Howard Gurney

Nivolumab versus Everolimus in Advanced Renal-Cell Carcinoma

BACKGROUND Nivolumab, a programmed death 1 (PD-1) checkpoint inhibitor, was associated with encouraging overall survival in uncontrolled studies involving previously treated patients with advanced renal-cell carcinoma. This randomized, open-label, phase 3 study compared nivolumab with everolimus in patients with renal-cell carcinoma who had received previous treatment. METHODS A total of 821 patients with advanced clear-cell renal-cell carcinoma for which they had received previous treatment with one or two regimens of antiangiogenic therapy were randomly assigned (in a 1:1 ratio) to receive 3 mg of nivolumab per kilogram of body weight intravenously every 2 weeks or a 10-mg everolimus tablet orally once daily. The primary end point was overall survival. The secondary end points included the objective response rate and safety. RESULTS The median overall survival was 25.0 months (95% confidence interval [CI], 21.8 to not estimable) with nivolumab and 19.6 months (95% CI, 17.6 to 23.1) with everolimus. The hazard ratio for death with nivolumab versus everolimus was 0.73 (98.5% CI, 0.57 to 0.93; P=0.002), which met the prespecified criterion for superiority (P≤0.0148). The objective response rate was greater with nivolumab than with everolimus (25% vs. 5%; odds ratio, 5.98 [95% CI, 3.68 to 9.72]; P<0.001). The median progression-free survival was 4.6 months (95% CI, 3.7 to 5.4) with nivolumab and 4.4 months (95% CI, 3.7 to 5.5) with everolimus (hazard ratio, 0.88; 95% CI, 0.75 to 1.03; P=0.11). Grade 3 or 4 treatment-related adverse events occurred in 19% of the patients receiving nivolumab and in 37% of the patients receiving everolimus; the most common event with nivolumab was fatigue (in 2% of the patients), and the most common event with everolimus was anemia (in 8%). CONCLUSIONS Among patients with previously treated advanced renal-cell carcinoma, overall survival was longer and fewer grade 3 or 4 adverse events occurred with nivolumab than with everolimus. (Funded by Bristol-Myers Squibb; CheckMate 025 ClinicalTrials.gov number, NCT01668784.).

Pembrolizumab as Second-Line Therapy for Advanced Urothelial Carcinoma

Background Patients with advanced urothelial carcinoma that progresses after platinum‐based chemotherapy have a poor prognosis and limited treatment options. Methods In this open‐label, international, phase 3 trial, we randomly assigned 542 patients with advanced urothelial cancer that recurred or progressed after platinum‐based chemotherapy to receive pembrolizumab (a highly selective, humanized monoclonal IgG4κ isotype antibody against programmed death 1 [PD‐1]) at a dose of 200 mg every 3 weeks or the investigators choice of chemotherapy with paclitaxel, docetaxel, or vinflunine. The coprimary end points were overall survival and progression‐free survival, which were assessed among all patients and among patients who had a tumor PD‐1 ligand (PD‐L1) combined positive score (the percentage of PD‐L1–expressing tumor and infiltrating immune cells relative to the total number of tumor cells) of 10% or more. Results The median overall survival in the total population was 10.3 months (95% confidence interval [CI], 8.0 to 11.8) in the pembrolizumab group, as compared with 7.4 months (95% CI, 6.1 to 8.3) in the chemotherapy group (hazard ratio for death, 0.73; 95% CI, 0.59 to 0.91; P=0.002). The median overall survival among patients who had a tumor PD‐L1 combined positive score of 10% or more was 8.0 months (95% CI, 5.0 to 12.3) in the pembrolizumab group, as compared with 5.2 months (95% CI, 4.0 to 7.4) in the chemotherapy group (hazard ratio, 0.57; 95% CI, 0.37 to 0.88; P=0.005). There was no significant between‐group difference in the duration of progression‐free survival in the total population (hazard ratio for death or disease progression, 0.98; 95% CI, 0.81 to 1.19; P=0.42) or among patients who had a tumor PD‐L1 combined positive score of 10% or more (hazard ratio, 0.89; 95% CI, 0.61 to 1.28; P=0.24). Fewer treatment‐related adverse events of any grade were reported in the pembrolizumab group than in the chemotherapy group (60.9% vs. 90.2%); there were also fewer events of grade 3, 4, or 5 severity reported in the pembrolizumab group than in the chemotherapy group (15.0% vs. 49.4%). Conclusions Pembrolizumab was associated with significantly longer overall survival (by approximately 3 months) and with a lower rate of treatment‐related adverse events than chemotherapy as second‐line therapy for platinum‐refractory advanced urothelial carcinoma. (Funded by Merck; KEYNOTE‐045 ClinicalTrials.gov number, NCT02256436.)

Dose calculation of anticancer drugs: a review of the current practice and introduction of an alternative.

PURPOSE To review the current dose-calculation practice and propose a non-body-surface area (BSA)-based dose-calculation method. METHODS Data that supported the introduction of BSA-based dose calculation in the late 1950s were reviewed. Data on 18 drugs that correlated pharmacokinetic (PK) variables for cytotoxic drugs with BSA were examined. Other methods of dose calculation, such as therapeutic drug monitoring (TDM) and adaptive control, were also examined. RESULTS The BSA-based method of dose calculation was adopted without adequate investigation of its accuracy. BSA fails to standardize the marked interpatient variation in PK for most cytotoxic drugs. A definite correlation was found between PK variables and BSA for only one drug (docetaxel). PK parameters correlate with toxicity, as well as response in some tumors, but do not completely explain the variation in drug effect between individuals. The complexities of TDM may make its universal use impractical. A non-BSA-based dose calculation method is proposed that defines three mandatory steps: prime dose, modified dose, and toxicity-adjusted dose (PMT dosing). Prime dose is the fixed dose of a drug used alone or in combination and is derived from the reanalysis of phase I/II studies and from clinical practice. Modified dose is an adjustment of the prime dose before administration, based on dose-adjustment guidelines that predict the drug-handling ability of an individual. Population pharmacodynamic studies may be used for the development of these guidelines. Subsequent doses are adjusted in each patient according to a target toxicity, such as nadir neutrophil count or other objective toxicity, that serves as a surrogate marker for potential antitumor effect (toxicity-adjusted dose). Patients who are predicted to have very abnormal drug handling should be excluded from such a dosing scheme and TDM may be more suitable. CONCLUSION The routine use of BSA for dose calculation should be reevaluated. Other methods of dose calculation should be investigated. TDM may be impractical in all patients and remains unvalidated. PMT dosing ensures that the condition of each individual is considered, to predict drug effects better. Clinical dose-calculation systems such as PMT dosing should be evaluated prospectively.

Initial Paclitaxel Improves Outcome Compared With CMFP Combination Chemotherapy as Front-Line Therapy in Untreated Metastatic Breast Cancer

PURPOSE To determine the place of single-agent paclitaxel compared with nonanthracycline combination chemotherapy as front-line therapy in metastatic breast cancer. PATIENTS AND METHODS Patients with previously untreated metastatic breast cancer were randomized to receive either paclitaxel 200 mg/m(2) intravenously (IV) over 3 hours for eight cycles (24 weeks) or standard cyclophosphamide 100 mg/m(2)/d orally on days 1 to 14, methotrexate 40 mg/m(2) IV on days 1 and 8, fluorouracil 600 mg/m(2) IV on days 1 and 8, and prednisone 40 mg/m(2)/d orally on days 1 to 14 (CMFP) for six cycles (24 weeks) with epirubicin recommended as second-line therapy. RESULTS A total of 209 eligible patients were randomized with a median survival duration of 17.3 months for paclitaxel and 13.9 months for CMFP. Multivariate analysis showed that patients who received paclitaxel survived significantly longer than those who received CMFP (P =.025). Paclitaxel produced significantly less severe leukopenia, thrombocytopenia, mucositis, documented infections (all P <.001), nausea or vomiting (P =.003), and fever without documented infection (P =.007), and less hospitalization for febrile neutropenia than did CMFP (P =.001). Alopecia, peripheral neuropathy, and myalgia or arthralgia were more severe with paclitaxel (all P <.0001). Overall, quality of life was similar for both treatments (P > = .07). CONCLUSION Initial paclitaxel was associated with significantly less myelosuppression and fewer infections, with longer survival and similar quality of life and control of metastatic breast cancer compared with CMFP.

Imatinib Disposition and ABCB1 (MDR1, P-Glycoprotein) Genotype

The aim of this study was to explore the impact of individual variation in drug elimination on imatinib disposition. Twenty‐two patients with gastrointestinal stromal tumor or chronic myeloid leukemia initially received imatinib 600 mg daily with dosage subsequently toxicity adjusted. Pharmacokinetic parameters on day 1 and at steady‐state were compared with elimination phenotype and single‐nucleotide polymorphisms of CYP3A5 and ABCB1. A fivefold variation in estimated imatinib clearance (CL/F) was present on day 1 and mean CL/F had fallen by 26% at steady state. This reduction in imatinib CL/F was associated with ABCB1 genotype, being least apparent in thymidine homozygotes at the 1236T>C, 2677G>T/A and 3435C>T loci. Toxicity‐related dose reduction also tended to be less common in these individuals. ABCB1 genotype was associated with steady‐state CL/F due to an apparent genotype‐specific influence of imatinib on elimination. Further evaluation of ABCB1 genotype and imatinib dosage is warranted.

Factors affecting epirubicin pharmacokinetics and toxicity: evidence against using body-surface area for dose calculation.

PURPOSE An exploratory study to test whether body-surface area (BSA) should be used for the calculation of epirubicin dose. PATIENTS AND METHODS The relationship between pretreatment characteristics and the effects of epirubicin were investigated in 20 chemotherapy-naive patients. Measurements of body size, renal and hepatic function, and other factors were correlated with epirubicin pharmacokinetics (PK) and epirubicin-induced neutropenia. All patients received 150 mg of epirubicin infused continuously over 120 hours, regardless of body size. Factors were analyzed by univariate and multivariate linear regression. RESULTS There were no correlations between BSA or weight with any PK parameter or with the degree of neutropenia. In multivariate analysis, indicators of liver function were the only factors that correlated with neutropenia and epirubicin PK. Thus, correlations for neutropenia were seen with antipyrine clearance (P = .003), activated partial thromboplastin time (APTT) (P = .005) and serum transferrin (P = .01). Further, the area under the concentration-time curve (AUC) for epirubicin correlated with prothrombin index (P < .01), antipyrine clearance (P < .01), and serum bile salt concentration (P = .03), and there were similar correlations for epirubicin steady-state concentration (CpSS). Epirubicin clearance correlated with antipyrine clearance (P = .02). PK parameters for dihydroepirubicin correlated with prothombin index, serum transferrin, and bile salt concentrations (P < .001 for all correlations). Because of the number of statistical examinations performed, some of these correlations may be spurious. However, some are likely to be real, since the same variables repeatedly correlated with different epirubicin-associated outcomes. There were no correlations between epirubicin PK indices or neutropenia and serum aminotransferase levels or other biochemical liver function tests, creatinine, or any of the clinical factors examined. CONCLUSION These results led us to question the use of BSA for epirubicin dose calculation. In contrast, quantitative liver function tests may give a better indication of drug handling and toxicity and may be useful to determine more accurate methods for dose calculation of epirubicin.

Evidence for Therapeutic Drug Monitoring of Targeted Anticancer Therapies

Therapeutic drug monitoring (TDM) provides valuable guidance for dose adjustment of antibiotics, immunosuppressives, antiepileptics, and other drugs, but its use for traditional anticancer therapies has been limited. Perhaps the most important obstacle is the impractical requirement of multiple blood samples to adequately define systemic exposure of drugs that have a short elimination half-life and are given by intermittent intravenous injections. However, the newer targeted anticancer therapies have different pharmacokinetic (PK) and dosing characteristics compared with traditional cytotoxic drugs, making it possible to estimate the steady-state drug exposure with a single trough-level measurement. Recent evidence indicates that certain PK parameters, including trough levels, are correlated with clinical outcomes for many of these agents, including imatinib, sunitinib, rituximab, and cetuximab. Although the current evidence is insufficient to mandate TDM in routine practice, a concerted investigation should be encouraged to determine whether the steady-state trough measurements of targeted agents will have a practical place in the clinical care of patients with cancer.

Nivolumab plus Ipilimumab versus Sunitinib in Advanced Renal-Cell Carcinoma

BACKGROUND Nivolumab plus ipilimumab produced objective responses in patients with advanced renal‐cell carcinoma in a pilot study. This phase 3 trial compared nivolumab plus ipilimumab with sunitinib for previously untreated clear‐cell advanced renal‐cell carcinoma. METHODS We randomly assigned adults in a 1:1 ratio to receive either nivolumab (3 mg per kilogram of body weight) plus ipilimumab (1 mg per kilogram) intravenously every 3 weeks for four doses, followed by nivolumab (3 mg per kilogram) every 2 weeks, or sunitinib (50 mg) orally once daily for 4 weeks (6‐week cycle). The coprimary end points were overall survival (alpha level,0.04), objective response rate (alpha level,0.001), and progression‐free survival (alpha level,0.009) among patients with intermediate or poor prognostic risk. RESULTS A total of 1096 patients were assigned to receive nivolumab plus ipilimumab (550 patients) or sunitinib (546 patients); 425 and 422, respectively, had intermediate or poor risk. At a median follow‐up of 25.2 months in intermediate‐ and poor‐risk patients, the 18‐month overall survival rate was 75% (95% confidence interval [CI], 70 to 78) with nivolumab plus ipilimumab and 60% (95% CI, 55 to 65) with sunitinib; the median overall survival was not reached with nivolumab plus ipilimumab versus 26.0 months with sunitinib (hazard ratio for death, 0.63; P<0.001). The objective response rate was 42% versus 27% (P<0.001), and the complete response rate was 9% versus 1%. The median progression‐free survival was 11.6 months and 8.4 months, respectively (hazard ratio for disease progression or death, 0.82; P=0.03, not significant per the prespecified 0.009 threshold). Treatment‐related adverse events occurred in 509 of 547 patients (93%) in the nivolumab‐plus‐ipilimumab group and 521 of 535 patients (97%) in the sunitinib group; grade 3 or 4 events occurred in 250 patients (46%) and 335 patients (63%), respectively. Treatment‐related adverse events leading to discontinuation occurred in 22% and 12% of the patients in the respective groups. CONCLUSIONS Overall survival and objective response rates were significantly higher with nivolumab plus ipilimumab than with sunitinib among intermediate‐ and poor‐risk patients with previously untreated advanced renal‐cell carcinoma. (Funded by Bristol‐Myers Squibb and Ono Pharmaceutical; CheckMate 214 ClinicalTrials.gov number, NCT02231749.)

CYP3A5 Genotype and Midazolam Clearance in Australian Patients Receiving Chemotherapy

Cytochrome P450 (CYP) 3A enzymes are key metabolizing enzymes for many chemotherapeutic agents, and detection of functionally significant CYP3A genetic variants may be useful in predicting interpatient variation of drug clearance. We have examined the significance of CYP3A5*3 single‐nucleotide polymorphism to overall CYP3A activity in vivo in a predominantly Caucasian Australian cancer population.

Parathyroid hormone-related protein and response to pamidronate in tumour-induced hypercalcaemia

To find out if the concentration of parathyroid hormone-related protein (PTHrP) predicts the response of tumour-inducing hypercalcaemia (TIH) to pamidronate, we studied 44 patients. Pretreatment measurements of serum PTHrP, calcium and phosphate, nephrogenous cyclic AMP, tubular threshold for calcium and phosphate (TmP), and the presence of bone metastases were correlated with response to pamidronate. Response was considered good (normal calcium concentration corrected for albumin [CCa] for > 14 days), or poor (failure of CCa to fall, or a rise above normal < or = 14 days). PTHrP correlated significantly with response (good vs poor, p = 0.02). Undetectable PTHrP (< 2 pmol/L) was associated with a good response in all seven treatments, PTHrP in the range 2-12 pmol/L was associated with good response in 10 of 14 treatments, while PTHrP > or = 12 pmol/L was associated with a poor response in all 11 treatments. Tubular threshold for calcium correlated with the fall in CCa by day 6 after treatment (p = 0.02). Urinary clearance estimations in poor responders suggested that there was an incomplete reversal of the renal tubular component of hypercalcaemia. Serum PTHrP correlates with response to pamidronate in the treatment of TIH; which may be associated with a renal tubular mechanism not significantly affected by currently available treatment. Drugs that inhibit tubular reabsorption of calcium or PTHrP secretion may help in patients who do not respond to pamidronate.