Long-acting pasireotide safe, effective for recurrent Cushing’s disease

October 20, 2017

In patients with persistent or recurring Cushing’s disease after surgery, monthly pasireotide was safe and effective, leading to normal urinary free cortisol levels in about 40% of patients after 12 months, according to findings from a phase 3 clinical trial.

“Surgical resection of the causative pituitary adenoma is the first-line treatment of choice for most patients with Cushing’s disease, which leads to remission in greater than 75% of patients if done by an expert pituitary surgeon,” Andre Lacroix, MD, professor in the department of medicine at University of Montreal teaching hospital, and colleagues wrote in the study background. “However, surgery is not always successful, and disease recurrence can occur several years after initial remission, while some patients refuse or are not candidates for surgery. As a result, many patients require additional treatment options.”

Lacroix and colleagues analyzed data from 150 patients with a confirmed diagnosis of persistent, recurrent or new Cushing’s disease with mean urinary free cortisol level concentration 1.5 to five times the upper limit of normal, normal or greater than normal plasma and confirmed pituitary source of Cushing’s disease. Patients were recruited between December 2011 and December 2014; those who received mitotane therapy within 6 months, pituitary irradiation within 10 years or previous pasireotide treatment were excluded. Researchers randomly assigned patients to 10 mg (n = 74) or 30 mg (n = 76) monthly intramuscular pasireotide (Signifor LAR, Novartis) for 12 months, with investigators and patients masked to the group allocation and dose. Pasireotide was up-titrated from 10 mg to 30 mg or from 30 mg to 40 mg at month 4, or at month 7, 9 or 12 if urinary free cortisol concentrations remained greater than 1.5 times the upper limit of normal. At month 12, patients considered to be receiving clinical benefit from the therapy (mean urinary free cortisol concentration at or less than the upper limit of normal) could continue to receive it during an open-ended extension phase. The primary outcome was to assess the proportion of patients achieving mean urinary free cortisol concentration less than or equal to the upper limit of normal by month 7, regardless of dose.

Within the cohort, 41.9% of patients in the 10-mg group and 40.8% of patients in the 40-mg group met the primary endpoint at month 7, whereas 5% of patients in the 10-mg group and 13% of patients in the 40-mg group achieved partial control. Researchers did not observe between-sex differences or differences in response among those who did or did not undergo previous surgery.

The number of patients who achieved the primary endpoint at month 7 without an up-titration in dose was smaller, but not significantly different between the 10-mg and 40-mg dose groups (28.4% and 31.6%, respectively), according to researchers. Among those who received an up-titration in dose in the 10-mg and 40-mg groups (42% and 37%, respectively), 32% and 25%, respectively, were considered responders at month 7.

Researchers also observed improvements in several metabolic parameters during the 12-month course of treatment with both doses, including improvements in systolic and diastolic blood pressure; reductions in waist circumference, BMI and body weight; and improvement in scores for the Cushing’s Quality of Life questionnaire. The most common adverse events were hyperglycemia, diarrhea, cholelithiasis, diabetes and nausea.

The researchers noted that, in both dose groups, the reductions in mean urinary free cortisol concentration were observed within 1 month, with concentrations remaining below baseline levels for the 12-month study period.

“This large phase 3 trial showed that long-acting pasireotide administered for 12 months can reduce [median urinary free cortisol] concentrations, is associated with improvements in clinical signs and [health-related quality of life] and has a similar safety profile to that of twice-daily pasireotide,” the researchers wrote, adding that the long-acting formulation provides a convenient monthly administration schedule. – by Regina Schaffer

Disclosures: Novartis funded this study. Lacroix reports he has received grants and personal fees as a clinical investigator, study steering committee member and advisory board member for Novartis, Stonebridge and UpToDate. Please see the study for all other authors’ relevant financial disclosures.

From https://www.healio.com/endocrinology/adrenal/news/in-the-journals/%7B55988079-312b-478d-8788-036a465b1881%7D/long-acting-pasireotide-safe-effective-for-recurrent-cushings-disease

Intraoperative MRI improves complete resection of pituitary macroadenoma

A 63-year-old man was referred to the Massachusetts General Hospital Neuroendocrine & Pituitary Tumor Clinical Center for management of a pituitary macroadenoma. He experienced increasingly severe retro-orbital headaches in the past year. He reported no double vision, fatigue, orthostatic dizziness, change in beard growth or reduction in libido. An outside head CT scan showed an enlarged pituitary gland.

Imaging and laboratory tests

A pituitary MRI with magnified pituitary slices and gadolinium contrast was ordered. A well-circumscribed “snowman-shaped” sellar mass was identified, measuring 2.6 cm x 2 cm x 1.8 cm (anteroposterior x transverse x craniocaudal) with suprasellar extension (Figure 1). The lesion was heterogeneous on T1-weighted scans after enhancement with IV gadolinium contrast. An area of hypointensity in the superior margin was consistent with a small area of cystic or hemorrhagic degeneration.

Although the mass did not extend laterally into the cavernous sinus, the sellar mass extended upward into the suprasellar cistern through a hole in the dural, the diaphragma sellae, to compress the optic chiasm. The restriction of adenoma growth by the diaphragma sellae results in the snowman shape of the macroadenoma. The optic chiasm and infundibulum (pituitary stalk) could not be identified on coronal or sagittal images (Figure 1). Visual field on confrontation suggested lateral field deficits (bilateral lateral hemianopsia) that were confirmed on formal Goldmann kinetic perimetry visual fields.

Figure 1. Preoperative MRI scan. A large “snowman-shaped” pituitary adenoma (green arrow) has heterogeneous enhancement after gadolinium contrast administration. A small hypodense area in the adenoma likely represented hemorrhage/cystic degeneration (yellow arrow). The tumor does not surround the carotid siphon, an S-shaped portion of the internal carotid artery (red arrows) within the cavernous sinus located laterally from the sella turcica where the pituitary gland resides. (A) Coronal image. (B) Sagittal image. Abbreviation: SS = spenoid sinus.

Source: Stephanie L. Lee, MD, PhD, ECNU. Reprinted with permission.

Initial hormonal evaluation was normal and included morning adrenocorticotropic hormone 18 pg/mL, cortisol 13.64 µg/dL, thyroid-stimulating hormone 2.14 uIU/mL, free thyroxine 1.2 ng/dL and prolactin 12.6 ng/mL. The patient’s morning testosterone level was normal at 324 ng/dL, with follicle-stimulating hormone 2.4 mIU/mL and luteinizing hormone 1.6 mIU/mL. His insulin-like growth factor I level was normal at 124 ng/mL.

Tumor resection

The patient was treated preoperatively with stress-dose hydrocortisone 50 mg. He then underwent transsphenoidal pituitary tumor resection. After the surgeon believed there was an adequate excision of the tumor, the extent of tumor resection was confirmed by an intraoperative MRI (Figure 2 on page 8).

Figure 2. Intraoperative MRI scan. The large macroadenoma is not seen after transsphenoidal surgery. The optic chiasm (yellow arrow) can be seen after removal of the tumor. (A) Coronal image. (B) Sagittal image. Abbreviation: SS = spenoid sinus.

The operation was concluded after the imaging confirmed the complete resection of the pituitary adenoma. The patient’s postoperative course was uneventful. Imaging 4 weeks after the resection confirmed complete resection of the suprasellar mass with residual enhancement of the resection bed and sphenoid sinuses (Figure 3 on page 8). The postoperative MRI revealed a normal optical chiasm and a downward tending of the infundibulum to the residual pituitary gland located inferiorly along the sella turcica (pituitary fossa) of the sphenoid bone. Pathology confirmed a pituitary adenoma. His anterior and posterior pituitary function were normal 6 weeks postoperatively, and his visual field deficit improved.

Intraoperative MRI

Imaging like that used in this case occurs in a specially designed operating room that allows MRI scans during surgery without moving the patient from the surgical table. The MRI is kept in a shielded enclosure during the procedure and then moved along a track into the operating room for imaging. Clinical indications for the use of intraoperative MRI in neurosurgery include resection of pituitary macroadenomas. In the past, these tumors underwent transsphenoidal resection, and the postoperative MRI was performed after 1 or more days after the procedure to check for complete removal. If residual tumor was found, the patients underwent watchful waiting, external radiation or repeat surgery.

The strategic advantage of an intraoperative MRI is that the imaging is performed during the operative procedure, and if there is any residual tumor, surgery can be resumed after the MRI is moved back into the shielded enclosure.

Figure 3. Four-week postoperative MRI scan. The large macroadenoma is not seen after the transsphenoidal survey. The optic chiasm and infundibulum (pituitary stalk) can be seen after resection of the tumor. The pituitary stalk is deviated to the left of the sella where the residual normal thyroid is locate along the sella turcica. The floor of the sella enhances with gadolinium infusion after surgery due to postoperative inflammation. (A) Coronal image. (B) Sagittal image. Abbreviation: SS = spenoid sinus.

It has been reported that the use of intraoperative MRI does not increase complication rates compared with conventional transsphenoidal surgery. Reports on the improvement of gross tumor resection using intraoperative MRI are variable, perhaps due to the expertise of the surgeon. Several reports suggest the use of intraoperative MRI allowed additional resection of noninvasive macroadenomas in 67% to 83% of the patients with a gross tumor resection. These results suggest that a substantial volume reduction and increased gross tumor resection of pituitary macroadenomas occurs with the use of intraoperative MRI compared with standard surgery. One study demonstrated that the gross tumor resection rates of invasive tumors was also improved with the use of intraoperative MRI compared with usual preoperative imaging and surgery (25% vs. 7%).

The use of intraoperative MRI, especially with transsphenoidal reoperations for invasive and noninvasive pituitary macroadenomas, leads to significantly higher “gross tumor resection” rates. This method prevents additional operations or treatment, such as radiation, because it reduces the number of patients with residual adenoma after surgery. This technology is usually found in specialized tertiary care hospitals but should be considered for reoperation for large pituitary macroadenomas or initial operation for large invasive pituitary macroadenomas.

Disclosures: Lee and Swearingen report no relevant financial disclosures.

From https://www.healio.com/endocrinology/neuroendocrinology/news/print/endocrine-today/%7B23183444-4d29-477b-844f-6eb995ac74f4%7D/intraoperative-mri-improves-complete-resection-of-pituitary-macroadenoma

Increase in Glucose Uptake by Cushing’s Disease-associated Tumors Could Improve Early Detection

An increase in glucose uptake by Cushing’s disease-associated pituitary tumors could improve their detection, new research shows.

The study, “Corticotropin releasing hormone can selectively stimulate glucose uptake in corticotropinoma via glucose transporter 1,” appeared in the journal Molecular and Cellular Endocrinology.

The study’s senior author was Dr. Prashant Chittiboina, MD, from the Department of Neurosurgery, Wexner Medical Center, The Ohio State University, in Columbus, Ohio.

Microadenomas – tumors in the pituitary gland measuring less than 10 mm in diameter – that release corticotropin, or corticotropinomas, can lead to Cushing’s disease. The presurgical detection of these microadenomas could improve surgical outcomes in patients with Cushing’s.

But current tumor visualization methodologies – magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) – failed to detect a significant percentage of pituitary microadenomas.

Stimulation with corticotropin-releasing hormone (CRH), which increases glucose uptake, has been suggested as a method of increasing the detection of adenomas with 18F-FDG PET, by augmenting the uptake of 18F-FDG – a glucose analog.

However, previous studies aiming to validate this idea have failed, leading the research team to hypothesize that it may be due to a delayed elevation in glucose uptake in corticotropinomas.

The scientists used clinical data to determine the effectiveness of CRH in improving the detection of corticotropinomas with 18F-FDG PET in Cushing’s disease.

They found that CRH increased glucose uptake in human and mouse tumor cells, but not in healthy mouse or human pituitary cells that produce the adrenocorticotropic hormone (ACTH). Exposure to CRH increased glucose uptake in mouse tumor cells, with a maximal effect at four hours after stimulation.

Similarly, the glucose transporter GLUT1, which is located at the cell membrane, was increased two hours after stimulation, as was GLUT1-mediated glucose transport.

These findings indicate a potential mechanism linking CRH exposure to augmented glucose uptake through GLUT1. Expectedly, the inhibition of glucose transport with fasentin suppressed glucose uptake.

The researchers consistently observed exaggerated evidence of GLUT1 in human corticotropinomas. In addition, human corticotroph tumor cells showed an increased breakdown of glucose, which indicates that, unlike healthy cells, pituitary adenomas use glucose as their primary source of energy.

Overall, the study shows that corticotropin-releasing hormone (CRH) leads to a specific and delayed increase in glucose uptake in tumor corticotrophs.

“Taken together, these novel findings support the potential use of delayed 18F-FDG PET imaging following CRH stimulation to improve microadenoma detection in [Cushing’s disease],” researchers wrote. The scientists are now conducting a clinical trial to further explore this promising finding.

From https://cushingsdiseasenews.com/2017/10/12/glucose-uptake-in-cushings-disease-could-improve-presurgical-tumor-detection/

Cortisol Modulator Shows Early Signs of Safety, Efficacy in Healthy Volunteers

The glucocorticoid receptor antagonist CORT125134 is safe and has shown preliminary signs of efficacy in healthy volunteers participating in a Phase 1 trial, say researchers in England.

Their study, “Assessment of Safety, Tolerability, Pharmacokinetics, and Pharmacological Effect of Orally Administered CORT125134: An Adaptive, Double-Blind, Randomized, Placebo-Controlled Phase 1 Clinical Study,” appeared in the journal Clinical Pharmacology in Drug Development.”

Cortisol signaling is indirectly controlled by the glucocorticoid receptor (GR). When cortisol binds the GR, the receptor becomes activated and migrates to the nucleus, where it regulates the expression of many genes. This influences a myriad of processes, including inflammation, immune response and brain function.

CORT125134, also known as relacorilant, is being developed by Corcept Therapeutics of Menlo Park, California, for Cushing’s disease patients and others who may benefit from it. The drug is a GR antagonist, blocking the receptor’s activity.

In order to evaluate the safety and tolerability of CORT125134, and learn how it behaves in the body, Corcept researchers conduced a Phase 1 trial in healthy subjects.

The British study, conducted at the Quotient Clinical in Nottingham, included 81 adults who received a single ascending-dose of CORT125134 or placebo, and 48 subjects who received multiple-ascending doses of the drug versus placebo.

Single doses were tested in nine distinct groups. Six tested six different doses of CORT125134, one tested a 150 mg dose in subjects receiving a high-fat meal, and two groups included patients receiving prednisone (a well-known GR activator), prednisone plus Korlym (mifepristone), or prednisone plus CORT125134.

Korlym is a medicine approved for Cushing’s  patients with high blood sugar levels due to high cortisol in circulation. But the drug targets the progesterone receptor and is associated with side effects like pregnancy termination and irregular vaginal bleeding.

Multiple doses, given for up to 14 days, were tested in four additional cohorts. Researchers observed that CORT125134 was rapidly absorbed and eliminated, presenting a suitable profile for once-daily dosing.

Efficacy was determined by CORT125134’s ability to counteract the effects of prednisone. In addition, a single dose of 500 mg or multiple dosing with 250 mg had similar effects as those seen with 600 mg of Korlym — the therapeutic dose used for Cushing’s treatments.

Most common treatment-related adverse events reported in the single-ascending dose part of the study were nausea, vomiting and thirst; most were mild. In those given multiple-ascending doses, adverse events included mild musculoskeletal and connective tissue disorders, as well as gastrointestinal system disorders.

Multiple 500 mg doses exceeded the maximum tolerated dose, as it led to musculoskeletal symptoms that forced researchers to stop treatment.

“This first-in-human study has demonstrated that CORT125134 is well tolerated following single doses up to 500 mg and repeated doses up to 250 mg once daily for 14 days,” researchers wrote. “Pharmacological activity was confirmed following the administration of a single 500-mg dose and daily administration of 250 mg.”

Corcept is now enrolling participants into a Phase 2 open-label trial (NCT02804750) to evaluate CORT125134 in patients with Cushing’s syndrome. This trial is being conducted in the United States and Europe and will include 80 participants. Top-line results are expected in the first quarter of 2018.

From https://cushingsdiseasenews.com/2017/10/10/phase-1-data-demonstrates-efficacy-safety-of-cort125134-in-healthy-volunteers/

In Memory: Edward H. Oldfield, MD, 1947–2017

Dr. Oldfield was my pituitary surgeon at NIH back in 1987.  This was back in the olden days of transsphenoidal surgery.  I honestly expected to die but this man saved my life.

 

Ed started as Senior Staff Fellow in the Surgical Neurology Branch at the NIH (1981). After 5 years, Ed would become the Chief of the Surgical Neurology Branch. He would stay on as Branch Chief and lead the neurosurgical effort at the NIH for the next 21 years. During his tenure, he developed clinical, research, and training programs in epilepsy, congenital malformations, syringomyelia, nervous system neoplasia, drug delivery, and vascular malformations. The strength of these programs was his leadership and their multidisciplinary nature, which incorporated physicians and scientists across the basic, translational, and clinical arenas. Research investigation was always targeted at defined clinical problems. Under his direction, these programs shaped understanding of the studied neurological disorders, as well as improving patient care.

Read the entire obituary here: Edward H. Oldfield, MD, 1947–2017

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