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

New ACTH Detection Method Improves Cure Rates in Cushing’s Disease Patients

Researchers have identified a new, quick method for detecting ACTH-producing tumors – called Elecsys – that can improve the cure rates of Cushing’s disease patients undergoing surgery.

The study, “Long-term outcomes of tissue-based ACTH-antibody assay–guided transsphenoidal resection of pituitary adenomas in Cushing disease,” was published in the Journal of Neurosurgery.

Transsphenoidal resection (TSR) – a surgical procedure performed through the nose and sphenoid sinus to remove a pituitary tumor – has been the method of choice for treatment for Cushing’s disease.

However, it often fails to localize the tumor with precision, leading to an incomplete resection (removal). This is likely a result of the preoperative methods used to guide surgeons before surgery, which include both magnetic resonance imaging (MRI) and a minimally invasive procedure called bilateral inferior petrosal sinus sampling (BIPSS) that measures ACTH in the veins that drain the pituitary gland.

However, both “suffer from suboptimal sensitivity and thus allow for incomplete resections, specially if pathological frozen sections fail to identify tumor,” researchers wrote.

MRI, for example, detects only 50 percent of Cushing’s adenomas, limiting surgeons’ ability to conduct curative TSR surgeries. Therefore, better diagnostic and tumor localization techniques are needed to increase the likelihood that initial surgeries can remove the entire tumor and cure patients.

A team of researchers at Yale School of Medicine evaluated a new method for guiding tumor localization during TSR. The method – a double-antibody sandwich assay for ACTH – is performed in the operating room in resected pituitary samples from patients. ACTH (adrenocorticotropic hormone) is a hormone produced in the pituitary gland in the brain, that simulated cortisol production in the adrenal glands. In patients with Cushing disease the pituitary gland releases too much ACTH.

In the new method – called Elecsys – samples are squeezed between sandwich-like system composed of two antibodies that recognize two sections of the ACTH protein. The three-step procedure is quick, allowing doctors to analyze samples in the operating room and determine if they have removed the entire tumors.

The performance and outcomes associated with the Elecsys were assessed by reviewing data of tissue samples from 14 patients with ACTH-secreting adenomas, who underwent TSR surgeries between 2009 and 2014.

“The intraoperative TSR protocol was modified with the introduction of the ACTH assay such that if either the assay or the frozen-section pathology returned results positive for tumor, that area of the gland was resected,” the researchers explained.

The new ACTH method detected tumor tissue and was capable of distinguishing it from normal tissue with a 95% sensitivity and 71.3% specificity. These values are comparable to those using the standard method for tumor localization, which requires frozen sections of the tumor. This suggests that the test can be used either in conjunction with or in place of frozen sections.

Also, 85.7% of the patients achieved long-term disease remission, with the remission rate exceeding the rate with previous methods (71.9%).

Overall, “these preliminary findings reflect the promising potential of tissue-based ACTH-antibody-guided assay for improving the cure rates of Cushing’s disease patients undergoing TSR. Further studies with larger sample sizes, further refinements of assay interpretation, and longer-term follow-ups are needed,” the study concluded.

From https://cushingsdiseasenews.com/2017/10/19/acth-detection-method-improved-cure-rates-cushings-disease-study-shows/

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

Blood Sample from Tributary Adrenal Gland Veins May Help to Diagnose Subclinical Cushing’s Syndrome

Researchers report a new technique for collecting blood samples from tiny veins of the adrenal glands, called super-selective adrenal venous sampling (ssAVS). The technique can be used to help diagnose diseases marked by excessive release of adrenal hormones, such as subclinical Cushing’s syndrome (SCS) or primary aldesteronism (PA).

The study, titled “A Novel Method: Super-selective Adrenal Venous Sampling,” was published in JOVE, the Journal of Visualized Experiments. JOVE has also made a video that demonstrates the procedure.

The adrenal glands are a pair of glands found above the kidneys that produce a variety of hormones, including adrenaline and the steroids aldosterone and cortisol. Excessive production of cortisol in the adrenal glands is the cause SCS, and aldosterone of PA.

These glands have central veins running through them, and three tributary veins (veins that empty into a larger vein). Conventional AVS collects blood from the central veins, but these veins have blood from the adrenal glands as well as blood in wider circulation flowing through them.

ssAVS uses tiny catheters — very long, narrow tubes inserted into blood vessels, called microcatheters — to collect blood from the tributary veins in both adrenal glands. Only blood from the adrenal glands flows through the tributary veins, making analysis of hormone levels easier, and pinpointing the region, or segment, of the gland that is not working properly.

A medical imaging technique, known as angiography, is used to track the positions of the microcatheters. Angiography is a procedure widely used to visualize the inside of blood vessels and organs, and takes roughly 90 minutes.

The paper reported on the use of ssAVS in three patients with adrenal gland disorders, and one (case #2) was diagnosed with SCS and PA. “Overall, in Cases #1 and #2, the ssAVS method clearly indicated segmental adrenal hormone production, not only for aldosterone, but for cortisol, and enabled these patients to be treated by surgery,”  the researchers reported.

Conventional AVS measures hormone levels in whole glands. It is useful for identifying which of the two glands is diseased, and the type of hormone that is overproduced. But sometimes both glands are affected, and only removal of the diseased parts in both glands is safe and effective.

That’s one of the reasons why ssAVS is so useful. By sampling the smaller, tributary veins in three different regions of each gland, the diseased parts can be identified. The diseased parts can then be removed from both glands, if medically advisable, leaving the healthy parts of the glands intact and functional.

ssAVS is also useful because it collects samples of blood coming directly from the adrenal glands, making analysis of hormone levels more reliable.

Researchers concluded that ssAVS is useful in both the diagnosis of adrenal gland disorders and for research that might lead to new therapies.

“Between October 2014 and September 2015, two angiographers … performed ssAVS on 125 cases … with a 100 % success rate and within a reasonable time (58 – 130 min) without adrenal rupture or thrombosis that required surgery,” they wrote. “The ssAVS method is not difficult for expert angiographers, and, thus, is recommended worldwide to treat PA cases for which cAVS does not represent a viable surgical treatment option.”

From https://cushingsdiseasenews.com/2017/10/17/subclinical-cushings-syndrome-may-be-diagnosed-via-blood-from-tributary-adrenal-gland-veins/

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/

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