Rapid disease progression in a patient with mismatch repair-deficient and cortisol secreting adrenocortical carcinoma treated with pembrolizumab

CONTEXT

Metastatic adrenocortical carcinoma (ACC) is an aggressive malignancy with a poor prognosis and limited therapeutic options. A subset of ACC is due to Lynch syndrome, an inherited tumor syndrome resulting from germline mutations in mismatch repair (MMR) genes. It has been demonstrated that several cancers characterized by MMR deficiency are sensitive to immune checkpoint inhibitors that target PD-1. Here, we provide the first report of PD-1 blockade with pembrolizumab in a patient with Lynch syndrome and progressive cortisol-secreting metastatic ACC.

CASE REPORT

A 58-year-old female with known Lynch syndrome presented with severe Cushing's syndrome and was diagnosed with a cortisol-secreting ACC. Three months following surgical resection and adjuvant mitotane therapy the patient developed metastatic disease and persistent hypercortisolemia. She commenced pembrolizumab, but her second cycle was delayed due to a transient transaminitis. Computed tomography performed after 12 weeks and 2 cycles of pembrolizumab administration revealed significant disease progression and treatment was discontinued. After 7 weeks, the patient became jaundiced and soon died due to fulminant liver failure.

CONCLUSION

Treatment of MMR-deficient cortisol-secreting ACC with pembrolizumab may be ineffective due to supraphysiological levels of circulating corticosteroids, which may in turn mask severe drug-induced organ damage.

Biopharmaceuticals and monoclonal antibodies in oncology trials--a cross-sectional analysis

Protein engineering has led to a significantly improved understanding of the biophysical properties of proteins and, importantly, of the molecular mechanisms of disease. Moreover, it has enabled scientists to modify the molecular characteristics of peptides and proteins, leading to improved pharmacokinetics and pharmacodynamics of protein therapeutics. Consequently, biopharmaceuticals, such as monoclonal antibodies (mAbs), interferons/cytokines or vaccines, contribute increasingly to clinical practice. Some of these new treatments have dramatically changed the outcome of specific diseases. However, treatment options remain limited in many conditions, particularly in malignant disease, despite a much-improved understanding of the molecular mechanisms underlying cancer. With the successful pre-clinical development of therapeutic biomolecules, the most significant barrier prior to implementation into clinical practice is proof of concept in humans. This is in part addressed by clinical trials that evaluate the toxicology, dose response and efficacy of the molecules. This observational study summarises the current state of biopharmaceuticals in clinical trials and provides a particular focus on oncology trials. It identifies those cancer types that are most likely to benefit from the efforts made in pre-clinical protein science and establishes evidence that engineered proteins and peptides are set to play a growing role in clinical practice. This study was based on the 95,254 trials registered on the National Institute of Health Clinical Trials Database by 31 August 2010. Of these, 25,525 trials assigned to cancer conditions, including leukaemia and lymphoma, were further analysed, with a particular focus on the 3653 interventional trials that were based on biological interventions. The inclusion criterion for the analysis was registration on the Clinical Trials Database by the above date. No other trials were included. Biopharmaceuticals were the more prevalent intervention in cancer trials (14%) compared with trials in non-cancer conditions (6%). Further subgroup analysis based on the 20 cancer subtypes with the highest mortality revealed that biological therapeutics comprise 43% in malignant melanoma trials and more than 20% in five other cancer types. Two-thirds of all monoclonal antibody are registered in cancer trials (1033, 4.6% of all cancer trials). The subgroup analysis demonstrated a predominance of lymphoma and leukaemia trials for antibody interventions, with 204 and 163 trials registered, respectively. In non-cancer conditions only 503 (0.9%) trials investigate monoclonal antibody interventions. A retrospective longitudinal analysis of the trials demonstrated that monoclonal antibody trials are increasingly frequently registered in non-cancer as well as cancer conditions. However, biopharmaceutical trials continue to be registered more frequently only in non-cancer conditions, but have come to a plateau in cancers. This study is limited by analysis of data from one database only. While the NIH Clinical Trials Database used is the most comprehensive and internationally recognised of its kind, it is possible that the results may have been modified if other databases were also included. Protein engineering has paved the way for biopharmaceutical clinical interventions. A cross-sectional analysis of trials registered on the NIH Clinical Trial Database shows that biological interventions are increasingly entered into clinical trials. While oncological diseases used to lead this effort, biotherapeutic trials in non-cancer conditions have now become more frequent in comparison. Monoclonal antibodies, however, are still mainly investigated in oncological conditions. Haemato-oncological diseases are most frequently investigated for mAb interventions, although they are not among the eight most common causes of cancer mortality. This may reflect the fact that pre-clinical research, understanding of molecular mechanisms and target identification in other malignancies and diseases is less developed.

Exploring new routes for neuroprotective drug development in traumatic brain injury

Worldwide, traumatic brain injury (TBI) is a major cause of mortality and morbidity with a substantial predicted increase in incidence. Despite an obvious need, there are no pharmacological treatment options for TBI because translation of neuroprotection from preclinical studies to clinical practice has so far failed. Here, we identify potential causes for this failure. We suggest that the monitoring and investigation tools that are commonly used in patients with TBI may provide an experimental medicine route to facilitate a more rational approach to translational research. This suggestion is underpinned by existing research data on disease biology, drug delivery, and treatment response obtained with these methods.

Designing a metal-binding site in the scaffold of Escherichia coli KDO8PS

KDO8PS (3-deoxy-d-manno-octulosonate-8-phosphate synthase) and DAH7PS (3-deoxy-d-arabino-heptulosonic acid-7-phosphate synthase) enzymes catalyse analogous condensation reactions between phosphoenolpyruvate and arabinose 5-phosphate or erythrose 4-phosphate, respectively. All known DAH7PS and some of KDO8PS enzymes (Aquifex aeolicus KDO8PS) require a metal ion for activity whereas another class of KDO8PS (including Escherichia coli KDO8PS) does not. Based on sequence alignment of all known KDO8PS and DAH7PS enzymes, we identified a single amino acid residue that might define the metal dependence of KDO8PS activity. One of the four metal-binding residues, a cysteine, is conserved only among metal-binding KDO8PS and DAH7PS enzymes and is replaced by an asparagine residue in other KDO8PS enzymes. We introduced a metal binding site into E.coli KDO8PS by a single N26C and a double M25P N26C mutation, which led to an increased k(cat) of the enzymes in the presence of activating Mn(2+) ions. The M25P N26C mutant of E.coli KDO8PS had a value of k(cat)/K(M) in the presence of Mn(2+) ions four times higher than A.aeolicus KDO8PS. KDO8PS and DAH7PS may have evolved from a common ancestor protein that required a divalent metal ion for activity. A non-metal-binding KDO8PSs may have evolved from an ancestor protein that was able to bind Mn(2+) but no longer required Mn(2+) to function and eventually lost one of metal-binding residues.

Characterization of the calcium-release channel/ryanodine receptor from zebrafish skeletal muscle

Calcium (Ca2+)-mediated signaling is fueled by two sources for Ca2+: Ca2+ can enter through Ca2+ channels located in the plasma membrane and can also be released from intracellular stores. In the present study the intracellular Ca2+ release channel/ryanodine receptor (RyR) from zebrafish skeletal muscle was characterized. Two RyR isoforms could be identified using immunoblotting and single-channel recordings. Biophysical properties as well as the regulation by modulators of RyR, ryanodine, ruthenium red and caffeine, were measured. Comparison with other RyRs showed that the zebrafish RyRs have features observed with all RyRs described to date and thus, can serve as a model system in future genetic and physiological studies. However, some differences in the biophysical properties were observed. The slope conductance for both isoforms was higher than that of the mammalian RyR type 1 (RyR1) measured with divalent ions. Also, inhibition by millimolar Ca2+ concentrations of the RyR isoform that is inhibited by high Ca2+ concentrations (teleost alpha RyR isoform) was attenuated when compared to mammalian RyRs. Due to the widespread expression of RyR these findings have important implications for the interpretation of the role of the RyR in Ca2+ signaling when comparing zebrafish with mammalian physiology, especially when analyzing mutations underlying physiological changes in zebrafish.

Conservation of localization patterns of IP(3) receptor type 1 in cerebellar Purkinje cells across vertebrate species

The distribution of inositol 1,4,5-trisphosphate (IP(3)) receptor type 1 (IP(3)R1) protein was studied in the adult cerebella of six different vertebrate species, zebrafish, skate, claw frog, rat, hamster, and mouse. The receptor was found at high expression levels in Purkinje cells in all species examined using a subtype-specific polyclonal antiserum against IP(3)R1 and fluorescence immunocytochemistry. The immunoreactivity for IP(3)R1 was found intracellularly at high concentrations in dendrites and somata and at lower levels in axons of these cells. Despite the morphological and functional differences of the cerebella the staining patterns of IP(3)R1 labeling in Purkinje cells was preserved. This is notable because the cerebella were taken from organisms representing a large segment of vertebrate phylogenetic development. The high expression levels of IP(3)R1 in Purkinje cells were found independent of the degree of the formation of fissures and folia and of the degree of branching of Purkinje cell dendrites. The conservation of cerebellar structures not only at the cellular level but more importantly at the molecular level suggests that identical intracellular calcium signaling mechanisms are used in a number of species that represent different areas of phylogenetic development and specialization.