Evaluating the reactogenicity of COVID-19 vaccines from network-meta analyses

BACKGROUND

Evidence-based reassurances addressing vaccine-related concerns are crucial to promoting primary vaccination, completion of the primary series, and booster vaccination. By summarizing and comparing the reactogenicity of COVID-19 vaccines authorized by the European Medicines Agency, this analysis aims to support in-formed decision-making by the lay public and help overcome vaccine hesitancy.

RESEARCH DESIGN AND METHODS

A systematic literature review identified 24 records reporting solicited adverse events for AZD1222, BNT162b2, mRNA-1273, NVX-Cov2373, and VLA2001 in individuals aged 16 or older. Network meta-analyses were conducted for each solicited adverse events reported for at least two vaccines that were not compared head-to-head but could be connected through a common comparator.

RESULTS

A total of 56 adverse events were investigated through network meta-analyses within a Bayesian framework with random-effects models. Overall, the two mRNA vaccines were found to be the most reactogenic vaccines. VLA2001 had the highest likelihood of being the least reactogenic vaccine after the first and second vaccine dose, especially for systemic adverse events after the first dose.

CONCLUSIONS

The reduced chance of experiencing an adverse event with some COVID-19 vaccines may help to overcome vaccine hesitancy in population groups with concerns about the side effects of vaccines.

Patient preferences for features of HER2-targeted treatment of advanced or metastatic breast cancer: a discrete-choice experiment study

BACKGROUND

We aimed to quantify patients' benefit-risk preferences for attributes associated with human epidermal growth factor receptor 2 (HER2)-targeted breast cancer treatments and estimate minimum acceptable benefits (MABs), denominated in additional months of progression-free survival (PFS), for given treatment-related adverse events (AEs).

METHODS

We conducted an online discrete-choice experiment (DCE) among patients with self-reported advanced/metastatic breast cancer in the United States, United Kingdom, and Japan (N = 302). In a series of nine DCE questions, respondents chose between two hypothetical treatment profiles created by an experimental design. Profiles were defined by six attributes with varying levels: PFS, nausea/vomiting, diarrhea, liver function problems, risk of heart failure, and risk of serious lung damage and infections. Data were analyzed using an error component random-parameters logit model.

RESULTS

Among the attributes, patients placed the most importance on a change in PFS from 5 to 26 months; change from no diarrhea to severe diarrhea was the least important. Avoiding a 15% risk of heart failure had the largest MAB (5.8 additional months of PFS), followed by avoiding a 15% risk of serious lung damage and infections (4.6 months), possible severe liver function problems (4.2 months), severe nausea/vomiting (3.7 months), and severe diarrhea (2.3 months) compared with having none of the AEs. The relative importance of 21 additional months of PFS (increasing from 5 to 26 months) increased for women with HER2-negative disease and those with children.

CONCLUSIONS

Patients valued PFS gain higher than the potential risk of AEs when deciding between hypothetical breast cancer treatments.

A Comparison of Seven Oncology External Control Arm Case Studies: Critiques From Regulatory and Health Technology Assessment Agencies

OBJECTIVES

The development of accelerated approval programs for high morbidity and unmet need conditions has driven the use of single-arm studies in drug development. Regulatory and health technology assessment (HTA) agencies are recognizing that high-quality external control arms (ECAs), built using real-world data, can reduce uncertainties arising from single-arm studies. This review compared 7 case studies of regulatory and HTA agencies' evaluations of oncology ECAs.

METHODS

Food and Drug Administration multidisciplinary reviews for oncology submissions from 2014 to 2021 were screened to identify 7 cases (2 blinatumomab indications, avelumab, and erdafitinib, entrectinib, trastuzumab deruxtecan, and idecabtagene vicleucel) with ECAs to support efficacy claims. Regulatory (Food and Drug Administration, European Medicines Agency, Health Canada) and HTA (pan-Canadian Oncology Drug Review, National Institute for Health and Care Excellence, Federal Joint Committee, Haute Autorité de Santé, and Pharmaceutical Benefits Advisory Committee) submissions for these cases were reviewed. The decision makers' ECA critiques and the level of influence on the decision were analyzed and categorized.

RESULTS

Across case studies, selection bias and confounding were the most common ECA critiques. Nevertheless, agreement in critiques between and among regulators and HTA bodies was low. ECA influence on agencies' decisions also varied.

CONCLUSIONS

Evaluating the same ECA evidence, agencies focused on methodologic issues (ie, selection bias and confounding), but were often not aligned on their critiques. Further research is needed to fully characterize how agencies evaluate ECAs. This study is a first step in critically evaluating agencies' critiques of ECAs and highlights the need for future guidance development around ECA design and generation.

Real-world data of HER2-low metastatic breast cancer: A population based cohort study

BACKGROUND

With the introduction of investigational human epidermal growth factor receptor 2 (HER2) targeting treatments, thorough understanding of breast cancer with different HER2 expression levels is critical. The aim of this study was to compare clinicopathologic characteristics and survival of patients with metastatic breast cancer according to the level of HER2 expression.

METHODS

Women with distant metastatic breast cancer during 2008-2016 were selected from PALGA, the Dutch Pathology Registry, and linked to the PHARMO Database Network. Breast cancer samples were categorised as HER2 immunohistochemistry score 0 (IHC0), HER2-low or HER2+.

RESULTS

Among women with hormone receptor (HR) positive metastatic breast cancer (n = 989), 373 (38%) cancers were HER2 IHC0, 472 (48%) were HER2-low and 144 (15%) were HER2+. Among HR negative patients (n = 272), the proportion of HER2 IHC0, HER2-low and HER2+ was 110 (40%), 104 (38%) and 58 (21%) respectively. Within the HR + cohort, patients with HER2 IHC0 or HER2-low cancer were significantly older compared to HER2+ patients. This age difference was not seen in the HR-cohort. The localisation of distant metastases differed significantly between HER2 IHC0 or HER2-low versus HER2+ cases. Survival rates did not differ markedly by subtypes.

CONCLUSION

Substantial proportion of patients had a HER2-low breast cancer. No clear differences in survival were found when comparing HER2 and HR status. Getting more granular insights in the level of HER2 expression and addressing HER2-low as a separate category could help to assess the impact of emerging treatment strategies. Therefore, more detailed information on HER2 expression should be routinely reported.

Quality-adjusted time without symptoms or toxicity (Q-TWiST) of trastuzumab deruxtecan (T-DXd) versus chemotherapy in patients with advanced gastric cancer from the DESTINY-Gastric01 trial

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Background: DESTINY-Gastric01 (NCT03329690) is a randomized, phase 2 study evaluating trastuzumab deruxtecan (T-DXd) in patients with HER2-positive advanced gastric cancer who progressed after ≥2 regimens. T-DXd significantly improved objective response rate (51% vs. 14%; P < 0.001) and overall survival (median OS; 12.5 vs. 8.4 months; P = 0.01) relative to chemotherapy (irinotecan or paclitaxel), leading to regulatory approval in USA and Japan. This post hoc analysis evaluated the overall effect of treatment differences on the quality of survival after discounting for time spent with toxicities or disease progression by comparing the Q-TWiST for patients who received T-DXd versus those who received chemotherapy. Methods: Patients were randomized 2:1 to receive T-DXd or chemotherapy. For each treatment arm, OS, truncated at 10.1 months (the median OS for the entire analysis population, following Q-TWiST convention), was partitioned into three health states: time with grade ≥3 toxicities before disease progression (TOX), time before disease progression without symptoms of disease progression or toxicity (TWiST), and time following disease progression prior to death or censoring (PROG). Mean duration in each state was weighted by a utility score, determined first in a threshold analysis, using a range of hypothetical utility values to generate quality-adjusted states, and then based on observed EQ-5D-5L scores, for that state; the sum of the utility-weighted durations yielded the Q-TWiST value for the time until the end of 10.1 months’ follow-up. In both threshold and observed utility analyses, 95% confidence intervals (CIs) and two-sided P values were calculated using the bootstrap method. Results: Relative to patients receiving chemotherapy (n = 62), patients receiving T-DXd (n = 125) had significantly longer unweighted durations of TOX (3.0 vs. 1.6 months; P < 0.01) and TWiST (3.1 vs. 2.1 months; P < 0.05) and a shorter unweighted duration of PROG (2.4 vs. 3.7 months; P < 0.01). Using a matrix of 25 hypothetical utility-weight combinations, with a TWiST utility of 1 and TOX and PROG utilities ranging from 0 to 1, Q-TWiST differences between treatment arms ranged from −0.5 to 2.3 months, favoring T-DXd in 22 combinations, of which 15 were statistically significant. Using observed EQ-5D-5L utility values, Q-TWiST was 0.9 months (95% CI, 0.2-1.5) longer for T-DXd than for chemotherapy (6.6 vs. 5.7 months), significantly favoring T-DXd ( P < 0.05). Conclusions: Over a 10-month follow-up period, treatment with T-DXd was associated with a statistically significant gain in quality-adjusted OS versus chemotherapy among previously treated patients with gastric cancer. An analysis using observed EQ-5D-5L utility scores found a statistically significant advantage in Q-TWiST for T-DXd. Clinical trial information: NCT03329690.

The Impact of Patent Expiry on Drug Prices: A Systematic Literature Review

OBJECTIVE

The aim of this study was to evaluate the impact of patent expiry on drug prices by means of a systematic literature review.

METHODS

A systematic literature search was performed in PubMed to identify all published literature on the impact of patent expiration on drug prices. Additional literature was identified using a less distinct syntax in Google Scholar and EconLit. Data extraction followed a standardized assessment form containing the domains study type, study aim, reported outcomes, number of drugs and drug classes assessed, and originators or generics assessed.

RESULTS

The 16 identified studies that assessed impact of patent expiry on drug prices showed that price developments after patent expiration varied between countries. The included studies assessed price developments for the USA, Canada, Australia, the UK, the Netherlands, Germany and France, Spain, Italy, Norway, Sweden and Denmark. The number of drugs included within different studies ranged between 1 and 219. The identified studies indicated that drug prices decreased significantly after patent expiry with drug price ratios ranging from 6.6 to 66% 1-5 years after patent expiry.

CONCLUSION

Drug prices decrease significantly after patent expiry. The extent of this price reduction varied greatly between products and countries. For this reason, country-specific analyses on price developments after patent expiry should be used when these are considered in decision making. Future research should be dedicated to gathering more country-specific data to reduce the uncertainty with regard to price developments.