An approach to the evaluation and treatment of Cushing’s disease

Budget impact of pasireotide for the treatment of Cushing's disease, a rare endocrine disorder associated with considerable comorbidities

OBJECTIVES

Cushing's disease (CD) is a rare condition with a prevalence of roughly 39 cases per million in the general population. Healthcare costs are substantial for CD patients with either untreated or inadequately controlled disease. This study assesses the 3-year budget impact of pasireotide on a US managed care health plan following pasireotide (Signifor) availability.

METHODS

Two scenarios were evaluated to understand the differences in costs associated with the introduction of pasireotide. The first scenario evaluates the budget impact of pasireotide from the perspective of an entire health plan (total budget impact) and the second from the perspective of the pharmacy budget (pharmacy budget impact). Both scenarios evaluate the annual incremental budget impact with and without pasireotide. Scenario 1 includes costs for medical procedures, drug therapies, monitoring, surgical complications, comorbidities for patients with controlled or uncontrolled CD, and adverse events. Procedures include transsphenoidal surgery, bilateral adrenalectomy, radiotherapy and radiosurgery. Drugs include pasireotide (indicated for CD), mifepristone (indicated to control hyperglycemia secondary to hypercortisolism in patients with Cushing's syndrome) as well as several off-label treatments (ketoconazole, cabergoline, mitotane). Scenario 2 considers costs solely from the perspective of a health plan pharmacy. Costs are in $2013.

RESULTS

The estimated total budget impact is $0.0115 per-member per-month (PMPM) in the first year following FDA approval, $0.0184 in the second year, and $0.0194 in the third year. Introduction of pasireotide is expected to increase the pharmacy budget by $0.0257 PMPM in the first year, $0.0363 in the second year, and $0.0360 in the third year.

LIMITATIONS

Model inputs rely on the small body of literature available for Cushing's disease.

CONCLUSIONS

Cushing's disease is severe disease with debilitating comorbidities and substantial healthcare costs when untreated or inadequately controlled. The inclusion of pasireotide in a health plan formulary appears to have only a small impact on the total health plan or pharmacy budget.

Transsphenoidal surgery for Cushing disease: experience with 136 patients

BACKGROUND

This is a retrospective study of 136 patients with Cushing disease treated with transsphenoidal microsurgery.

OBJECTIVE

To evaluate factors influencing immediate postoperative results and long-term outcomes.

METHODS

Data regarding clinical presentation, endocrine evaluation, imaging studies, surgical technique, immediate postoperative biochemical remission (IPBR), and long-term results were entered into a database and analyzed statistically. IPBR was based on biochemical evidence of adrenal cortical insufficiency and clinical evidence of such insufficiency.

RESULTS

IPBR for the entire series was 83.4%. In microadenomas, IPBR was 89.8% with a mean immediate postoperative plasma cortisol (IPPC) of 2.1 μg/dL (range, <0.5-5.3). Positive magnetic resonance imaging (MRI) was associated with 18 times greater odds of finding microadenoma at surgery (P < .001) and with 4.1 times greater odds of IPBR (P = .07). In patients with a negative MRI, a positive inferior petrosal sinus sampling (IPSS) test was associated with 93% of IPBR (P = .004). IPBR in macroadenomas was 30.7%. Of patients followed for 12 months or longer, 34.8% required glucocorticoid replacement for the duration of follow-up. The mean follow-up in microadenomas was 68.4 months with a 9.67% incidence of recurrences. The estimated actuarial incidence of recurrences increased with the passage of time and IPPC of greater than 2 μg/dL was associated with higher incidence of recurrences, although without statistical significance (P = .08).

CONCLUSION

In microadenomas, a positive MRI and positive IPSS test were associated with a higher incidence of IPBR. Recurrences increased with the passage of time, and an IPPC of greater than 2 μg/dL may be associated with higher incidence of recurrences.

Current state of the art in the diagnosis and surgical treatment of Cushing disease: early experience with a purely endoscopic endonasal technique

Object

Transsphenoidal pituitary surgery is the primary therapy for Cushing disease because of its potential to produce lasting remission without the need for long-term drug or hormone replacement therapy. The authors evaluated the current role of pure endoscopic endonasal pituitary surgery in the treatment of Cushing disease.

Methods

Twenty-five patients underwent pure endoscopic surgery for confirmed Cushing disease. Thirteen patients had microadenomas and seven had macroadenomas; magnetic resonance images obtained in five patients were only suspicious or nondiagnostic, and thus they underwent inferior petrosal sinus sampling. Two patients had evidence of cavernous sinus involvement. Final histological results were consistent with adrenocorticotropin hormone (ACTH)–secreting adenoma in 20 patients.

Results

Twenty patients (80%) had clinical remission and laboratory confirmation of hypocortisolemia (serum cortisol < 100 nmol/L requiring substitution therapy), suppression to low-dose dexamethasone, and normal 24-hour urinary free cortisol. The median follow-up period was 17 months (range 3–32 months). There was no recurrence at the time of the last follow-up. Three patients presented with new anterior pituitary deficiency, but no one had permanent diabetes insipidus. In one patient a cerebrospinal fluid leak developed but later resolved following lumbar drainage. Treatment failure was attributable to involvement of the cavernous sinus in two patients, incomplete tumor removal in one, negative exploration in one, and nodular corticotroph hyperplasia of the pituitary gland in one.

Conclusions

Early results indicated that endoscopic endonasal surgery is a safe and effective treatment for ACTH-producing adenomas. The rate of remission in this study is comparable to those in previous series, and the rate of major postoperative complications is extremely low. Further studies with a larger number of patients and longer follow-ups are required to determine whether this more minimally invasive pure endoscopic approach should become the standard of care for the surgical treatment of Cushing disease.