence is documented.
Cell-free DNA (cfDNA) refers to DNA molecules that circulate in the bloodstream after cell apoptosis or necrosis. A specific portion of cfDNA that originates from tumor cells is referred to as circulating tumor DNA (ctDNA), which can be detected in the cell-free component of peripheral blood samples in almost all patients with advanced solid tumors including advanced colorectal cancer. ctDNA is a valuable biomarker and allows early detection of relapse. Several studies have shown that detectable ctDNA following surgery for early stage cancers, is associated with a very high risk of recurrence. The authors in this publication report on the results of a correlative biomarker study in patients with Stage III colon cancer, undergoing standard adjuvant chemotherapy.
A multicenter, population-based, cohort study was conducted to determine whether serial post-surgical and post-chemotherapy ctDNA analysis could provide a real-time indication of efficacy of adjuvant therapy in Stage III colon cancer. In this study, 100 patients with newly diagnosed Stage III colon cancer who were planned to receive 24 weeks of adjuvant chemotherapy were enrolled. Patients had R0 resection with no evidence of metastatic disease on staging CT of the chest, abdomen, and pelvis before surgery. The chemotherapy regimen was chosen by the treating physician, who was blinded to the ctDNA result. High-risk patients were defined as those having pT4 and/or pN2 disease according to the pTNM staging system. Blood samples for ctDNA and CEA (CarcinoEmbryonic Antigen) analysis were collected 4-10 weeks after surgery prior to commencement of adjuvant chemotherapy and at the completion of adjuvant therapy, within 6 weeks of the final cycle of chemotherapy. All patients had a surveillance CT scan 4-8 weeks after completion of adjuvant chemotherapy. Follow up surveillance included clinical exam every 3 months along with CEA measurement and annual CT imaging for 3 years. Serial plasma samples were collected after surgery and after chemotherapy. Somatic mutations in individual patient tumors were identified by massively parallel sequencing of 15 genes commonly mutated in colorectal cancer, and personalized assays were designed to quantify ctDNA. For each patient, one mutation identified in the tumor tissue was assessed in the plasma for the presence of ctDNA. The median duration of follow up was 28.9 months and the primary aim of this study was to demonstrate the association between postsurgical and post-chemotherapy ctDNA detection and the risk of recurrence.
Among the 96 evaluable patients, circulating tumor DNA was detectable in 20 of 96 (21%) post-surgical samples and these patients had an increased risk of recurrence with associated inferior Recurrence-Free Survival, (HR=3.8; P<0.001). The estimated 3 year Recurrence Free Interval (RFI) for patients with positive ctDNA findings was 47% and for those with ctDNA-negative findings was 76%. Circulating tumor DNA was detectable in 15 of 88 (17%) post-chemotherapy samples. The estimated 3 year RFI was 30% when ctDNA was detectable after chemotherapy and 77% when ctDNA was undetectable (HR=6.8; P<0.001). Postsurgical ctDNA status was an independent predictor of disease recurrence after adjusting for known clinicopathologic risk factors (HR=7.5; P<0.001).
The authors concluded that post-surgical and post-chemotherapy circulating tumor DNA analyses is a promising prognostic marker in Stage III colon cancer, and may identify patients at high risk of recurrence, despite completing standard adjuvant treatment. This high-risk population presents a unique opportunity to explore additional therapeutic approaches. Circulating Tumor DNA Analyses as Markers of Recurrence Risk and Benefit of Adjuvant Therapy for Stage III Colon Cancer. Tie J, Cohen JD, Wang Y, et al. JAMA Oncol. 2019;5:1710-1717.

Association Between Pseudoprogression and Outcomes in Men with Metastatic Castration-Resistant Prostate Cancer Treated with XTANDI®

SUMMARY: Prostate cancer is the most common cancer in American men with the exclusion of skin cancer, and 1 in 9 men will be diagnosed with prostate cancer during their lifetime. It is estimated that in the United States, about 174,650 new cases of prostate cancer were diagnosed in 2019 and 31,620 men died of the disease. The development and progression of prostate cancer is driven by androgens. Androgen Deprivation Therapy (ADT) or testosterone suppression has therefore been the cornerstone of treatment of advanced prostate cancer and is the first treatment intervention. Androgen Deprivation Therapies have included bilateral orchiectomy or Gonadotropin Releasing Hormone (GnRH) analogues, with or without first generation Androgen Receptor (AR) inhibitors such as CASODEX® (Bicalutamide), NILANDRON® (Nilutamide) and EULEXIN® (Flutamide) or with second-generation, anti-androgen agents, which include, ZYTIGA® (Abiraterone), XTANDI® (Enzalutamide), ERLEADA® (Apalutamide) and NUBEQA® (Darolutamide). Approximately 10-20% of patients with advanced prostate cancer will progress to Castration Resistant Prostate Cancer (CRPC) within five years during ADT, and over 80% of these patients will have metastatic disease at the time of CRPC diagnosis (mCRPC). Among those patients without metastases at CRPC diagnosis, 33% are likely to develop metastases within two years. The estimated mean survival of patients with CRPC is 9-36 months.
The skeletal system is the most common site for distant metastases among patients with prostate cancer and over 80% of patients with advanced prostate cancer develop bone metastases, which are osteoblastic (or sclerotic), characterized by deposition of new bone. Bone scan is the most common and cost effective modality for the diagnosis of bone metastases and Technetium (Tc) 99m-labeled methylene diphosphonate is the most widely used bone scanning agent. Bone scans are commonly used to both diagnose and monitor disease progression in the bone, among patients with advanced prostate cancer, with a sensitivity ranging from 60-90% but with lower specificity. Bone scan however is more sensitive and specific than plain films and CT scans, whereas MRI is superior in evaluating vertebral metastases. Bone scan provides information on osteoblastic activity and skeletal vascularity, with preferential uptake at sites of active bone formation, reflecting the metabolic reaction of bone to the disease activity, regardless of whether it is neoplastic, traumatic or inflammatory. It is for these reasons it has been well known that bone scans can be misleading in determining whether a patient with bone metastases is benefiting from a treatment, particularly endocrine therapy. The Prostate Cancer Working Group (PCWG) recommended that the assessment of disease progression in bone in the absence of other signs of progression, requires that new lesions detected on the first post-treatment scan be confirmed with the documentation of additional new lesions on the next follow-up scan, in the absence of other signs of disease progression. This is because the new lesions detected on the first post-treatment scan may either reflect true progression or can be the result of bone healing known as pseudoprogression (also known as bone scan flare) that can be misinterpreted as treatment failure, and lead to the premature discontinuation of an effective therapy. Even though the occurrence of pseudoprogression is well documented, its association with clinical outcomes in large prospective studies has not been evaluated.
The authors therefore conducted a post hoc retrospective analysis of the PREVAIL (A Safety and Efficacy Study of Oral MDV3100 in Chemotherapy-Naive Patients With Progressive Metastatic Prostate Cancer) and AFFIRM (Safety and Efficacy Study of MDV3100 in Patients With Castration-Resistant Prostate Cancer Who Have Been Previously Treated With Docetaxel-based Chemotherapy) studies to determine the association between new unconfirmed lesions detected on a follow up bone scan, and clinical outcomes in XTANDI® (Enzalutamide)-treated men with mCRPC. The PREVAIL and AFFIRM trials were both designed in accordance with the PCWG guidelines. This analysis included 643 patients from the PREVAIL study who had not received Docetaxel and 404 men from the AFFIRM study who had previously received Docetaxel. Eligible patients had stable disease or response to therapy based on non-bone disease criteria, including assessment of PSA and soft-tissue disease response. Pseudoprogression was defined as detection of one or more lesions on a first post-treatment bone scan (at week 9 in PREVAIL or 13 in AFFIRM) or a second bone scan (at week 17 in PREVAIL or 25 in AFFIRM), without subsequent new lesions detected at later assessments. The authors evaluated the association of the new lesions detected on the first and second bone scans, with radiographic Progression Free Survival (rPFS), Overall Survival (OS), PSA decline, Objective Response in soft tissue, and Quality of Life.
In the PREVAIL study, new unconfirmed bone lesions were detected on bone scans in 27.5% of Docetaxel-naive patients. The rPFS, OS and time to PSA progression among these patients was similar to those without new lesions, suggesting pseudoprogression. In the AFFIRM study, new, unconfirmed lesions were detected in 18.1% of Docetaxel-treated patients and the rPFS, and time to PSA progression among these patients was similar to those without new lesions on bone scans. However, the OS was significantly worse among these patients, compared with those without new lesions on bone scan, suggesting true disease progression. Most lesions were detected on the first follow up bone scan and investigators were unable to identify any pretreatment factor associated with the development of new, unconfirmed lesions in patients responding to XTANDI®, in either clinical setting.
It was concluded that new unconfirmed lesions detected on follow up bone scans within the first 4 months of treatment initiation may represent pseudoprogression in men with mCRPC and are indicative of a favorable treatment response to XTANDI®. However, new unconfirmed bone lesions in men with mCRPC who were previously treated with Docetaxel may reflect disease heterogeneity and true progression with associated worse Overall Survival. Treatment discontinuation can be considered in this patient group, taking into consideration other disease manifestations such as changes in PSA level, finding on soft tissue imaging, symptoms, and patient preferences. These findings reinforce the importance of functional imaging for diagnosing bone metastases. Association Between New Unconfirmed Bone Lesions and Outcomes in Men With Metastatic Castration-Resistant Prostate Cancer Treated With Enzalutamide: Secondary Analysis of the PREVAIL and AFFIRM Randomized Clinical Trials. Armstrong AJ, Al-Adhami M, Lin P, et al. JAMA Oncol. 2019 Dec 12. doi: 10.1001/jamaoncol.2019.4636. [Epub ahead of print]

IDHIFA® plus VIDAZA® Significantly Improves Complete Remission and Overall Response in Newly Diagnosed IDH2-Mutated AML

SUMMARY: The American Cancer Society estimates that in 2019, 21,450 new cases of Acute Myeloid Leukemia (AML) will be diagnosed in the United States and 10,920 patients will die of the disease. AML can be considered as a group of heterogeneous diseases with different clinical behavior and outcomes. A significant percentage of patients with newly diagnosed AML are not candidates for intensive chemotherapy. Even with the best available therapies, the 5 year Overall Survival in patients 65 years of age or older is less than 5%. Cytogenetic analysis has been part of routine evaluation when caring for patients with AML. By predicting resistance to therapy, tumor cytogenetics will stratify patients, based on risk and help manage them accordingly. Even though cytotoxic chemotherapy may lead to long term remission and cure in a minority of patients with favorable cytogenetics, patients with high risk features such as unfavorable cytogenetics, molecular abnormalities, prior myelodysplasia and advanced age, have poor outcomes with conventional chemotherapy alone. More importantly, with the understanding of molecular pathology of AML, personalized and targeted therapies are becoming an important part of the AML treatment armamentarium.

Isocitrate DeHydrogenase (IDH) is a metabolic enzyme that helps generate energy from glucose and other metabolites, by catalyzing the conversion of Isocitrate to Alpha-Ketoglutarate. Alpha-ketoglutarate is required to properly regulate DNA and histone methylation, which in turn is important for gene expression and cellular differentiation. IDH mutations lead to aberrant DNA methylation and altered gene expression thereby preventing cellular differentiation, with resulting immature undifferentiated cells. IDH mutations can thus promote leukemogenesis in Acute Myeloid Leukemia and tumorigenesis in solid tumors and can result in inferior outcomes. There are three isoforms of IDH. IDH1 is mainly found in the cytoplasm, as well as in peroxisomes, whereas IDH2 and IDH3 are found in the mitochondria, and are a part of the Krebs cycle. Approximately 20% of patients with AML, 70% of patients with Low-grade Glioma and secondary Glioblastoma, 50% of patients with Chondrosarcoma, 20% of patients with Intrahepatic cholangiocarcinoma, 30% of patients with Angioimmunoblastic T-cell lymphoma and 8% of patients with Myelodysplastic syndromes/Myeloproliferative neoplasms, are associated with IDH mutations.

IDHIFA® (Enasidenib) is a selective, oral, small molecule inhibitor of mutated IDH2 protein that promotes myeloid cell differentiation. IDHIFA® indirectly reduces DNA methylation by suppressing the oncometabolite, 2-HydroxyGlutarate, thereby restoring function to Alpha-Ketoglutarate-dependent TET family enzymes. IDHIFA® was approved in the US in 2017 for the treatment of adult patients with relapsed or refractory Acute Myeloid Leukemia (AML), with an IDH2 mutation. Further, treatment with single agent IDHIFA® resulted in an Overall Response Rate (ORR) of 31% and a Completer Response (CR) rate of 18% in patients with newly diagnosed AML. VIDAZA® (Azacitidine) is a hypomethylating agent that promotes DNA hypomethylation by inhibiting DNA methyltransferases. VIDAZA® has been shown to significantly improve Overall Survival (OS) when compared to conventional care regimens in elderly unfit patients with newly diagnosed AML, who are not candidates for intensive chemotherapy. In vitro studies demonstrated that a combination of IDHIFA® and VIDAZA® enhance cell differentiation and apoptosis.

Based on this preclinical data and early clinical trials, an open label, Phase I/II study was conducted comparing a combination of IDHIFA® and VIDAZA® with single agent VIDAZA® in patients with newly diagnosed IDH2 mutated AML, who are not candidates for intensive chemotherapy. The authors reported the first interim outcomes from the randomized, Phase II portion of this ongoing study. The Phase II portion of the trial enrolled 101 patients with newly diagnosed IDH2-mutant AML who were ineligible to receive intensive chemotherapy. Patients had an ECOG PS score of 2 or less and were randomized in a 2:1 ratio to receive IDHIFA® plus VIDAZA® or VIDAZA® alone in repeated 28-day cycles. All patients received VIDAZA® 75 mg/m2/day SC for the first 7 days of each treatment cycle, whereas patients randomized to IDHIFA® plus VIDAZA® also received IDHIFA® 100 mg orally QD continuously. The median patient age was 75 years, and 78% in the combination group and 90% in the VIDAZA® only group had intermediate-risk cytogenetics respectively, and 18% and 10% had poor-risk cytogenetics. The median number of treatment cycles was 8. The Primary endpoint was Overall Response Rate (ORR), which included Complete Remission (CR), CR with incomplete blood or platelet count recovery (CRi/CRp), Partial Remission (PR), and Morphologic Leukemia-Free State (MLFS), per modified IWG 2003 AML response criteria. Mutant IDH2 Variant Allele Frequencies (VAF) in bone marrow mononuclear cells was assessed by digital PCR.

It was noted that the ORR were significantly higher with combination treatment vs VIDAZA® alone (71% versus 42% respectively, P=0.0064) and the CR rates were 53% versus 12% (P=0.0001). The time to first response was about 2 months in each treatment group and the median Duration of Response was 24.1 months with the combination treatment and 12.1 months with VIDAZA® alone. Responses were observed in patients with RAS pathway co-mutations, which have been usually associated with resistance to IDHIFA® monotherapy. The maximal mutant IDH2 VAF suppression from baseline was significantly greater with the combination treatment versus single agent VIDAZA® (median –69.3% versus –14.1% respectively, P=0.0004). Treatment related Grade 3-4 Adverse Events occurring in 10% or more of patients in the combination group were neutropenia, thrombocytopenia, anemia, febrile neutropenia and IDH differentiation syndrome.

It was concluded that a combination of IDHIFA® plus VIDAZA® was associated with significantly improved Complete Remission and Overall Response Rates, with significant mutant IDH2 Variant Allele Frequencies reductions, compared with VIDAZA® alone, in patients with newly diagnosed IDH2-mutant AML. Further the combination treatment was generally well tolerated, with a safety profile similar to that reported for monotherapy with either of these two agents. Enasidenib Plus Azacitidine Significantly Improves Complete Remission and Overall Response Compared with Azacitidine Alone in Patients with Newly Diagnosed Acute Myeloid Leukemia (AML) with Isocitrate dehydrogenase 2 (IDH2) Mutations: Interim Phase II Results from an Ongoing, Randomized Study. DiNardo CD, Schuh AC, Stein EM, et al. Presented at 2019 ASH Annual Meeting; December 7-10, 2019; Orlando, FL. Abstract 643.

FDA Approves LYNPARZA® for Germline BRCA-Mutated Metastatic Pancreatic Adenocarcinoma

SUMMARY: The FDA on December 27, 2019 approved LYNPARZA® (Olaparib) for the maintenance treatment of adult patients with deleterious or suspected deleterious germline BRCA-mutated (gBRCAm) metastatic pancreatic adenocarcinoma, as detected by an FDA-approved test, whose disease has not progressed on at least 16 weeks of a first-line Platinum-based chemotherapy regimen. The FDA also approved the BRACAnalysis CDx test (Myriad Genetic Laboratories, Inc.) as a companion diagnostic for the selection of patients with pancreatic cancer for treatment with LYNPARZA® based upon the identification of deleterious or suspected deleterious germline mutations in BRCA1 or BRCA2 genes.

The American Cancer Society estimates that for 2019, about 56,770 people will be diagnosed with pancreatic cancer and about 45,750 people will die of the disease. Pancreatic cancer is the fourth most common cause of cancer-related deaths in the United States and Western Europe. Unfortunately, unlike other malignancies, very little progress has been made and outcome for patients with advanced pancreatic cancer has been dismal, with a 5-year survival rate for metastatic pancreatic cancer of approximately 2%. Pancreatic cancer has surpassed breast cancer as the third leading cause of cancer death in the United States and is on track to surpass colorectal cancer, to move to the second leading cause of cancer related deaths in the United States around 2020.

BRCA1 and BRCA2 are tumor suppressor genes located on chromosome 17 and chromosome 13 respectively. They control cell growth by repairing DNA damage and thus prevent tumor development. Mutations in these genes predispose an individual to develop malignant tumors. It is well established that the presence of BRCA1 and BRCA2 mutations can significantly increase the lifetime risk for developing breast and ovarian cancer, as high as 85% and 40% respectively. BRCA1/2 mutations have been detected in 4-7% of patients with pancreatic cancer, with a 2-6 fold increase in risk, associated with these mutations. These patients tend to be younger. Among pancreatic cancer patients with Ashkenazi Jewish ancestry, the prevalence of BRCA1/2 mutations is 6-19%, with mutations more common for BRCA2. NCCN guideline recommends that germline testing should be considered for all patients with pancreatic cancer and is especially recommended for those with a personal history of cancer, family history or clinical suspicion of a family history of pancreatic cancer. Approximately 10% of pancreatic cancer cases have a familial component. When hereditary cancer syndrome is suspected in patients with pancreatic cancer, genetic counseling should be considered.

BRCA mutations can either be inherited (Germline) and present in all individual cells or can be acquired and occur exclusively in the tumor cells (Somatic). The BRCA gene plays an important role in DNA repair via Homologous Recombination (HR). Mutation of BRCA gene results in loss of BRCA function and likely deregulates Homologous Recombination (HR) pathway. Majority of patients with Germline BRCA mutations (gBRCA) have HR Deficiency (HRD) resulting in inability to repair double strand breaks. HRD can also occur due to other mechanisms, such as somatic mutations and epigenetic modifications of other genes involved in the HR pathway. Patients with HRD exhibit specific clinical behaviors, and improved responses to treatments, such as platinum-based chemotherapy and PARP Inhibitors. The PARP (Poly ADP Ribose Polymerase) family of enzymes, include PARP1 and PARP2, which repair damaged DNA. LYNPARZA® is a first-in-class PARP enzyme inhibitor that causes cell death in tumors that already have a DNA repair defect, such as those with BRCA1 and BRCA2 mutations, through the concept of synthetic lethality. Malignancies such as epithelial ovarian cancers with Homologous Recombination Deficiency, have demonstrated sensitivity to PARP inhibitors. Recent studies have confirmed that PARP inhibitors are effective not only in ovarian cancers displaying germline or somatic BRCA mutations but also in cancers with HRD caused by other underlying etiologies. LYNPARZA® in a Phase II trial demonstrated antitumor activity in heavily pretreated metastatic pancreatic cancer patients with a germline BRCA mutation. Maintenance treatment with LYNPARZA® in BRCA mutated ovarian cancer patients resulted in significant improvement in Progression Free Survival.

The POLO (Pancreas Cancer Olaparib Ongoing) trial was conducted to evaluate the efficacy of maintenance therapy with LYNPARZA® in metastatic pancreatic adenocarcinoma patients with a germline BRCA mutation whose disease had not progressed during first-line platinum-based chemotherapy. In this international, multicenter, randomized, double-blind, placebo-controlled Phase III study, 154 patients with BRCA mutant disease were randomly assigned in a 3:2 ratio, to receive maintenance LYNPARZA® tablets 300 mg twice daily (N=92) or matching placebo (N=62). The median patient age was 57 years. Eligible patients should have received at least 16 weeks of continuous first-line platinum-based chemotherapy for metastatic pancreatic cancer and maintenance treatment was initiated 4-8 weeks after the last dose of first-line chemotherapy had been administered. Maintenance intervention was continued until disease progression. Crossover to LYNPARZA® was not permitted during this trial. The Primary end point was Progression Free Survival (PFS) and Secondary end points included Objective Response Rate (ORR) and Quality of Life.

The median PFS was significantly longer in the LYNPARZA® group compared to the placebo group (7.4 months versus 3.8 months; HR for disease progression or death=0.53; P=0.004). This suggested a 47% reduction in the risk of disease progression or death. At 2 years, 22% of the patients in the LYNPARZA® group did not have disease progression compared with 9.6% of patients in the placebo group. The ORR among patients who had measurable disease at baseline was 23% in the LYNPARZA® group and 12% in the placebo group. The interim analysis of Overall Survival showed no significant difference, with a median 18.9 months for the LYNPARZA® group and 18.1 months for the placebo group (HR=0.91; P=0.68). Health-related Quality of Life scores were also not significantly different. Grade 3 or higher adverse events were 40% in the LYNPARZA® group and 23% in the placebo group and 5% and 2% of the patients, respectively, discontinued therapy because of an adverse event.

It was concluded that among metastatic pancreatic cancer patients with germline BRCA mutation and whose cancer has not progressed during platinum-based chemotherapy, Progression Free Survival was significantly longer with maintenance LYNPARZA® than with placebo. This study allows identifying patients with metastatic pancreatic cancer who will likely benefit from PARP inhibition. Maintenance Olaparib for Germline BRCA-Mutated Metastatic Pancreatic Cancer. Golan T, Hammel P, Reni M, et al. N Engl J Med 2019; 381:317-327

LYNPARZA® (Olaparib)

The FDA on December 27, 2019 approved LYNPARZA® for the maintenance treatment of adult patients with deleterious or suspected deleterious germline BRCA-mutated (gBRCAm) metastatic pancreatic adenocarcinoma, as detected by an FDA-approved test, whose disease has not progressed on at least 16 weeks of a first-line Platinum-based chemotherapy regimen. The FDA also approved the BRACAnalysis CDx test (Myriad Genetic Laboratories, Inc.) as a companion diagnostic for the selection of patients with pancreatic cancer for treatment with LYNPARZA®, based upon the identification of deleterious or suspected deleterious germline mutations in BRCA1 or BRCA2 genes. LYNPARZA® is a product of AstraZeneca Pharmaceuticals LP.