Antibody Drug Conjugates: Nonclinical Safety Considerations

Antibody drug conjugates (ADCs) are biopharmaceutical molecules consisting of a cytotoxic small molecule covalently linked to a targeted protein carrier via a stable cleavable or noncleavable linker. The process of conjugation yields a highly complex molecule with biochemical properties that are distinct from those of the unconjugated components. The impact of these biochemical differences on the safety and pharmacokinetic (PK) profile of the conjugate must be considered when determining the types of nonclinical safety studies required to support clinical development of ADCs. The hybrid nature of ADCs highlights the need for a science-based approach to safety assessment that incorporates relevant aspects of small and large molecule testing paradigms. This thinking is reflected in current regulatory guidelines, where sections pertaining to conjugates allow for a flexible approach to nonclinical safety testing. The aim of this article is to review regulatory expectations regarding early assessment of nonclinical safety considerations and discuss how recent advances in our understanding of ADC-mediated toxicity can be used to guide the types of nonclinical safety studies needed to support ADC clinical development. The review will also explore nonclinical testing strategies that can be used to streamline ADC development by assessing the safety and efficacy of next generation ADC constructs using a rodent screen approach.KEY WORDS: antibody drug conjugates, regulatory guidance, safety assessment, therapeutic index     

Malan syndrome: Sotos-like overgrowth with de novo NFIX sequence variants and deletions in six new patients and a review of the literature

De novo monoallelic variants in NFIX cause two distinct syndromes. Whole gene deletions, nonsense variants and missense variants affecting the DNA-binding domain have been seen in association with a Sotos-like phenotype that we propose is referred to as Malan syndrome. Frameshift and splice-site variants thought to avoid nonsense-mediated RNA decay have been seen in Marshall–Smith syndrome. We report six additional patients with Malan syndrome and de novo NFIX deletions or sequence variants and review the 20 patients now reported. The phenotype is characterised by moderate postnatal overgrowth and macrocephaly. Median height and head circumference in childhood are 2.0 and 2.3 standard deviations (SD) above the mean, respectively. There is overlap of the facial phenotype with NSD1-positive Sotos syndrome in some cases including a prominent forehead, high anterior hairline, downslanting palpebral fissures and prominent chin. Neonatal feeding difficulties and/or hypotonia have been reported in 30% of patients. Developmental delay/learning disability have been reported in all cases and are typically moderate. Ocular phenotypes are common, including strabismus (65%), nystagmus (25% ) and optic disc pallor/hypoplasia (25%). Other recurrent features include pectus excavatum (40%) and scoliosis (25%). Eight reported patients have a deletion also encompassing CACNA1A, haploinsufficiency of which causes episodic ataxia type 2 or familial hemiplegic migraine. One previous case had episodic ataxia and one case we report has had cyclical vomiting responsive to pizotifen. In individuals with this contiguous gene deletion syndrome, awareness of possible later neurological manifestations is important, although their penetrance is not yet clear.     

Dynamic consent: a patient interface for twenty-first century research networks

Biomedical research is being transformed through the application of information technologies that allow ever greater amounts of data to be shared on an unprecedented scale. However, the methods for involving participants have not kept pace with changes in research capability. In an era when information is shared digitally at the global level, mechanisms of informed consent remain static, paper-based and organised around national boundaries and legal frameworks. Dynamic consent (DC) is both a specific project and a wider concept that offers a new approach to consent; one designed to meet the needs of the twenty-first century research landscape. At the heart of DC is a personalised, digital communication interface that connects researchers and participants, placing participants at the heart of decision making. The interface facilitates two-way communication to stimulate a more engaged, informed and scientifically literate participant population where individuals can tailor and manage their own consent preferences. The technical architecture of DC includes components that can securely encrypt sensitive data and allow participant consent preferences to travel with their data and samples when they are shared with third parties. In addition to improving transparency and public trust, this system benefits researchers by streamlining recruitment and enabling more efficient participant recontact. DC has mainly been developed in biobanking contexts, but it also has potential application in other domains for a variety of purposes.     

Designing a Primary Care–Based Deprescribing Intervention for Patients with Dementia and Multiple Chronic Conditions: a Qualitative Study

BackgroundPatients with dementia and multiple chronic conditions (MCC) frequently experience polypharmacy, increasing their risk of adverse drug events.ObjectivesTo elucidate patient, family, and physician perspectives on medication discontinuation and recommended language for deprescribing discussions in order to inform an intervention to increase awareness of deprescribing among individuals with dementia and MCC, family caregivers and primary care physicians. We also explored participant views on culturally competent approaches to deprescribing.DesignQualitative approach based on semi-structured interviews with patients, caregivers, and physicians.ParticipantsPatients aged ≥ 65 years with claims-based diagnosis of dementia, ≥ 1 additional chronic condition, and ≥ 5 chronic medications were recruited from an integrated delivery system in Colorado and an academic medical center in Maryland. We included caregivers when present or if patients were unable to participate due to severe cognitive impairment. Physicians were recruited within the same systems and through snowball sampling, targeting areas with large African American and Hispanic populations.ApproachWe used constant comparison to identify and compare themes between patients, caregivers, and physicians.Key ResultsWe conducted interviews with 17 patients, 16 caregivers, and 16 physicians. All groups said it was important to earn trust before deprescribing, frame deprescribing as routine and positive, align deprescribing with goals of dementia care, and respect caregivers’ expertise. As in other areas of medicine, racial, ethnic, and language concordance was important to patients and caregivers from minority cultural backgrounds. Participants favored direct-to-patient educational materials, support from pharmacists and other team members, and close follow-up during deprescribing. Patients and caregivers favored language that explained deprescribing in terms of altered physiology with aging. Physicians desired communication tips addressing specific clinical situations.ConclusionsCulturally sensitive communication within a trusted patient-physician relationship supplemented by pharmacists, and language tailored to specific clinical situations may support deprescribing in primary care for patients with dementia and MCC.Electronic supplementary materialThe online version of this article (10.1007/s11606-020-06063-y) contains supplementary material, which is available to authorized users.KEY WORDS: deprescribing, patient-physician communication, dementia     

Anti-CD22 ligand-blocking antibody HB22.7 has independent lymphomacidal properties and augments the efficacy of 90Y-DOTA-peptide-Lym-1 in lymphoma xenografts

CD22 is a membrane glycophosphoprotein found on nearly all healthy B-lymphocytes and most B-cell lymphomas. Recent in vitro studies have identified several anti-CD22 monoclonal antibodies (mAbs) that block the interaction of CD22 with its ligand. One of these mAbs, HB22.7, has been shown to effectively induce apoptosis in several B-cell lymphoma cell lines. Lymphoma xenograft studies with Raji-xenograft mice were used to assess the toxicity and efficacy of HB22.7 alone and with combined modality immunotherapy (CMIT) with yttrium (90)Y-DOTA-peptide-Lym-1 radioimmunotherapy (RIT). The effect of the sequence of these agents on the combined treatment was assessed by administering HB22.7 24 hours before, simultaneously with, or 24 hours after RIT. Within the groups treated with RIT alone or with RIT and HB22.7 (CMIT), the reduction in tumor volume was the greatest when HB22.7 was administered simultaneously with and 24 hours after RIT, and in the RIT treatment groups, this translated into the greatest overall response and survival, respectively. Overall survival rates at the end of the 84-day CMIT trial were 67% and 50% in the groups treated with HB22.7 simultaneously and 24 hours after RIT, respectively. This compared favorably with the untreated and the RIT alone groups, which had survival rates of 38% and 43% at the end of the trial. Surprisingly, when compared with untreated controls and all other treatment groups, the greatest cure and overall survival rates were observed in the group treated with HB22.7 alone, with 47% cured and 76% surviving at the end of the 84-day trial. RIT clearance was not affected by treatment with HB22.7. When compared with RIT alone, there was no significant additional hematologic (white blood cell, red blood cell, or platelet count) toxicity when HB22.7 was added to RIT. Nonhematologic toxicity (assessed as change in body weight) was also unchanged when HB22.7 was added to RIT. Thus the anti-CD22 ligand-blocking antibody HB22.7 has independent lymphomacidal properties and augments the efficacy of (90)Y-DOTA-peptide-Lym-1 in lymphoma xenografts without significant toxicity.     

Interlocking trajectories of loss-related events and depressive symptoms among elders

OBJECTIVES: As people age, their peers (who are also aging) become increasingly susceptible to health decline and death, implying potential growth in stressful loss-related events over time for the individual. Yet little research has examined trajectories of stress and their relationship to trajectories of depression among elders. The purpose of this research was to determine whether growth in loss-related events occurs for elders and whether stress growth is related to the well-known growth in depressive symptomatology in later life. METHODS: Three waves of National Institute on Aging Established Populations for Epidemiologic Studies of the Elderly (Duke University site) data were used in the analyses. Latent growth curve models were estimated for stress, for depressive symptoms, and for stress predicting depression net of several covariates. RESULTS: Findings include that (a) loss-events evidence clear growth across age at the aggregate level, but with much variation within the sample, and (b) variation in growth in stress is strongly related to variation in growth in depressive symptoms. DISCUSSION: The results suggest that stress in later life may be conceived of as a growth process, with strong consequences for trajectories of mental health.