Addressing Unmet Medical Needs in Type 1 Diabetes: A Review of Drugs Under Development.

INTRODUCTION: The incidence of type 1 diabetes (T1D) is increasing worldwide and there is a very large need for effective therapies. Essentially no therapies other than insulin are currently approved for the treatment of T1D. Drugs already in use for type 2 diabetes and many new drugs are under clinical development for T1D, including compounds with both established and new mechanisms of action. Content of the Review: Most of the new compounds in clinical development are currently in Phase 1 and 2. Drug classes discussed in this review include new insulins, SGLT inhibitors, GLP-1 agonists, immunomodulatory drugs including autoantigens and anti-cytokines, agents that regenerate ß-cells and others. Regulatory Considerations: In addition, considerations are provided with regard to the regulatory environment for the clinical development of drugs for T1D, with a focus on the United States Food and Drug Administration and the European Medicines Agency. Future opportunities, such as combination treatments of immunomodulatory and beta-cell regenerating therapies, are also discussed.

Addressing unmet medical needs in type 2 diabetes: a narrative review of drugs under development.

The global burden of type 2 diabetes is increasing worldwide, and successful treatment of this disease needs constant provision of new drugs. Twelve classes of antidiabetic drugs are currently available, and many new drugs are under clinical development. These include compounds with known mechanisms of action but unique properties, such as once-weekly DPP4 inhibitors or oral insulin. They also include drugs with new mechanisms of action, the focus of this review. Most of these compounds are in Phase 1 and 2, with only a small number having made it to Phase 3 at this time. The new drug classes described include PPAR agonists/modulators, glucokinase activators, glucagon receptor antagonists, anti-inflammatory compounds, G-protein coupled receptor agonists, gastrointestinal peptide agonists other than GLP-1, apical sodium-dependent bile acid transporter (ASBT) inhibitors, SGLT1 and dual SGLT1/SGLT2 inhibitors, and 11beta- HSD1 inhibitors.

A novel activating mutation in transmembrane helix 6 of the thyrotropin receptor as cause of hereditary nonautoimmune hyperthyroidism.

Constitutively-activating germline mutations of the thyrotropin receptor (TSHR) gene are very rare and are considered the cause of hereditary nonautoimmune hyperthyroidism. We describe four affected individuals from a Caucasian family: a mother and her three children, and an unaffected father. The mother and her first two children presented in a similar manner: lifelong histories of heat intolerance, hyperactivity, fast heart rate, reduced energy, increased appetite, and scrawny build. They all developed goiter in childhood and showed a suppressed TSH and elevated thyroxine (T(4)). The last child, a 12-year-old female, presented with no clinical symptoms or palpable neck mass, but with a suppressed TSH, elevated T(4) and thyromegaly detected by ultrasound. Mutation analysis of the TSHR gene in all family members revealed a novel heterozygous germline mutation resulting in the substitution of phenylalanine (TTC) by serine (TCC) at codon 631 in transmembrane helix 6 in the mother and all three children. Functional characterization of this germline mutation showed constitutive activation of the G(s)-mediated cyclic adenosine monophosphate (cAMP) pathway, which controls thyroid hormone production and thyroid growth. Molecular characterization of F631S demonstrates that this activating mutation plays a key role in the development of hereditary hyperthyroidism in this family although the timing of onset of clinical manifestations in the subjects may depend on other, as yet unidentified, factors.

Clinical uses of recombinant human thyrotropin.

Recombinant human thyroid-stimulating hormone (rhTSH), used to enhance diagnostic radioiodine whole body scanning and thyroglobulin testing, has dramatically altered the management of patients with thyroid cancer. Withdrawal from thyroid hormone suppression therapy and subsequent hypothyroidism is no longer the only safe and effective method for thyroid cancer surveillance. Currently, rhTSH is only approved for the monitoring of low-risk patients with well-differentiated thyroid cancer and radioactive iodine administration, in selected cases. Additional applications of rhTSH include enhancing the sensitivity of positron emission tomography in thyroid cancer, the management of multinodular goiter, and dynamic testing of thyroid reserve. The diagnostic and therapeutic role of rhTSH in these areas is discussed in this review.

Unresolved issues, dilemmas and points of interest in thyroid cancer: a current perspective.

Thyroid cancer (TC) is the commonest endocrine malignancy. In the overwhelming majority of cases, thyroid carcinomas are well-differentiated malignancies that respond favorably to treatment; however, this outcome cannot be absolutely guaranteed. The absence of large prospective randomized clinical trials in TC-due to its low incidence and protracted clinical course in cases with persistent/recurrent metastatic disease-results in considerable debates regarding the optimal treatment and follow-up regimens in this malignancy. Some of these debates originated several decades ago, yet are still ongoing despite interim advancements in other domains of oncology. Here we discuss what we believe are the issues of major controversy in TC; these are mentioned in the following non-exhaustive list: (i) the optimal management of solitary and multiple thyroid nodules; (ii) the role of basal calcitonin measurements in the diagnostic investigation of nodular thyroid disease; (iii) the extent of the initial operation after establishment of the diagnosis of TC; (iv) the intensity and frequency of radioactive iodine (RAI; (131)I) therapies (especially in patients with persistent/recurrent metastatic disease); (v) the degree and duration of long-term thyroid hormone suppression therapy (THST) required for optimal outcomes in TC patients; (vi) the optimal management of patients with RAI-refractory disease or other "high-risk" clinicopathologic features; and, finally, (vii) the optimal algorithm for lifelong follow-up of TC patients after their initial treatment. We present elements of the above controversies as pertinent to the various types of TC. We have opted for breadth rather than depth of commentary, at the same time providing the reader with extended up-to-date bibliography.

MR imaging features of thyrotropin-secreting pituitary adenomas at initial presentation.

OBJECTIVE: We report the MR imaging characteristics of thyrotropin-producing pituitary adenomas at their initial presentation and also report the role of MR imaging in predicting surgical outcome in these rare tumors. MATERIALS AND METHODS: We reviewed the records and MR images of 21 patients with thyrotropin-producing pituitary adenomas from 1984 to 1999. The imaging features of these tumors were examined, including enhancing characteristics and tumor volumes. A staging system of tumor invasion was designed by grading cavernous and sphenoid sinus invasion and suprasellar extension. A cumulative invasion score was then used as a predictor of short-term surgical outcome. RESULTS: Twenty patients had macroadenomas, and one patient had a microadenoma. In 17 of 21 patients, the thyrotropin-producing pituitary adenoma was clearly visualized as a hypoenhancing mass compressing the normal pituitary gland. Conversely, in four patients, the pituitary gland was not discernible because of complete distortion by the adenoma. Thyrotropin-producing pituitary adenomas were large and showed a tendency to invade surrounding structures. Tumor volume ranged from 0.42 to 94.2 cm(3) (mean +/- SD, 16.0 +/- 17.8 cm(3)). The mean score of tumor invasion was 4.77 +/- 2.06 of a maximal possible value of 9.0. A high staging score was found to be predictive of an unfavorable response to surgery. CONCLUSION: Thyrotropin-producing pituitary adenomas are usually large tumors at initial presentation with hypoenhancing features compared with normal pituitary tissue; they tend to be invasive. Greater amounts of invasion correlate with incomplete surgical removal of the tumor and continued hormonal secretion.

In-111 DTPA-octreotide scintigraphy for disease detection in metastatic thyroid cancer: comparison with F-18 FDG positron emission tomography and extensive conventional radiographic imaging.

PURPOSE: The utility of In-111 DTPA octreotide scintigraphy (SRS) for disease detection in patients with metastatic thyroid carcinoma (TCA) remains controversial. The authors compared the sensitivity of In-111-based SRS, F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET), and extensive conventional radiographic imaging (CRI) in this type of cancer. METHODS: SRS, FDG PET, and CRI were performed concurrently in 21 patients (age, 56.4 +/- 12.9 years) who had aggressive TCA. Concordance rates % of lesion positivity among pairs of different techniques (A and B) were calculated as the ratio of the number of lesions positive with both techniques divided by the sum of the total number of lesions positive with technique A + total number of lesions positive with technique B, which was then multiplied by 200. RESULTS: The combined use of CRI, FDG PET, and SRS resulted in the detection of 105 lesions, presumed to be due to metastatic deposits. Sensitivities for SRS and FDG-PET imaging were 49.5% and 67.6%, respectively. The lesion detection concordance rates were as follows: CRI versus FDG PET, 80.8%; CRI versus SRS, 74.2%; and FDG-PET versus SRS, 58.6%. Importantly, SRS detected five unexpected lesions, which were negative by both CRI and FDG-PET imaging. In two representative patients, a positive correlation (Spearman's rank = 0.71; = 0.0576) existed between the percentage of lesional In-111 DTPA octreotide uptake and the standard uptake value in eight concordant lesions. CONCLUSION: Although SRS has only moderate sensitivity for disease detection in metastatic TCA, sometimes it can reveal lesions that otherwise would be undetectable by either CRI or FDG-PET imaging.

Localization of medullary thyroid carcinoma metastasis in a multiple endocrine neoplasia type 2A patient by 6-[18F]-fluorodopamine positron emission tomography.

6-[(18)F]fluorodopamine, a substrate for the norepinephrine transporter, has been used as a tumor-seeking tracer in positron emission tomography (PET) to localize pheochromocytomas and other chromaffin tumors. Here, we report the case of a 42-yr-old woman with multiple endocrine neoplasia type 2A, in whom biopsy-proven recurrent medullary thyroid cancer (MTC) was detected by 6-[(18)F]fluorodopamine PET scanning. The patient had previously undergone bilateral adrenalectomy for pheochromocytoma, total thyroidectomy, and extirpation of a parapharyngeal MTC metastatic deposit. An increase in plasma calcitonin 5 yr after her initial presentation was further investigated, leading to the discovery of a mass in the left parapharyngeal space. Levels of serum and urine catecholamines and metanephrines were normal. To exclude a hormonally silent pheochromocytoma metastasis, 6-[(18)F]fluorodopamine PET was performed. The study showed a focus of radionuclide accumulation corresponding to the parapharyngeal mass. After resection of the latter, pathology confirmed metastatic MTC. To our knowledge, this is the first case of metastatic, histologically proven MTC, which was unequivocally detected by 6-[(18)F]fluorodopamine PET scanning. Because norepinephrine transporter systems have been previously found in MTC, it is conceivable that 6-[(18)F]fluorodopamine PET scanning can be used for the diagnostic localization of this tumor and its metastatic deposits because total and early resection is beneficial to the outcome of the patient.

Role of metastasectomy in the management of thyroid carcinoma: the NIH experience.

BACKGROUND AND OBJECTIVES: We studied the impact of metatasectomy on disease outcome in 29 advanced nonmedullary thyroid carcinoma (ThyrCa) patients who were operated on between 1969 and 2001 at NIH to further define its role in the management of this malignancy. METHODS: Data were extracted by retrospective chart review. A Kaplan-Meyer survival curve was constructed, and comparative stratification for various parameters was performed. RESULTS: During 47 surgeries, the following lesions were resected from mid-mediastinum/hila, 17; lung parenchyma, 12; skeleton, 14; kidneys, 2; and brain, 2. All patients received multiple radioiodine (RAI) treatments. External-beam radiotherapy, chemotherapy and other palliative measures were used in selected patients. Six patients (21%) died within 74.7 +/- 54.7 months after the first distant metastasectomy. The outcome of the remaining patients was as follows: complete remission, 3; partial remission, 10; and 10: progressive disease, 10, with a follow-up of 175 patient-years. Metastasectomy led to a decrease of 38% in thyroglobulin levels in 23 patients. Cumulative survival rates were 78.5 +/- 8.4% at 5 years and 50.2 +/- 12.5% at 10 years (mean +/-SEM) after initial distant metastasectomy. CONCLUSIONS: Our data show that extensive targeted metastasectomy in the setting of a tertiary center can be beneficial to patients with disseminated ThyrCa with persistent or recurrent distant disease, when used in conjunction with nonsurgical treatment modalities.

Successful outcome after surgical management in two cases of the "painful variant" of Hashimoto's thyroiditis.

OBJECTIVE: To describe two cases of the rare "painful variant" of Hashimoto's thyroiditis (HT) that were refractory to medical management and in which surgical intervention provided the definitive treatment. METHODS: We thoroughly review the clinical history as well as the laboratory, imaging, and surgical pathology data in these cases, and follow-up of the clinical response over time is provided. The relevant literature is also discussed. RESULTS: A 56-year-old woman, who had remotely undergone a left hemithyroidectomy and had been diagnosed with HT, sought further assessment because of neck pain and edema. Treatment with corticosteroids was partially successful but led to the development of Cushing's syndrome. A 32-year-old man had pain and swelling of the thyroid and was diagnosed with HT shortly thereafter. Levothyroxine treatment was unsuccessful. Both patients underwent thyroidectomy. Chronic lymphocytic thyroiditis (HT) with a variable degree of fibrosis was found on assessment of pathology specimens. The patients remained asymptomatic after the surgical procedure and did not require any further anti-inflammatory therapy. CONCLUSION: In selected cases, surgical treatment may become necessary for effective and permanent control of symptoms and local signs in painful HT. Access to experienced endocrine surgeons is important in order to avoid postoperative complications because the thyroid gland may be small or fibrosed in this rare variant of HT.

Juxtathyroidal neck soft tissue angiosarcoma presenting as an undifferentiated thyroid carcinoma.

Angiosarcoma is a malignant growth of endothelial origin, uncommon in the head and neck. We present the case of a 38-year-old woman with long-standing goiter who presented with a rapidly growing 6.0-cm neck mass. Fine-needle aspiration biopsy of the tumor showed features of "undifferentiated thyroid carcinoma (ThyrCa)." Total thyroidectomy resulted in extirpation of all gross disease. Pathology revealed a high-grade angiosarcoma of the neck invading the thyroid gland, coexisting with papillary ThyrCa (follicular variant) in the contralateral lobe. Aggressive external electron beam radiotherapy was initiated for local control. Despite the absence of systemic dissemination initially, bulky neck recurrences, and pulmonary metastases developed rapidly, leading to the patient's demise on postoperative day 41. Autopsy showed metastatic disease involving most organs. This case illustrates that neck angiosarcomas need to be considered in the differential diagnosis of "poorly differentiated" thyroid malignancies. These soft tissue neck tumors may complicate postoperative management due to their bleeding tendency and aggressive infiltrative behavior, and carry a dismal prognosis because of the rapidity of development of local recurrence and distant metastases.

Lack of association between Hashimoto thyroiditis and breast cancer: a quantitative research synthesis.

Several authors have suggested a positive association between Hashimoto thyroiditis (HT) and breast cancer (BrCa). Others have refuted these findings; hence, this subject remains controversial. We therefore reviewed the world literature on this subject accumulated over the last 50 years and performed a quantitative research synthesis, a meta-analysis variant. The incidence risk ratios and 95% confidence intervals (CI's) were calculated for each study and the combined relative risk (RR) was estimated. We found 37 relevant studies, of which only 13 were accessible to analysis. A significant association (RR=1.40; CI=1.29-1.53, P<0.022) was found for 6 of the 13 studies pertaining to 1,431 women. However, in the cumulative population of 14,226 women (from all 13 studies), we failed to demonstrate an association between the diagnoses of HT and BrCa (RR=1.07; CI=0.99-1.15; P=0.08). In conclusion, we believe that selection bias or institutional referral bias, in at least some of the "positive" studies, may have led to the spurious recognition of an association between HT and BrCa, especially as both of these conditions are highly prevalent in women between the 4th and 7th decade of life.

Effects of thyroid hormone suppression therapy on adverse clinical outcomes in thyroid cancer.

BACKGROUND: Long-term thyroid hormone (TH) therapy aiming at the suppression of serum thyrotropin (TSH) has been traditionally used in the management of well differentiated thyroid cancer (ThyrCa). However, formal validation of the effects of thyroid hormone suppression therapy (THST) through randomized controlled trials is lacking. Additionally, the role - if any - of TSH effect at low ambient concentrations upon human thyroid tumorigenesis remains unclear. AIM: Evaluation of the effect of THST on the clinical outcomes of papillary and/or follicular ThyrCa. METHODS: By using a quantitative research synthesis approach in a cumulative ThyrCa cohort, we evaluated the effect of THST on the likelihood of major adverse clinical events (disease progression/recurrence and death). A total of 28 clinical trials published during the period 1934-2001 were identified; only 10 were amenable to meta-analysis. Causality was assessed by Hill criteria. RESULTS: Out of 4, 174 patients with ThyrCa, 2, 880 (69%) were reported as being on THST. Meta-analysis showed that the group of patients who received THST had a decreased risk of major adverse clinical events (RR = 0.73; Cl = 0.60-0.88; P < 0.05). Further, by applying a Likert scale, 15/17 interpretable studies showed either a 'likely' or 'questionable' beneficial effect of THST. Assessment of causality between TSHT and reduction of major adverse clinical events suggested a probable association. CONCLUSIONS: THST appears justified in ThyrCa patients following initial therapy. As most primary studies were imperfect, future research will better define the effect of THST upon ThyrCa clinical outcomes.