Modular Titratable Polypills for Personalized Medicine and Simplification of Complex Medication Regimens

Simplification of complex medication regimens in polypharmacy positively contributes to treatment adherence and cost-effective improved health outcomes. Even though fixed dose combination (FDC) drug products are the only currently available single dose poly-pill regimens, the lack of flexibility in dose adjustment of a single drug in the combination limits their efficacy. To fill the existing gap in drug dose personalization and simplification of complex medication regimens commonly encountered in the treatment of cardiovascular disease, tuberculosis, and tapering of corticosteroid therapy, a modular titratable polypill approach that simultaneously addresses both aspects is proposed. The polypill consists of modular units that contain different drugs at incremental or decremental doses to be assembled in a single titratable polypill at the required dose for each drug through a stacking or interlocking process. The variable dose (VD) modular tablets are subjected to quality control tests and found to comply to pharmacopeia's acceptance criteria and requirements specified in the respective drug monographs. A cost-effectiveness analysis is conducted supporting the VD strategy as cost-effective compared to the FDC strategy and more effective and less expensive than standard of care. The VD approach stands to enable pill burden reduction, ease of administration, enhancement of treatment adherence, and potential cost-saving benefits.

Respirators in Healthcare: Material, Design, Regulatory, Environmental, and Economic Considerations for Clinical Efficacy

Maintaining an ample supply of personal protective equipment continues to be a challenge for the healthcare industry, especially during emergency situations and times of strain on the supply chain. Most critically, healthcare workers exposed to potential airborne hazards require sufficient respiratory protection. Respirators are the only type of personal protective equipment able to provide adequate respiratory protection. However, their ability to shield hazards depends on design, material, proper fit, and environmental conditions. As a result, not all respirators may be adequate for all scenarios. Additionally, factors including user comfort, ease of use, and cost contribute to respirator effectiveness. Therefore, a careful consideration of these parameters is essential for ensuring respiratory protection for those working in the healthcare industry. Here respirator design and material characteristics are reviewed, as well as properties of airborne hazards and potential filtration mechanisms, regulatory standards of governmental agencies, respirator efficacy in the clinical setting, attitude of healthcare personnel toward respiratory protection, and environmental and economic considerations of respirator manufacturing and distribution.

Dynamic Monitoring of Systemic Biomarkers with Gastric Sensors

Continuous monitoring in the intensive care setting has transformed the capacity to rapidly respond with interventions for patients in extremis. Noninvasive monitoring has generally been limited to transdermal or intravascular systems coupled to transducers including oxygen saturation or pressure. Here it is hypothesized that gastric fluid (GF) and gases, accessible through nasogastric (NG) tubes, commonly found in intensive care settings, can provide continuous access to a broad range of biomarkers. A broad characterization of biomarkers in swine GF coupled to time-matched serum is conducted . The relationship and kinetics of GF-derived analyte level dynamics is established by correlating these to serum levels in an acute renal failure and an inducible stress model performed in swine. The ability to monitor ketone levels and an inhaled anaesthetic agent (isoflurane) in vivo is demonstrated with novel NG-compatible sensor systems in swine. Gastric access remains a main stay in the care of the critically ill patient, and here the potential is established to harness this establishes route for analyte evaluation for clinical management.

Patient and Health Care Worker Perceptions of Communication and Ability to Identify Emotion When Wearing Standard and Transparent Masks

IMPORTANCE

Adoption of mask wearing in response to the COVID-19 pandemic alters daily communication.

OBJECTIVE

To assess communication barriers associated with mask wearing in patient-clinician interactions and individuals who are deaf and hard of hearing.

DESIGN, SETTING, AND PARTICIPANTS

This pilot cross-sectional survey study included the general population, health care workers, and health care workers who are deaf or hard of hearing in the United States. Volunteers were sampled via an opt-in survey panel and nonrandomized convenience sampling. The general population survey was conducted between January 5 and January 8, 2021. The health care worker surveys were conducted between December 3, 2020, and January 3, 2021. Respondents viewed 2 short videos of a study author wearing both a standard and transparent N95 mask and answered questions regarding mask use, communication, preference, and fit. Surveys took 15 to 20 minutes to complete.

MAIN OUTCOMES AND MEASURES

Participants' perceptions were assessed surrounding the use of both mask types related to communication and the ability to express emotions.

RESULTS

The national survey consisted of 1000 participants (mean [SD] age, 48.7 [18.5] years; 496 [49.6%] women) with a response rate of 92.25%. The survey of general health care workers consisted of 123 participants (mean [SD] age, 49.5 [9.0] years; 84 [68.3%] women), with a response rate of 11.14%. The survey of health care workers who are deaf or hard of hearing consisted of 45 participants (mean [SD] age, 54.5 [9.0] years; 30 [66.7%] women) with a response rate of 23.95%. After viewing a video demonstrating a study author wearing a transparent N95 mask, 781 (78.1%) in the general population, 109 general health care workers (88.6%), and 38 health care workers who are deaf or hard of hearing (84.4%) were able to identify the emotion being expressed, in contrast with 201 (20.1%), 25 (20.5%), and 11 (24.4%) for the standard opaque N95 mask. In the general population, 450 (45.0%) felt positively about interacting with a health care worker wearing a transparent mask; 76 general health care workers (61.8%) and 37 health care workers who are deaf or hard of hearing (82.2%) felt positively about wearing a transparent mask to communicate with patients.

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that transparent masks could help improve communication during the COVID-19 pandemic, particularly for individuals who are deaf and hard of hearing.

Personalized Radiation Attenuating Materials for Gastrointestinal Mucosal Protection

Cancer patients undergoing therapeutic radiation routinely develop injury of the adjacent gastrointestinal (GI) tract mucosa due to treatment. To reduce radiation dose to critical GI structures including the rectum and oral mucosa, 3D-printed GI radioprotective devices composed of high-Z materials are generated from patient CT scans. In a radiation proctitis rat model, a significant reduction in crypt injury is demonstrated with the device compared to without (p < 0.0087). Optimal device placement for radiation attenuation is further confirmed in a swine model. Dosimetric modeling in oral cavity cancer patients demonstrates a 30% radiation dose reduction to the normal buccal mucosa and a 15.2% dose reduction in the rectum for prostate cancer patients with the radioprotectant material in place compared to without. Finally, it is found that the rectal radioprotectant device is more cost-effective compared to a hydrogel rectal spacer. Taken together, these data suggest that personalized radioprotectant devices may be used to reduce GI tissue injury in cancer patients undergoing therapeutic radiation.

Assessment of the Acceptability and Feasibility of Using Mobile Robotic Systems for Patient Evaluation

IMPORTANCE

Before the widespread implementation of robotic systems to provide patient care during the COVID-19 pandemic occurs, it is important to understand the acceptability of these systems among patients and the economic consequences associated with the adoption of robotics in health care settings.

OBJECTIVE

To assess the acceptability and feasibility of using a mobile robotic system to facilitate health care tasks.

DESIGN, SETTING, AND PARTICIPANTS

This study included 2 components: a national survey to examine the acceptability of using robotic systems to perform health care tasks in a hospital setting and a single-site cohort study of patient experiences and satisfaction with the use of a mobile robotic system to facilitate triage and telehealth tasks in the emergency department (ED). The national survey comprised individuals living in the US who participated in a sampling-based survey via an online analytic platform. Participants completed the national survey between August 18 and August 21, 2020. The single-site cohort study included patients living in the US who presented to the ED of a large urban academic hospital providing quaternary care in Boston, Massachusetts between April and August 2020. All data were analyzed from August to October 2020.

EXPOSURES

Participants in the national survey completed an online survey to measure the acceptability of using a mobile robotic system to perform health care tasks (facilitating telehealth interviews, acquiring vital signs, obtaining nasal or oral swabs, placing an intravenous catheter, performing phlebotomy, and turning a patient in bed) in a hospital setting in the contexts of general interaction and interaction during the COVID-19 pandemic. Patients in the cohort study were exposed to a mobile robotic system, which was controlled by an ED clinician and used to facilitate a triage interview. After exposure, patients completed an assessment to measure their satisfaction with the robotic system.

MAIN OUTCOMES AND MEASURES

Acceptability of the use of a mobile robotic system to facilitate health care tasks in a hospital setting (national survey) and feasibility and patient satisfaction regarding the use of a mobile robotic system in the ED (cohort study).

RESULTS

For the national survey, 1154 participants completed all acceptability questions, representing a participation rate of 35%. After sample matching, a nationally representative sample of 1000 participants (mean [SD] age, 48.7 [17.0] years; 535 women [53.5%]) was included in the analysis. With regard to the usefulness of a robotic system to perform specific health care tasks, the response of "somewhat useful" was selected by 373 participants (37.3%) for facilitating telehealth interviews, 350 participants (35.0%) for acquiring vital signs, 307 participants (30.7%) for obtaining nasal or oral swabs, 228 participants (22.8%) for placing an intravenous catheter, 249 participants (24.9%) for performing phlebotomy, and 371 participants (37.1%) for turning a patient in bed. The response of "extremely useful" was selected by 287 participants (28.7%) for facilitating telehealth interviews, 413 participants (41.3%) for acquiring vital signs, 192 participants (19.2%) for obtaining nasal or oral swabs, 159 participants (15.9%) for placing an intravenous catheter, 167 participants (16.7%) for performing phlebotomy, and 371 participants (37.1%) for turning a patient in bed. In the context of the COVID-19 pandemic, the median number of individuals who perceived the application of robotic systems to be acceptable for completing telehealth interviews, obtaining nasal and oral swabs, placing an intravenous catheter, and performing phlebotomy increased. For the ED cohort study, 51 individuals were invited to participate, and 41 participants (80.4%) enrolled. One participant was unable to complete the study procedures because of a signaling malfunction in the robotic system. Forty patients (mean [SD] age, 45.8 [2.7] years; 29 women [72.5%]) completed the mobile robotic system-facilitated triage interview, and 37 patients (92.5%) reported that the interaction was satisfactory. A total of 33 participants (82.5%) reported that their experience of receiving an interview facilitated by a mobile robotic system was as satisfactory as receiving an in-person interview from a clinician.

CONCLUSIONS AND RELEVANCE

In this study, a mobile robotic system was perceived to be acceptable for use in a broad set of health care tasks among survey respondents across the US. The use of a mobile robotic system enabled the facilitation of contactless triage interviews of patients in the ED and was considered acceptable among participants. Most patients in the ED rated the quality of mobile robotic system-facilitated interaction to be equivalent to in-person interaction with a clinician.

Prospective Evaluation of the Transparent, Elastomeric, Adaptable, Long-Lasting (TEAL) Respirator

N95 filtering facepiece respirators (FFR) and surgical masks are essential in reducing airborne disease transmission, particularly during the COVID-19 pandemic. However, currently available FFR's and masks have major limitations, including masking facial features, waste, and integrity after decontamination. In a multi-institutional trial, we evaluated a transparent, elastomeric, adaptable, long-lasting (TEAL) respirator to evaluate success of qualitative fit test with user experience and biometric evaluation of temperature, respiratory rate, and fit of respirator using a novel sensor. There was a 100% successful fit test among participants, with feedback demonstrating excellent or good fit (90% of participants), breathability (77.5%), and filter exchange (95%). Biometric testing demonstrated significant differences between exhalation and inhalation pressures among a poorly fitting respirator, well-fitting respirator, and the occlusion of one filter of the respirator. We have designed and evaluated a transparent elastomeric respirator and a novel biometric feedback system that could be implemented in the hospital setting.

Development of a long-acting direct-acting antiviral system for hepatitis C virus treatment in swine

Chronic hepatitis C virus (HCV) infection is a leading cause of cirrhosis worldwide and kills more Americans than 59 other infections, including HIV and tuberculosis, combined. While direct-acting antiviral (DAA) treatments are effective, limited uptake of therapy, particularly in high-risk groups, remains a substantial barrier to eliminating HCV. We developed a long-acting DAA system (LA-DAAS) capable of prolonged dosing and explored its cost-effectiveness. We designed a retrievable coil-shaped LA-DAAS compatible with nasogastric tube administration and the capacity to encapsulate and release gram levels of drugs while resident in the stomach. We formulated DAAs in drug-polymer pills and studied the release kinetics for 1 mo in vitro and in vivo in a swine model. The LA-DAAS was equipped with ethanol and temperature sensors linked via Bluetooth to a phone application to provide patient engagement. We then performed a cost-effectiveness analysis comparing LA-DAAS to DAA alone in various patient groups, including people who inject drugs. Tunable release kinetics of DAAs was enabled for 1 mo with drug-polymer pills in vitro, and the LA-DAAS safely and successfully provided at least month-long release of sofosbuvir in vivo. Temperature and alcohol sensors could interface with external sources for at least 1 mo. The LA-DAAS was cost-effective compared to DAA therapy alone in all groups considered (base case incremental cost-effectiveness ratio $39,800). We believe that the LA-DAA system can provide a cost-effective and patient-centric method for HCV treatment, including in high-risk populations who are currently undertreated.

Cost-Effectiveness Analysis of Biomarker-Guided Treatment for Metastatic Gastric Cancer in the Second-Line Setting

BACKGROUND

The 5-year survival rate of patients with metastatic gastric cancer (GC) is only 5%. However, trials have demonstrated promising antitumor activity for targeted therapies/immunotherapies among chemorefractory metastatic GC patients. Pembrolizumab has shown particular efficacy among patients with programmed death ligand-1 (PD-L1) expression and high microsatellite instability (MSI-H). The aim of this study was to assess the effectiveness and cost-effectiveness of biomarker-guided second-line GC treatment.

METHODS

We constructed a Markov decision-analytic model using clinical trial data. Our model compared pembrolizumab monotherapy and ramucirumab/paclitaxel combination therapy for all patients and pembrolizumab for patients based on MSI status or PD-L1 expression. Paclitaxel monotherapy and best supportive care for all patients were additional comparators. Costs of drugs, treatment administration, follow-up, and management of adverse events were estimated from a US payer perspective. The primary outcomes were quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) with a willingness-to-pay threshold of $100,000/QALY over 60 months. Secondary outcomes were unadjusted life years (survival) and costs. Deterministic and probabilistic sensitivity analyses were performed to evaluate model uncertainty.

RESULTS

The most effective strategy was pembrolizumab for MSI-H patients and ramucirumab/paclitaxel for all other patients, adding 3.8 months or 2.0 quality-adjusted months compared to paclitaxel. However, this strategy resulted in a prohibitively high ICER of $1,074,620/QALY. The only cost-effective strategy was paclitaxel monotherapy for all patients, with an ICER of $53,705/QALY.

CONCLUSION

Biomarker-based treatments with targeted therapies/immunotherapies for second-line metastatic GC patients substantially improve unadjusted and quality-adjusted survival but are not cost-effective at current drug prices.

Flu vaccination rate of patients with severe immune-related adverse events

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Background: Infection with influenza in adults with cancer carries an increased risk of morbidity and mortality. Vaccination against seasonal influenza (Flu-V) can decrease the incidence of influenza, shorten its course, and reduce influenza-associated morbidity. Recent data has suggested that the administration of the Flu-V to patients on an ICI leads to an exaggerated inflammatory response and an increased risk of irAE. However, this trend was demonstrated in a small cohort of patients with lung cancer. Current recommendation for annual Flu-V in patients treated with ICI is unclear and literature about safety is limited. We compared rates of Flu-V for patients on ICI admitted with severe toxicity vs those patients on ICI who were admitted for reasons other than toxicity. We also evaluated rate of Flu-V among oncology patients who had received non-immunotherapy modalities. Methods: We retrospectively evaluated patients treated with ICI who were admitted to Massachusetts General Hospital from February 5, 2011- June 12, 2017. Patients received ipilimumab, pembrolizumab, nivolumab, atezolizumab, durvalumab, avelumab, or a combination in treatment of an advanced solid tumor malignancies including melanoma, NSCLC, SCCHN. Admissions due to irAE were confirmed by review of clinical, radiologic, and pathologic features. Flu-V status was determined by rigorous chart review. Nearest neighbor matching was used to create a control group of cancer patients treated with non-ICI modalities. Descriptive statistics compared rates and timing of Flu-V relative to admission. Statistical significance was determined using Fischer’s Exact Test, p < 0.05. Results: Of 540 patients on ICI, 28% were admitted for irAE, 72% had a non-irAE reason for admission. The rate of Flu-V in the flu season prior to admission for irAE group was lower than for non-irAE (18.5% vs 29.6%; p value = 0.01). There were no differences in vaccination rates within ≤30 days (2.7% vs 3.6%, p = 0.80), ≤90 days (4.0% vs 9.3%, p = 0.05), or ≤180 days of admission (11.9% vs 18.5%, p = 0.07). Flu-V rate overall in patients on ICI was 26.5%. In comparison, Flu-V rate in the nearest neighbor non-immunotherapy oncology patients was 67% (n = 101). Conclusions: Flu-V rates were much lower in patients treated with ICI compared to patients treated with non-ICI modalities. We did not see a higher rate of Flu-V in patients admitted with irAE compared to non-irAE which suggests that Flu-V and severe irAE may not be linked in clinical practice. Additional studies are needed, but Flu-V in patients on ICI holds potential to improve care.

Second-line treatment of metastatic gastric cancer in the era of predictive biomarkers: A cost-effectiveness analysis

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Background: Gastric cancer is the third leading cause of cancer-related mortality, with only a 30% five-year survival rate. Patients who progress after one round of systemic therapy face an especially poor prognosis. The National Comprehensive Cancer Network guidelines include both pembrolizumab (PEM) and ramucirumab plus paclitaxel (RAM/PAC) as second-line (2L) therapy for gastric cancer based on data from the Phase II KEYNOTE-059 and Phase III RAINBOW trials, respectively. Recently, the Phase III KEYNOTE-061 trial reported on the effectiveness of PEM for patients with programmed death-ligand 1 (PD-L1) expression and high microsatellite instability (MSI-H). Given the high prices of targeted therapies, it is important to determine if cost-effectiveness is possible using personalized treatment strategies. The aim of this study was to assess the cost-effectiveness of these regimens in both the general patient population and specific biomarker populations. Methods: A decision-analytic (Markov) model was constructed using data from the KEYNOTE-059, KEYNOTE-061, RAINBOW, and REGARD trials. The analysis compared PEM and RAM/PAC for all patients, as well as PEM for patients based on MSI status or PD-L1 expression (combined positive score of 1% or 10%) in the 2L setting. Comparators were paclitaxel monotherapy (PAC) for all patients and best supportive care (BSC) for all patients. Costs (USD) and utility values were estimated from Medicare and the literature. The primary outcome was the incremental cost-effectiveness ratio (ICER) with a willingness-to-pay (WTP) threshold of $100,000. Results: The only cost-effective strategy was PAC monotherapy for all patients, with an ICER of $53,705/QALY. PEM for MSI-H patients and RAM/PAC for microsatellite stable patients was the most effective strategy (greatest QALYs), but was not cost-effective with an ICER of $1,074,620/QALY. Conclusions: Despite their effectiveness, PEM and RAM/PAC are not cost-effective as 2L treatments for metastatic gastric cancer. Although personalizing treatment based on biomarkers improved cost-effectiveness, the ICERs surpassed the WTP threshold at current drug prices.

Cost-effectiveness of immune checkpoint inhibitors for microsatellite instability-high/mismatch repair-deficient metastatic colorectal cancer

BACKGROUND

Patients with microsatellite instability-high (MSI-H)/mismatch repair-deficient (dMMR) metastatic colorectal cancer (mCRC) show a significant response to checkpoint inhibitor therapies, but the economic impact of these therapies is unknown. A decision analytic model was used to explore the effectiveness and cost burden of MSI-H/dMMR mCRC treatment.

METHODS

The treatment of hypothetical patients with MSI-H/dMMR mCRC was simulated in 2 treatment scenarios: a third-line treatment and an exploratory first-line treatment. The treatments compared were nivolumab, ipilimumab and nivolumab, trifluridine and tipiracil (third-line treatment), and mFOLFOX6 and cetuximab (first-line treatment). Disease progression, drug toxicity, and survival rates were based on the CheckMate 142, study of TAS-102 in patients with metastatic colorectal cancer refractory to standard chemotherapies (RECOURSE), and Cancer and Leukemia Group B/Southwest Oncology Group 80405 trials. The analyzed outcomes included survival (life-years), quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs).

RESULTS

Ipilimumab with nivolumab was the most effective strategy (10.69 life-years and 9.25 QALYs for the third line; 10.69 life-years and 9.44 QALYs for the first line) in comparison with nivolumab (8.21 life-years and 6.76 QALYs for the third line; 8.21 life-years and 7.00 QALYs for the first line), trifluridine and tipiracil (0.74 life-years and 0.07 QALYs), and mFOLFOX6 and cetuximab (2.72 life-years and 1.63 QALYs). However, neither checkpoint inhibitor therapy was cost-effective in comparison with trifluridine and tipiracil (nivolumab ICER, $153,000; ipilimumab and nivolumab ICER, $162,700) or mFOLFOX6 and cetuximab (nivolumab ICER, $150,700; ipilimumab and nivolumab ICER, $158,700).

CONCLUSIONS

This modeling analysis found that both single and dual checkpoint blockade could be significantly more effective for MSI-H/dMMR mCRC than chemotherapy, but they were not cost-effective, largely because of drug costs. Decreases in drug pricing and/or the duration of maintenance nivolumab could make ipilimumab and nivolumab cost-effective. Prospective clinical trials should be performed to explore the optimal duration of maintenance nivolumab.

Surgical vs Endoscopic Management of T1 Esophageal Adenocarcinoma: A Modeling Decision Analysis

BACKGROUND & AIMS

Although treatment of T1a esophageal adenocarcinoma (EAC) is shifting from esophagectomy to endoscopic therapy, T1b EACs are considered too high risk to be treated endoscopically. We investigated the effectiveness and cost effectiveness of esophagectomy vs endoscopic therapy for T1a and T1b EACs, and the effects of age and comorbidities, using a decision analytic Markov model.

METHODS

We developed a model to simulate a hypothetical cohort of men 75 years old with Charlson comorbidity index scores of 0 and either T1aN0M0 or T1bN0M0 EAC, as a base case. We used the model to compare the effects of esophagectomy vs serial endoscopic therapy. We performed sensitivity analyses based on age at diagnosis of 60-85 years, comorbidity indices of 0-2, and utilities. Post-procedure cancer-specific mortality was derived from the Surveillance, Epidemiology, and End Results Medicare database.

RESULTS

In the T1a base case, esophagectomy yielded more unadjusted life years than endoscopic therapy (6.97 vs 6.81), but fewer quality-adjusted life years (QALYs, 4.95 for esophagectomy vs 5.22 for endoscopic therapy). In the T1b base case, esophagectomy yielded more unadjusted life years than endoscopic therapy (5.73 vs 5.01) and QALYs (4.07 vs 3.85 for endoscopic therapy), but was not cost effective (incremental cost-effectiveness ratio $156,981). Sensitivity analyses showed endoscopic therapy optimized QALYs for patients more than 80 years old with a comorbidity index of 1 or 2, or if the ratio of post-esophagectomy to post-endoscopic therapy utilities was below 0.875.

CONCLUSION

In a Markov model, we showed that endoscopic therapy of T1a EAC yields more QALYs and is more cost effective than esophagectomy for patients of all ages and comorbidity indices tested. In contrast, selection of therapy for T1b EAC depends on age and comorbidities, due to surgical mortality and the competing risk of non-cancer death.

Nivolumab versus nivolumab with ipilimumab versus trifluridine/tipiracil for metastatic microsatellite instability-high colorectal cancer: A modeling decision analysis

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Background: Microsatellite instability-high (MSI-H) metastatic colorectal cancer (mCRC) patients who have failed chemotherapy have shown response to checkpoint blockade. We investigate optimal third-line treatment in MSI-H mCRC with regard to overall survival, quality of life years gained (QALYs), and cost-effectiveness. Methods: A Markov Model was created for a base case of a 57 year old man with MSI-H mCRC refractory to two lines of chemotherapy. Treatments compared were nivolumab, nivolumab with ipilimumab, and trifluridine/tipiracil. Patients could remain stable, progress to fourth-line chemotherapy or palliative care, experience drug toxicity, die from age/sex mortality, or die from cancer over their simulated lifetimes. Transitions between health states were based on the CheckMate 142 and RECOURSE trials. Outcomes were survival or unadjusted life years, QALYs, and incremental cost-effectiveness ratios (ICERs). The willingness to pay threshold was $100,000/QALY. Results: Nivolumab with ipilimumab was the most effective strategy as it yielded more unadjusted life-years (4.24) and QALYs (2.53) compared to nivolumab (3.95 LY, 2.33 QALYs) and trifluridine/tipiracil (0.74 LY, 0.07 QALYs). However, nivolumab with ipilimumab was not cost-effective compared to nivolumab and neither treatment strategy was cost-effective compared to trifluridine/tipiracil. Sensitivity analysis found nivolumab monotherapy could be cost-effective with decrease in drug cost to $2000/dose. Conclusions: Our modeling analysis finds that both single and dual checkpoint blockade yield significantly increased overall survival and QALYs for MSI-H mCRC compared to third-line chemotherapy, but were not cost-effective because of nivolumab cost. Decreases in drug pricing and/or duration of maintenance nivolumab could make nivolumab monotherapy cost-effective. [Table: see text]

Cost-effectiveness of immune checkpoint inhibition in metastatic gastric and esophageal tumors

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Background: Immune checkpoint inhibition has shown early promising results in patients with chemotherapy-refractory metastatic or advanced tumors of the esophagus, gastroesophageal junction, and stomach. We explore the cost-effectiveness of checkpoint inhibitors as second-line treatment agents for this group of patients using a decision analytic approach. Methods: A Markov model was developed to simulate the course of a virtual cohort of patients treated by (i) nivolumab 3 mg/kg, (ii) combination of ipilimumab 3 mg/kg and nivolumab 1 mg/kg, and (iii) best supportive care (BSC). Patients in the hypothetical cohort were 55-year-olds in an advanced/metastatic stage who had received at least one prior line of chemotherapy. Patients who remained stable in treatment were monitored for adverse events until death. Rates of cancer-specific mortality, disease progression, and drug-related adverse events were estimated using results from the CheckMate 032 clinical trial. The primary endpoints were survival, measured in life-years (LY), quality adjusted life years (QALY), and incremental cost-effectiveness ratios (ICER). Cost-effectiveness of each strategy was evaluated from a US-payer perspective considering costs of drugs, treatment, and management of immune-related adverse events. Cost-effectiveness was defined with a willingness to pay threshold of $100,000/QALY. Results: Combination therapy with nivolumab and ipilimumab yielded the highest effectiveness (QALYs = 0.47, LYs = 1.09) in our base case modeling results, compared with nivolumab (QALYs = 0.43, LYs = 1.03), and BSC (QALYs = 0.19, LYs = 0.42). Nivolumab had an incremental cost of $84,555/QALY compared with BSC, while nivolumab with ipilimumab resulted in an incremental cost of $1.1M/QALY compared with nivolumab alone. The cost gap between the two was associated with the higher price of ipilimumab, and costs of managing increased toxicity. Conclusions: Our modeling analysis finds that combination therapy of ipilimumab and nivolumab is the most effective, but from a cost-effectiveness perspective, it is expensive, making nivolumab monotherapy the cost-effective option. Additional clinical data are needed to confirm our modeling results.

Long-term expression of human coagulation factor VIII in a tolerant mouse model using the φC31 integrase system

We generated a mouse model for hemophilia A that combines a homozygous knockout for murine factor VIII (FVIII) and a homozygous addition of a mutant human FVIII (hFVIII). The resulting mouse, having no detectable FVIII protein or activity and tolerant to hFVIII, is useful for evaluating FVIII gene-therapy protocols. This model was used to develop an effective gene-therapy strategy using the φC31 integrase to mediate permanent genomic integration of an hFVIII cDNA deleted for the B-domain. Various plasmids encoding φC31 integrase and hFVIII were delivered to the livers of these mice by using hydrodynamic tail-vein injection. Long-term expression of therapeutic levels of hFVIII was observed over a 6-month time course when an intron was included in the hFVIII expression cassette and wild-type φC31 integrase was used. A second dose of the hFVIII and integrase plasmids resulted in higher long-term hFVIII levels, indicating that incremental doses were beneficial and that a second dose of φC31 integrase was tolerated. We observed a significant decrease in the bleeding time after a tail-clip challenge in mice treated with plasmids expressing hFVIII and φC31 integrase. Genomic integration of the hFVIII expression plasmid was demonstrated by junction PCR at a known hotspot for integration in mouse liver. The φC31 integrase system provided a nonviral method to achieve long-term FVIII gene therapy in a relevant mouse model of hemophilia A.

Kinetics and longevity of ΦC31 integrase in mouse liver and cultured cells

The ΦC31 integrase system provides genomic integration of plasmid DNA that may be useful in gene therapy. For example, the ΦC31 system has been used in combination with hydrodynamic injection to achieve long-term expression of factor IX in mouse liver. However, a concern is that prolonged expression of ΦC31 integrase within cells could potentially stimulate chromosome rearrangements or an immune response. Western blot and immunofluorescence analyses were performed to investigate the duration of ΦC31 integrase expression in mouse liver. Integrase was expressed within 2 to 3 hr after hydrodynamic injection of a plasmid expressing ΦC31 integrase. Expression peaked between 8 and 16 hr and fell to background levels by 24-48 hr postinjection. Analysis of the amount of integrase plasmid DNA present in the liver over time suggested that the brief period of integrase expression could largely be accounted for by rapid loss of the bulk of the plasmid DNA, as well as by silencing of plasmid expression. PCR analysis of integration indicated that ΦC31 integrase carried out genomic integration of a codelivered attB-containing plasmid by 3 hr after plasmid injection. Integrase was expressed for longer times and at higher levels in transfected cultured cells compared with liver. Inhibitor studies suggested that the enzyme had a short half-life and was degraded by the 26S proteasome. The short duration of integrase expression in liver and rapid integration reaction appear to be features favorable for use in gene therapy.