Fixed Versus Body-Sized-Based Dosing of Monoclonal Antibodies.

Monoclonal antibody products are an increasing portion of novel drug approvals. The labeling of initial drug approvals frequently involves body-size-based rather than fixed-dose administration regimens for adults without clear rationale for doing so. This presents challenges when prescribing these products for patients with extremes of body habitus who constitute a small portion of enrollment in pre-approval investigations. Fixed-dose regimens allow for standardized preparation with the potential to reduce the risk of calculation errors, drug waste, and make home administration more practical. Fixed-dose rather than body-size-based monoclonal antibody regimens should serve as the initial approach in early phase 1 clinical trials.

Clinical Study of Aspirin and Zileuton on Biomarkers of Tobacco-Related Carcinogenesis in Current Smokers.

The chemopreventive effect of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) on lung cancer risk is supported by epidemiologic and preclinical studies. Zileuton, a 5-lipoxygenase inhibitor, has additive activity with NSAIDs against tobacco carcinogenesis in preclinical models. We hypothesized that cyclooxygenase plus 5-lipoxygenase inhibition would be more effective than a placebo in modulating the nasal epithelium gene signatures of tobacco exposure and lung cancer. We conducted a randomized, double-blinded study of low-dose aspirin plus zileuton vs. double placebo in current smokers to compare the modulating effects on nasal gene expression and arachidonic acid metabolism. In total, 63 participants took aspirin 81 mg daily plus zileuton (Zyflo CR) 600 mg BID or the placebo for 12 weeks. Nasal brushes from the baseline, end-of-intervention, and one-week post intervention were profiled via microarray. Aspirin plus zilueton had minimal effects on the modulation of the nasal or bronchial gene expression signatures of smoking, lung cancer, and COPD but favorably modulated a bronchial gene expression signature of squamous dysplasia. Aspirin plus zileuton suppressed urinary leukotriene but not prostaglandin E2, suggesting shunting through the cyclooxygenase pathway when combined with 5-lipoxygenase inhibition. Continued investigation of leukotriene inhibitors is needed to confirm these findings, understand the long-term effects on the airway epithelium, and identify the safest, optimally dosed agents.

The relationship of vancomycin 24-hour AUC and trough concentration.

PURPOSE: Prior to the 2020 release of a joint consensus guideline on monitoring of vancomycin therapy for serious methicillin-resistant Staphylococcus aureus (MRSA) infections, clinicians had escalated vancomycin doses for 2 decades while targeting trough concentrations of 15 to 20 µg/mL, leading to an increased frequency of nephrotoxicity. For MRSA infections, the 2020 guideline recommends adjusting doses to achieve a 24-hour area under the concentration-time curve (AUC) of 400 to 600 µg · h/mL; however, monitoring of trough concentrations has been entrenched for 3 decades. Calculating dose regimens based on AUC will require obtaining an increased number of vancomycin serum concentrations and, possibly, advanced software. The aim of this investigation was to determine the relationship between AUC and trough concentration and the influence of dosing regimen on goal achievement. METHODS: The relationship between trough concentration and AUC was explored through derivation of an equation based on a 1-compartment model and simulations. RESULTS: 24-hour AUC is related to dosing interval divided by half-life in a nonlinear fashion. The target trough concentration can be individualized to achieve a desired AUC range, and limiting use of large doses (>15-20 mg/kg) can protect against excessive 24-hour AUC with trough-only monitoring. CONCLUSION: After initially determining pharmacokinetic parameters, subsequent monitoring of AUC can be accomplished using trough concentrations only. Trough concentration may be used as a surrogate for AUC, although the acceptable target trough concentration will vary depending on dosing interval and elimination rate constant. This work included development of an AUC-trough equation to establish a patient-specific target for steady-state trough concentration.

A Systematic Review of the Prevalence and Diagnostic Workup of PIK3CA Mutations in HR+/HER2- Metastatic Breast Cancer.

PIK3CA mutation frequency varies among breast cancer (BC) subtypes. Recent evidence suggests combination therapy with the PI3K inhibitor (PI3Ki) alpelisib and endocrine therapy (ET) improves response rates and progression-free survival (PFS) in PIK3CA-mutant, hormone receptor positive (HR+) BC versus ET alone; thus, better understanding the clinical and epidemiologic elements of these mutations is warranted. This systematic review characterizes the PIK3CA mutation epidemiology, type of testing approaches (e.g., liquid or tissue tumor biopsy), and stability/concordance (e.g., consistency in results by liquid versus solid tumor sample, by the same method over time) in patients with HR+/HER2- advanced (locally unresectable) or metastatic disease (HR+/HER2- mBC) and explores performance (e.g., pairwise concordance, sensitivity, specificity, or predictive value) of respective mutation findings. A comprehensive search of PubMed/MEDLINE, EMBASE, Cochrane Central, and select conference abstracts (i.e., AACR, ASCO, SABCS, ECCO, and ESMO conferences between 2014 and 2017) identified 39 studies of patients with HR+, HER2- mBC. The median prevalence of PIK3CA mutation was 36% (range: 13.3% to 61.5%); identified testing approaches more commonly used tissue over liquid biopsies and primarily utilized next-generation sequencing (NGS), polymerase chain reaction (PCR), or Sanger sequencing. There was concordance and stability between tissues (range: 70.4% to 94%) based on limited data. Given the clinical benefit of the PI3Ki alpelisib in patients with PIK3CA mutant HR+/HER2- mBC, determination of tumor PIK3CA mutation status is of importance in managing patients with HR+/HER2- mBC. Prevalence of this mutation and utility of test methodologies likely warrants PIK3CA mutation testing in all patients with this breast cancer subtype via definitive assessment of PIK3CA mutational status.

A Systematic Literature Review of the Prognostic and Predictive Value of PIK3CA Mutations in HR+/HER2- Metastatic Breast Cancer.

PIK3CA mutations may have prognostic value for patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer, representing an important potential target for systemic therapy. Prognostic and predictive values associated with PIK3CA mutations are not well understood. A comprehensive search of PubMed/MEDLINE, EMBASE, Cochrane Central, and conference abstracts was performed for English-language articles published January 1993 through April 2019. Articles were categorized by treatment arms based on experimental and treatment drug classes. Information on progression-free survival (PFS), hazard ratios, overall survival, response rate, and clinical benefit rate was obtained. A total of 17 studies were included. Among those evaluating non-PI3Ki based therapies, 91% showed numerically shorter median PFS, ranging from 1.5 to 19.2 months and 1.8 to 29.6 months for the mutant versus non-mutant subgroups, respectively. Where reported (n = 13 studies), PFS was shorter between those arms offering endocrine monotherapy (range, 1.6-14.7 months) compared with a corresponding targeted therapy + endocrine monotherapy (range, 3.9-29.6 months). Of 5 PI3Ki-based arms comparing PFS, higher median PFS in PIK3CA mutant versus non-mutant cases was demonstrated. PFS was shorter for patients with PIK3CA mutant (range, 1.6-19.2 months) compared with PIK3CA wild-type (range, 1.8-29.6 months) in 10 (71%) of 14 treatment arms reporting PFS. Studies (n = 4) not reporting PFS reported response rate, but there were no clear directional trends. The presence of PIK3CA mutations may be associated with worse clinical outcomes in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer. Clinical outcomes such as PFS may be improved using a combination of PI3Ki-based therapies and endocrine therapies among this population. However, more research is warranted to fully elucidate this association.

Effect of Intermittent Versus Continuous Low-Dose Aspirin on Nasal Epithelium Gene Expression in Current Smokers: A Randomized, Double-Blinded Trial.

A chemopreventive effect of aspirin (ASA) on lung cancer risk is supported by epidemiologic and preclinical studies. We conducted a randomized, double-blinded study in current heavy smokers to compare modulating effects of intermittent versus continuous low-dose ASA on nasal epithelium gene expression and arachidonic acid (ARA) metabolism. Fifty-four participants were randomized to intermittent (ASA 81 mg daily for one week/placebo for one week) or continuous (ASA 81 mg daily) for 12 weeks. Low-dose ASA suppressed urinary prostaglandin E2 metabolite (PGEM; change of -4.55 ± 11.52 from baseline 15.44 ± 13.79 ng/mg creatinine for arms combined, P = 0.02), a surrogate of COX-mediated ARA metabolism, but had minimal effects on nasal gene expression of nasal or bronchial gene-expression signatures associated with smoking, lung cancer, and chronic obstructive pulmonary disease. Suppression of urinary PGEM correlated with favorable changes in a smoking-associated gene signature (P < 0.01). Gene set enrichment analysis (GSEA) showed that ASA intervention led to 1,079 enriched gene sets from the Canonical Pathways within the Molecular Signatures Database. In conclusion, low-dose ASA had minimal effects on known carcinogenesis gene signatures in nasal epithelium of current smokers but results in wide-ranging genomic changes in the nasal epithelium, demonstrating utility of nasal brushings as a surrogate to measure gene-expression responses to chemoprevention. PGEM may serve as a marker for smoking-associated gene-expression changes and systemic inflammation. Future studies should focus on NSAIDs or agent combinations with broader inhibition of pro-inflammatory ARA metabolism to shift gene signatures in an anti-carcinogenic direction.

PD-1 Inhibition Achieves a Complete Metabolic Response in a Patient with Malignant Peripheral Nerve Sheath Tumor.

High-grade malignant peripheral nerve sheath tumors (MPNST) have a poor prognosis with limited responsiveness to systemic therapy. We document a case of a complete metabolic response to pembrolizumab monotherapy in metastatic disease. Tumor molecular profiling identified programmed-death ligand-1 (PD-L1) positivity. This characteristic provided a rationale for immune-checkpoint therapy. Treatment with pembrolizumab resulted in a complete metabolic response after four cycles of therapy. Patients with PD-L1-positive, metastatic MPNST may be candidates for immune-checkpoint therapy, which may produce a durable complete remission. Future study of anti-PD-1/PD-L1 therapy is warranted.

Autophagy Inhibition to Augment mTOR Inhibition: a Phase I/II Trial of Everolimus and Hydroxychloroquine in Patients with Previously Treated Renal Cell Carcinoma.

PURPOSE: Everolimus inhibits the mTOR, activating cytoprotective autophagy. Hydroxychloroquine inhibits autophagy. On the basis of preclinical data demonstrating synergistic cytotoxicity when mTOR inhibitors are combined with an autophagy inhibitor, we launched a clinical trial of combined everolimus and hydroxychloroquine, to determine its safety and activity in patients with clear-cell renal cell carcinoma (ccRCC). PATIENTS AND METHODS: Three centers conducted a phase I/II trial of everolimus 10 mg daily and hydroxychloroquine in patients with advanced ccRCC. The objectives were to determine the MTD of hydroxychloroquine with daily everolimus, and to estimate the rate of 6-month progression-free survival (PFS) in patients with ccRCC receiving everolimus/hydroxychloroquine after 1-3 prior treatment regimens. Correlative studies to identify patient subpopulations that achieved the most benefit included population pharmacokinetics, measurement of autophagosomes by electron microscopy, and next-generation tumor sequencing. RESULTS: No dose-limiting toxicity was observed in the phase I trial. The recommended phase II dose of hydroxychloroquine 600 mg twice daily with everolimus was identified. Disease control [stable disease + partial response (PR)] occurred in 22 of 33 (67%) evaluable patients. PR was observed in 2 of 33 patients (6%). PFS ≥ 6 months was achieved in 15 of 33 (45%) of patients who achieved disease control. CONCLUSIONS: Combined hydroxychloroquine 600 mg twice daily with 10 mg daily everolimus was tolerable. The primary endpoint of >40% 6-month PFS rate was met. Hydroxychloroquine is a tolerable autophagy inhibitor in future RCC or other trials.

The evolution of biomarkers to guide the treatment of metastatic colorectal cancer.

In the United States, colon cancer is one of the leading causes of death and cancer-related death. There is a critical need to improve clinical outcomes in patients with metastatic colorectal cancer (mCRC), as current survival rates are unsatisfactory. There have been significant advances in the treatment of mCRC over the past decade. Molecular characteristics of mCRC and identification of mutations can serve predictive and prognostic indicators of disease response to treatment. These biomarkers can be incorporated into clinical decision making when developing an individualized treatment plan. Targeted therapies have improved the survival of patients with mCRC. As we learn about the various molecular alterations in this disease, additional emerging therapies can be developed to improve clinical outcomes in patients with mCRC.

Combined autophagy and proteasome inhibition: a phase 1 trial of hydroxychloroquine and bortezomib in patients with relapsed/refractory myeloma.

The efficacy of proteasome inhibition for myeloma is limited by therapeutic resistance, which may be mediated by activation of the autophagy pathway as an alternative mechanism of protein degradation. Preclinical studies demonstrate that autophagy inhibition with hydroxychloroquine augments the antimyeloma efficacy of the proteasome inhibitor bortezomib. We conducted a phase I trial combining bortezomib and hydroxychloroquine for relapsed or refractory myeloma. We enrolled 25 patients, including 11 (44%) refractory to prior bortezomib. No protocol-defined dose-limiting toxicities occurred, and we identified a recommended phase 2 dose of hydroxychloroquine 600 mg twice daily with standard doses of bortezomib, at which we observed dose-related gastrointestinal toxicity and cytopenias. Of 22 patients evaluable for response, 3 (14%) had very good partial responses, 3 (14%) had minor responses, and 10 (45%) had a period of stable disease. Electron micrographs of bone marrow plasma cells collected at baseline, after a hydroxychloroquine run-in, and after combined therapy showed therapy-associated increases in autophagic vacuoles, consistent with the combined effects of increased trafficking of misfolded proteins to autophagic vacuoles and inhibition of their degradative capacity. Combined targeting of proteasomal and autophagic protein degradation using bortezomib and hydroxychloroquine is therefore feasible and a potentially useful strategy for improving outcomes in myeloma therapy.

Combined autophagy and HDAC inhibition: a phase I safety, tolerability, pharmacokinetic, and pharmacodynamic analysis of hydroxychloroquine in combination with the HDAC inhibitor vorinostat in patients with advanced solid tumors.

We previously reported that inhibition of autophagy significantly augmented the anticancer activity of the histone deacetylase (HDAC) inhibitor vorinostat (VOR) through a cathepsin D-mediated mechanism. We thus conducted a first-in-human study to investigate the safety, preliminary efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of the combination of the autophagy inhibitor hydroxychloroquine (HCQ) and VOR in patients with advanced solid tumors. Of 27 patients treated in the study, 24 were considered fully evaluable for study assessments and toxicity. Patients were treated orally with escalating doses of HCQ daily (QD) (d 2 to 21 of a 21-d cycle) in combination with 400 mg VOR QD (d one to 21). Treatment-related adverse events (AE) included grade 1 to 2 nausea, diarrhea, fatigue, weight loss, anemia, and elevated creatinine. Grade 3 fatigue and/or myelosuppression were observed in a minority of patients. Fatigue and gastrointestinal AE were dose-limiting toxicities. Six-hundred milligrams HCQ and 400 mg VOR was established as the maximum tolerated dose and recommended phase II regimen. One patient with renal cell carcinoma had a confirmed durable partial response and 2 patients with colorectal cancer had prolonged stable disease. The addition of HCQ did not significantly impact the PK profile of VOR. Treatment-related increases in the expression of CDKN1A and CTSD were more pronounced in tumor biopsies than peripheral blood mononuclear cells. Based on the safety and preliminary efficacy of this combination, additional clinical studies are currently being planned to further investigate autophagy inhibition as a new approach to increase the efficacy of HDAC inhibitors.

Combined MTOR and autophagy inhibition: phase I trial of hydroxychloroquine and temsirolimus in patients with advanced solid tumors and melanoma.

The combination of temsirolimus (TEM), an MTOR inhibitor, and hydroxychloroquine (HCQ), an autophagy inhibitor, augments cell death in preclinical models. This phase 1 dose-escalation study evaluated the maximum tolerated dose (MTD), safety, preliminary activity, pharmacokinetics, and pharmacodynamics of HCQ in combination with TEM in cancer patients. In the dose escalation portion, 27 patients with advanced solid malignancies were enrolled, followed by a cohort expansion at the top dose level in 12 patients with metastatic melanoma. The combination of HCQ and TEM was well tolerated, and grade 3 or 4 toxicity was limited to anorexia (7%), fatigue (7%), and nausea (7%). An MTD was not reached for HCQ, and the recommended phase II dose was HCQ 600 mg twice daily in combination with TEM 25 mg weekly. Other common grade 1 or 2 toxicities included fatigue, anorexia, nausea, stomatitis, rash, and weight loss. No responses were observed; however, 14/21 (67%) patients in the dose escalation and 14/19 (74%) patients with melanoma achieved stable disease. The median progression-free survival in 13 melanoma patients treated with HCQ 1200mg/d in combination with TEM was 3.5 mo. Novel 18-fluorodeoxyglucose positron emission tomography (FDG-PET) measurements predicted clinical outcome and provided further evidence that the addition of HCQ to TEM produced metabolic stress on tumors in patients that experienced clinical benefit. Pharmacodynamic evidence of autophagy inhibition was evident in serial PBMC and tumor biopsies only in patients treated with 1200 mg daily HCQ. This study indicates that TEM and HCQ is safe and tolerable, modulates autophagy in patients, and has significant antitumor activity. Further studies combining MTOR and autophagy inhibitors in cancer patients are warranted.

Phase I trial of hydroxychloroquine with dose-intense temozolomide in patients with advanced solid tumors and melanoma.

Blocking autophagy with hydroxychloroquine (HCQ) augments cell death associated with alkylating chemotherapy in preclinical models. This phase I study evaluated the maximum tolerated dose (MTD), safety, preliminary activity, pharmacokinetics, and pharmacodynamics of HCQ in combination with dose-intense temozolomide (TMZ) in patients with advanced solid malignancies. Forty patients (73% metastatic melanoma) were treated with oral HCQ 200 to 1200 mg daily with dose-intense oral TMZ 150 mg/m (2) daily for 7/14 d. This combination was well tolerated with no recurrent dose-limiting toxicities observed. An MTD was not reached for HCQ and the recommended phase II dose was HCQ 600 mg twice daily combined with dose-intense TMZ. Common toxicities included grade 2 fatigue (55%), anorexia (28%), nausea (48%), constipation (20%), and diarrhea (20%). Partial responses and stable disease were observed in 3/22 (14%) and 6/22 (27%) patients with metastatic melanoma. In the final dose cohort 2/6 patients with refractory BRAF wild-type melanoma had a near complete response, and prolonged stable disease, respectively. A significant accumulation in autophagic vacuoles (AV) in peripheral blood mononuclear cells was observed in response to combined therapy. Population pharmacokinetics (PK) modeling, individual PK simulations, and PK-pharmacodynamics (PD) analysis identified a threshold HCQ peak concentration that predicts therapy-associated AV accumulation. This study indicates that the combination of high-dose HCQ and dose-intense TMZ is safe and tolerable, and is associated with autophagy modulation in patients. Prolonged stable disease and responses suggest antitumor activity in melanoma patients, warranting further studies of this combination, or combinations of more potent autophagy inhibitors and chemotherapy in melanoma.

A phase I/II trial of hydroxychloroquine in conjunction with radiation therapy and concurrent and adjuvant temozolomide in patients with newly diagnosed glioblastoma multiforme.

Preclinical studies indicate autophagy inhibition with hydroxychloroquine (HCQ) can augment the efficacy of DNA-damaging therapy. The primary objective of this trial was to determine the maximum tolerated dose (MTD) and efficacy of HCQ in combination with radiation therapy (RT) and temozolomide (TMZ) for newly diagnosed glioblastoma (GB). A 3 + 3 phase I trial design followed by a noncomparative phase II study was conducted in GB patients after initial resection. Patients received HCQ (200 to 800 mg oral daily) with RT and concurrent and adjuvant TMZ. Quantitative electron microscopy and immunoblotting were used to assess changes in autophagic vacuoles (AVs) in peripheral blood mononuclear cells (PBMC). Population pharmacokinetic (PK) modeling enabled PK-pharmacodynamic correlations. Sixteen phase I subjects were evaluable for dose-limiting toxicities. At 800 mg HCQ/d, 3/3 subjects experienced Grade 3 and 4 neutropenia and thrombocytopenia, 1 with sepsis. HCQ 600 mg/d was found to be the MTD in this combination. The phase II cohort (n = 76) had a median survival of 15.6 mos with survival rates at 12, 18, and 24 mo of 70%, 36%, and 25%. PK analysis indicated dose-proportional exposure for HCQ. Significant therapy-associated increases in AV and LC3-II were observed in PBMC and correlated with higher HCQ exposure. These data establish that autophagy inhibition is achievable with HCQ, but dose-limiting toxicity prevented escalation to higher doses of HCQ. At HCQ 600 mg/d, autophagy inhibition was not consistently achieved in patients treated with this regimen, and no significant improvement in overall survival was observed. Therefore, a definitive test of the role of autophagy inhibition in the adjuvant setting for glioma patients awaits the development of lower-toxicity compounds that can achieve more consistent inhibition of autophagy than HCQ.

Autophagy inhibitor Lys05 has single-agent antitumor activity and reproduces the phenotype of a genetic autophagy deficiency.

Autophagy is a lysosome-dependent degradative process that protects cancer cells from multiple stresses. In preclinical models, autophagy inhibition with chloroquine (CQ) derivatives augments the efficacy of many anticancer therapies, but CQ has limited activity as a single agent. Clinical trials are underway combining anticancer agents with hydroxychloroquine (HCQ), but concentrations of HCQ required to inhibit autophagy are not consistently achievable in the clinic. We report the synthesis and characterization of bisaminoquinoline autophagy inhibitors that potently inhibit autophagy and impair tumor growth in vivo. The structural motifs that are necessary for improved autophagy inhibition compared with CQ include the presence of two aminoquinoline rings and a triamine linker and C-7 chlorine. The lead compound, Lys01, is a 10-fold more potent autophagy inhibitor than HCQ. Compared with HCQ, Lys05, a water-soluble salt of Lys01, more potently accumulates within and deacidifies the lysosome, resulting in impaired autophagy and tumor growth. At the highest dose administered, some mice develop Paneth cell dysfunction that resembles the intestinal phenotype of mice and humans with genetic defects in the autophagy gene ATG16L1, providing in vivo evidence that Lys05 targets autophagy. Unlike HCQ, significant single-agent antitumor activity is observed without toxicity in mice treated with lower doses of Lys05, establishing the therapeutic potential of this compound in cancer.

Zoledronic acid: a new parenteral bisphosphonate.

BACKGROUND: Inhibition of bone resorption using bisphosphonates is an important step in palliation of complications of advanced cancer, such as hypercalcemia and metastatic bone disease. OBJECTIVE: The goal of this article was to describe the pharmacologic properties of zoledronic acid (zoledronate) and discuss findings from preclinical and clinical studies of its use in skeletal disorders. METHODS: Relevant English-language literature was identified using the terms zoledronic acid, zoledronate, Zometa, and 118072-93-8 through searches of MEDLINE (1966-June 2003) and International Pharmaceutical Abstracts (1970-June 2003), and abstract proceedings from the American Society of Clinical Oncology (1997-2002). RESULTS: Zoledronic acid is a nitrogen-containing bisphosphonate that inhibits bone resorption. It is indicated for the treatment of hypercalcemia of malignancy and for the treatment of patients with multiple myeloma or documented metastasis from solid tumors, in conjunction with standard antineoplastic therapy. The recommended dosage is 4 mg via IV over >or= 15 minutes every 3 or 4 weeks. Compared with pamidronate 90 mg, zoledronic acid 4 and 8 mg provided a higher complete response rate for hypercalcemia of malignancy by day 10 (88.4% and 86.7% vs 69.7%; P = 0.002 and P = 0.015) and longer duration of action (median time to relapse, 30 and 40 days vs 17 days; P = 0.001 and P = 0.007). In patients with breast cancer or multiple myeloma, zoledronic acid was as effective as pamidronate in delaying time to a first skeletal-related event (373 days vs 363 days). In patients with hormone-refractory prostate cancer and bone metastases, zoledronic acid 4 mg reduced the proportion of patients who experienced a skeletal-related event (33% vs 44% with placebo; P = 0.021) or a skeletal fracture (13% vs 22% with placebo; P = 0.015). In patients with bone metastases from solid tumors, zoledronic acid delayed the median time to a first skeletal-related event (230 days vs 163 days with placebo; P = 0.023). Common adverse events include fever, nausea, constipation, fatigue, and bone pain. CONCLUSION: Zoledronic acid is an effective and generally well-tolerated treatment for hypercalcemia of malignancy and skeletal complications of metastatic bone disease.