Jeffrey Sivik

Effect of the Tyrosine Kinase Inhibitors (sunitinib, sorafenib, dasatinib, and imatinib) on Blood Glucose Levels in Diabetic and Nondiabetic Patients in General Clinical Practice

Tyrosine kinase is a key enzyme activity utilized in many intracellular messaging pathways. Understanding the role of particular tyrosine kinases in malignancies has allowed for the design of tyrosine kinase inhibitors (TKIs), which can target these enzymes and interfere with downstream signaling. TKIs have proven to be successful in the treatment of chronic myeloid leukemia, renal cell carcinoma and gastrointestinal stromal tumor, and other malignancies. Scattered reports have suggested that these agents appear to affect blood glucose (BG). We retrospectively studied the BG concentrations in diabetic (17) and nondiabetic (61) patients treated with dasatinib (8), imatinib (39), sorafenib (23), and sunitinib (30) in our clinical practice. Mean declines of BG were dasatinib (53 mg/dL), imatinib (9 mg/dL), sorafenib (12 mg/dL), and sunitinib (14 mg/dL). All these declines in BG were statistically significant. Of note, 47% (8/17) of the patients with diabetes were able to discontinue their medications, including insulin in some patients. Only one diabetic patient developed symptomatic hypoglycemia while on sunitinib. The mechanism for the hypoglycemic effect of these drugs is unclear, but of the four agents tested, c-kit and PDGFRβ are the common target kinases. Clinicians should keep the potential hypoglycemic effects of these agents in mind; modification of hypoglycemic agents may be required in diabetic patients. These results also suggest that inhibition of a tyrosine kinase, be it c-kit, PDGFRβ or some other undefined target, may improve diabetes mellitus BG control and it deserves further study as a potential novel therapeutic option.

Breakthrough invasive fungal infection in an immunocompromised host while on posaconazole prophylaxis: an omission in patient counseling and follow-up

Posaconazole (Noxafil ® Schering-Plough Corporation) is a triazole antifungal approved in the United States for the treatment of oropharyngeal candidiasis and for the prophylaxis of Candida and Aspergillus infections in the immunocompromised host. Posaconazole is available only as an oral suspension. When used for the prevention of Candida and Aspergillus infections, posaconazole should be taken three times daily with a high fat meal to maximize oral absorption. Failure to take posaconazole with food will lead to subtherapeutic serum levels and decreased clinical effectiveness of the drug. We report the case of a 49-year-old woman with acute myeloid leukemia who received 4 months of posaconazole as an outpatient for the labeled indication of prophylaxis of Candida and Aspergillus infections. During her last admission, the patient presented with an invasive sinus infection diagnosed as a mixed Aspergillus and Mucor etiology. The patient succumbed to this infection five weeks after presentation. Upon investigation it was found that the patient did not self-administer posaconazole as required in the product labeling, which may have led to drug failure in this patient. We submit this case to illustrate the importance of patient education regarding proper administration of posaconazole. The important role of the outpatient physician, nurse, and pharmacist in this setting is underscored. J Oncol Pharm Practice (2008) 14: 189—193.

Durable complete responses off all treatment in patients with metastatic malignant melanoma after sequential immunotherapy followed by a finite course of BRAF inhibitor therapy

We report 3 cases of durable complete response (CR) in patients with BRAF-mutated metastatic melanoma who were initially treated unsuccessfully with sequential immunotherapies (high dose interleukin 2 followed by ipilimumab with or without concurrent radiation therapy). After progression during or post immunotherapy, these patients were given BRAF inhibitor therapy and developed rapid CRs. Based on the concomitant presence of autoimmune manifestations (including vitiligo and hypophysitis), we postulated that there was a synergistic effect between the prior immune therapy and the BRAF targeting agents. Accordingly, the inhibitors were gradually weaned off beginning at 3 months and were stopped completely at 9–12 months. The three patients remain well and in CR off of all therapy at up to 15 months radiographic follow-up. The institution of the BRAF therapy was associated with development of severe rheumatoid-like arthritis in 2 patients which persisted for months after discontinuation of therapy, suggesting it was not merely a known toxicity of BRAF inhibitors (arthralgias). On immunologic analysis, these patients had high levels of non-T-regulatory, CD4 positive effector phenotype T-cells, which persisted after completion of therapy. Of note, we had previously reported a similar phenomenon in patients with metastatic melanoma who failed high dose interleukin-2 and were then placed on a finite course of temozolomide with rapid complete responses that have remained durable for many years after discontinuation of temozolomide. We postulate that a finite course of cytotoxic or targeted therapy specific for melanoma given after apparent failure of prior immunotherapy can result in complete and durable remissions that may persist long after the specific cytotoxic or targeted agents have been discontinued suggesting the existence of sequence specific synergism between immunotherapy and these agents. Here, we discuss these cases in the context of the literature on synergy between conventional or targeted cytotoxic therapy and immunotherapy in cancer treatment.

BU and CY as conditioning regimen for autologous transplant in patients with multiple myeloma

High-dose melphalan is considered the current standard of care among the preparative regimens used in peripheral blood autologous SCT (ASCT) for multiple myeloma (MM). We report the results of a single ASCT in 79 MM patients using the BU/CY conditioning regimen, with BU 1 mg/kg p.o. or 0.8 mg/kg i.v. every 6 h × 16 doses, and CY 60 mg/kg per day i.v. for 2 days. ASCT was carried out in first (62%) or subsequent remission/refractory disease (38%). For an overall RR of 86%, 48 and 20 patients achieved PR and CR, respectively. At a median follow-up of 41 months (range 2–132 months), the estimated median OS and PFS were 45 months (95% confidence interval (CI)=38–92) and 20 months (95% CI=15–25), respectively. The BU/CY regimen was well tolerated, and transplant-related mortality was 4%. Clinical outcomes of the BU/CY regimen are not superior to those obtained in historical controls with high-dose melphalan followed by a single ASCT. Therefore, considering even the greater complexity of administration of the BU/CY regimen compared with that of single-agent melphalan, we believe the latter should remain the conditioning regimen of choice for ASCT in MM.

Central neurotoxicity of immunomodulatory drugs in multiple myeloma

Immunomodulatory drugs (IMiDs) currently used in the treatment of multiple myeloma, are thalidomide, lenalidomide and pomalidomide. One of the most common side effects of thalidomide is neurotoxicity, predominantly in the form of peripheral neuropathy. We report 6 cases of significant central neurotoxicity associated with IMiD therapy. Treatment with thalidomide (1 patient), lenalidomide (4 patients), and pomalidomide (1 patient) was associated with various clinical manifestations of central neurotoxicity, including reversible coma, amnesia, expressive aphasia, and dysarthria. Central neurotoxicity should be recognized as an important side effect of IMiD therapy.

Bortezomib-induced acute pancreatitis: Case report and review of the literature

Acute pancreatitis is a rare complication of chemotherapy agents. We describe the case of a patient with multiple myeloma who developed acute pancreatitis after treatment with bortezomib, a proteasome inhibitor commonly used in the treatment of this disease. We reviewed the available medical literature on this topic, and found other seven similar cases, all after intravenous bortezomib. Our case is the first one occurring with the subcutaneous route of administration.

A Novel Adverse Event Associated with Olaparib Therapy in a Patient with Metastatic Breast Cancer

Olaparib was first FDA approved for use in women with advanced ovarian cancer and germline BRCA mutations. Based on the results of subsequent research, the use of this drug has been expanded to patients with metastatic breast cancer with germline BRCA mutation. With the use of a relatively new medication and a larger patient population eligible for therapy, monitoring for novel adverse events associated with therapy is important. This case represents a patient with metastatic breast cancer and germline BRCA2 mutation who developed erythema nodosum after initiation of therapy with olaparib capsules. Her characteristic rash appeared shortly after starting olaparib and recurred after restarting olaparib an additional two times. She was treated with short courses of prednisone therapy with or without holding olaparib with resolution of her rash. The patient was later restarted on olaparib capsules 200 mg twice daily, and she more recently has been maintained on olaparib tablets 300 mg twice daily. On both regimens, the patient experienced only attenuated episodes of erythema nodosum that have not required cessation of therapy or steroid therapy.

Characteristics of pulmonary complications in non-Hodgkin’s lymphoma patients treated with rituximab-containing chemotherapy and impact on survival

Patients with non-Hodgkin’s lymphoma (NHL) receiving rituximab-containing chemotherapy are at risk of developing respiratory complications, but comprehensive information on these complications and their impact on survival is lacking. We performed a retrospective cohort analysis on 123 NHL patients who received rituximab-containing chemotherapy between 2009 and 2016 in order to describe the incidence, etiologies and effect on survival of respiratory complications defined by new or worsening respiratory symptoms requiring diagnostic work-up or hospitalization. Thirty patients (24%) developed respiratory complications during a follow-up time of 825 (555–1338) days after chemotherapy. They had a higher prevalence of congestive heart failure and lung or pleural involvement at diagnosis as compared to patients who did not develop complications. Overall, 58 episodes of pulmonary complications were observed after median (interquartile) times from the first and last rituximab doses of 205 (75–580) days and 27 (14–163) days respectively. Infectious etiologies accounted for 75% of the respiratory complications, followed by heart failure exacerbation, lymphomatous involvement, and ARDS. Two Pneumocystis jirovecii pneumonias were observed, and no complication was ascribed to rituximab toxicity. Respiratory complications required ICU admission in 19 cases (33%) and invasive mechanical ventilation in 14 cases (24%). Using a time-dependent Cox regression analysis, we observed that the occurrence of respiratory complications was associated with a 170% increase in death hazard (hazard ratio 2.65, 95% CI 1.60–4.40, p = 0.001). In conclusion, respiratory complications in NHL patients receiving chemotherapy are relatively frequent, severe, and mostly infectious and are associated with increased mortality.