GD2-CAR T cell therapy for H3K27M-mutated diffuse midline gliomas.

Diffuse intrinsic pontine glioma (DIPG) and other H3K27M-mutated diffuse midline gliomas (DMGs) are universally lethal paediatric tumours of the central nervous system1. We have previously shown that the disialoganglioside GD2 is highly expressed on H3K27M-mutated glioma cells and have demonstrated promising preclinical efficacy of GD2-directed chimeric antigen receptor (CAR) T cells2, providing the rationale for a first-in-human phase I clinical trial (NCT04196413). Because CAR T cell-induced brainstem inflammation can result in obstructive hydrocephalus, increased intracranial pressure and dangerous tissue shifts, neurocritical care precautions were incorporated. Here we present the clinical experience from the first four patients with H3K27M-mutated DIPG or spinal cord DMG treated with GD2-CAR T cells at dose level 1 (1 × 106 GD2-CAR T cells per kg administered intravenously). Patients who exhibited clinical benefit were eligible for subsequent GD2-CAR T cell infusions administered intracerebroventricularly3. Toxicity was largely related to the location of the tumour and was reversible with intensive supportive care. On-target, off-tumour toxicity was not observed. Three of four patients exhibited clinical and radiographic improvement. Pro-inflammatory cytokine levels were increased in the plasma and cerebrospinal fluid. Transcriptomic analyses of 65,598 single cells from CAR T cell products and cerebrospinal fluid elucidate heterogeneity in response between participants and administration routes. These early results underscore the promise of this therapeutic approach for patients with H3K27M-mutated DIPG or spinal cord DMG.

Feasibility of implementing a text-based symptom-monitoring program of endometrial, ovarian, and breast cancer patients during treatment.

PURPOSE: To evaluate the feasibility of implementing systematic patient symptom monitoring during treatment using a smartphone. METHODS: Endometrial [n = 50], ovarian [n = 70] and breast [n = 193] cancer patients participated in text-based symptom reporting for up to 12 months. In order to promote equity, patients without a smartphone were provided with a device, with the phone charges paid by program funds. Each month, patients completed the Patient Health Questionnaire (PHQ-9), and 4 single items assessing fatigue, sleep quality, pain, and global quality of life during the past 7 days rated on a 0 (low) -10 (high) scale. Patients' responses were captured using REDCap, with oncologists receiving monthly feedback. Lay navigators provided assistance to patients with non-medical needs. RESULTS: Patients utilizing this voluntary program had an overall mean age of 60.5 (range 26-87), and 85% were non-Hispanic white. iPhones were provided to 42 patients, and navigation services were used by 69 patients. Average adherence with monthly surveys ranged between 75-77%, with breast patients having lower adherence after 5 months. The most commonly reported symptoms across cancer types were moderate levels (scores of 4-7) of fatigue and sleep disturbance. At 6 months, 71-77% of all patients believed the surveys were useful to them and their health care team. CONCLUSIONS: We established the feasibility of initiating and managing patients in a monthly text-based symptom-monitoring program. The provision of smartphones and patient navigation were unique and vital components of this program.

Increasing Adherence to Adjuvant Hormone Therapy Among Patients With Breast Cancer: A Smart Phone App-Based Pilot Study.

PURPOSE: This study tested the feasibility and efficacy of using a text-based intervention to increase initiation, decrease discontinuation, and improve adherence as prescribed to adjuvant hormone therapy (AHT) among hyphenate post-menopausal breast cancer survivors. METHODS: The 3-month intervention consisted of daily text message reminders to take medication, coupled with a dynamic (eg, feedback on progress) tailored intervention using weekly interactive surveys delivered by a smartphone app. Five clinic sites within the Alliance for Clinical Trials in Oncology participated. Hormone levels were measured prior to AHT initiation and at study exit. RESULTS: Of the 39 patients recruited to the pilot study, 27 (69.2%) completed all study requirements (completed both the baseline and the exit surveys, both blood draws, and did not miss more than 2 weekly surveys). Significant improvements were observed pre- to postintervention for self-reported medication adherence (P = .015), mental health functioning (P = .007), and perceived stress (P = .04). Significant decreases in estradiol, estrogen, and estrone hormone levels were observed from baseline to study exit (P < .001), indicating the accuracy of self-reported AHT adherence. Participants (91.9%) and physicians (100%) agreed that participant participation in the intervention was beneficial. CONCLUSIONS: The results of this pilot study established the general feasibility and efficacy of an app-based intervention to support patient AHT adherence. Larger controlled, randomized trials are needed to examine the effectiveness of the app-based intervention in improving AHT and quality of life among breast cancer survivors.

Heterozygous mutations in natriuretic peptide receptor-B (NPR2) gene as a cause of short stature.

Based on the observation of reduced stature in relatives of patients with acromesomelic dysplasia, Maroteaux type (AMDM), caused by homozygous or compound heterozygous mutations in natriuretic peptide receptor-B gene (NPR2), it has been suggested that heterozygous mutations in this gene could be responsible for the growth impairment observed in some cases of idiopathic short stature (ISS). We enrolled 192 unrelated patients with short stature and 192 controls of normal height and identified seven heterozygous NPR2 missense or splice site mutations all in the short stature patients, including one de novo splice site variant. Three of the six inherited variants segregated with short stature in the family. Nine additional rare nonsynonymous NPR2 variants were found in three additional cohorts. Functional studies identified eight loss-of-function mutations in short individuals and one gain-of-function mutation in tall individuals. With these data, we were able to rigorously verify that NPR2 functional haploinsufficiency contributes to short stature. We estimate a prevalence of NPR2 haploinsufficiency of between 0 and 1/26 in people with ISS. We suggest that NPR2 gain of function may be a more common cause of tall stature than previously recognized.

Functional significance of single nucleotide polymorphisms in the lactase gene in diverse US patients and evidence for a novel lactase persistence allele at -13909 in those of European ancestry.

OBJECTIVES: Recent data from mainly homogeneous European and African populations implicate a 140-bp region 5' to the transcriptional start site of LCT (the lactase gene) as a regulatory site for lactase persistence and nonpersistence. Because there are no studies of US nonhomogeneous populations, we performed genotype/phenotype analysis of the -13910 and -22018 LCT single nucleotide polymorphisms (SNPs) in New England children, mostly of European ancestry. METHODS: Duodenal biopsies were processed for disaccharidase activities, RNA quantification by reverse transcription polymerase chain reaction (RT-PCR), allelic expression ratios by PCR, and genotyping and SNP analysis. Results were compared with clinical information. RESULTS: Lactase activity and mRNA levels, and sucrase-to-lactase ratios of enzyme activity and mRNA, showed robust correlations with genotype. None of the other LCT SNPs showed as strong a correlation with enzyme or mRNA levels as did -13910. Data were consistent, with the -13910 being the causal sequence variant instead of -22018. Four individuals heterozygous for -13910T/C had allelic expression patterns similar to individuals with -13910C/C genotypes; of these, 2 showed equal LCT expression from the 2 alleles and a novel variant (-13909C>A) associated with lactase persistence. CONCLUSIONS: The identification of -13910C/C genotype is likely to predict lactase nonpersistence, consistent with prior published studies. A -13910T/T genotype will frequently, but not perfectly, predict lactase persistence in this mixed European-ancestry population; a -13910T/C genotype will not predict the phenotype. A long, rare haplotype in 2 individuals with -13910T/C genotype but equal allele-specific expression contains a novel lactase persistence allele present at -13909.

Diversity efforts, admissions, and national rankings: can we align priorities?

BACKGROUND: Increasing student body diversity is a priority for national health education and professional organizations and for many medical schools. However, national rankings of medical schools, such as those published by U.S. News & World Report, place a heavy emphasis on grade point average (GPA) and Medical College Admissions Test (MCAT) scores, without considering student body diversity. These rankings affect organizational reputation and admissions outcomes, even though there is considerable controversy surrounding the predictive value of GPA and MCAT scores. SUMMARY: Our aim in this article was to explore the relationship between standard admissions practices, which typically aim to attract students with the highest academic scores, and student body diversity. We examined how changes in GPA and MCAT scores over 5 years correlated with the percentage of enrolled students who are underrepresented in medicine. In a majority of medical schools in the United States from 2005 to 2009, average GPA and MCAT scores of applicants increased, whereas the percentage of enrolled students who are underrepresented in medicine decreased. CONCLUSIONS: Our findings suggest that efforts to increase the diversity of medical school student bodies may be complicated by a desire to maintain high average GPA and MCAT scores. We propose that U.S. News revise its ranking methodology by incorporating a new diversity score into its student selectivity score and by reducing the weight placed on GPA and MCAT scores.

CD22 CAR T cells demonstrate high response rates and safety in pediatric and adult B-ALL: Phase 1b results.

Chimeric antigen receptor (CAR) T cells targeting CD22 (CD22-CAR) provide a therapeutic option for patients with CD22+ malignancies with progression after CD19-directed therapies. Using on-site, automated, closed-loop manufacturing, we conducted parallel Phase 1b clinical trials investigating a humanized CD22-CAR with 41BB costimulatory domain in children and adults with heavily treated, relapsed/refractory (r/r) B-ALL. Of 19 patients enrolled, 18 had successful CD22-CAR manufacturing, and 16 patients were infused. High grade (3-4) cytokine release syndrome (CRS) and immune effector-cell-associated neurotoxicity syndrome (ICANS) each occurred in only one patient; however, three patients experienced immune-effector-cell-associated hemophagocytic lymphohistiocytosis-like syndrome (IEC-HS). Twelve of 16 patients (75%) achieved CR with an overall 56% MRD-negative CR rate. Duration of response was overall limited (median 77 days), and CD22 expression was downregulated in 4/12 (33%) available samples at relapse. In summary, we demonstrate that closed-loop manufacturing of CD22-CAR T cells is feasible and is associated with a favorable safety profile and high CR rates in pediatric and adult r/r B-ALL, a cohort with limited CD22-CAR reporting.

Sequential intravenous and intracerebroventricular GD2-CAR T-cell therapy for H3K27M-mutated diffuse midline gliomas.

H3K27M-mutant diffuse midline gliomas (DMGs) express high levels of the GD2 disialoganglioside and chimeric antigen receptor modified T-cells targeting GD2 (GD2-CART) eradicate DMGs in preclinical models. Arm A of the Phase I trial NCT04196413 administered one IV dose of autologous GD2-CART to patients with H3K27M-mutant pontine (DIPG) or spinal (sDMG) diffuse midline glioma at two dose levels (DL1=1e6/kg; DL2=3e6/kg) following lymphodepleting (LD) chemotherapy. Patients with clinical or imaging benefit were eligible for subsequent intracerebroventricular (ICV) GD2-CART infusions (10-30e6 GD2-CART). Primary objectives were manufacturing feasibility, tolerability, and identification of a maximally tolerated dose of IV GD2-CART. Secondary objectives included preliminary assessments of benefit. Thirteen patients enrolled and 11 received IV GD2-CART on study [n=3 DL1(3 DIPG); n=8 DL2(6 DIPG/2 sDMG). GD2-CART manufacturing was successful for all patients. No dose-limiting toxicities (DLTs) occurred on DL1, but three patients experienced DLT on DL2 due to grade 4 cytokine release syndrome (CRS). Nine patients received ICV infusions, which were not associated with DLTs. All patients exhibited tumor inflammation-associated neurotoxicity (TIAN). Four patients demonstrated major volumetric tumor reductions (52%, 54%, 91% and 100%). One patient exhibited a complete response ongoing for >30 months since enrollment. Eight patients demonstrated neurological benefit based upon a protocol-directed Clinical Improvement Score. Sequential IV followed by ICV GD2-CART induced tumor regressions and neurological improvements in patients with DIPG and sDMG. DL1 was established as the maximally tolerated IV GD2-CART dose. Neurotoxicity was safely managed with intensive monitoring and close adherence to a management algorithm.

Chromosome silencing in vitro reveals trisomy 21 causes cell-autonomous deficits in angiogenesis and early dysregulation in Notch signaling.

Despite the prevalence of Down syndrome (DS), little is known regarding the specific cell pathologies that underlie this multi-system disorder. To understand which cell types and pathways are more directly affected by trisomy 21 (T21), we used an inducible-XIST system to silence one chromosome 21 in vitro. T21 caused the dysregulation of Notch signaling in iPSCs, potentially affecting cell-type programming. Further analyses identified dysregulation of pathways important for two cell types: neurogenesis and angiogenesis. Angiogenesis is essential to many bodily systems, yet is understudied in DS; therefore, we focused next on whether T21 affects endothelial cells. An in vitro assay for microvasculature formation revealed a cellular pathology involving delayed tube formation in response to angiogenic signals. Parallel transcriptomic analysis of endothelia further showed deficits in angiogenesis regulators. Results indicate a direct cell-autonomous impact of T21 on endothelial function, highlighting the importance of angiogenesis, with wide-reaching implications for development and disease progression.

PIF1 directly and indirectly regulates chlorophyll biosynthesis to optimize the greening process in Arabidopsis.

Plants depend on light signals to modulate many aspects of their development and optimize their photosynthetic capacity. Phytochromes (phys), a family of photoreceptors, initiate a signal transduction pathway that alters expression of a large number of genes to induce these responses. Recently, phyA and phyB were shown to bind members of a basic helix-loop-helix family of transcription factors called phy-interacting factors (PIFs). PIF1 negatively regulates chlorophyll biosynthesis and seed germination in the dark, and light-induced degradation of PIF1 relieves this negative regulation to promote photomorphogenesis. Here, we report that PIF1 regulates expression of a discrete set of genes in the dark, including protochlorophyllide oxidoreductase (POR), ferrochelatase (FeChII), and heme oxygenase (HO3), which are involved in controlling the chlorophyll biosynthetic pathway. Using ChIP and DNA gel-shift assays, we demonstrate that PIF1 directly binds to a G-box (CACGTG) DNA sequence element present in the PORC promoter. Moreover, in transient assays, PIF1 activates transcription of PORC in a G-box-dependent manner. These data strongly suggest that PIF1 directly and indirectly regulates key genes involved in chlorophyll biosynthesis to optimize the greening process in Arabidopsis.

Developing a Culture of Mentorship to Strengthen Academic Medical Centers.

Mentorship is central to academic medicine and its missions, and it has long played a critical role in the training and career development of physicians and scientists. A growing body of literature has documented the positive impact of mentorship on various outcomes, including research productivity, academic promotion, faculty retention, and career satisfaction. These benefits span academic medical centers' missions and have the potential to enhance biomedical research, patient care, education, and faculty diversity and leadership.In this Invited Commentary, the authors argue that a dynamic culture of mentorship is essential to the success of academic medical centers and should be elevated to the level of a major strategic priority. This culture of mentorship would capitalize on an institution's intellectual resources and seek to develop leaders in biomedical discovery, patient care, and education. The bidirectional transmission of knowledge between mentors and mentees, through both formal programs and informal relationships, can foster the growth of faculty members needed to meet the complex challenges currently confronting medical schools and teaching hospitals.Developing a culture of mentorship requires a strong commitment by leaders at all levels to nurture the next generation of physicians and scientists as well as grassroots efforts by trainees and faculty to seek out and create mentorship opportunities. The authors conclude by outlining possible mechanisms and incentives for elevating mentorship to the level of a strategic priority to strengthen academic medical centers across their missions.

Analgesic efficacy and safety of non-prescription doses of naproxen sodium in the management of moderate osteoarthritis of the knee or hip.

OBJECTIVES: Current osteoarthritis therapies aim to alleviate pain and maintain joint function. Non-prescription oral non-steroidal anti-inflammatory drugs are frequently used alone for pain relief in osteoarthritis. This post-hoc pooled analysis evaluated the analgesic efficacy and safety of two non-prescription doses of naproxen sodium for short-term use in patients with osteoarthritis of the knee or hip. A separate sub-group analysis of older patients who were administered a lower dose of naproxen sodium was performed. METHODS: In four multi-center, multi-dose, randomized, parallel, double-blind, placebo-controlled studies, oral naproxen sodium (age-based dosing regimen: <65 years, 660 mg/day; ≥65 years, 440 mg/day) or placebo was administered over 7 days. Data at baseline and after 7 days in 818 patients who received naproxen sodium or placebo (n = 409 in each group) was pooled and analyzed. Five-point rating scales were used to assess knee or hip joint pain, stiffness after rest, day and night pain, and patient and investigator assessment of treatment, while function was evaluated using a timed 50-foot walk test. RESULTS: Compared with placebo, there were significant improvements in pain and physical function with naproxen sodium (p < .05), and treatment was rated "good" to "excellent" significantly more often (p < .001) by investigators and patients. Efficacy results were similar among younger and older patients. There were no significant differences in adverse events between groups, regardless of age. CONCLUSIONS: For the acute management of underlying pain in patients with moderate osteoarthritis of the hip or knee, non-prescription naproxen sodium is effective and well tolerated in patients of all ages.

Novel germline mutation (Leu512Met) in the thyrotropin receptor gene (TSHR) leading to sporadic non-autoimmune hyperthyroidism.

BACKGROUND: Primary nonautoimmune hyperthyroidism is a rare cause of neonatal hyperthyroidism. This results from an activating mutation in the thyrotropin-receptor (TSHR). It can be inherited in an autosomal dominant manner or occur sporadically as a de novo mutation. Affected individuals display a wide phenotype from severe neonatal to mild subclinical hyperthyroidism. We describe a 6-month-old boy with a de novo mutation in the TSHR gene who presented with accelerated growth, enlarging head circumference, tremor and thyrotoxicosis. METHODS: Genomic DNA from the patient's and parents' peripheral blood leukocytes was extracted. Exons 9 and 10 of the TSHR gene were amplified by PCR and sequenced. RESULTS: Sequencing exon 10 of the TSHR gene revealed a novel heterozygous missense mutation substituting cytosine to adenine at nucleotide position 1534 in the patient's peripheral blood leukocytes. This leads to a substitution of leucine to methionine at amino acid position 512. The mutation was absent in the parents. In silico modeling by PolyPhen-2 and SIFT predicted the mutation to be deleterious. CONCLUSIONS: The p.Leu512Met mutation (c.1534C>A) of the TSHR gene has not been previously described in germline or somatic mutations. This case presentation highlights the possibility of mild thyrotoxicosis in affected individuals and contributes to the understanding of sporadic non-autoimmune primary hyperthyroidism.

Structural forms of the human amylase locus and their relationships to SNPs, haplotypes and obesity.

Hundreds of genes reside in structurally complex, poorly understood regions of the human genome. One such region contains the three amylase genes (AMY2B, AMY2A and AMY1) responsible for digesting starch into sugar. Copy number of AMY1 is reported to be the largest genomic influence on obesity, although genome-wide association studies for obesity have found this locus unremarkable. Using whole-genome sequence analysis, droplet digital PCR and genome mapping, we identified eight common structural haplotypes of the amylase locus that suggest its mutational history. We found that the AMY1 copy number in an individual's genome is generally even (rather than odd) and partially correlates with nearby SNPs, which do not associate with body mass index (BMI). We measured amylase gene copy number in 1,000 obese or lean Estonians and in 2 other cohorts totaling ∼3,500 individuals. We had 99% power to detect the lower bound of the reported effects on BMI, yet found no association.

Using reflective learning to improve the impact of short courses and workshops.

For a variety of reasons, short courses and workshops often have no impact on workplace practice and are, therefore, a waste of money. The notion of "impact" on work practice is introduced, and it provides a focus toward which all elements on a short course should contribute (including the administrative processes). This article discusses the distinction between teaching and learning and some variables about the quality of the learning process that should be taken into account: the approach the learner takes and the learner's stage of conception of the structure of knowledge. The support of good-quality learning is a principal attribute of good teaching, and the nature of good teaching is discussed on this basis. Teaching and learning in a short course can usefully be structured by a framework to improve the impact of short courses and workshops. This also provides a structure for reflective activities. This article briefly discusses the definition of reflection and considers how it might be implemented. Finally, as another tactic in the focusing on impact, the components of short courses are analyzed on the basis that every component needs to work toward the improvement of the impact of the course.

A novel deletion of IGF1 in a patient with idiopathic short stature provides insight Into IGF1 haploinsufficiency.

CONTEXT: Short stature is a common reason for referral to pediatric endocrinology centers. Frequently, the underlying etiology of short stature is unknown, resulting in a diagnosis of idiopathic short stature. Rare genetic defects in the GH/IGF-1 axis have been found to cause short stature. OBJECTIVE: The objective of this study was to identify the genetic etiology of short stature in a patient with Idiopathic Short Stature and to review the clinical presentation of patients with genetic defects in IGF1, and specifically IGF-1 haploinsufficiency. DESIGN/SETTING/PARTICIPANTS: The index patient was evaluated at an academic medical center, and DNA was obtained from the proband and both parents. INTERVENTION: Genome-wide copy number analysis was performed in the proband with confirmatory quantitative PCR in the proband and his parents. MAIN OUTCOME MEASURE: We measured novel copy number variants (CNVs) thought to explain the patient's short stature. RESULTS: CNV analysis revealed that the proband carried a paternally inherited heterozygous IGF1 gene deletion. His phenotypic features are consistent with those found in previous case reports of IGF-1 deficiency. CONCLUSIONS: This study, as the first case of a complete heterozygous 1GF1 deletion, provides insight into the effects of true IGF-1 haploinsufficiency. Given the similarities in phenotype between the present proband and those previously described, it is highly likely that his IGF1 deletion is the cause for his short stature. Broadly, this study emphasizes how CNV analysis and other genetic sequencing techniques are evolving as an important tool to identify genetic causes underlying human disease, allowing for improved diagnosis and targeted treatment.

Whole exome sequencing to identify genetic causes of short stature.

BACKGROUND/AIMS: Short stature is a common reason for presentation to pediatric endocrinology clinics. However, for most patients, no cause for the short stature can be identified. As genetics plays a strong role in height, we sought to identify known and novel genetic causes of short stature. METHODS: We recruited 14 children with severe short stature of unknown etiology. We conducted whole exome sequencing of the patients and their family members. We used an analysis pipeline to identify rare non-synonymous genetic variants that cause the short stature. RESULTS: We identified a genetic cause of short stature in 5 of the 14 patients. This included cases of floating-harbor syndrome, Kenny-Caffey syndrome, the progeroid form of Ehlers-Danlos syndrome, as well as 2 cases of the 3-M syndrome. For the remaining patients, we have generated lists of candidate variants. CONCLUSIONS: Whole exome sequencing can help identify genetic causes of short stature in the context of defined genetic syndromes, but may be less effective in identifying novel genetic causes of short stature in individual families. Utilized in the clinic, whole exome sequencing can provide clinically relevant diagnoses for these patients. Rare syndromic causes of short stature may be underrecognized and underdiagnosed in pediatric endocrinology clinics.

Evaluation of lipids, drug concentration, and safety parameters following cessation of treatment with the cholesteryl ester transfer protein inhibitor anacetrapib in patients with or at high risk for coronary heart disease.

The aim of this study was to assess the effects on lipids and safety during a 12-week reversal period after 18 months of treatment with anacetrapib. The cholesteryl ester transfer protein inhibitor anacetrapib was previously shown to reduce low-density lipoprotein cholesterol by 39.8% (estimated using the Friedewald equation) and increase high-density lipoprotein (HDL) cholesterol by 138.1%, with an acceptable side-effect profile, in patients with or at high risk for coronary heart disease in the Determining the Efficacy and Tolerability of CETP Inhibition With Anacetrapib (DEFINE) trial. A total of 1,398 patients entered the 12-week reversal-phase study, either after completion of the active-treatment phase or after early discontinuation of the study medication. In patients allocated to anacetrapib, placebo-adjusted mean percentage decreases from baseline were observed at 12 weeks off the study drug for Friedewald-calculated low-density lipoprotein cholesterol (18.6%), non-HDL cholesterol (17.6%), and apolipoprotein B (10.2%); placebo-adjusted mean percentage increases were observed for HDL cholesterol (73.0%) and apolipoprotein A-I (24.5%). Residual plasma anacetrapib levels (about 40% of on-treatment apparent steady-state trough levels) were also detected 12 weeks after cessation of anacetrapib. No clinically important elevations in liver enzymes, blood pressure, electrolytes, or adverse experiences were observed during the reversal phase. Preliminary data from a small cohort (n = 30) revealed the presence of low concentrations of anacetrapib in plasma 2.5 to 4 years after the last anacetrapib dose. In conclusion, after the cessation of active treatment, anacetrapib plasma lipid changes and drug levels decreased to approximately 40% of on-treatment trough levels at 12 weeks after dosing, but modest HDL cholesterol elevations and low drug concentrations were still detectable 2 to 4 years after the last dosing.

Lipids, safety parameters, and drug concentrations after an additional 2 years of treatment with anacetrapib in the DEFINE study.

Anacetrapib is a cholesteryl ester transfer protein (CETP) inhibitor that has previously been shown to reduce low-density lipoprotein cholesterol (LDL-C) and raise high-density lipoprotein cholesterol (HDL-C) in patients with or at high risk of coronary heart disease in the 76-week, placebo-controlled, Determining the Efficacy and Tolerability of CETP Inhibition with Anacetrapib (DEFINE) trial. Here, we report the results of the 2-year extension to the DEFINE study where patients (n = 803) continued on the same assigned treatment as in the original 76-week study. Treatment with anacetrapib during the 2-year extension was well tolerated with a safety profile similar to patients on placebo. No clinically important abnormalities in liver enzymes, blood pressure, electrolytes, or adverse experiences were observed during the extension. At the end of the extension study, relative to the original baseline value, anacetrapib reduced Friedewald-calculated LDL-C by 39.9% and increased HDL-C by 153.3%, compared to placebo. The apparent steady state mean plasma trough concentration of anacetrapib was ∼640 nmol/L. Geometric mean plasma concentrations of anacetrapib did not appear to increase beyond week 40 of the 2-year extension of the 76-week DEFINE base study. In conclusion, an additional 2 years of treatment with anacetrapib were well tolerated with durable lipid-modifying effects on LDL-C and HDL-C.