A Modified Technique for Inducing Polycystic Ovary Syndrome in Mice.

Polycystic ovary syndrome (PCOS) is one of the leading causes of infertility in women. Animal models are widely used to study the etiologic mechanisms of PCOS and for related drug development. Letrozole-induced mouse models replicate the metabolic and reproductive phenotypes of patients with PCOS. The traditional method of letrozole treatment in PCOS mice requires daily dosing over a certain period, which can be labor-intensive and cause significant stress to the mice. This study describes a simple and effective method for inducing PCOS in mice by implanting a controlled letrozole-releasing mini-pump. A mini-pump capable of stable, continuous release of a quantitative amount of letrozole was fabricated and implanted subcutaneously in mice under anesthesia. This study demonstrated that the mouse model successfully mimicked PCOS features after letrozole mini-pump implantation. The materials and equipment used in this study are readily available to most laboratories, requiring no special customization. Collectively, this article provides a unique, easy-to-perform method for inducing PCOS in mice.

Effect of aromatase inhibitors for preventing ovarian hyperstimulation syndrome in infertile patients undergoing in vitro fertilization: a systematic review and meta-analysis.

PURPOSE: To summarize the findings of relevant randomized controlled trials (RCTs) and conduct a meta-analysis to investigate the potential effect of aromatase inhibitors on preventing moderate to severe ovarian hyperstimulation syndrome (OHSS) in infertile women undergoing in vitro fertilization (IVF). METHODS: We searched for relevant RCTs in electronic databases, including MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov (from inception to August 2023). In addition, we manually searched the related reviews and reference lists of included studies for further relevant studies. We included RCTs where aromatase inhibitors prescribed either during controlled ovarian stimulation (COS) or in early luteal phase. The meta-analysis was performed using RevMan 5.4.1 software. The primary outcome was the incidence of moderate to severe OHSS. A descriptive analysis was conducted in cases where a meta-analysis was not feasible due to heterogeneity or lack of comparable data. RESULTS: 2858 records were retrieved and 12 RCTs were finally included. Letrozole was administered in the treatment group during COS in seven RCTs, whereas in the early luteal phase in five RCTs. Compared with the control group, the risk of moderate to severe OHSS significantly reduced by 55% in the letrozole group (RR 0.45, 95% CI 0.32 to 0.64, I2 = 0%, 5 RCTs, 494 patients). Moreover, serum estradiol (E2) levels on hCG trigger day significantly decreased with the administration of letrozole during COS (MD -847.23, 95% CI -1398.00 to -296.47, I2 = 93%, 5 RCTs, 374 patients). And serum E2 levels on the 4th, 5th and 7th to 10th day after hCG trigger were also significantly lower than those in the control group when letrozole was administered in the early luteal phase. CONCLUSIONS: Patients with high risk of OHSS probably benefit from letrozole, which has been revealed to reduce the incidence of moderate to severe OHSS by this systematic review. However, the very limited number of participants and the quality of the included studies does not allow to recommend letrozole for the prevention of severe OHSS.

The Efficacy of Letrozole Co-Treatment in an Antagonist Protocol for Women with Polycystic Ovary Syndrome Undergoing IVF: A Retrospective Study.

Objective: Our objective was to investigate the efficacy of letrozole co-treatment in an antagonist protocol for infertile women with polycystic ovary syndrome (PCOS). Patients and Methods: This retrospective cohort study included infertile women with PCOS undergoing IVF/ICSI with and without letrozole co-treatment in an antagonist protocol from 2007-2021 at Shanghai Ninth People's Hospital (Shanghai, China). A total of 1559 participants were enrolled, with 1227 women in the antagonist group and 332 women in the letrozole co-treatment group. Propensity score-based patient-matching model was conducted to balance covariates between the groups. The primary outcome was the number of retrieved oocytes, with secondary outcomes including endocrine parameters, ovarian stimulation outcomes, pregnancy outcomes, and obstetrical and neonatal complications. Results: Letrozole co-treatment induced significant changes in hormonal regulation, increased the percentage of large follicles, and resulted in fewer retrieved oocytes (P < 0.05). However, there was no negative impact on the number of usable embryos or good-quality embryos (P > 0.05). The live birth rates following fresh embryo transfer were comparable between the letrozole and control groups (single embryo transfer: 28.9% vs 29.7%, P > 0.05; double embryo transfer: 37.3% vs 45.6%, P > 0.05). Additionally, there were no significant differences between the two groups in the live birth rate per patient after frozen embryo transfer and the cumulative live birth rate (P > 0.05). No significant differences in obstetrical and neonatal complications were observed between the groups (P > 0.05). Conclusion: The addition of letrozole to the antagonist protocol for women with PCOS undergoing IVF induces a higher percentage of large follicles during oocyte retrieval, while reducing the overall number of retrieved oocytes. Moreover, the use of letrozole demonstrates comparable clinical outcomes following embryo transfers. These findings highlight the potential application of letrozole in an antagonist protocol for women with PCOS.

The Active Tumor Vaccination in Combination With CDK4/6 Inhibitor Treatment: A Case Report.

BACKGROUND: Current standard treatment for metastatic breast cancer (MBC) involves cyclin-dependent kinase 4/6 (CDK4/6) inhibitors with endocrine therapy, showing potential in enhancing anti-tumor immune responses. CASE REPORT: This report details a clinical case of MBC where palbociclib was co-administered with letrozole. The integration of allogeneic tumor vaccination to this treatment led to heightened interferon-γ production, expansion of CD8+ and NK cell populations, and positive delayed-type hypersensitivity reactions, indicating successful development of anti-tumor immunity. The induced production of interferon-γ by tumor vaccination was associated with manageable modulation of sensitivity to palbociclib-letrozole therapy. Administration of the BioNTech/Pfizer Covid-19 vaccine compromised the anti-tumor immune response by reducing cytotoxic cell populations and increasing immunosuppressive cytokine production. The patient undergoing combined treatment achieved a progressive-free survival of 42 months. CONCLUSION: Incorporating active tumor vaccination with CDK4/6 inhibitor therapy presents a feasible approach for metastatic breast cancer. The precise regulation of the microenvironment emerges as a crucial factor and warrants careful consideration.

Low Dose hCG Support in Modified Natural Frozen Embryo Transfer Cycles.

What is the effect of a single low-dose recombinant hCG injection after embryo transfer (ET) in letrozole-induced modified natural frozen embryo transfer cycles (mNC-FET)?. An observational study was conducted in the university-affiliated referral clinic between 2022 and 2024. Women aged 18-42 with at least one vitrified blastocyst obtained from the previous cycle(s) were included. Ovulation induction for endometrial preparation was initiated with oral letrozol (5 mg/day) for five days. Ovulation was triggered using 6500 IU rec hCG sc when the leading follicle > 17 mm, endometrial thickness > 7.5 mm, and serum progesterone (P) < 1.5 ng/ml. All women received 30 mg dydrogesterone/day po for additional five-day luteal support. On the 6th day, ET was performed. Based on a quasi-randomized design, a group of women additionally received a half single bolus of (3250 IU) rec hCG (sc) on the morning of 3rd day of ET (hCG group). Women who did not receive additional hCG were assigned as controls. One hundred fifty-four women were detected to be eligible for the study among 2150 initiated FET cycles during the period. Demographic data of the groups, including mean women's age, BMI, serum AMH, and infertility etiologies, were comparable in terms of variables. Mean serum progesterone values and the number of transferred embryos were also similar. A significantly higher ongoing pregnancy/started cycle was documented in the hCG group than in controls (46.7% vs 33.6% respectively, p = 0.03*). A single low-dose hCG injection after ET may improve the OPRs of women in letrozole mNC-FET cycles.

Progestin-primed ovarian stimulation with letrozole using different doses of medroxyprogesterone acetate per day: a retrospective cohort study.

Background: In the progestin-primed ovarian stimulation protocol, the oral administration of medroxyprogesterone acetate has been observed to effectively inhibit the LH surge during ovarian stimulation in patients experiencing infertility. Nevertheless, the use of utilizing medroxyprogesterone acetate during ovarian stimulation can result in more pronounced pituitary suppression, potentially necessitating increased doses of gonadotropins and extended treatment durations. Therefore, it is necessary to determine the optimal dose of medroxyprogesterone acetate, aiming to use relatively lower concentrations of medroxyprogesterone acetate to effectively and safely suppress early LH surges. Method: This retrospective cohort study included 710 patients who underwent cycles of in vitro fertilization or intracytoplasmic sperm injection and were subjected the progestin-primed ovarian stimulation protocol utilizing letrozole between from 1st January 2021 to 31st December 2021. The study population was divided into low, medium, and high concentration groups based on the daily dosage of medroxyprogesterone acetate.The primary focus of this investigation was on the cumulative live birth rate. Secondary outcomes encompassed the occurrence of a premature surge in luteinizing hormone, the quantity of retrieved oocytes, viable embryos, and high-quality embryos, as well as clinical pregnancy rate, abortion rate, ectopic pregnancy rate, and multiple pregnancy rate. Results: In this study, significant differences were observed among three groups in various parameters including body mass index, baseline levels of Anti-Müllerian hormone and luteinizing hormone, antral follicle count, total dose of gonadotropin, and duration of gonadotropin administration (p<0.05). The number of oocytes and viable embryos were significantly higher in medium group and higher than those in the low dose group. Following adjustments for confounding factors related to medroxyprogesterone acetate for various outcome measures, we conducted multiple regression analysis to investigate the independent effects of daily medroxyprogesterone acetate dosage within the combined progestin-primed ovarian stimulation and letrozole protocol. Following multivariable regression analysis, no disparities were found in embryo characteristics (number of oocytes retrieved, number of available embryos, number of high-quality embryos) or pregnancy outcomes (clinical pregnancy rate, cumulative live birth rate) among the three groups. Conclusion: Progestin-primed ovarian stimulation with letrozole using different dose of medroxyprogesterone acetate per day was comparable in terms of the number of oocytes retrieved, the number of high-quality embryos, clinical pregnancy rate and cumulative live birth rate after frozen embryo transfer.

Comparison of Various Therapeutic Approaches to Manage Infertility in Polycystic Ovarian Syndrome.

OBJECTIVE: To compare the efficacies of common therapeutic regimens and their combinations, used in polycystic ovarian syndrome (PCOS) to improve fertility in reproductive-age women. STUDY DESIGN: A descriptive study. Place and Duration of the Study: Department of Obstetric Gynaecologist, Medicare Cardiac and General Hospital, Karachi, Pakistan, from November 2022 to July 2023. METHODOLOGY: Out of 300 patients with the symptoms of menstrual irregularities and infertility, 152 were diagnosed as PCOS patients based on the ultrasound and hormonal assays and selected for study purpose. They were divided according to their therapeutic regimen into four treatment groups, treated by different therapeutic agents. Group A received metformin 500 mg/day (n = 38); Group B received metformin + myo-inositol 1g (n = 49); Group C received metformin + letrozole 2.5 mg (n = 36), and Group D received metformin + letrozole + myo-inositol (n = 29), orally for three months. All continuous variables, such as body mass index (BMI), FSH, LH, FT4, and FSI were analysed by applying t-test to all therapeutic groups, keeping p ≤0.05 as the level of significance. RESULTS: HCG-positive was found as 86% (n = 33) in Group A, 63% (n = 31) in Group B, 52% (n = 19) in Group C, and 27% (n = 08) in Group D. There were statistically significant (p <0.001) changes in BMI, FSH, LH, FT4, and FSI as well. Metformin alone and metformin plus myo-inositol came out to be more effective than other regimens. CONCLUSION: Metformin alone and myo-inositol plus metformin are effective therapeutic options in PCOS-induced infertility problems. KEY WORDS: Polycystic ovarian syndrome, Infertility, Metformin, Myo-inositol, Letrozole, Menstrual irregularities.

Impact of coadministration of proton-pump inhibitors and palbociclib in hormone receptor-positive/HER2-negative advanced breast cancer.

BACKGROUND: The capsule formulation of CDK4/6 inhibitor palbociclib has reduced solubility at gastric pH > 4.5 and may have decreased activity when used with proton-pump inhibitors (PPI). Herein, we report the effect of PPI on palbociclib capsule activity and safety in the PARSIFAL study. METHODS: First-line endocrine-sensitive, hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) patients received palbociclib capsules plus fulvestrant or letrozole. The primary endpoint was progression-free survival (PFS). This post-hoc analysis compared PPI use. Patients were PPI-naïve (N-PPI) if not on PPI during the study, and either early (E-PPI) or long-term PPI (LT-PPI) if on PPI at study entry or for at least ≥⅔ of treatment, respectively. PPI groups were not mutually exclusive. RESULTS: Among 486 patients, 66.9 % were N-PPI, 13.2 % E-PPI, 18.7 % LT-PPI, and 11.5 % of the PPI users were defined as neither. Median PFS (mPFS) was 29.6 months in the study population, 28.7 months in N-PPI, 23.0 months in E-PPI (Hazard Ratio [HR] 1.5; 95%Confidence Interval [CI] 1.1-2.2; p = 0.024), and 23.0 months in LT-PPI (HR 1.4; 95%CI 1.0-1.9; p = 0.035). By landmark analysis, PPI use was associated with poorer mPFS at 3 and 12 months. Grade ≥3 hematological adverse events occurred in 71.7 % of N-PPI, 57.8 % of E-PPI (p = 0.021), and 54.9 % of LT-PPI (p = 0.003). Dose reductions and dosing delays due to hematological toxicity occurred in 70.8 % of N-PPI, 56.3 % of E-PPI (p = 0.018), and 52.7 % of LT-PPI (p = 0.002). CONCLUSIONS: PPI use may reduce palbociclib capsule toxicity, dose modifications, and clinical activity in HR+/HER2- ABC.

Comparing the effectiveness of letrozole versus methotrexate for treatment of ectopic pregnancy: A randomized controlled trial.

OBJECTIVE: To evaluate the efficacy of two different regimens of Letrozole, an aromatase inhibitor, in the management of ectopic pregnancy compared to methotrexate. STUDY DESIGN: This randomized controlled trial was conducted on 88 women diagnosed with ectopic pregnancy with a baseline level of serum beta-human chorionic gonadotropin under 3000 mIU/mL between June 30, 2023, and December 30, 2023, at the Department of Obstetrics and Gynecology of the Vali-e-Asr Hospital affiliated with Tehran University of Medical Sciences. Participants were allocated into either methotrexate (n = 43), 5-day course Letrozole (n = 24), or 10-day course Letrozole (n = 21) treatments. The methotrexate group received a single dose of 50 mg/m2 dosage intramuscular methotrexate. The 5-day Letrozole group received a 2.5 mg Letrozole tablet three times daily for 5 days, whereas the 10-day Letrozole group received a 2.5 mg Letrozole tablet twice daily for 10 days. The primary outcome was the treatment response, defined as the achievement of a negative serum beta-human chorionic level without the need for additional methotrexate treatment or surgery. The secondary outcomes were the need for additional methotrexate dose or laparoscopic surgery intervention. The trial protocol was prospectively registered in ClinicalTrials.gov with code NCT05918718. RESULTS: The treatment response rates in methotrexate, 5-day Letrozole, and 10-day Letrozole groups were 76.7 %, 75.0 %, and 90.5 %, respectively, with no significant differences between the groups (P-value = 0.358). A total of 10 (23.3 %) patients from the methotrexate group, 3 (12.5 %) from the 5-day Letrozole group, and 2 (9.5 %) from the 10-day Letrozole group required an additional methotrexate dose, with no significant differences between the groups (P-value = 0.307). Furthermore, only 3 (12.5 %) patients, all from the 5-day Letrozole group, were suspected of tubal rupture and underwent surgery (P-value = 0.016). CONCLUSION: Our findings suggest Letrozole as a safe alternative to methotrexate in treating stable ectopic pregnancies, with a favorable treatment response rate. However, there is still a need for future larger studies to determine the applicability of Letrozole in the EP management. Also, the non-significant higher effectiveness of the 10-day Letrozole regimen than the 5-day Letrozole group underscores the need for future research to determine the optimal Letrozole regimen for the management of ectopic pregnancy.

Palbociclib in adults aged 70 years and older with advanced breast cancer: A phase 2 multicenter trial (Alliance A171601).

INTRODUCTION: Palbociclib is a widely used treatment for advanced breast cancer in older adults. However, the existing evidence regarding its safety and tolerability in this age group is inconsistent and limited to retrospective subgroup or pooled analyses. MATERIALS AND METHODS: We conducted a prospective single-arm multicenter phase 2 study to evaluate the safety and tolerability of palbociclib in participants aged 70 years or older with advanced hormone receptor-positive breast cancer. Participants were given palbociclib in combination with their physician's choice of endocrine therapy (letrozole or fulvestrant). The primary endpoint was the incidence of grade 3+ adverse events (AEs) by six months. Secondary endpoints included AE-related dose delays, dose reductions, early discontinuations, and hospitalizations. Additionally, we compared these endpoints by age groups (70-74 and ≥ 75 years). RESULTS: Of the 90 participants (median age 74 years [70-87]) enrolled, 75.6% (95% confidence interval [CI], 65.4-84.0) had grade 3+ AEs by six months. The most frequent grade 3+ AEs were neutropenia (61%), fatigue (4%), and nausea (3%). Febrile neutropenia was uncommon (1.1%). Due to AEs, 36% had dose delays, 34% had dose reductions, 10% had early discontinuations, and 10% had hospitalizations. Compared to those aged 70-74 years, participants aged ≥75 years had higher rates of early discontinuations (5.9% vs 15.9%, a difference of 9.5% [95% CI 3.5%-22.5%]). DISCUSSION: Palbociclib has an overall favorable safety profile in adults aged ≥70 with advanced breast cancer. However, adults ≥75 years had a trend toward higher rates of AE-related early discontinuations compared to those 70-74 years. Further research is needed to evaluate tolerability and improve the delivery of palbociclib in older adults. CLINICALTRIALS: gov:NCT03633331.

Letrozole ovulation regimen for frozen-thawed embryo transfer in women with polycystic ovary syndrome: study protocol for a randomized controlled trial.

BACKGROUND: Women with polycystic ovary syndrome (PCOS) are usually selected to undergo an ovulation induction regimen or a programmed regimen for endometrial preparation in the frozen-thawed embryo transfer (FET) during their IVF/ICSI treatment. The programmed regimen permits flexible scheduling of embryo transfer but requires long-term usage of exogenous estrogen and higher dosages of luteal support while the letrozole ovulation regimen needs lower dosages of luteal support only. Recently, multiple studies have shown that the letrozole ovulation regimen can improve pregnancy outcomes of FET in women with PCOS compared with the programmed regimen. However, most of these studies are retrospective, and prospective studies are urgently needed the evidence from the perspective study is insufficient. METHODS/DESIGN: We are undertaking a multicentre, randomized, controlled clinical trial of an endometrial preparation regimen for FET in women with PCOS. The eligible women are randomly assigned to either the letrozole ovulation regimen or the programmed regimen for endometrial preparation. The primary outcome is the clinical pregnancy rate. DISCUSSION: The results of this study will provide evidence for whether the letrozole ovulation regimen for endometrial preparation could improve pregnancy outcomes in PCOS women undergoing FET. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2200062244. Registered on 31 July 2022.

Randomized Phase III Study of Amcenestrant Plus Palbociclib Versus Letrozole Plus Palbociclib in Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: Primary Results From AMEERA-5.

PURPOSE: AMEERA-5 investigated amcenestrant (oral selective estrogen receptor [ER] degrader) plus palbociclib versus letrozole plus palbociclib as first-line treatment for ER-positive/human epidermal growth factor receptor 2-negative (ER+/HER2-) advanced/metastatic breast cancer (aBC). MATERIALS AND METHODS: In AMEERA-5 (ClinicalTrials.gov identifier: NCT04478266), a double-blind, double-dummy, international phase III trial, adult pre-/post-menopausal women and men without previous systemic therapy for ER+/HER2- aBC were randomly assigned 1:1 to amcenestrant 200 mg once daily + standard palbociclib dosage (125 mg once daily, 21 days on/7 days off) or letrozole 2.5 mg once daily + standard palbociclib dosage, stratified by de novo metastatic disease, postmenopausal women, and visceral metastasis. The primary end point was progression-free survival (PFS), compared using a stratified log-rank test with one-sided type I error rate of 2.5%. Secondary end points included overall survival (key secondary), pharmacokinetics, and safety. RESULTS: Between October 14, 2020, and December 2, 2021, 1,068 patients were randomly assigned to amcenestrant + palbociclib (N = 534) or letrozole + palbociclib (N = 534). At the interim analysis (median follow-up 8.4 months), the stratified hazard ratio for PFS was 1.209 (95% CI, 0.939 to 1.557; one-sided P value = .9304); therefore, the study was stopped for futility. The 6-month PFS rate was 82.7% (95% CI, 79.0 to 85.8) with amcenestrant + palbociclib versus 86.9% (95% CI, 83.5 to 89.6) with letrozole + palbociclib. In the amcenestrant + palbociclib versus letrozole + palbociclib groups, treatment-emergent adverse events (any grade) occurred in 85.6% versus 85.4% of patients and grade ≥3 events in 46.3% versus 60.8%, respectively. CONCLUSION: The AMEERA-5 study was discontinued on the basis of the recommendation of the data monitoring committee at the interim futility analysis. No new safety signals were identified.

A highly sensitive first derivative synchronous spectrofluorimetric approach for the simultaneous analysis of the anti-breast cancer co-administered drugs, letrozole and tramadol in dosage forms and human plasma at nanogram levels.

Letrozole is an anticancer medication prescribed for the management of estrogen receptor-positive breast cancer in postmenopausal women. Chronic pain is prevalent in patients receiving chemotherapy, leading to the use of adjuvant analgesics such as tramadol. This work introduces the first analytical approach for the concurrent quantification of letrozole and tramadol, two co-administered drugs, employing a rapid, highly sensitive, eco-friendly, and cost-effective first derivative synchronous spectrofluorimetric technique. The fluorescence of tramadol and letrozole was measured at wavelengths of 235.9 nm and 241.9 nm, respectively using a wavelength difference (Δλ) of 60.0 nm. The developed approach demonstrated exceptional linearity (r ˃ 0.999) within the specified concentration ranges for tramadol (10.0-1200.0 ng/mL) and letrozole (1.0-140.0 ng/mL). The results demonstrated that the proposed technique exhibits a high level of sensitivity, with detection limits of 0.569 and 0.143 ng/mL for tramadol and letrozole, respectively, indicating the good bioanalytical applicability. The within-run precisions, both intra-day and inter-day, for both analytes, were less than 0.71 % RSD. The developed approach was effectively applied to simultaneously estimate the mentioned drugs in their tablets and human plasma samples, achieving high percentage recoveries and low % RSD values. In order to assess the environmental sustainability of the developed approach, Analytical GREEnnessNNESS (AGREE) and the Green Analytical Procedure Index (GAPI) metric tools were employed. Both tools revealed that the developed approach is excellent green, suggesting its usage as an environmentally-friendly alternative for the routine assayof the investigated pharmaceuticals. The developed approach was validated according to the ICHQ2 (R1) requirements.

Identification of non-adherence to adjuvant letrozole using a population pharmacokinetics approach in hormone receptor-positive breast cancer patients.

BACKGROUND: Letrozole, an aromatase inhibitor metabolised via CYP2A6 and CYP3A4/5 enzymes, is used as adjuvant therapy for women with hormone receptor (HR)-positive early breast cancer. The objective of this study was to quantify the impact of CYP2A6 genotype on letrozole pharmacokinetics (PK), to identify non-adherent patients using a population approach and explore the possibility of a relationship between non-adherence and early relapse. METHODS: Breast cancer patients enrolled in the prospective PHACS study (ClinicalTrials.gov NCT01127295) and treated with adjuvant letrozole 2.5 mg/day were included. Trough letrozole concentrations (Css,trough) were measured every 6 months for 3 years by a validated LC-MS/MS method. Concentration-time data were analysed using non-linear mixed effects modelling. Three methods were evaluated for identification of non-adherent subjects using the base PK model. RESULTS: 617 patients contributing 2534 plasma concentrations were included and led to a one-compartment PK model with linear absorption and elimination. Model-based methods identified 28 % of patients as non-adherent based on high fluctuations of their Css,trough compared to 3 % based on patient declarations. The covariate analysis performed in adherent subjects revealed that CYP2A6 intermediate (IM) and slow metabolisers (SM) had 21 % (CI95 % = 12 - 30 %) and 46 % (CI95 % = 41 - 51 %) lower apparent clearance, respectively, compared to normal and ultrarapid metabolisers (NM+UM). Early relapse (19 patients) was not associated with model-estimated, concentration-based or declared adherence in the total population (p = 0.41, p = 0.37 and p = 0.45, respectively). CONCLUSIONS: These findings will help future investigations focusing on the exposure-efficacy relationship for letrozole in adjuvant setting.

Adding Letrozole to Growth Hormone and Gonadotropin-Releasing Hormone Analog Increases Height in Girls With Short Stature: A Hospital Record-Based Retrospective Study.

OBJECTIVE: There have been rare data on letrozole for height improvement in girls. This study aimed to clarify the efficacy and safety of combination therapy with recombinant human growth hormone (rhGH), GnRHa, and letrozole in improving the height of girls with short stature and advanced bone age. METHODS: This was a hospital record-based retrospective study. Follow-up was conducted on girls with short stature who received treatment with rhGH, GnRHa, and letrozole in our hospital. The treatment group included a total of 29 participants. Before treatment, the mean age of the patients was 11.17 years, and the mean treatment duration was 17.31 months. The control group consisted of 29 short-statured girls who received rhGH/GnRHa treatment, with the mean age and treatment duration of 12.43 years and 16.59 months, respectively. RESULTS: The predicted adult heights (PAHs) before and after treatment were 155.38 and 161.32 cm (P < .001). The ΔPAH in the treatment group was 4 cm higher than that in the control group (5.85 vs 1.82 cm, P < .001). Significant differences were noted in the height standard deviation scores of bone age (P < .001) and chronological age (P = .003) before and after treatment. There was an increasing body mass index during therapy (P = .039). The height gain was 8.71 ± 4.46 cm, and the growth rate was 6.78 ± 3.84 cm per year. CONCLUSION: Combined treatment with GH, GnRHa, and letrozole can enhance the adult height and PAH in short-statured girls, and no significant side effects have been reported.

Abemaciclib plus a nonsteroidal aromatase inhibitor as initial therapy for HR+, HER2- advanced breast cancer: final overall survival results of MONARCH 3.

BACKGROUND: In MONARCH 2, the addition of abemaciclib to fulvestrant significantly improved both progression-free survival (PFS) and overall survival (OS) in patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) with disease progression on prior endocrine therapy. In MONARCH 3, the addition of abemaciclib to a nonsteroidal aromatase inhibitor (NSAI) as initial therapy for HR+, HER2- ABC significantly improved PFS. Here, we present the prespecified final OS results for MONARCH 3. PATIENTS AND METHODS: MONARCH 3 is a randomized, double-blind, phase III study of abemaciclib plus NSAI (anastrozole or letrozole) versus placebo plus NSAI in postmenopausal women with HR+, HER2- ABC without prior systemic therapy in the advanced setting. The primary objective was investigator-assessed PFS; OS was a gated secondary endpoint, and chemotherapy-free survival was an exploratory endpoint. RESULTS: A total of 493 women were randomized 2 : 1 to receive abemaciclib plus NSAI (n = 328) or placebo plus NSAI (n = 165). After a median follow-up of 8.1 years, there were 198 OS events (60.4%) in the abemaciclib arm and 116 (70.3%) in the placebo arm (hazard ratio, 0.804; 95% confidence interval 0.637-1.015; P = 0.0664, non-significant). Median OS was 66.8 versus 53.7 months for abemaciclib versus placebo. In the subgroup with visceral disease, there were 113 OS events (65.3%) in the abemaciclib arm and 65 (72.2%) in the placebo arm (hazard ratio, 0.758; 95% confidence interval 0.558-1.030; P = 0.0757, non-significant). Median OS was 63.7 months versus 48.8 months for abemaciclib versus placebo. The previously demonstrated PFS benefit was sustained, and chemotherapy-free survival numerically improved with the addition of abemaciclib. No new safety signals were observed. CONCLUSIONS: Abemaciclib combined with an NSAI resulted in clinically meaningful improvement in median OS (intent-to-treat population: 13.1 months; subgroup with visceral disease: 14.9 months) in patients with HR+ HER2- ABC; however, statistical significance was not reached.

Effect of vitamin D in addition to letrozole on the ovulation rate of women with polycystic ovary syndrome: protocol of a multicentre randomised double-blind controlled trial.

INTRODUCTION: Low vitamin D status is prevalent among women with polycystic ovary syndrome (PCOS). The objective of the study is to assess the effect of vitamin D supplementation on (1) the ovulation rate to letrozole and (2) other reproductive, endocrine and metabolic outcomes after 1 year of supplementation in women with PCOS. METHODS AND ANALYSIS: This is a multicentre, randomised, double-blind, controlled clinical trial. A total of 220 anovulatory women with PCOS diagnosed by the Rotterdam criteria will be recruited. They will be randomly assigned to either the (1) vitamin D supplementation group or (2) placebo group. Those in the vitamin D group will take oral Vitamin D3 50 000 IU/week for 4 weeks, followed by 50 000 IU once every 2 weeks for 52 weeks. Those who remain anovulatory after 6 months will be treated with a 6-month course of letrozole (2.5 mg to 7.5 mg for 5 days per cycle titrated according to response) for ovulation induction. The primary outcome is the ovulation rate. All statistical analyses will be performed using intention-to-treat and per protocol analyses. ETHICS AND DISSEMINATION: Ethics approval was sought from the Institutional Review Board of the participating units. All participants will provide written informed consent before joining the study. The results of the study will be submitted to scientific conferences and peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04650880.

Ribociclib plus Endocrine Therapy in Early Breast Cancer.

BACKGROUND: Ribociclib has been shown to have a significant overall survival benefit in patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced breast cancer. Whether this benefit in advanced breast cancer extends to early breast cancer is unclear. METHODS: In this international, open-label, randomized, phase 3 trial, we randomly assigned patients with HR-positive, HER2-negative early breast cancer in a 1:1 ratio to receive ribociclib (at a dose of 400 mg per day for 3 weeks, followed by 1 week off, for 3 years) plus a nonsteroidal aromatase inhibitor (NSAI; letrozole at a dose of 2.5 mg per day or anastrozole at a dose of 1 mg per day for ≥5 years) or an NSAI alone. Premenopausal women and men also received goserelin every 28 days. Eligible patients had anatomical stage II or III breast cancer. Here we report the results of a prespecified interim analysis of invasive disease-free survival, the primary end point; other efficacy and safety results are also reported. Invasive disease-free survival was evaluated with the use of the Kaplan-Meier method. The statistical comparison was made with the use of a stratified log-rank test, with a protocol-specified stopping boundary of a one-sided P-value threshold of 0.0128 for superior efficacy. RESULTS: As of the data-cutoff date for this prespecified interim analysis (January 11, 2023), a total of 426 patients had had invasive disease, recurrence, or death. A significant invasive disease-free survival benefit was seen with ribociclib plus an NSAI as compared with an NSAI alone. At 3 years, invasive disease-free survival was 90.4% with ribociclib plus an NSAI and 87.1% with an NSAI alone (hazard ratio for invasive disease, recurrence, or death, 0.75; 95% confidence interval, 0.62 to 0.91; P = 0.003). Secondary end points - distant disease-free survival and recurrence-free survival - also favored ribociclib plus an NSAI. The 3-year regimen of ribociclib at a 400-mg starting dose plus an NSAI was not associated with any new safety signals. CONCLUSIONS: Ribociclib plus an NSAI significantly improved invasive disease-free survival among patients with HR-positive, HER2-negative stage II or III early breast cancer. (Funded by Novartis; NATALEE ClinicalTrials.gov number, NCT03701334.).

A Phase 0/I Pharmacokinetic and Pharmacodynamics and Safety and Tolerability Study of Letrozole in Combination with Standard Therapy in Recurrent High-Grade Gliomas.

PURPOSE: High-grade gliomas (HGG) carry a poor prognosis, with glioblastoma accounting for almost 50% of primary brain malignancies in the elderly. Unfortunately, despite the use of multiple treatment modalities, the prognosis remains poor in this population. Our preclinical studies suggest that the presence of aromatase expression, encoded by CYP19A1, is significantly upregulated in HGGs. Remarkably, we find that letrozole (LTZ), an FDA-approved aromatase inhibitor, has marked activity against HGGs. PATIENTS AND METHODS: We conducted a phase 0/I single-center clinical trial (NCT03122197) to assess the tumoral availability, pharmacokinetics (PK), safety, and tolerability of LTZ in recurrent patients with HGG. Planned dose cohorts included 2.5, 5, 10, 12.5, 15, 17.5, and 20 mg of LTZ administered daily pre- and postsurgery or biopsy. Tumor samples were assayed for LTZ content and relevant biomarkers. The recommended phase 2 dose (R2PD) was determined as the dose that resulted in predicted steady-state tumoral extracellular fluid (ECF; Css,ecf) >2 µmol/L and did not result in ≥33% dose-limiting adverse events (AE) assessed using CTCAE v5.0. RESULTS: Twenty-one patients were enrolled. Common LTZ-related AEs included fatigue, nausea, musculoskeletal, anxiety, and dysphoric mood. No DLTs were observed. The 15 mg dose achieved a Css,ecf of 3.6 ± 0.59 µmol/L. LTZ caused dose-dependent inhibition of estradiol synthesis and modulated DNA damage pathways in tumor tissues as evident using RNA-sequencing analysis. CONCLUSIONS: On the basis of safety, brain tumoral PK, and mechanistic data, 15 mg daily is identified as the RP2D for future trials.