Carlos D. Flombaum

Phase I Trial of Bevacizumab Plus Escalated Doses of Sunitinib in Patients With Metastatic Renal Cell Carcinoma

PURPOSEnBoth bevacizumab and sunitinib target the vascular endothelial growth factor pathway and demonstrate activity against advanced renal cell carcinoma (RCC). In this phase I study, the maximum-tolerated dose (MTD) and safety of sunitinib in combination with bevacizumab were examined in patients with advanced RCC.nnnPATIENTS AND METHODSnThree cohorts of three to six patients were treated with escalated doses of daily oral sunitinib (ie, 25 mg, 37.5 mg, 50 mg) for 4 weeks followed by a 2-week break and with fixed doses of bevacizumab (10 mg/kg) intravenously once every 2 weeks. Dose-limiting toxicities (DLTs) were assessed during the first cycle to determine the MTD, and an expanded cohort was treated to obtain additional safety information.nnnRESULTSnOf 26 study participants, 25 received treatment at one of three dose levels. Grade 4 hemorrhage, identified as a DLT, occurred in one patient in each of cohorts 2 and 3. The MTD was determined to be sunitinib 50 mg/bevacizumab 10 mg/kg, but chronic therapy at this dose level frequently resulted in grades 3 to 4 hypertension and hematologic and vascular toxicities. Overall, 48% of patients discontinued treatment because of adverse events. One complete and 12 partial responses were observed, which provided an objective response rate of 52%.nnnCONCLUSIONnIn this phase I trial of patients with metastatic RCC, the combination of sunitinib and bevacizumab caused a high degree of hypertension and vascular and hematologic toxicities at the highest dose level. We do not plan to pursue additional study of this regimen at these doses in patients with RCC.

Sequential Dose-Intensive Paclitaxel, Ifosfamide, Carboplatin, and Etoposide Salvage Therapy for Germ Cell Tumor Patients

PURPOSEnTo evaluate the efficacy and toxicity of sequential, dose-intensified chemotherapy with paclitaxel/ifosfamide and carboplatin/etoposide administered plus peripheral blood-derived stem-cell (PBSC) support for patients with germ cell tumors (GCT) who have unfavorable prognostic features in response to conventional-dose salvage programs. Carboplatin was dose escalated by target area under the curve (AUC; in [milligrams per milliliter] x minutes) among patient cohorts, and pharmacokinetic studies were performed for comparison.nnnPATIENTS AND METHODSnThirty-seven previously treated patients who had cisplatin-resistant GCT and unfavorable prognostic features for response to conventional-dose salvage therapy were treated. Two cycles of paclitaxel 200 mg/m(2) plus ifosfamide 6 g/m(2) were given 2 weeks apart with leukapheresis, followed by three cycles of carboplatin plus etoposide given 14 to 21 days apart with reinfusion of PBSCs. The dose of etoposide was 1, 200 mg/m(2), and the carboplatin target AUC ranged among cohorts from 12 to 32 (mg/mL) x min. Pharmacokinetic studies of carboplatin were performed for comparison of target to measured AUC.nnnRESULTSnTwenty-one patients (57%) achieved a complete response and an additional two patients (5%) achieved a partial response with normal tumor markers; therefore, 23 (62%) achieved a favorable response. Eight patients relapsed, and 15 (41%) of the favorable responses remained durable at a median follow-up of 30 months. Myelosuppression was the major toxicity; 58% of carboplatin/etoposide cycles were associated with hospitalization for nadir fever. The AUC of carboplatin measured in serum was lower than the target AUC; this may be related to underestimation of the glomerular filtration rate used in the dosing formula.nnnCONCLUSIONnDose-intense therapy with sequential, accelerated chemotherapy of paclitaxel/ifosfamide and carboplatin/etoposide administered with PBSC support was relatively well tolerated. The durable complete response proportion was substantial in patients with unfavorable prognostic features for achieving durable complete response to conventional-dose salvage programs. Optimal dosing of carboplatin in the high-dose setting warrants further investigation.

High-Dose Leucovorin as Sole Therapy for Methotrexate Toxicity

PURPOSEnHemodialysis, hemoperfusion, thymidine, and carboxypeptidase have been recommended together with high-dose (HD) leucovorin (LV) to treat patients at risk for methotrexate (MTX) toxicity. To elucidate the efficacy of high LV rescue as the sole salvage modality for severe MTX intoxication, we studied 13 patients who were treated in this fashion at Memorial Sloan-Kettering Cancer Center (New York, NY).nnnPATIENTS AND METHODSnTo identify patients at high risk for severe MTX toxicity, we performed a retrospective review of all patients with MTX levels greater than 100 micromol/L at 24 hours and greater than 10 micromol/L at 48 hours after HD MTX.nnnRESULTSnA total of 13 patients were identified. The median MTX concentration was 164 micromol/L at 24 hours (range, 102 to 940 micromol/L), 16.3 micromol/L at 48 hours (range, 10.5 to 190 micromol/L), and 6.2 micromol/L at 72 hours (range, 1.35 to 39 micromol/L). MTX levels remained greater than 0.1 micromol/L for an average of 11 +/- 3 days (mean +/- SD) (range, 7 to 17 days). In addition to supportive treatment with hydration and sodium bicarbonate administration, all patients were treated solely with HD LV, which was started within the first 24 hours in nine patients, 48 hours in three patients, and 72 hours in one patient in doses that varied from 0.24 to 8 g/d. Significant neutropenia (neutrophil count < 1,000/ microL) occurred in eight patients and lasted for 1 to 5 days. Thrombocytopenia (platelet count < 100,000/microL) occurred in seven patients and lasted for 5 to 10 days. Other toxic manifestations included mucositis of varying degrees, diarrhea, and neutropenic fever, but all patients recovered.nnnCONCLUSIONnIn the range of MTX levels observed, HD LV can be used as a sole therapy for MTX toxicity without the need for extracorporeal removal and with tolerable morbidity.

Feasibility Trial of Letrozole in Combination With Bevacizumab in Patients With Metastatic Breast Cancer

PURPOSEnPreclinical models suggest that the use of anti-vascular endothelial growth factor (anti-VEGF) therapy with antiestrogens may prevent or delay the development of endocrine therapy resistance. We therefore performed a feasibility study to evaluate the safety of letrozole plus bevacizumab in patients with hormone receptor-positive metastatic breast cancer (MBC).nnnMETHODSnPatients with locally advanced breast cancer or MBC were treated with the aromatase inhibitor (AI) letrozole (2.5 mg orally daily) and the anti-VEGF antibody bevacizumab (15 mg/kg intravenously every 3 weeks). The primary end point was safety, defined by grade 4 toxicity using the National Cancer Institute Common Toxicity Criteria, version 3.0. Secondary end points included response rate, clinical benefit rate, and progression-free survival (PFS). Prior nonsteroidal AIs (NSAIs) were permitted in the absence of progressive disease.nnnRESULTSnForty-three patients were treated. After a median of 13 cycles (range, 1 to 71 cycles), select treatment-related toxicities included hypertension (58%; grades 2 and 3 in 19% and 26%), proteinuria (67%; grades 2 and 3 in 14% and 19%), headache (51%; grades 2 and 3 in 16% and 7%), fatigue (74%; grades 2 and 3 in 19% and 2%), and joint pain (63%; grades 2 and 3 in 19% and 0%). Eighty-four percent of patients had at least stable disease on an NSAI, confounding efficacy results. Partial responses were seen in 9% of patients and stable disease >or= 24 weeks was noted in 67%. Median PFS was 17.1 months.nnnCONCLUSIONnCombination letrozole and bevacizumab was feasible with expected bevacizumab-related events of hypertension, headache, and proteinuria. Phase III proof-of-efficacy trials of endocrine therapy plus bevacizumab are in progress (Cancer and Leukemia Group B 40503).

Nephrotoxicities Associated with the Use of Tyrosine Kinase Inhibitors: A Single-Center Experience and Review of the Literature

Background: Sunitinib is an oral multitargeted tyrosine kinase receptor inhibitor (MTKI) used for the treatment of renal cell carcinoma. These small-molecule agents inhibit signaling through receptor tyrosine kinases such as vascular endothelial growth factor receptor, platelet-derived growth factor receptor and cytokine stem cell factor receptor, among others. Although the development of these novel molecular-targeted agents represents a substantial advance in the treatment of metastatic cancer, the spectrum of their adverse effects may be broader than initially predicted. Method: We performed a retrospective chart review of patients who had received sunitinib and developed renal insufficiency. Results: We describe 4 patients with renal cell carcinoma and 1 patient with transitional cell carcinoma treated with sunitinib who experienced various degrees of nephrotoxicity including hypertension, proteinuria, thrombotic microangiopathy, and acute and chronic kidney injury which resolved upon cessation of MTKI. Conclusions: Nephrologists and oncologists should be aware of the potential for toxic renal effects, and we recommend guidelines for early recognition and treatment of these conditions in patients receiving MTKI.

High‐dose calcitriol, zoledronate, and dexamethasone for the treatment of progressive prostate carcinoma

Preclinical and clinical data have suggested that high‐dose calcitriol (1,25‐dihydroxycholecalciferol) has activity against prostate carcinoma. Pulse‐dosed calcitriol and dexamethasone may maximize tolerability and efficacy. The authors examined the toxicity of pulse‐dosed calcitriol with zoledronate and with the addition of dexamethasone at the time of disease progression.

Carboplatin-based chemotherapy with pharmacokinetic analysis for patients with hemodialysis-dependent renal insufficiency

SummaryThree patients with renal insufficiency requiring hemodialysis were treated with carboplatin at 100 mg/m2 in combination with etoposide for advanced germ-cell tumor (GCT, two cases) or Adriamycin + vinblastine for a transitional-cell carcinoma of the ureter (one case). Hemodialysis was performed 24 h after the administration of carboplatin. Both patients with GCT achieved a complete response, and the patient with transitional-cell carcinoma of the ureter was inevaluable for response but his disease has not progressed. The dose of carboplatin was increased in one patient as renal function improved on therapy. In two patients, the pharmacokinetics of carboplatin were determined; the pre-dialysis half-lives, AUC, and total body clearances of free carboplatin-derived platinum were estimated to be 32 and 18.3 h, 4.93 and 6.17 mg ml−1 min, and 18.2 and 18.7 ml/min, respectively. The dialysis elimination half-lives (t1/2β) of 2 and 3 h, respectively, for these two patients were markedly lower than the predialysis values, indicating that carboplatin was dialyzed. In summary, carboplatin can be given to patients with severe renal insufficiency. Adequate AUCs were achieved and dialysis limited systemic exposure to free carboplatin.

Long–Term Renal Outcomes after Cisplatin Treatment

BACKGROUND AND OBJECTIVESnNephrotoxicity remains the dose-limiting side effect of cisplatin, an effective chemotherapeutic agent with applications across diverse tumor types. This study presents data on renal outcomes across multiple tumor types in 821 adults. We report on incidence of AKI, initial and long-term changes in eGFR after cisplatin, and relationships between cumulative dose, initial eGFR, age, sex, and long-term renal function.nnnDESIGN, SETTING, PARTICIPANTS, & MEASUREMENTSnThis was a retrospective study of adult patients treated with cisplatin from January 1, 2000 to September 21, 2011 who had survived ≥5 years after initial dose. The Modification of Diet in Renal Disease equation was used to calculate eGFR. AKI was defined as an increase from the baseline creatinine of >25% within 30 days after the first cycle of cisplatin. Chi-squared tests were done to evaluate the relationships between categorical or ordinal variables; ANOVAs or t tests were used to evaluate continuous or categorical variables. Changes in eGFR over time were evaluated in a growth curve model.nnnRESULTSnMean follow-up was 6 years (25th and 75th percentiles, 4 and 9 years). AKI occurred in 31.5% of patients, with a median initial decline in eGFR of 10 ml/min per 1.73 m(2) (25th and 75th percentiles, -41.5 and -23.3 ml/min per 1.73 m(2)). At any time point after the first cycle of cisplatin, <3% of patients progressed to eGFR<29 ml/min per 1.73 m(2), and none were known to be on dialysis. Age was associated with a higher risk for AKI after cisplatin. Compared with age <25 years old, the odds ratios for AKI versus no AKI are 1.22 for >26-44 years old (95% confidence interval [95% CI], 0.60 to 2.4), 1.54 for >45-65 years old (95% CI, 0.78 to 3), and 2.96 for >66 years old (95% CI, 1.4 to 6.1). The lowest dose categories of cisplatin (≤100 and 101-250 mg/m(2)) are associated with increases in eGFR (P=0.06 and P=0.02, respectively) compared with the highest dose category (>701 mg/m(2)).nnnCONCLUSIONSnThis is the largest study of adult patients with cancer who received cisplatin for treatment across multiple tumor types. Most patients experience small but permanent declines in eGFR, but none progressed to ESRD requiring hemodialysis.

High-Dose Methotrexate-Induced Renal Dysfunction: Is Glucarpidase Necessary for Rescue?

TO THEEDITOR: Widemann et al 1 report the use of glucarpidase, leucovorin, and thymidine for high-dose methotrexate-induced renal dysfunction. When patients develop delayed excretion of methotrexate and impaired renal function after the administration of high-dose methotrexate there are two equally important imperatives. First, we must protect the patients from the potential toxicity of prolonged exposure to the antifolate drug methotrexate. Potential toxicities include myelosuppression, mucositis, and hepatoxicity, and can be lethal. The second imperative is to have the patient’s renal function return to normal to allow continuation of the chemotherapy needed to treat the underlying malignancy. The authors performed an analysis to determine which factors predicted greater than or equal to grade 4 toxicity. They noted that inappropriate increase in leucovorin predicted perfectly for development of greater than or equal to grade 4 toxicity and therefore could not be included in their multiple factor logistic regression analysis. We have reported our experience treating patients who have delayed methotrexate excretion and renal failure after high-dose methotrexate administration using high-dose leucovorin as the sole form of rescue. 2 All patients in our experience were salvaged. None of our patients died. The authors report that the median time to recovery of renal function for their cohort was 22 days. Our experience, albeit considerably smaller, achieved at least as good a time to recovery of normal renal function. One possible interpretation of the results that the authors report is that glucarpidase was not an essential component of rescue for patients experiencing high-dose methotrexate-related renal dysfunction and that similar results could have been achieved with the use of high-doses of leucovorin alone. Glucarpidase is unquestionably an excellent way to lower the plasma methotrexate concentration. This effect, however, has no impact on intracellular concentrations of methotrexate or on renal function. Protection of cells from intracellular methotrexate still requires the administration of high-doses of leucovorin and renal recovery appears to take place independently of glucarpidase administration. The authors’ conclusion that early intervention with the combination of leucovorin and glucarpidase is highly effective in patients who develop high-dose methotrexate-related renal dysfunction may be true but the authors should consider the possibility that similar results could be achieved with leucovorin alone.

Ifosfamide may be safely used in patients with end stage renal disease on hemodialysis.

Background. Pharmacokinetic data on clearance of ifosfamide in hemodialysis patients are limited. Consequently, these patients are excluded from therapy with this agent. We review the outcomes for patients at our institution with end stage renal disease on dialysis who received ifosfamide for metastatic sarcoma. Patients and Methods. We treated three patients with end stage renal disease on hemodialysis with escalating doses of ifosfamide. Data on radiographic response to therapy, WBC and platelet counts, signs or symptoms of infection, neuropathy and bladder toxicity are reported. Starting doses of ifosfamide were based on review of the literature available with subsequent modifications based on each patients prior exposure to myelosuppressive agents and on symptoms of neurotoxicity and the degree of myelosuppression following each cycle of chemotherapy. Results. Myelosuppression was the most common side effect from therapy, but no patient developed a life threatening infection, neurotoxicity, or hematuria. One patient developed epistaxis in the setting of thrombocytopenia while on warfarin therapy. All patients had clinical evidence for therapeutic response and two had documented radiographic improvement following ifosfamide administration. Conclusion. Ifosfamide can be used safely in combination with hemodialysis in patients with end stage renal disease.