Cetuximab every 2 weeks versus standard weekly dosing administration schedule

Cetuximab every 2 weeks (Q2W) dosing schedule is approved by the US FDA and by the Japanese Pharmaceuticals and Medical Devices Agency in patients with metastatic colorectal cancer and squamous cell carcinoma of the head and neck. Phase II trials have found comparable efficacy and safety for the weekly (Q1W) and Q2W schedules, and real-world studies have shown noninferiority of the Q2W compared with the Q1W schedule. Several guidelines recommend cetuximab Q2W administration as an alternative to the Q1W dosing schedule. Cetuximab Q2W can be administered with a Q2W dose of chemotherapy, making it a more convenient option to the Q1W schedule, potentially resulting in reduced costs for administration, increased flexibility for clinical staff and improved patient adherence.

Comparison of clinical safety between standard versus extended interval dosing of immune checkpoint inhibitors: a real-world retrospective cohort study

BACKGROUND

Extended interval dosing (ED) for inhibitors of programmed cell death protein 1 (anti-PD-1) (nivolumab, pembrolizumab) or its ligand (anti-PD-L1) (durvalumab) were recently approved based on pharmacokinetic model results that predicted a benefit-risk profile comparable with the standard dosing (SD) regimen. However, safety data in real-world condition of use are lacking. The objective was to compare the incidence and the risk factors of serious immune-related adverse events (irAEs) and any-grade irAEs between the SD and ED regimens in patients treated with anti-PD-1 or anti-PD-L1.

MATERIALS AND METHODS

IrAEs were assessed from medical records in all new users of nivolumab, pembrolizumab, or durvalumab between 1 January 2019 and 31 December 2020 across two oncology centers in France. The incidence of irAEs was compared between both dosing regimens using Cox proportional hazards models adjusting for the main available confounders.

RESULTS

Among 686 patients included, 63% were new users of an SD regimen, 14% of ED regimen, and 23% started with SD and switched to ED regimen during follow-up. Overall, 34.6% of patients experienced at least one irAE of any grade and 11.4% presented at least one serious grade ≥3 irAE. No statistical difference was found between the SD and ED regimen on the risk of grade ≥3 irAEs [adjusted hazard ratio (HR) 1.40, 95% confidence interval (CI) 0.71-2.76] but our results suggest an increased risk of any-grade irAEs with the ED regimen (adjusted HR 1.46, 95% CI 1.00-2.12, P = 0.048). IrAEs resolved without sequelae in 46.4% of cases, and they were fatal for three patients (0.4%). Autoimmune pre-existing condition was confirmed as a risk factor for grade ≥3 irAEs (HR 2.56, 95% CI 1.53-4.27) and for all-grade irAEs (HR 1.60, 95% CI 1.17-2.20).

CONCLUSIONS

In a real-world setting, according to the regimen chosen by the oncologist based on clinical characteristics, we did not observe an increase in grade ≥3 irAE incidence between the SD and ED regimens.

Second International Consensus Study of Antipsychotic Dosing (ICSAD-2)

BACKGROUND

Expert consensus-based clinically equivalent dose estimates and dosing recommendations can provide valuable support for the use of drugs for psychosis in clinical practice and research.

AIMS

This second International Consensus Study of Antipsychotic Dosing provides dosing equivalencies and recommendations for newer drugs for psychosis and previously reported drugs with low consensus.

METHODS

We used a two-step Delphi survey process to establish and update consensus with a broad, international sample of clinical and research experts regarding 26 drug formulations to obtain dosing recommendations (start, target range, and maximum) and estimates of clinically equivalent doses for the treatment of schizophrenia. Reference agents for equivalent dose estimates were oral olanzapine 20 mg/day for 15 oral and 7 long-acting injectable (LAI) agents and intramuscular haloperidol 5 mg for 4 short-acting injectable (SAI) agents. We also provide a contemporary list of equivalency estimates and dosing recommendations for a total of 44 oral, 16 LAI, and 14 SAI drugs for psychosis.

RESULTS

Survey participants (N = 72) from 24 countries provided equivalency estimates and dosing recommendations for oral, LAI, and SAI formulations. Consensus improved from survey stages I to II. The final consensus was highest for LAI formulations, intermediate for oral agents, and lowest for SAI formulations of drugs for psychosis.

CONCLUSIONS

As randomized, controlled, fixed, multiple-dose trials to optimize the dosing of drugs for psychosis remain rare, expert consensus remains a useful alternative for estimating clinical dosing equivalents. The present findings can support clinical practice, guideline development, and research design and interpretation involving drugs for psychosis.

Alternate Pembrolizumab Dosing Interval in Advanced NSCLC with PD-L1 TPS ≥ 50%: 3 Weekly Compared to 6 Weekly Dosing

BACKGROUND

A fixed dose of 200 mg of pembrolizumab every 3 weeks (Q3W) is the standard of care for patients with stage IV non-small cell lung cancer (NSCLC) and PDL1 ≥50%. In April 2020, based on pharmacokinetic modeling without formal comparative studies, the FDA approved 400 mg every 6 weeks (Q6W). Pharmacokinetic studies also suggested comparable target engagement with weight-based and flat dosing for the respective schedules. The objective of this study was to determine if overall survival (OS) differs based on the Q3W vs. Q6W dosing schedule of pembrolizumab.

METHODS

BC Cancer patients with stage IV NSCLC and PDL1 ≥50% treated with pembrolizumab were retrospectively reviewed. Patients were treated with weight-based dosing, per institution standard, of pembrolizumab 2 mg/kg Q3W or 4 mg/kg Q6W. Patient demographics, treatment and outcome were recorded. Patients were assigned to Q3W or Q6W according to the schedule that was used for the majority of treatment (greater than 50%).

RESULTS

718 patients with NSCLC and PDL1 ≥50% received first-line pembrolizumab between 2017 and2021, Q3W/Q6W dosing 677/41 patients. Baseline characteristics with respect to age, sex, smoking status, histology and performance status (PS) were similar between groups. In the multivariate model, including age, sex, PS and dosing schedule, the hazard ratio for death (HR) for OS Q3W vs. Q6W was 0.759 (p = 0.230). A 2:1 case-matched analysis for OS was performed, controlling for sex, age ± 5 years, PS and duration on pembrolizumab ± 2 months for Q3W vs. Q6W (n = 113) with a HR 0.834 (p = 0.500).

CONCLUSIONS

There was no OS difference demonstrated with pembrolizumab dosing Q3W compared to Q6W in a multivariate analysis that included age, sex and PS. A case-matched analysis that controlled for these variables and for duration of treatment confirmed these findings. This study supports the use of Q6W pembrolizumab dosing, allowing for less frequent interactions with the medical system.

Five-day versus 7-day treatment regimen with azacitidine in lower risk myelodysplastic syndrome: A phase 2, multicenter, randomized trial

BACKGROUND

Low-dose azacitidine (AZA) regimens, primarily 5-day AZA, have been used in lower risk myelodysplastic syndrome (LrMDS) but they have yet to be directly compared to the standard 7-day, uninterrupted dosing schedule.

METHOD

In this phase 2, multicenter, randomized trial, 55 patients with adult LrMDS (low and intermediate-1 risk by international prognostic scoring system [IPSS]) were randomly assigned and received either 5-day (n = 26) or 7-day (n = 29) AZA between March 2012 and August 2020. The trial was stopped prematurely because of the slow accrual of patients. The primary end point was the overall response rate (ORR) of the 5-day AZA as compared to that of the 7-day regimen.

RESULTS

Median patient age was 59 years, and IPSS intermediate-1 risk comprised the majority (81.8%). The median number of cycles in both arms was six. In the ITT subset (n = 53), in each of the 5-day and 7-day arms, the ORR of 48.0% and 39.3%, hematologic improvement of 44.0% and 39.3%, and RBC transfusion independence of 35.3% and 40.0% were observed respectively, and none of these findings were significantly different between the two arms. A cytogenetic response rate was significantly higher in the 7-day arm (8.3% and 53.8%, p = .027). Survival and adverse events were similar between the groups, although gastrointestinal toxicities, grade ≥3 thrombocytopenia, and febrile neutropenia were less frequent in the 5-day arm.

CONCLUSION

The 5-day AZA in LrMDS showed comparable efficacy to a 7-day regimen in terms of similar overall response and other outcomes, despite significantly higher rates of cytogenetic responses in the 7-day regimen.

LAY SUMMARY

Azacitidine (75 mg/m² /day for 7 consecutive days per 28-day cycle) has shown survival benefit in patients with higher risk myelodysplastic syndrome (MDS). Although the use of azacitidine is less-well studied for lower risk MDS, it is generally accepted as a feasible option for lower risk MDS (LrMDS).

Dynamics of Acquired Resistance to Nivolumab Therapies Varies From Administration Strategies

PURPOSE

The identification of optimal drug administration schedules to overcome the emergence of resistance that causes treatment failure is a major challenge in cancer research. We report the outcomes of a computational strategy to assess the dynamics of tumor progression as a function of time under different treatment regimens.

METHODS

We developed an evolutionary game theory model that combined Lotka-Volterra equations and pharmacokinetic properties with 2 competing cancer species: nivolumab-response cells and Janus kinase (JAK1/2) mutation cells. We selected 3 therapeutic schemes that have been tested in the clinical trials: 3 mg/kg Q2w, 10 mg/kg Q2w, and 480 mg Q4w. The simulation was performed under the intervals of 75, 125, and 175 days, respectively, for each regimen. The data sources of the pharmacokinetic parameters used in this study were collected from previous published clinical trials. Other parameters in the evolutionary model come from the existing references.

FINDINGS

Predictions under various dose schedules indicated a strong selection for nivolumab-independent cells. Under the 3 mg/kg dose strategy, the reproduction rate of JAK mutation cells was highest, with strongest tumor elimination ability at a 75-day interval between treatments. Prolonged drug intervals to 125 or 175 days delayed tumor evolution but accelerated tumor recurrence. Although 10 mg/kg Q2w had an obvious clinical effect in a short time, it further promotes the progress of resistant population compared with the 3 mg/kg dose. Our model suggests that 480 mg Q4w would be more valuable in terms of clinical efficacy, but complete resistant occurs earlier regardless the interval.

IMPLICATIONS

The results of this study emphasize that increasing the dose or shortening the interval between doses accelerates the evolution of heterogeneous populations, although the short-term effect is significant. In practice, the therapeutic regimen should be balanced according to the evolutionary principle.

Pneumococcal vaccine implementation in the African meningitis belt countries: the emerging need for alternative strategies

Introduction: Besides meningococcal disease, the African meningitis belt (AMB) region is also affected by pneumococcal disease. Most AMB countries have introduced pneumococcal conjugate vaccines (PCV) following a schedule of three primary doses without a booster or a catch-up campaign. PCV is expected to help control pneumococcal disease through both direct and indirect effects. Whether and how fast this will be achieved greatly depends on implementation strategies. Pre-PCV data from the AMB indicate high carriage rates of the pneumococcus, not only in infants but also in older children, and a risk of disease and death that spans lifetime. Post-PCV data highlight the protection of vaccinated children, but pneumococcal transmission remains important, resulting in a lack of indirect protection for unvaccinated persons.Areas covered: A non-systematic literature review focused on AMB countries. Relevant search terms were used in PubMed, and selected studies before and after PCV introduction were summarized narratively to appraise the suitability of current PCV programmatic strategies.Expert opinion: The current implementation strategy of PCV in the AMB appears suboptimal regarding the generation of indirect protection. We propose and discuss alternative programmatic strategies, including the implementation of broader age group mass campaigns, to accelerate disease control in this high transmission setting.

Once-weekly (70 mg/m2 ) vs twice-weekly (56 mg/m2 ) dosing of carfilzomib in patients with relapsed or refractory multiple myeloma: A post hoc analysis of the ENDEAVOR, A.R.R.O.W., and CHAMPION-1 trials

Combination of carfilzomib with dexamethasone (Kd) is approved for use in relapsed and/or refractory multiple myeloma (RRMM), with carfilzomib administered twice weekly at 56 mg/m² (Kd56 BIW) or once weekly at 70 mg/m² (Kd70 QW). Post hoc cross‐trial comparisons were performed to compare efficacy and safety profiles of Kd70 QW vs Kd56 BIW dosing schedules using data from three trials of patients with RRMM: A.R.R.O.W., CHAMPION‐1, and ENDEAVOR. To select for comparable patient populations, side‐by‐side efficacy and safety comparisons were performed in subgroups of patients with 2‐3 prior lines of therapy who were not refractory to bortezomib. The overall response rate (ORR) was 69.9% (95% confidence interval [CI], 61.7‐77.2) for Kd70 QW and 72.4% (95% CI, 65.9‐78.2) for Kd56 BIW. Median progression‐free survival (PFS) was 12.1 months (95% CI, 8.4‐14.3) for Kd70 QW and 14.5 months (95% CI, 10.2—not evaluable) for Kd56 BIW. Frequency of grade ≥ 3 adverse events (AEs) was 67.6% for Kd70 QW and 85.3% for Kd56 BIW. Regression analyses (adjusting for prognostic factors) of all patients in the trials who received Kd70 QW vs Kd56 BIW estimated a PFS hazard ratio of 0.91 (95% CI, 0.69‐1.19; P = .47) and an ORR odds ratio of 1.12 (95% CI, 0.74‐1.69; P = .61). These results suggest that Kd70 QW has a comparable efficacy profile compared with Kd56 BIW and represents a convenient and well‐tolerated treatment for patients with RRMM.

Daily oral administration of low-dose methotrexate has greater antirheumatic effects in collagen-induced arthritis rats

Objectives

Methotrexate (MTX) is administered once or thrice weekly to patients with rheumatoid arthritis (RA). Even though RA continually progresses, MTX is not administered daily. Therefore, we investigated whether the daily administration of a low dose of MTX inhibits the progression of arthritis in collagen‐induced arthritis (CIA) rats.

Methods

Methotrexate was orally administered once weekly, thrice weekly and once daily to CIA rats, and arthritis scores were measured.

Key findings

When the same dose of MTX was administered, the exacerbation of arthritis was inhibited significantly more in the once‐daily group than in the other groups. When the dose in the once‐daily group was reduced to one‐fourth that of the current standard dosing method, arthritis scores were markedly lower in the once‐daily group than in the once and thrice‐weekly groups.

Conclusions

The daily administration of a low dose of MTX not only maintained normal levels that estimated adverse effects but also suppressed the progression of arthritis significantly more than the current standard dosing method. The results indicate that the reconsideration of dosing schedules based on the characteristics of MTX will lead to more effective RA therapy than that currently used in clinical practice.

intermittent sunitinib dosing schedule in metastatic renal cell cancer patients

Aim of the study

Sunitinib-related side effects may develop as a result of the pharmacokinetic pathway affects the of the drug.

Material and methods

Data on mRCC patients were obtained from the hospital archives. Outcomes of patients were evaluated in terms of related prognostic factors, sunitinib adverse events during the treatment, and two different sunitinib dosing schedules.

Results

Seventy patients diagnosed with mRCC and treated with sunitinib were analyzed for prognostic factors and survival rates. During the mean follow-up of 33.5 months, 38 (54%) patients were alive and 32 (46%) patients died. The median time of overall survival (OS) and progression-free survival (PFS) was 27 months (12–61) and 19 months (5–45), respectively. In univariate analysis, good prognostic risk group according to the Memorial Sloan-Kettering Cancer Center (MSKCC), hypothyroidism as sunitinib toxicity and patients on sunitinib treatment more than 1 year were favorable prognostic factors for OS. Leukopenia and fatigue as sunitinib toxicity were poor prognostic factors for OS. PFS and OS of the patients were not significantly different when we compared intermittent (4/2) vs. continuous treatment dosing schedules.

Conclusions

As a result of this trial, having hypothyroidism as an adverse effect of sunitinib was a favorable prognostic factor for OS and PFS in mRCC patients. It was also found that 4/2 and continuous dosing schedules of sunitinib did not give rise to different outcomes in mRCC patients.

Clinical efficacy of dalbavancin for the treatment of acute bacterial skin and skin structure infections (ABSSSI)

Acute bacterial skin and skin structure infections (ABSSSI) are a common disease causing patients to seek treatment through the health care system. With the continued increase of drug-resistant bacterial pathogens, these infections are becoming more difficult to successfully cure. Lipoglycopeptides have unique properties that allow the drug to remain active toward both common and challenging pathogens at the infected site for lengthy periods of time. Dalbavancin, a new lipoglycopeptide, provides two unique dosing regimens for the treatment of ABSSSI. The original regimen of 1,000 mg intravenous infusion followed by a 500 mg intravenous infusion after a week has been shown as safe and effective in multiple, randomized noninferiority trials. These studies also demonstrated that dalbavancin was similar to standard regimens in terms of both safety and tolerability. Recently a single 1,500 mg dose was demonstrated to be equivalent to the dalbavancin two-dose regimen for treating ABSSSI. With the introduction of dalbavancin, clinicians have the option to provide an intravenous antimicrobial agent shown to be as effective as traditional therapies, without requiring admission into the hospitals or prescribing a medication which may not be utilized optimally. Further understanding of dalbavancin and its unusual properties can provide unique treatment situations with potential benefits for both the patient and the overall health care system, which should be further explored.

Simultaneous Determination of Plasma Deferasirox and Deferasirox-Iron Complex Using an HPLC-UV System and Pharmacokinetics of Deferasirox in Patients With β-Thalassemia Major: Once-daily Versus Twice-daily Administration

PURPOSE

Deferasirox (DEFR), when administered BID, improves iron overload and decreases DEFR-related adverse effects in patients with β-thalassemia major. However, the pharmacokinetic (PK) disposition of DEFR and the iron-DEFR complex (Fe-[DEFR]2) in this dosing strategy is unclear.

METHODS

Chromatographic analysis was performed using a solvent delivery system coupled to an HPLC-UV detector to determine the steady-state concentrations of DEFR (CDEFR) and Fe-(DEFR)2 (CFe-[DEFR]2) in β-thalassemia major patients (n = 8) following either once-daily or BID dosing, during which the PK parameters of the 2 dosing schedules were compared.

FINDINGS

An HPLC-UV system for the analysis of blood samples following solid-phase extraction was validated. Patients who received 40 mg/kg of DEFR had higher mean CDEFR and CFe-[DEFR]2 values at all sampling times. However, concentrations of iron-DEFR complex were similar in patients who received 30 or 40 mg/kg of DEFR in the once-daily group at the 6- to 24-hour sampling times. There was no significant difference in any of the PK parameters; however, DEFR administration BID increased the mean trough levels of DEFR (183.8 [157.5] μmol/L) compared with once daily (87.7 [56.8] μmol/L), whereas all the patients had increased peak levels per individual DEFR dose when they were switched from once daily to BID (139.0 [59.8] μmol/L vs 289.2 [145.8] μmol/L, respectively).

IMPLICATIONS

Splitting the dose increased the peak levels of DEFR per unit dose in all patients and tends to increase drug exposures, but there were no significant differences in DEFR PK parameter estimates. Switching from once daily to BID may be considered for patients with an inadequate response to chelation therapy to achieve optimal drug levels. Further research is needed with a larger sample size to determine the clinical importance of the significant results due to the interindividual variability of DEFR.

Negative impact of physician prescribed drug dosing schedule requirements on patient adherence to cardiovascular drugs

PURPOSE

The aim of this study was to determine whether dosing schedule requirements impair overall cardiovascular drug adherence.

METHODS

A cohort study was performed with hospitalized patients at high risk of cardiovascular disease between April and September 2011. Patients were asked whether the prescribed time for taking their statin and antiplatelet drugs created any inconvenience in their daily routine and, if so, were asked to describe the reasons. Patient adherence to treatment was assessed using the Morisky Medication Adherence Scale (MMAS-8). A cohort of physicians was separately studied between June and September 2011. Physicians were interviewed to determine their dosing schedule preference when prescribing statin and anti-platelet drugs, and the rationale for choosing a specific dosing schedule.

RESULTS

In the study, 103 patients and 59 physicians were included. Statins were most frequently prescribed in the evening (90%). Thienopyridines were prescribed both at lunch time (41%) and in the morning (35%). Aspirin was most frequently (65.3%) prescribed at lunch time. In total, 24.3% of patients reported being inconvenienced by their drug dosing schedule, and these subjects were less adherent to their drug regimen than those who did not report inconvenience (46.2% versus 16.7%, p = 0.014). Our results also demonstrate that there is no pharmacologic rationale for prescribing a particular drug dosing schedule for statin or anti-platelet drugs.

CONCLUSIONS

Physicians should assess patient convenience, when prescribing medication, to optimize treatment adherence.

Efficacy of protracted temozolomide dosing is limited in MGMT unmethylated GBM xenograft models

BACKGROUND

Temozolomide (TMZ) is important chemotherapy for glioblastoma multiforme (GBM), but the optimal dosing schedule is unclear.

METHODS

The efficacies of different clinically relevant dosing regimens were compared in a panel of 7 primary GBM xenografts in an intracranial therapy evaluation model.

RESULTS

Protracted TMZ therapy (TMZ daily M-F, 3 wk every 4) provided superior survival to a placebo-treated group in 1 of 4 O(6)-DNA methylguanine-methyltransferase (MGMT) promoter hypermethylated lines (GBM12) and none of the 3 MGMT unmethylated lines, while standard therapy (TMZ daily M-F, 1 wk every 4) provided superior survival to the placebo-treated group in 2 of 3 MGMT unmethylated lines (GBM14 and GBM43) and none of the methylated lines. In comparing GBM12, GBM14, and GBM43 intracranial specimens, both GBM14 and GBM43 mice treated with protracted TMZ had a significant elevation in MGMT levels compared with placebo. Similarly, high MGMT was found in a second model of acquired TMZ resistance in GBM14 flank xenografts, and resistance was reversed in vitro by treatment with the MGMT inhibitor O(6)-benzylguanine, demonstrating a mechanistic link between MGMT overexpression and TMZ resistance in this line. Additionally, in an analysis of gene expression data, comparison of parental and TMZ-resistant GBM14 demonstrated enrichment of functional ontologies for cell cycle control within the S, G2, and M phases of the cell cycle and DNA damage checkpoints.

CONCLUSIONS

Across the 7 tumor models studied, there was no consistent difference between protracted and standard TMZ regimens. The efficacy of protracted TMZ regimens may be limited in a subset of MGMT unmethylated tumors by induction of MGMT expression.

A randomized, masked study of weekly erythropoietin dosing in preterm infants

OBJECTIVE

To compare reticulocyte responses of once-per-week erythropoietin (EPO) dosing with 3-times-a-week dosing in preterm infants.

STUDY DESIGN

Infants weighing ≤ 1500 g and ≥ 7 days of age were randomized to once-per-week EPO, 1200 U/kg/dose, or 3-times-a-week EPO, 400 U/kg/dose, subcutaneously for 4 weeks, along with iron and vitamin supplementation. Complete blood counts, absolute reticulocyte counts (ARCs), transfusions, phlebotomy losses, and adverse events were recorded.

RESULTS

Twenty preterm infants (962 ± 55 g, 27.9 ± 0.4 weeks, 17 ± 3 days of age) were enrolled. Groups were similar at baseline. Infants in both groups had increased ARCs, which were similar between treatment groups at the start and end of 4 weeks. Hematocrit remained stable, and similar numbers of transfusions were administered. No adverse effects of either dosing schedule were noted.

CONCLUSIONS

Preterm infants respond to weekly EPO by increasing ARCs and maintaining hematocrit. We speculate that once-per-week EPO dosing might be beneficial to preterm infants requiring increased erythropoiesis.

Antipsychotic dosing: how much but also how often?

Considerable focus has been devoted to how much antipsychotic is appropriate for optimal clinical response, although how often antipsychotics need to be administered is also less than clear. Clinicians are aware of the increased risk of relapse related to antipsychotic nonadherence/discontinuation, and current practice dictates continuous antipsychotic exposure with the goal of achieving steady state-levels to maintain effectiveness and prevent relapse. Does this mean we need to (or should) administer antipsychotics at least daily? There is a body of evidence challenging this long-established clinical axiom.