Clinical benefit and safety profile of cross-line therapy with CDK4/6 inhibitors:a retrospective study of HR+/HER2–advanced breast cancer

Objective:CDK4/6 inhibitors(CDK4/6is)in combination with endocrine therapy have secured a central role in the treatment of hormone receptor(HR)-positive advanced breast cancer(ABC)and have transformed the therapeutic landscape.Cross-line CDK4/6i therapy in which another CDK4/6i is continued after progression on a prior CDK4/6i may still offer advantageous therapeutic effects.Cross-line CDK4/6i therapy is an area of active investigation in the ongoing pursuit to improve outcomes for patients with HR+/human epidermal growth factor receptor 2(HER2)–ABC.Methods:This retrospective study enrolled 82 patients with HR+/HER2–ABC who were treated with cross-line CDK4/6is(abemaciclib,palbociclib,ribociclib,and dalpiciclib)after progression with another CDK4/6i.The primary endpoint was progression-free survival(PFS)according to version 1.1 of the Response Evaluation Criteria in Solid Tumors.Secondary endpoints included toxicity,objective response rate,disease control rate,and overall survival.Adverse events(AEs)were graded according to version 5.0 of the Common Terminology Criteria for Adverse Events,as promulgated by the U.S.Department of Health and Human Services.Results:Eighty-two HR+/HER2–ABC patients who received cross-line CDK4/6i therapy from January 2022 to February 2024 were enrolled.The median age of the patients was 60 years.The median PFS of all patients was 7.6 months(95%CI,5.9-9.2).Cox regression analysis identified lung metastasis and a switch to endocrine therapy following prior CDK4/6i therapy as independent predictive factors for PFS.Notably,patients who previously received abemaciclib and switched to palbociclib upon disease progression had a median PFS of 10.7 months.The strategy of transitioning to chemotherapy after progression on a prior CDK4/6i,then to a subsequent CDK4/6i merits further investigation.Hematologic toxicity was the most common grade≥3 AEs.No instances of fatal safety events were observed.Conclusions:Cross-line CDK4/6i therapy is associated with significant clinical benefits and manageable safety profiles in patients with HR+/HER2–ABC,which underscores cross-line CDK4/6i therapy potential as an effective treatment strategy.

Macrophage modulation with dipeptidyl peptidase-4 inhibitors:A new frontier for treating diabetic cardiomyopathy?

This editorial introduces the potential of targeting macrophage function for diabetic cardiomyopathy(DCM)treatment by dipeptidyl peptidase-4(DPP-4)inhibitors.Zhang et al studied teneligliptin,a DPP-4 inhibitor used for diabetes management,and its potential cardioprotective effects in a diabetic mouse model.They suggested teneligliptin administration may reverse established markers of DCM,including cardiac hypertrophy and compromised function.It also inhibited the NLRP3 inflammasome and reduced inflammatory cytokine production in diabetic mice.Macrophages play crucial roles in DCM pathogenesis.Chronic hyperglycemia disturbs the balance between pro-inflammatory(M1)and antiinflammatory(M2)macrophages,favoring a pro-inflammatory state contributing to heart damage.Here,we highlight the potential of DPP-4 inhibitors to modulate macrophage function and promote an anti-inflammatory environment.These compounds may achieve this by elevating glucagon-like peptide-1 levels and potentially inhibiting the NLRP3 inflammasome.Further studies on teneligliptin in combination with other therapies targeting different aspects of DCM could be suggested for developing more effective treatment strategies to improve cardiovascular health in diabetic patients.

Sodium-dependent glucose transporter 2 inhibitors effects on myocardial function in patients with type 2 diabetes and asymptomatic heart failure

BACKGROUND Sodium-dependent glucose transporter 2 inhibitors(SGLT2i)have shown efficacy in reducing heart failure(HF)burden in a very heterogeneous groups of patients,raising doubts about some contemporary assumptions of their mechanism of action.We previously published a prospective observational study that evaluated mechanisms of action of SGLT2i in patients with type 2 diabetes who were in HF stages A and B on dual hypoglycemic therapy.Two groups of patients were included in the study:the ones receiving SGLT2i as an add-on agent to metformin and the others on dipeptidyl peptidase-4 inhibitors as an add-on to metformin due to suboptimal glycemic control.AIM To evaluate the outcomes regarding natriuretic peptide,oxidative stress,inflammation,blood pressure,heart rate,cardiac function,and body weight.METHODS The study outcomes were examined by dividing each treatment arm into two subgroups according to baseline parameters of global longitudinal strain(GLS),N-terminal pro-brain natriuretic peptide,myeloperoxidase(MPO),high-sensitivity C-reactive protein(hsCRP),and systolic and diastolic blood pressure.To evaluate the possible predictors of observed changes in the SGLT2i arm during follow-up,a rise in stroke volume index,body mass index(BMI)decrease,and lack of heart rate increase,linear regression analysis was performed.RESULTS There was a greater reduction of MPO,hsCRP,GLS,and blood pressure in the groups with higher baseline values of mentioned parameters irrespective of the therapeutic arm after 6 months of follow-up.Significant independent predictors of heart rate decrease were a reduction in early mitral inflow velocity to early diastolic mitral annular velocity at the interventricular septal annulus ratio and BMI,while the predictor of stroke volume index increase was SGLT2i therapy itself.CONCLUSION SGLT2i affect body composition,reduce cardiac load,improve diastolic/systolic function,and attenuate the sympathetic response.Glycemic control contributes to the improvement of heart function,blood pressure control,oxidative stress,and reduction in inflammation.

Repositioning of dipeptidyl peptidase-4 inhibitors and glucagon like peptide-1 agonists as potential neuroprotective agents

Repositioning of dipeptidyl peptidase-4 inhibitors and glucagon like peptide-1 receptor agonists is a breakthrough in the field of neural regeneration research increasing glucagon like peptide-1 bioavailability, hence its neuroprotective activities. In this article, the authors suggest not only crossing blood-brain barrier and neurodegenerative disease as off target for dipeptidyl peptidase-4 inhibitors and glucagon like peptide-1 receptor agonists, but also for ophthalmic preparations for diabetic retinopathy, which may be the latest breakthrough in the field if prepared and used in an appropriate nano-formulation to target the retinal nerves. The relation of neurodegenerative diseases' different mechanisms to the dipeptidyl peptidase-4 inhibitors and glucagon like peptide-1 receptor agonists should be further examined in preclinical and clinical settings. The repositioning of already marketed antidiabetic drugs for neurodegenerative diseases should save the high cost of the time-consuming normal drug development process. Drug repositioning is a hot topic as an alternative to molecular target based drug discovery or therapeutic switching. It is a relatively inexpensive pathway due to availability of previous pharmacological and safety data. The glucagon like peptide-1 produced in brain has been linked to enhanced learning and memory functions as a physiologic regulator in central nervous system by restoring insulin signaling. Intranasal administration of all marketed gliptins(or glucagon like peptide-1 receptor agonists) may show enhanced blood-brain barrier crossing and increased glucagon like peptide-1 levels in the brain after direct crossing of the drug for the olfactory region, targeting the cerebrospinal fluid. Further blood-brain barrier crossing tests may extend dipeptidyl peptidase-4 inhibitors' effects beyond the anti-hyperglycemic control to intranasal spray, intranasal powder, or drops targeting the blood-brain barrier and neurodegenerative diseases with the most suitable formula. Moreover, novel nano-formulation is encouraged either to obtain favorable pharmacokinetic parameters or to achieve promising blood-brain barrier penetration directly through the olfactory region. Many surfactants should be investigated either as a solubilizing agent for hydrophobic drugs or as penetration enhancers. Different formulae based on in vitro and in vivo characterizations, working on sister gliptins(or glucagon like peptide-1 receptor agonists), different routes of administration, pharmacokinetic studies, dose response relationship studies, monitoring of plasma/brain concentration ratio after single and multiple dose, and neurodegenerative disease animal models are required to prove the new method of use(utility) for dipeptidyl peptidase-4 inhibitors as potential neuroprotective agents. Furthermore, investigations of glucagon like peptide-1 receptor agonists' neuroprotective effects on animal models will be considered carefully because they crossed the blood-brain barrier in previous studies, enabling their direct action on the central nervous system. Combination therapy of dipeptidyl peptidase-4 inhibitors or glucagon like peptide-1 receptor agonists with already marketed drugs for neurodegenerative disease should be considered, especially regarding the novel intranasal route of administration.

Treatment of type 2 diabetes, lifestyle, GLP1 agonists and DPP4 inhibitors

In recent years the treatment focus for type 2 diabetes has shifted to prevention by lifestyle change and to more aggressive reduction of blood sugars during the early stage of treatment. Weight reduction is an important goal for many people with type 2 diabetes.Bariatric surgery is no longer considered a last resort treatment. Glucagon-like peptide-1 agonists given by injection are emerging as a useful treatment since they not only lower blood sugar but are associated with a modest weight reduction. The role of the oral dipeptidyl peptidase 4 inhibitors is emerging as second line treatment ahead of sulphonylureas due to a possible beneficial effect on the beta cell and weight neutrality.Drugs which inhibit glucose re-absorption in the kidney,sodium/glucose co-transport 2 inhibitors, may have a role in the treatment of diabetes. Insulin treatment still remains the cornerstone of treatment in many patients with type 2 diabetes.

Diabetes therapies in hemodialysis patients: Dipeptidase-4 inhibitors

Although several previous studies have been published on the effects of dipeptidase-4(DPP-4) inhibitors in diabetic hemodialysis(HD) patients, the findings have yet to be reviewed comprehensively. Eyesight failure caused by diabetic retinopathy and aging-related dementia make multiple daily insulin injections difficult for HD patients. Therefore, we reviewed the effects of DPP-4 inhibitors with a focus on oral antidiabetic drugs as a new treatment strategy in HD patients with diabetes. The following 7 DPP-4 inhibitors are available worldwide: sitagliptin, vildagliptin, alogliptin, linagliptin, teneligliptin, anagliptin, and saxagliptin. All of these are administered once daily with dose adjustments in HD patients. Four types of oral antidiabetic drugs can be administered for combination oral therapy with DPP-4 inhibitors, including sulfonylureas, meglitinide, thiazolidinediones, and alpha-glucosidase inhibitor. Nine studies examined the antidiabetic effects in HD patients. Treatments decreased hemoglobin A1 c and glycated albumin levels by 0.3% to 1.3% and 1.7% to 4.9%, respectively. The efficacy of DPP-4 inhibitor treatment is high among HD patients, and no patients exhibited significant severe adverse effects such as hypoglycemia and liver dysfunction. DPP-4 inhibitors are key drugs in new treatment strategies for HD patients with diabetes and with limited choices for diabetes treatment.

Drug repurposing of histone deacetylase inhibitors that alleviate neutrophilic inflammation in acute lung injury and idiopathic pulmonary fibrosis via inhibiting leukotriene a4 hydrolase and blocking LTB4 biosynthesis

OBJECTIVE Leukotriene B4(LTB4)biosynthesis and subsequently neutrophilic inflammation may provide a potential strategy for the treatment of acute lung injury(ALI)or idiopathic pulmonary fibrosis(IPF).To provide a potential strategy for the treatment of ALI or IPF,we identified potent inhibitors of Leukotriene A4 hydrolase(LTA4H),a key enzyme in the biosynthesis of LTB4.METHODS In this study,we identified two known histone deacetylase(HDAC)inhibitors,suberanilohydroxamic acid(SAHA)and its analogue 4-(dimethylamino)-N-[7-(hydroxyamino)-7-oxoheptyl]benzamide(M344),as effective inhibitors of LTA4H using enzymatic assay,thermofluor assay,and X-ray crystallographic investigation.We next tested the effect of SAHA and M344 on endogenous LTB4 biosynthesis in neutrophils by ELISA and neutrophil migration by transwell migration assay.A murine experimental model of ALI was induced by lipopolysaccharide(LPS)inhalation.Histopathological analysis of lung tissue using H&E staining revealed the serious pulmonary damage caused by LPS treatment and the effect of the SAHA.We next examined m RNA and protein levels of pro-inflammatory cytokines in lung tissue and bronchoalveolar lavage fluid using q RT-PCR and ELISA to further investigate the underlying mechanisms of anti-inflammatory activities by SAHA.We also investigated the effects of SAHA and M344 on a murine experimental model of bleomycin(BLM)-induced IPF model.RESULTS The results of enzymatic assay and X-ray crystallography showed that both SAHA and M344 bind to LTA4H,significantly decrease LTB4 levels in neutrophil,and markedly diminish early neutrophilic inflammation in mouse models of ALI and IPF under a clinical safety dose.CONCLUSION Collectively,SAHA and M344 would provide promising agents with well-known clinical safety for potential treatment in patients with ALI and IPF via pharmacologically inhibiting LAT4H and blocking LTB4 biosynthesis.

Synthesis of 5-substituted benzyl-2,4-diamino pyrimidine derivatives as c-Fms kinase inhibitors

A serials of novel 5-substituted benzyl-2,4-diamino pyrimidine derivatives have been synthesized and evaluated as inhibitors of c-Fms kinase by the standard MTT method.The results showed that compound 15,5-[3-methoxy-4-（pyridine-3-yl）benzyl]-2,4-diamino pyrimidine,had an IC50 of 1.45μmol/L in inhibiting the proliferation of M-CSF-dependent myeloid leukemia cells in mice （NFS-60）,which was similar with GW2580,a selective inhibitor of c-Fms kinase.

Role of dipeptidyl peptidase 4 inhibitors in the new era of antidiabetic treatment

The last few years important changes have occurred in the field of diabetes treatment.The priority in the therapy of patients with diabetes is not glycemic control per se rather an overall management of risk factors,while individualization of glycemic target is suggested.Furthermore,regulatory authorities now require evidence of cardiovascular(CV)safety in order to approve new antidiabetic agents.The most novel drug classes,i.e.,sodium-glucose transporter 2 inhibitors(SGLT2-i)and some glucagon-like peptide-1 receptor agonists(GLP-1 RA),have been demonstrated to reduce major adverse CV events and,thus,have a prominent position in the therapeutic algorithm of hyperglycemia.In this context,the role of previously used hypoglycemic agents,including dipeptidyl peptidase 4(DPP-4)inhibitors,has been modified.DPP-4 inhibitors have a favorable safety profile,do not cause hypoglycemia or weight gain and do not require dose uptitration.Furthermore,they can be administered in patients with chronic kidney disease after dose modification and elderly patients with diabetes.Still,though,they have been undermined to a third line therapeutic choice as they have not been shown to reduce CV events as is the case with SGLT2-i and GLP-1 RA.Overall,DPP-4 inhibitors appear to have a place in the management of patients with diabetes as a safe class of oral glucose lowering agents with great experience in their use.

Cardiovascular efficacy and safety of dipeptidyl peptidase-4 inhibitors:A meta-analysis of cardiovascular outcome trials

BACKGROUND Dipeptidyl peptidase-4(DPP-4)inhibitors are a generally safe and well tolerated antidiabetic drug class with proven efficacy in type 2 diabetes mellitus(T2DM).Recently,a series of large,randomized controlled trials(RCTs)addressing cardiovascular outcomes with DPP-4 inhibitors have been published.AIM To pool data from the aforementioned trials concerning the impact of DPP-4 inhibitors on surrogate cardiovascular efficacy outcomes and on major cardiac arrhythmias.METHODS We searched PubMed and grey literature sources for all published RCTs assessing cardiovascular outcomes with DPP-4 inhibitors compared to placebo until October 2020.We extracted data concerning the following“hard”efficacy outcomes:fatal and non-fatal myocardial infarction,fatal and non-fatal stroke,hospitalization for heart failure,hospitalization for unstable angina,hospitalization for coronary revascularization and cardiovascular death.We also extracted data regarding the risk for major cardiac arrhythmias,such as atrial fibrillation,atrial flutter,ventricular fibrillation and ventricular tachycardia.RESULTS We pooled data from 6 trials in a total of 52520 patients with T2DM assigned either to DPP-4 inhibitor or placebo.DPP-4 inhibitors compared to placebo led to a non-significant increase in the risk for fatal and non-fatal myocardial infarction[risk ratio(RR)=1.02,95%CI:0.94-1.11,I2=0%],hospitalization for heart failure(RR=1.09,95%CI:0.92-1.29,I2=65%)and cardiovascular death(RR=1.02,95%CI:0.93-1.11,I2=0%).DPP-4 inhibitors resulted in a non-significant decrease in the risk for fatal and non-fatal stroke(RR=0.96,95%CI:0.85-1.08,I2=0%)and coronary revascularization(RR=0.99,95%CI:0.90-1.09,I2=0%),Finally,DPP-4 inhibitors demonstrated a neutral effect on the risk for hospitalization due to unstable angina(RR=1.00,95%CI:0.85-1.18,I2=0%).As far as cardiac arrhythmias are concerned,DPP-4 inhibitors did not significantly affect the risk for atrial fibrillation(RR=0.95,95%CI:0.78-1.17,I2=0%),while they were associated with a significant increase in the risk for atrial flutter,equal to 52%(RR=1.52,95%CI:1.03-2.24,I2=0%).DPP-4 inhibitors did not have a significant impact on the risk for any of the rest assessed cardiac arrhythmias.CONCLUSION DPP-4 inhibitors do not seem to confer any significant cardiovascular benefit for patients with T2DM,while they do not seem to be associated with a significant risk for any major cardiac arrhythmias,except for atrial flutter.Therefore,this drug class should not be the treatment of choice for patients with established cardiovascular disease or multiple risk factors,except for those cases when newer antidiabetics(glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors)are not tolerated,contraindicated or not affordable for the patient.

Design and Synthesis of Pyrido[1,2-e]purin-4(3H)-one Derivatives as Potential PDE 5 Inhibitors

A novel series of pyrido[ 1,2-e]purin-4（3H）-one derivatives containing polar substituents on 5＇-position were designed and prepared as potential PDE5 inhibitors. This paper reports the synthetic routes, 1H-NMR data, and the PDE5 inhibitory activities of the target compounds. The polar piperazinyl group contained （on 5＇-position） compound, 3B2, showed the highest activity among the tested derivatives but less potency than sildenafil 1.

DPP-4 inhibitors and GLP-1RAs:cardiovascular safety and benefits

Glucagon-like peptide-1 receptor agonists(GLP-1RAs)and dipeptidyl peptidase-4 inhibitors are commonly used treatments for patients with type 2 diabetes mellitus(T2DM).Both anti-diabetic treatments function by playing key modulatory roles in the incretin system.Though these drugs have been deemed effective in treating T2DM,the Food and Drug Administration(FDA)and some members of the scientific community have questioned the safety of these therapeutics relative to important cardiovascular endpoints.As a result,since 2008,the FDA has required all new drugs for glycemic control in T2DM patients to demonstrate cardiovascular safety.The present review article strives to assess the safety and benefits of incretin-based therapy,a new class of antidiabetic drug,on the health of patient cardiovascular systems.In the process,this review will also provide a physiological overview of the incretin system and how key components function in T2DM.

Relook at DPP-4 inhibitors in the era of SGLT-2 inhibitors

SGLT-2 inhibitors(SGLT-2Is)have significantly improved cardio-renal outcomes and are preferred agents in people with cardiovascular diseases,heart failure,and diabetic kidney disease.Similarly,GLP-1 receptor agonists(GLP-1RAs)have significantly improved atherosclerotic cardiovascular outcomes.To this end,DPP-4 inhibitors(DPP-4Is)are cardiac-neutral drugs.While long-acting GLP-1RAs have shown a favorable HbA1c lowering compared to DPP-4Is,there is no clinically meaningful HbA1c lowering difference between SGLT-2Is vs DPP-4Is.Moreover,the glucose-lowering potential of SGLT-2Is gets compromised with a progressive decline in renal functions,unlike DPP-4Is.Furthermore,the HbA1c lowering potential of DPP-4Is is favorable in people with T2DM having a modest baseline HbA1c(8.0%-8.5%)compared with SGLT-2Is which lowers HbA1c larger in a background of higher baseline HbA1c(>8.5%-9.0%).These findings suggest that the role of DPP-4Is in the management of type 2 diabetes mellitus cannot be completely ignored even in the era of SGLT-2Is.

No significant association between dipeptidyl peptidase-4 inhibitors and adverse outcomes of COVID-19

BACKGROUND Dipeptidyl peptidase-4(DPP4)is commonly targeted to achieve glycemic control and has potent anti-inflammatory and immunoregulatory effects.Recent structural analyses indicated a potential tight interaction between DPP4 and severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),raising a promising hypothesis that DPP4 inhibitor(DPP4i)drugs might be an optimal strategy for treating coronavirus disease 2019(COVID-19)among patients with diabetes.However,there has been no direct clinical evidence illuminating the associations between DPP4i use and COVID-19 outcomes.AIM To illuminate the associations between DPP4i usage and the adverse outcomes of COVID-19.METHODS We conducted a multicenter,retrospective analysis including 2563 patients with type 2 diabetes who were hospitalized due to COVID-19 at 16 hospitals in Hubei Province,China.After excluding ineligible individuals,142 patients who received DPP4i drugs and 1115 patients who received non-DPP4i oral anti-diabetic drugs were included in the subsequent analysis.We performed a strict propensity score matching(PSM)analysis where age,sex,comorbidities,number of oral hypoglycemic agents,heart rate,blood pressure,pulse oxygen saturation(SpO2)<95%,CT diagnosed bilateral lung lesions,laboratory indicators,and proportion of insulin usage were matched.Finally,111 participants treated with DPP4i drugs were successfully matched to 333 non-DPP4i users.Then,a linear logistic model and mixed-effect Cox model were applied to analyze the associations between inhospital DPP4i use and adverse outcomes of COVID-19.RESULTS After rigorous matching and further adjustments for imbalanced variables in the linear logistic model and Cox adjusted model,we found that there was no significant association between in-hospital DPP4i use(DPP4i group)and 28-d allcause mortality(adjusted hazard ratio=0.44,95%CI:0.09-2.11,P=0.31).Likewise,the incidences and risks of secondary outcomes,including septic shock,acute respiratory distress syndrome,or acute organ(kidney,liver,and cardiac)injuries,were also comparable between the DPP4i and non-DPP4i groups.The performance of DPP4i agents in achieving glucose control(e.g.,the median level of fasting blood glucose and random blood glucose)and inflammatory regulation was approximately equivalent in the DPP4i and non-DPP4i groups.Furthermore,we did not observe substantial side effects such as uncontrolled glycemia or acidosis due to DPP4i application relative to the use of non-DPP4i agents in the study cohort.CONCLUSION Our findings demonstrated that DPP4i use is not significantly associated with poor outcomes of COVID-19 or other adverse effects of anti-diabetic treatment.The data support the continuation of DPP4i agents for diabetes management in the setting of COVID-19.

Combined immune checkpoint inhibitors of CTLA4 and PD-1 for hepatic melanoma of unknown primary origin: A case report

BACKGROUND Melanoma is uncommonly found in lymph nodes,subcutaneous tissue,or visceral organs without a primary lesion,where it is identified as metastatic melanoma with unknown primary(MUP).Hepatic MUP is extremely rare and has a poor prognosis.There is limited information on its pathogenesis,clinical and imaging features,and pathological findings.There are no guidelines for the use of immune checkpoint inhibitors(ICIs)in hepatic MUP,and the treatment outcome has rarely been reported.CASE SUMMARY A 42-year-old woman presented to our hospital with hepatic tumors found incidentally during a routine check-up.Contrast-enhanced abdominal computerized tomography showed multiple mass lesions in the liver.Pathological results revealed melanoma,which was confirmed by immunohistochemical staining for HMB-45(+),Melan-A(+),S-100(+),and SOX10(+).There was no evidence of primary cutaneous,ocular,gastrointestinal,or anal lesion on a comprehensive examination.The patient was diagnosed with hepatic MUP.She received combined antibodies against cytotoxic T-lymphocyte-associated antigen 4(CTLA-4,ipilimumab)and programmed death protein-1(PD-1,nivolumab).She died of hepatic failure 9 mo after hepatic MUP was diagnosed.This the first case of hepatic MUP treated with combined ipilimumab and nivolumab,who showed better outcome than previous cases.CONCLUSIONCombined ICIs of PD-1 and CTLA-4 may be considered as the first-line therapyfor patients with hepatic MUP.

Studies on the Compounds of d4T Combined with Nitric Oxide Donors and Nitric Oxide Synthase Inhibitors and their Anti-HIV and AIDS Activity

Stavudine, a potent anti HIV and AIDS related complex, is one of the Nucleoside Analogue Reverse Transcriptase Inhibitors (NARTIs). It is phosphorylated intracellularly and then inhibits the viral reverse transcriptase by acting as a false substrate. Modifications made on the hydrogen labile at the 5' position on the sugar is an interesting template for the elaboration of new potent anti HIV and AIDS drugs. The expected advantages of the modified stavudine prodrugs can be multiple: synergistic drug activities, enhancement of stavudine intracellular uptake, increase of stavudine brain delivery, and bypass of the first stavudine phosphorylation step into the cells. Nitric oxide synthase inhibitors of stavudine and nitric oxide donors of stavudine may hold significant promise for the treatment of HIV and AIDS.

Synthesis of N1-Substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyra-zolethiocarboxamide as Novel Small Molecule Inhibitors of Cysteine Protease of T.cruzi

A series of N1-substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyrazolethiocarboxamide were prepared from the Mannich bases of aryl ketones in good yields. Some derivatives were found to be active against the cysteine protease of T.cruzi..

Can cyclin-dependent kinase 4/6 inhibitors convert inoperable breast cancer relapse to operability? A case report

BACKGROUND Pathological complete response(pCR) is rare in hormone receptor-positive(HR+)HER2-negative breast cancer(BC) treated with either endocrine therapy(ET) or chemotherapy. Radical resection of locoregional relapse, although potentially curative in some cases, is challenging when the tumor invades critical structures.The oral cyclin-dependent kinase 4/6 inhibitor palbociclib in combination with ET has obtained a significant increase in objective response rates and progression-free survival in patients with advanced BC and is now being evaluated in the neoadjuvant setting. We present a clinical case of a patient with an inoperable locoregional relapse of HR+ HER2-negative BC who experienced p CR after treatment with palbociclib.CASE SUMMARY We report the clinical case of a 60-year-old patient who presented with an inoperable locoregional relapse of HR+, HER2-negative BC 10 years after the diagnosis of the primary tumor. During a routine follow-up visit, breast magnetic resonance imaging and positron emission tomography/computed tomography revealed a 4-cm lesion in the right subclavicular region, infiltrating the chest wall and extending to the subclavian vessels, but without bone or visceral involvement. Treatment was begun with palbociclib plus letrozole, converting the disease to operability over a period of 6 mo. Surgery was performed and a p CR achieved. Of note, during treatment the patient experienced a very uncommon toxicity characterized by burning tongue and glossodynia associated with dysgeusia, paresthesia, dysesthesia, and xerostomia. A reduction in the dose of palbociclib did not provide relief and treatment with the inhibitor was thus discontinued, resolving the tongue symptoms. Laboratory exams were unremarkable. Given that this was a late relapse, the tumor was classified asendocrine-sensitive, a condition associated with high sensitivity to palbociclib.CONCLUSION This case highlights the potential of the cyclin-dependent kinase 4/6 inhibitor plus ET combination to achieve pCR in locoregional relapse of BC, enabling surgical resection of a lesion initially considered inoperable.

CDK4/6 inhibitors in the treatment of hormone receptor-positive, HER2-negative advanced breast cancer

Endocrine therapy(ET)is the therapy backbone of hormone receptor(HR)-positive and human epidermal growth factor receptor 2(HER2)-negati ve advanced breast cancer.However,there are about 20%HR positive patients with no response to ET due to primary or acquired ET resistance.In this background,many agents have been studied to overcome ET resistance and of which the important agents are cyclin-dependent kinase 4/6(CDK4/6)inhibitors.The prognosis of advanced breast cancer has been improved by combing ET with CDK4/6 inhibitors.In this review,we mainly focused on the CDK4/6 inhibitors in the treatment of HR-positive,HER2-negative advanced breast cancer and discussed the action mechanisms of CDK4/6 inhibitors alone or combined with ET.We also summarized several molecular features that would predict response or resistance to CDK4/6 inhibitors.In addition,we put forward possible strategies to overcome CDK4/6 inhibitor resistance according to the latest research.

Impact of Drug-Drug Interaction between CDK4/6 Inhibitors and Proton Pump Inhibitors on Survival Outcomes in the Treatment of Metastatic Breast Cancer—Real World Data from a Portuguese Center

Introduction: Proton pump inhibitors (PPi) are widely prescribed, including in patients undergoing treatment for advanced breast cancer (ABC). Due to the pharmacokinetic characteristics of the CDK4/6 inhibitor (Ci) palbociclib a drug interaction with PPi was hypothesized. It was shown in a retrospective study that this association was an independent predictive factor for worse progression-free survival (PFS). Objective: To verify the impact of concomitant administration of PPi with Ci on overall survival (OS) and PFS. Material and Methods: This is a retrospective cohort study of patients treated with Ci for HR+HER2-ABC in the period from Feb/2017 to Aug/2020. SPSS software was used for data processing. Univariate analysis was done by the Kaplan-Meier method and log-rank test, and multivariate analysis by COX regression. P-value < 0.05 was considered significant. Results: 80 patients were included. The median age at diagnosis of ABC was 56 years (25 - 75). Treatment with Ci was 1st line for ABC in 68.8%. Choice of Ci was palbociclib in 73.8% (n = 59) and ribociclib in 26.3% (n = 21). The hormone partner was a nonsteroidal aromatase inhibitor in 45.0%, and fulvestrant in 55.0% of cases. 37.5% of patients were on PPi, and 70.0% of them were during the entire treatment (23.3% omeprazole, 73.4% pantoprazole, 3.3% others). Patients taking concomitant PPi and Ci had lower OS (OS-3 years 42.6% vs. 63.4%, p = 0.254) and PFS (PFS med 15 m. vs. 21 m., p = 0.733), although with no statistically significant difference. Discussion: In the sample, there was a numerical difference, without the statistical significance in the use of PPi in the survival of patients under Ci. This difference could be more evident with a longer follow-up and a larger sample size. This study intends to alert to the growing importance of checking for drug interactions. Polymedication, advanced age and the presence of several comorbidities are real problems in patients with ABC. Conclusion: Real-world data from this center demonstrate a negative, non-statistically significant impact of PPi treatment on survival outcomes, in patients treated with Ci for HR+HER2-ABC.