Clinical trials with antiviral drugs against COVID-19: some progress and many shattered hopes

Vaccines and drugs are the cornerstones in the fight against the SARS-CoV-2 pandemic. While vaccines were a success story, the development of antiviral drugs against SARS-CoV-2 turned out to be difficult. For an accelerated use of antivirals in the clinic, most SARS-CoV-2 antivirals represented repurposed drugs. The present article summarizes the outcomes of clinical trials with antiviral drugs in COVID-19 patients. Many antiviral drugs failed to demonstrate beneficial effects or showed mixed results. One reason for the low success rate of clinical trials was shortcomings of antiviral tests in cell culture systems and another reason was the abundance of ill-coordinated and underpowered clinical trials. However, large pragmatic clinical trials particularly of the British RECOVERY trial series demonstrated that even under emergency situation drug trials can be conducted in a timely way such that the therapy of COVID-19 patients can be based on evidence basis instead on expert opinion or even worse on political pressure.     

Rationale of using the dual chemokine receptor CCR2/CCR5 inhibitor cenicriviroc for the treatment of COVID-19

Coronavirus Disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), has created a global pandemic infecting over 230 million people and costing millions of lives. Therapies to attenuate severe disease are desperately needed. Cenicriviroc (CVC), a C-C chemokine receptor type 5 (CCR5) and C-C chemokine receptor type 2 (CCR2) antagonist, an agent previously studied in advanced clinical trials for patients with HIV or nonalcoholic steatohepatitis (NASH), may have the potential to reduce respiratory and cardiovascular organ failures related to COVID-19. Inhibiting the CCR2 and CCR5 pathways could attenuate or prevent inflammation or fibrosis in both early and late stages of the disease and improve outcomes of COVID-19. Clinical trials using CVC either in addition to standard of care (SoC; e.g., dexamethasone) or in combination with other investigational agents in patients with COVID-19 are currently ongoing. These trials intend to leverage the anti-inflammatory actions of CVC for ameliorating the clinical course of COVID-19 and prevent complications. This article reviews the literature surrounding the CCR2 and CCR5 pathways, their proposed role in COVID-19, and the potential role of CVC to improve outcomes.     

Emerging trends in COVID-19 treatment: learning from inflammatory conditions associated with cellular therapies

Coronavirus disease 2019 (SARS-CoV2) is an active global health threat for which treatments are desperately being sought. Even though most people infected experience mild to moderate respiratory symptoms and recover with supportive care, certain vulnerable hosts develop severe clinical deterioration. While several drugs are currently being investigated in clinical trials, there are currently no approved treatments or vaccines for COVID-19 and hence there is an unmet need to explore additional therapeutic options. At least three inflammatory disorders or syndromes associated with immune dysfunction have been described in the context of cellular therapy. Specifically, Cytokine Release Syndrome (CRS), Immune Reconstitution Inflammatory Syndrome (IRIS), and Secondary Hemophagocytic Lymphohistiocytosis (sHLH) all have clinical and laboratory characteristics in common with COVID19 and associated therapies that could be worth testing in the context of clinical trials. Here we discuss these diseases, their management, and potential applications of these treatment in the context of COVID-19. We also discuss current cellular therapies that are being evaluated for the treatment of COVID-19 and/or its associated symptoms.     

抗新型冠状病毒单克隆中和抗体药物研发进展*

随着新型冠状病毒肺炎(COVID-19)疫情在全球的不断蔓延,开发有效的治疗药物迫在眉睫。中和抗体作为最有希望的新型冠状病毒特异性治疗药物,已经在临床研究中展现很好的治疗效果。对抗新冠病毒单克隆中和抗体药物研发的进展、涉及的主要技术和主要临床试验结果进行了总结,以期为包括COVID-19在内的新发、突发传染病中和抗体药物研发提供参考。     

Levamisole and 5-fluorouracil therapy for resected colon cancer: a new indication.

OBJECTIVE: To evaluate the benefits and risks of postoperative treatment with levamisole plus 5-fluorouracil (5-FU) in patients with colon cancer. DESIGN: Computerized searches of MEDLINE and CANCERLIT were performed, and the reference list of each retrieved article was checked. Only randomized trials of therapy with levamisole alone or combined with 5-FU for colon cancer without distant metastases were included. The studies were then evaluated with the use of four criteria. RESULTS: We reviewed six randomized trials, of which three satisfied our criteria. Two studies demonstrated a significant improvement in the survival rate with levamisole plus 5-FU among patients with colon cancer and pathologically confirmed metastases to adjacent lymph nodes (Dukes'' stage C). A subgroup analysis in another study demonstrated a similar benefit. The toxic effects of the drugs were generally mild. The three other studies showed no difference in survival rates between the treatment groups; however, the samples were too small to detect a clinically or statistically important difference. CONCLUSIONS: Because many patients with colon cancer will suffer a relapse we recommend that they be offered the opportunity to participate in clinical trials of adjuvant therapy. For those with stage C disease not entering a clinical trial levamisole plus 5-FU is appropriate adjuvant therapy.     

Metformin Use in Diabetes Prior to Hospitalization: Effects on Mortality in Covid-19

Objective: Although type 2 diabetes mellitus (T2DM) has been reported as a risk factor for coronavirus disease 2019 (COVID-19), the effect of pharmacologic agents used to treat T2DM, such as metformin, on COVID-19 outcomes remains unclear. Metformin increases the expression of angiotensin converting enzyme 2, a known receptor for severe acute respiratory syndrome coronavirus 2. Data from people with T2DM hospitalized for COVID-19 were used to test the hypothesis that metformin use is associated with improved survival in this population.Methods: Retrospective analyses were performed on de-identified clinical data from a major hospital in Wuhan, China, that included patients with T2DM hospitalized for COVID-19 during the recent epidemic. One hundred and thirty-one patients diagnosed with COVID-19 and T2DM were used in this study. The primary outcome was mortality. Demographic, clinical characteristics, laboratory data, diabetes medications, and respiratory therapy data were also included in the analysis.Results: Of these 131 patients, 37 used metformin with or without other antidiabetes medications. Among the 37 metformin-taking patients, 35 (94.6%) survived and 2 (5.4%) did not survive. The mortality rates in the metformin-taking group versus the non-metformin group were 5.4% (2/37) versus 22.3% (21/94). Using multivariate analysis, metformin was found to be an independent predictor of survival in this cohort (P = .02).Conclusion: This study reveals a significant association between metformin use and survival in people with T2DM diagnosed with COVID-19. These clinical data are consistent with potential benefits of the use of metformin for COVID-19 patients with T2DM.     

Euthyroid Sick Syndrome as a Prognostic Indicator of COVID-19 Pulmonary Involvement,Associated With Poorer Disease Prognosis and Increased Mortality

ObjectiveThe prevalence of euthyroid sick syndrome (ESS) and its association with the prognosis of COVID-19 and mortality in patients with lung involvement in COVID-19 have not yet been elucidated.MethodsClinical and laboratory data of patients with COVID-19 with or without ESS were collected retrospectively and analyzed on admission. All subjects were admitted to the Department of Internal Diseases and Clinical Pharmacology at Bieganski Hospital between December 2020 and April 2021.ResultsIn total, 310 medical records of patients with COVID-19 were analyzed retrospectively. Among 215 enrolled patients, 82 cases of ESS were diagnosed. The patients with ESS had higher pro-inflammatory factor levels, longer hospitalizations, and a higher risk of requiring high-flow nasal oxygen therapy or intubation than the patients without ESS. The Kaplan-Meier curve indicated that the patients with ESS had a lower probability of survival when computed tomography showed ≤50% parenchymal involvement compared with that in patients without ESS. However, no differences in mortality were noted in those with more than 50% parenchymal involvement. The survival curve showed that ESS was associated with a higher risk of mortality during hospitalization.ConclusionESS is closely associated with a poor prognosis, including longer hospitalizations, more frequent intubation, transfer to the intensive care unit, and a higher mortality rate in patients with COVID-19. ESS is a potential prognostic predictor of survival, regardless of lung involvement in COVID-19.     

Different Laboratory Abnormalities in COVID-19 Patients with Hypertension or Diabetes

We reported recently that hypertension is a risk factor for severe cases of COVID-19, independent of age and other variables (Liu et al. 2020a). An important question is why patients with hypertension and diabetes yield poorer clinical outcomes than those without. Human pathogenic coronavirus SARS-CoV-2 utilizes angiotensin-converting enzyme 2 (ACE2) as a receptor for viral cell entry. Since the levels of ACE2 are substantially increased in patients with hypertension or diabetes, who are treated with ACE inhibitors (ACEIs) and angiotensin Ⅱ type-Ⅰ receptor blockers (ARBs) (Ferrario et al. 2005), Fang and colleagues hypothesized that ACE2-stimulating drugs could potentially increase the risk of developing severe COVID-19 (Fang et al. 2020). This was not supported by a recent study led by Dr. Reynolds (Reynolds et al. 2020), whose analysis showed no positive association for ACEIs or ARBs for either the risk of SARS-CoV-2 infection or severe illness (Reynolds et al. 2020). What else might explain the poorer clinical outcomes of COVID-19 patients with hypertension or diabetes?To explore this question, we re-analysed the same cohort of 99 COVID-19 patients discharged from the general wards of Renmin Hospital of Wuhan University between 5 February 2020 and 14 March 2020 (Ethics approval No: WDRY2020-K124) (Liu et al. 2020a, b).     

Antibodies at work in the time of severe acute respiratory syndrome coronavirus 2

In view of devastating effects of COVID-19 on human life, there is an urgent need for the licened vaccines or therapeutics for the SARS-CoV-2 infection. Age-old passive immunization with protective antibodies to neutralize the virus is one of the strategies for emergency prophylaxis and therapy for coronavirus disease 2019 (COVID-19). In this review, the authors discuss up-to-date advances in immune-based therapy for COVID-19. The use of convalescent plasma therapy as the first line of defense to treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been established, with encouraging results. Monoclonal antibodies (mAbs) that bind to the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein or block the interaction between SARS-CoV-2 RBD and the human angiotensin-converting enzyme 2 receptor have been found to be very promising as a countermeasure for tackling the SARS-CoV-2 infection, and clinical trials are underway. Considering the counterproductive antibody-dependent enhancement of the virus, mAbs therapy that is safe and efficacious, even in people with underlying conditions, will be a significant breakthrough. In addition, emerging immunotherapeutic interventions using nanobodies and cellular immunotherapy are promising avenues for tackling the COVID-19 pandemic. The authors also discuss the implication of mAbs as mediators of cytokine storm syndrome to modify the immune response of COVID-19 patients, thus reducing the fatality rate of COVID-19 infection.     

IL-15 immunotherapy is a viable strategy for COVID-19

Coronavirus disease 2019 (COVID-19) is a pulmonary inflammatory disease induced by a newly recognized coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). SARS-CoV-2 infection was detected for the first time in the city of Wuhan in China and spread all over the world at the beginning of 2020. Several millions of people have been infected with SARS-CoV-2, and almost 382,867 human deaths worldwide have been reported so far. Notably, there has been no specific, clinically approved vaccine or anti-viral treatment strategy for COVID-19. Herein, we review COVID-19, the viral replication, and its effect on promoting pulmonary fibro-inflammation via immune cell-mediated cytokine storms in humans. Several clinical trials are currently ongoing for anti-viral drugs, vaccines, and neutralizing antibodies against COVID-19. Viral clearance is the result of effective innate and adaptive immune responses. The pivotal role of interleukin (IL)-15 in viral clearance involves maintaining the balance of induced inflammatory cytokines and the homeostatic responses of natural killer and CD8⁺ T cells. This review presents supporting evidence of the impact of IL-15 immunotherapy on COVID-19.     

Vitamin D and Its Potential Benefit for the COVID-19 Pandemic

Vitamin D is known not only for its importance for bone health but also for its biologic activities on many other organ systems. This is due to the presence of the vitamin D receptor in various types of cells and tissues, including the skin, skeletal muscle, adipose tissue, endocrine pancreas, immune cells, and blood vessels. Experimental studies have shown that vitamin D exerts several actions that are thought to be protective against coronavirus disease (COVID-19) infectivity and severity. These include the immunomodulatory effects on the innate and adaptive immune systems, the regulatory effects on the renin-angiotensin-aldosterone-system in the kidneys and the lungs, and the protective effects against endothelial dysfunction and thrombosis. Prior to the COVID-19 pandemic, studies have shown that vitamin D supplementation is beneficial in protecting against risk of acquiring acute respiratory viral infection and may improve outcomes in sepsis and critically ill patients. There are a growing number of data connecting COVID-19 infectivity and severity with vitamin D status, suggesting a potential benefit of vitamin D supplementation for primary prevention or as an adjunctive treatment of COVID-19. Although the results from most ongoing randomized clinical trials aiming to prove the benefit of vitamin D supplementation for these purposes are still pending, there is no downside to increasing vitamin D intake and having sensible sunlight exposure to maintain serum 25-hydroxyvitamin D at a level of least 30 ng/mL (75 nmol/L) and preferably 40 to 60 ng/mL (100-150 nmol/L) to minimize the risk of COVID-19 infection and its severity.     

新型靶向治疗药物拉帕替尼的研究进展

拉帕替尼(lapatinib)是一种口服的、小分子可逆性EGFR和HER2双受体阻断剂。临床研究表明对HER2表达阳性的乳腺癌是有效的。近年来关于拉帕替尼在其他肿瘤的研究越来越多,拉帕替尼有望成为一种潜在、多肿瘤的靶向治疗药物。本文对拉帕替尼的作用机制、临床研究、药理特性及临床应用等做一综述。     

Mesenchymal stromal cells to fight SARS-CoV-2: Taking advantage of a pleiotropic therapy

The devastating global impact of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has prompted scientists to develop novel strategies to fight Coronavirus Disease of 2019 (COVID-19), including the examination of pre-existing treatments for other viral infections in COVID-19 patients. This review provides a reasoned discussion of the possible use of Mesenchymal Stromal Cells (MSC) or their products as a treatment in SARS-CoV-2-infected patients. The main benefits and concerns of using this cellular therapy, guided by preclinical and clinical data obtained from similar pathologies will be reviewed. MSC represent a highly immunomodulatory cell population and their use may be safe according to clinical studies developed in other pathologies. Notably, four clinical trials and four case reports that have already been performed in COVID-19 patients obtained promising results. The clinical application of MSC in COVID-19 is very preliminary and further investigational studies are required to determine the efficacy of the MSC therapy. Nevertheless, these preliminary studies were important to understand the therapeutic potential of MSC in COVID-19. Based on these encouraging results, the United States Food and Drug Administration (FDA) authorized the compassionate use of MSC, but only in patients with Acute Respiratory Distress Syndrome (ARDS) and a poor prognosis. In fact, patients with severe SARS-CoV-2 can present infection and tissue damage in different organs, such as lung, heart, liver, kidney, gut and brain, affecting their function. MSC may have pleiotropic activities in COVID-19, with the capacity to fight inflammation and repair lesions in several organs.     

ARB might be superior to ACEI for treatment of hypertensive COVID-19 patients

The administration of ACEI/ARB (angiotensin-converting enzyme inhibitors/Angiotension II receptor blockers) in COVID-19 (coronavirus disease 2019) patients with hypertension exhibits a lower risk of mortality compared with ACEI/ARB non-users. In this context, an important question arises: is ACEI or ARB more suitable for the treatment of hypertensive COVID-19 patients? Taken into consideration the following four rationales, ARB may offer a more significant benefit than ACEI for the short-term treatment of hypertensive COVID-19 patients: 1. ACEI has no inhibition on non-ACE-mediated Ang II production under infection conditions, whereas ARB can function properly regardless of how Ang II is produced; 2. ACEI-induced bradykinin accumulation may instigate severe ARDS while ARB has no effects on kinin metabolism; 3. ARB alleviates viscous sputa production and inflammatory reaction significantly in contrast to ACEI; 4. ARB may attenuate the lung fibrosis induced by mechanical ventilation in severe patients and improve their prognosis significantly compared with ACEI. To examine the advantages of ARB over ACEI on hypertensive COVID-19 patients, retrospective case-control studies comparing the clinical outcomes for COVID-19 patients receiving ARB or ACEI treatment is strikingly needed in order to provide guidance for the clinical application.     

Rapid generation of mouse model for emerging infectious disease with the case of severe COVID-19

Since the pandemic of COVID-19 has intensely struck human society, small animal model for this infectious disease is in urgent need for basic and pharmaceutical research. Although several COVID-19 animal models have been identified, many of them show either minimal or inadequate pathophysiology after SARS-CoV-2 challenge. Here, we describe a new and versatile strategy to rapidly establish a mouse model for emerging infectious diseases in one month by multi-route, multi-serotype transduction with recombinant adeno-associated virus (AAV) vectors expressing viral receptor. In this study, the proposed approach enables profound and enduring systemic expression of SARS-CoV-2-receptor hACE2 in wild-type mice and renders them vulnerable to SARS-CoV-2 infection. Upon virus challenge, generated AAV/hACE2 mice showed pathophysiology closely mimicking the patients with severe COVID-19. The efficacy of a novel therapeutic antibody cocktail RBD-chAbs for COVID-19 was tested and confirmed by using this AAV/hACE2 mouse model, further demonstrating its successful application in drug development.     

Prognostic factors and predictors of outcome in patients with COVID-19 and related pneumonia: a retrospective cohort study

The aim of the present study was to simultaneously assess several potential predictors of outcome (co-morbidity, previous and in-hospital treatment, radiologic Brixia score) in patients with COVID-19.This retrospective cohort study included 258 consecutive patients with confirmed COVID-19 admitted to a medical ward at Montichiari Hospital, Brescia, Italy from February 28th to April 30rd, 2020. Patients had SARS-CoV-2 related pneumonia with respiratory failure, and were treated with hydroxychloroquine and lopinavir plus ritonavir. In some patients, additional treatment with tocilizumab, dexamethasone and enoxaparin was adopted. Outcomes (death or recovery) were assessed at the end of the discharge period or at the end of the follow-up (August 2020).During hospitalization, 59 patients died, while 6 died after discharge. The following variables were demonstrated to be associated with a worse prognosis: Radiologic Brixia score higher than 8, presence at baseline of hypertension, diabetes, chronic obstructive pulmonary disease, heart disease, cancer, previous treatment with ACE-inhibitors or anti-platelet drugs. Anticoagulant treatment during hospital admission with enoxaparin at a dose higher than 4000 U once daily was associated with a better prognosis.In conclusion, our study demonstrates that some co-morbidities and cardiovascular risk factors may affect prognosis. The radiologic Brixia score may be a useful tool to stratify the risk of death at baseline. Anticoagulant treatment with enoxaparin might be associated to a clinical benefit in terms of survival in patients with COVID-19.     

Antiviral drug treatment for nonsevere COVID-19: a systematic review and network meta-analysis

Background:Randomized trial evidence suggests that some antiviral drugs are effective in patients with COVID-19. However, the comparative effectiveness of antiviral drugs in nonsevere COVID-19 is unclear.Methods:We searched the Epistemonikos COVID-19 L·OVE (Living Overview of Evidence) database for randomized trials comparing antiviral treatments, standard care or placebo in adult patients with nonsevere COVID-19 up to Apr. 25, 2022. Reviewers extracted data and assessed risk of bias. We performed a frequentist network meta-analysis and assessed the certainty of evidence using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.Results:We identified 41 trials, which included 18 568 patients. Compared with standard care or placebo, molnupiravir and nirmatrelvir–ritonavir each reduced risk of death with moderate certainty (10.9 fewer deaths per 1000, 95% confidence interval [CI] 12.6 to 4.5 fewer for molnupiravir; 11.7 fewer deaths per 1000, 95% CI 13.1 fewer to 2.6 more). Compared with molnupiravir, nirmatrelvir–ritonavir probably reduced risk of hospital admission (27.8 fewer admissions per 1000, 95% CI 32.8 to 18.3 fewer; moderate certainty). Remdesivir probably has no effect on risk of death, but may reduce hospital admissions (39.1 fewer admissions per 1000, 95% CI 48.7 to 13.7 fewer; low certainty).Interpretation:Molnupiravir and nirmatrelvir–ritonavir probably reduce risk of hospital admissions and death among patients with nonsevere COVID-19. Nirmatrelvir–ritonavir is probably more effective than molnupiravir for reducing risk of hospital admissions. Most trials were conducted with unvaccinated patients, before the emergence of the Omicron variant; the effectiveness of these drugs must thus be tested among vaccinated patients and against newer variants.

Most trials addressing the treatment of patients with COVID-19 have targeted patients admitted to hospital with severe or critical disease.¹ However, more recently, several treatments, including antiviral drugs, antidepressants, monoclonal antibodies and inhaled corticosteroids, have been studied for patients with nonsevere COVID-19.² Preliminary evidence from ongoing or recently completed trials suggests that 2 novel antiviral drugs — molnupiravir and nirmatrelvir–ritonavir (Paxlovid) — may be effective at reducing risk of hospital admission.^3–5 To date, evidence on antiviral drugs for nonsevere COVID-19 has not been systematically synthesized or appraised. Furthermore, although efficacy data from trials of molnupiravir, nirmatrelvir–ritonavir and remdesivir are promising, no head-to-head trials have compared these drugs.A network meta-analysis allows for comparison of treatments that have not been compared in randomized controlled trials (RCTs), using pooled estimates from direct and indirect evidence. They can provide guidance to clinicians and evidence users in determining which treatments are superior. This is particularly important as health care systems attempt to prioritize access to effective COVID-19 treatments in the early stages of the disease.We sought to compare the effectiveness of antiviral drugs for patients with nonsevere COVID-19.     

新型冠状病毒肺炎:实验室检测、治疗及疫苗

新型冠状病毒肺炎(2019 novel coronavirus disease,COVID-19),一种由动物来源的新型冠状病毒(severe acute respiratory syndrome coronavirus 2,SRAS-CoV-2)感染所致的疾病在全球范围内急速传播,严重的危害人类的健康.快速、准确的诊...     

Circulating biomarkers of response to sunitinib in gastroenteropancreatic neuroendocrine tumors: current data and clinical outlook

After years of limited progress in the treatment of patients with advanced-stage gastroenteropancreatic neuroendocrine tumors (GEP-NETs), strategies using targeted agents have been developed on the basis of increased knowledge of the biology of these tumors. Some of these agents, targeting vascular endothelial growth factor (VEGF) and the mammalian target of rapamycin (mTOR) pathway, have shown efficacy in randomized clinical trials. The tyrosine kinase inhibitor sunitinib and the mTOR inhibitor everolimus have received international approval for the treatment of advanced well differentiated pancreatic NETs after showing survival benefit in randomized phase III trials. There is now an imperative need to identify biomarkers of the biologic activity of such targeted therapies in specific disease contexts, as well as new markers of response and prognosis. This approach may allow rational development of drugs and early identification of patients who may obtain benefit from treatments. In this article, we review recent developments in circulating biomarkers of the clinical benefit of targeted therapies for GEP-NET, including soluble proteins and circulating cells, with an emphasis on sunitinib. No validated molecular biomarkers are yet integrated into clinical practice for sunitinib in NET, although some markers have shown correlation with clinical outcomes and may be implicated in resistance. The VEGF-pathway proteins and interleukin-8 (IL-8) are possibly prognostic in GEP-NET; other possible soluble markers of the activity of sunitinib and everolimus include stromal cell-derived factor 1α, chromogranin A, and neuron-specific enolase. We additionally discuss treatment-induced modulation of circulating endothelial cells and progenitors and subpopulations of cells of the myeloid lineage. These candidate markers should be considered in the development of future combination or sequential therapies.     

Cholesterol lowering and mortality: the importance of considering initial level of risk.

OBJECTIVE--To investigate the level of risk of death from coronary heart disease above which cholesterol lowering treatment produces net benefits. DESIGN--Meta-analysis of results of randomised controlled trials of cholesterol lowering treatments. METHODS--Published and unpublished data from all identified randomised controlled trials of cholesterol lowering treatments with six months or more follow up and with at least one death were included in the meta-analysis. The analyses were stratified by the rate of death from coronary heart disease in the control arms of the trials. MAIN OUTCOME MEASURES--Death from all causes, from coronary heart disease, and from causes other than coronary heart disease. RESULTS--In the pooled analysis, net benefit in terms of total mortality from cholesterol lowering was seen only for trials including patients at very high initial risk of coronary heart disease (odds ratio 0.74; 95% confidence interval 0.60 to 0.92). In a medium risk group no net effect was seen, and in the low risk group there were adverse treatment effects (1.22; 1.06 to 1.42). In a weighted regression analysis a significant (p < 0.001) trend of increasing benefit with increasing initial risk of coronary heart disease was shown. Raised mortality from causes other than coronary heart disease was seen in trials of drug treatment (1.21; 1.05 to 1.39) but not in the trials of non-drug treatments (1.02; 0.88 to 1.19). Cumulative meta-analysis showed that these results seem to have been stable as new trials appeared. CONCLUSION--Currently evaluated cholesterol lowering drugs seem to produce mortality benefits in only a small proportion of patients at very high risk of death from coronary heart disease. Population cholesterol screening could waste resources and even result in net harm in substantial groups of patients. Overall risk of coronary heart disease should be the main focus of clinical guidelines, and a cautious approach to the use of cholesterol lowering drugs should be advocated. Future trials should aim to clarify the level of risk above which treatment is of net benefit.