Population pharmacokinetics modeling and exposure-response analyses of cemiplimab in patients with recurrent or metastatic cervical cancer.

A population pharmacokinetic (PopPK) model was previously developed for cemiplimab in patients with solid tumors, including advanced cutaneous squamous cell carcinoma (CSCC). Here, we update the existing PopPK model and characterize exposure-response relationships using efficacy and safety data obtained in patients with recurrent or metastatic cervical cancer (R/M CC). To improve model stability and robustness of the existing PopPK model in 1062 patients, the random-effect error model was revised, and structural covariates were removed from the base model to be tested in the covariate analysis. The updated model was used for external validation of cemiplimab pharmacokinetics (PK) in patients with R/M CC on cemiplimab monotherapy (350 mg every 3 weeks intravenously) from a phase III study (NCT03257267). Exposure-response relationships for cemiplimab efficacy (overall survival [OS], progression-free survival [PFS], duration of response [DOR], objective response rate [ORR]), and safety (immune-related adverse events [irAEs]) were analyzed in 295 patients with R/M CC from the aforementioned study. The updated PopPK model showed improved stability with 94.8% successful bootstrap runs vs. 47.6% in the prior model. Cemiplimab exposure was similar across tumor types, including basal cell carcinoma, CSCC, and non-small cell lung cancer. External validation showed the updated model adequately described cemiplimab PK in patients with R/M CC. In exposure-response efficacy analyses, Cox proportional hazard modeling (CPHM) showed no trend between exposure and OS, Kaplan-Meier plots showed no trend between exposure and PFS or DOR, and logistic regression analyses conducted on ORR showed no exposure-response relationship. In exposure-response safety analyses, CPHM showed no trend between exposure and irAEs.

Translational findings for odronextamab: From preclinical research to a first-in-human study in patients with CD20+ B-cell malignancies.

Odronextamab is a fully-human IgG4-based CD20xCD3 bispecific antibody that binds to CD3 on T cells and CD20 on B cells, triggering T-cell-mediated cytotoxicity independent of T-cell-receptor recognition. Adequate safety, tolerability, and encouraging durable complete responses have been observed in an ongoing first-in-human (FIH) study of odronextamab in patients with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL; NCT02290951). We retrospectively evaluated the pharmacokinetic, pharmacodynamic, and antitumor characteristics of odronextamab in a series of in vitro/in vivo preclinical experiments, to assess their translational value to inform dose escalation for the FIH study. Half-maximal effective concentration values from in vitro cytokine release assays (range: 0.05-0.08 mg/L) provided a reasonable estimate of odronextamab concentrations in patients associated with cytokine release at a 0.5 mg dose (maximum serum concentration: 0.081 mg/L) on week 1/day 1, which could therefore be used to determine the week 1 clinical dose. Odronextamab concentrations resulting in 100% inhibition of tumor growth in a Raji xenograft tumor mouse model (1-10 mg/L) were useful to predict efficacious concentrations in patients and inform dose-escalation strategy. Although predicted human pharmacokinetic parameters derived from monkey data overestimated projected odronextamab exposure, they provided a conservative estimate for FIH starting doses. With step-up dosing, the highest-tested weekly odronextamab dose in patients (320 mg) exceeded the 1 mg/kg single dose in monkeys without step-up dosing. In conclusion, combination of odronextamab in vitro cytokine data, efficacious concentration data from mouse tumor models, and pharmacokinetic evaluations in monkeys has translational value to inform odronextamab FIH study design in patients with R/R B-NHL.

Population pharmacokinetic characteristics of cemiplimab in patients with advanced malignancies.

Cemiplimab, a human monoclonal antibody targeting programmed cell death-1 (PD-1) receptor, demonstrated antitumor activity in patients with advanced malignancies and a safety profile comparable to other anti-PD-1 therapies. This population pharmacokinetics (PopPK) analysis of cemiplimab included 11,178 pharmacokinetics (PK) observations from 548 patients pooled from a first-in-human study (Study 1423; NCT02383212) in advanced malignancies and a Phase 2 study (Study 1540; NCT02760498) in advanced cutaneous squamous cell carcinoma (CSCC). Most patients (80.3%) received cemiplimab 3 mg/kg every 2 weeks (Q2W) intravenously (IV). A PopPK model was developed by evaluating two-compartment linear models with an empirical non-linear function describing time-varying change in cemiplimab clearance and covariates that improved goodness-of-fit. PopPK simulations were used to describe cemiplimab exposure generated by a fixed 350 mg every 3 weeks (Q3W) IV dose regimen. PopPK modeling showed that a two-compartment model with zero-order IV infusion rate and first-order elimination rate well described individual concentrations of cemiplimab. Although several covariates, including baseline body weight and albumin concentrations, had a modest impact on cemiplimab exposure, the magnitude of influence was within the typical observed PK variability of approximately 30%. Based on PopPK simulation results, the 350 mg Q3W dose regimen was selected for further studies in advanced malignancies, including advanced CSCC. Similarity in observed cemiplimab exposure at the fixed 350 mg Q3W and the weight-based 3 mg/kg Q2W dose regimens confirmed this fixed dose selection. A robust PopPK model was developed to describe cemiplimab concentrations and supported use of the fixed 350 mg Q3W IV dose regimen.

Fixed Dose of Cemiplimab in Patients with Advanced Malignancies Based on Population Pharmacokinetic Analysis.

INTRODUCTION: This study outlined cemiplimab intravenous (IV) dosing strategy to move from body weight (BW)-based 3 mg/kg every-2-week (Q2W) dosing in first-in-human study (study 1423; NCT02383212) to fixed 350 mg every-3-week (Q3W) dosing, utilizing population pharmacokinetics (PopPK) modeling and simulations, and supported by a limited dataset from a phase 2 study (study 1540; NCT02760498). METHODS: Cemiplimab concentration data from a total of 505 patients were pooled from study 1423 in advanced malignancies and study 1540 in advanced cutaneous squamous cell carcinoma (CSCC). All patients received weight-based cemiplimab dose (1, 3, 10 mg/kg Q2W or 3 mg/kg Q3W) except 4% who received 200 mg Q2W. A linear two-compartment PopPK model incorporating covariates that improved goodness-of-fit statistics was developed to compare cemiplimab exposure at 350 mg Q3W versus 3 mg/kg Q2W. Upon availability, observed cemiplimab concentration at 350 mg Q3W in study 1540 was then compared with the simulated values. RESULTS: Post hoc estimates of cemiplimab exposure and variability (505 patients; weight range 30.9-156 kg; median 76.1 kg) at steady state were found to be similar at 350 mg Q3W and 3 mg/kg Q2W. Effect of BW on cemiplimab exposure was described by exposure versus BW plots and at extreme BW. Overlay of individual observed cemiplimab concentrations in 51 patients with metastatic CSCC on simulated concentration-time profiles in 2000 patients at 350 mg Q3W confirmed cemiplimab exposure similarity and demonstrated the robustness of dose optimization based on PopPK modeling and simulations. CONCLUSIONS: Cemiplimab 350 mg Q3W is being further investigated in multiple indications.

Pharmacokinetics and Pharmacodynamics of Subcutaneous Sarilumab and Intravenous Tocilizumab Following Single-Dose Administration in Patients With Active Rheumatoid Arthritis on Stable Methotrexate.

We assessed pharmacokinetics (PK), pharmacodynamics (PD), and PK/PD relationships of interleukin-6 (IL-6), soluble IL-6 receptor, and C-reactive protein (CRP) in serum, and absolute neutrophil count (ANC) in blood following single doses of subcutaneous sarilumab versus intravenous tocilizumab (NCT02097524) from patients with rheumatoid arthritis (RA) who are inadequate responders to methotrexate (MTX) and on a stable dose of MTX. Patients with RA randomized (1:1:1:1) to single-dose sarilumab (150 or 200 mg subcutaneously) or tocilizumab (4 or 8 mg/kg intravenously) were included (n = 101), and PK, PD, and PK/PD relationships and safety were assessed over 6 weeks postdose. PK profiles for both drugs are described by parallel linear and nonlinear target-mediated clearance pathways. PD markers showed similar onset of effect during the first week postdose, regardless of dose or route of administration. CRP and ANC decreased, with median postdose nadirs at 7-15 days for CRP and 3-5 days for ANC. Both drugs at low and high doses achieved the same nadir for ANC and a similar return toward baseline within 2 weeks postdose, suggesting a saturation of effect. Safety profiles of sarilumab and tocilizumab were generally similar. In conclusion, despite differences in PK, the onset of the decrease in CRP (efficacy) and ANC (safety) after a single dose were similar for subcutaneous sarilumab and intravenous tocilizumab. PD effects and safety were consistent with previous studies.

Evaluation of Potential Disease-Mediated Drug-Drug Interaction in Patients With Moderate-to-Severe Atopic Dermatitis Receiving Dupilumab.

This open-label drug-drug interaction study assessed whether blockade by dupilumab of interleukin (IL)-4 and IL-13 signaling affects the pharmacokinetics of drugs metabolized by cytochrome P450 (CYP450) enzymes. The pharmacokinetics of five CYP450 substrates given orally (midazolam, omeprazole, S-warfarin, caffeine, and metoprolol, metabolized by CYP3A, CYP2C19, CYP2C9, CYP1A2, and CYP2D6, respectively) were evaluated before and 28 days after initiation of dupilumab treatment (subcutaneous 300 mg weekly) in 14 patients with moderate-to-severe atopic dermatitis. Dupilumab had no clinically relevant effects on the pharmacokinetics of CYP450 substrates, provided substantial clinical benefit, and was generally well tolerated. Only one serious adverse event was reported, an episode of systemic inflammatory response syndrome that resolved after treatment was discontinued. In summary, blockade of IL-4/IL-13 signaling in patients with type 2 inflammation does not appear to significantly affect CYP450 enzyme activities; the use of dupilumab in atopic dermatitis patients is unlikely to influence the pharmacokinetics of CYP450 substrates.

Combining "Bottom-up" and "Top-down" Approaches to Assess the Impact of Food and Gastric pH on Pictilisib (GDC-0941) Pharmacokinetics.

Pictilisib, a weakly basic compound, is an orally administered, potent, and selective pan-inhibitor of phosphatidylinositol 3-kinases for oncology indications. To investigate the significance of high-fat food and gastric pH on pictilisib pharmacokinetics (PK) and enable label recommendations, a dedicated clinical study was conducted in healthy volunteers, whereby both top-down (population PK, PopPK) and bottom-up (physiologically based PK, PBPK) approaches were applied to enhance confidence of recommendation and facilitate the clinical development through scenario simulations. The PopPK model identified food (for absorption rate constant (Ka )) and proton pump inhibitors (PPI, for relative bioavailability (Frel ) and Ka ) as significant covariates. Food and PPI also impacted the variability of Frel . The PBPK model accounted for the supersaturation tendency of pictilisib, and gastric emptying physiology successfully predicted the food and PPI effect on pictilisib absorption. Our research highlights the importance of applying both quantitative approaches to address critical drug development questions.

Effects of RG7652, a Monoclonal Antibody Against PCSK9, on LDL-C, LDL-C Subfractions, and Inflammatory Biomarkers in Patients at High Risk of or With Established Coronary Heart Disease (from the Phase 2 EQUATOR Study).

RG7652 (MPSK3169A), a fully human immunoglobulin G1 (IgG1) monoclonal antibody directed against proprotein convertase subtilisin/kexin type 9 (PCSK9), blocks the interaction between PCSK9 and low-density lipoprotein (LDL) receptor. EQUATOR (ClinicalTrials.govNCT01609140), a randomized, double-blind, and dose-ranging phase 2 study, evaluated RG7652 in patients (1) at high risk for or (2) with coronary heart disease (CHD). The primary end point was change in LDL cholesterol (LDL-C) from baseline to day 169. Patients (n = 248; median age, 64 years; 57% men; 52% with established CHD; 82% on statins) with baseline LDL-C levels of 90 to 250 mg/dl (mean, 126 mg/dl) continuing on standard-of-care therapy were randomized to receive 1 of 5 RG7652 doses or placebo, subcutaneously every 4, 8, or 12 weeks for 24 weeks. Significant dose-dependent reductions in LDL-C levels from baseline to nadir (56 to 74 mg/dl [48% to 60%]) were observed in all RG7652-dosed patients; effects persisted to day 169 with the highest doses (reduction vs placebo up to 62 mg/dl [51%]) with no unexpected safety signals. RG7652 reduced apolipoprotein B and lipoprotein(a) levels. LDL-C subfraction analysis by nuclear magnetic resonance spectroscopy revealed a prominent decrease in large LDL-C and some decrease in small LDL particles. There was significant reduction in mean particle size of LDL-C on day 169 but no significant reductions in systemic markers of inflammation (high-sensitivity C-reactive protein, interleukin-6, and tumor necrosis factor-alpha). RG7652 reduced LDL-C levels and was well tolerated in patients at high risk for or with CHD on standard-of-care therapy. In conclusion, RG7562 treatment affected large LDL-C and, to a lesser extent, small LDL-C particles; RG7562 did not affect systemic circulating pro-inflammatory cytokines or high-sensitivity C-reactive protein.

Identifying Gaps and Inconsistencies in Urogynecologic Surgical Training of Obstetrics and Gynecology Residents.

OBJECTIVE: This study aims to determine the expectations of Obstetrics and Gynecology (ObGyn) residency and Female Pelvic Medicine & Reconstructive Surgery (FPMRS) fellowship program directors (FPDs) for the independent performance of urogynecologic procedures during residency and to compare these expectations with the Council on Resident Education in Obstetrics and Gynecology (CREOG) educational objectives. MATERIALS AND METHODS: Two parallel, anonymous surveys were distributed simultaneously to all directors of accredited ObGyn residency and FPMRS fellowship programs in the United States. Respondents provided their own professional and program demographic information and indicated whether they expected their residents to independently perform 27 selected urogynecologic procedures. RESULTS: Among residency program directors (RPDs) and FPDs, the online survey response rate was 24.8% (n = 59) and 51.9% (n = 27), respectively. More RPDs expected residents to perform prolapse procedures with mesh, including laparoscopic sacrocolpopexy, all apical suspensions, mesh excisions, and cystotomy repairs, than FPDs. In addition, RPDs expected mastery of most urogynecologic procedures by the Post Graduate Year 3 level, whereas most FPDs did not expect independent performance of these procedures during residency at all. There were notable differences between RPDs' expectations and CREOG objectives regarding several surgical procedures. Whereas CREOG recommends independent performance of anterior and posterior repair, vaginal suspension, vaginal hysterectomy, and transobturator slings, a significant number of RPDs did not report expecting mastery of these procedures during residency. Approximately 30% of RPDs expected residents to perform open sacrocolpopexy and vesicovaginal fistula repair, whereas CREOG recommends only the understanding of these, without procedural mastery. CONCLUSIONS: Although community needs vary by region and setting, CREOG objectives serve as the standard for resident surgical education. This study highlights the discordance between these objectives and ObGyn RDPs' reported expectations for resident performance as well as those held by FPMRS FPDs, the outcome of which reflects a misalignment in graduate medical education between RPDs and FPDs, thus hindering a clear standard for resident surgical competencies.

Population pharmacokinetic analysis from phase I and phase II studies of the humanized monovalent antibody, onartuzumab (MetMAb), in patients with advanced solid tumors.

Onartuzumab is a unique, humanized, monovalent (one-armed) monoclonal antibody (mAb) against the MET receptor. The intravenous (IV) pharmacokinetics (PK) of onartuzumab were investigated in a phase I study and a phase II study in recurrent non-small cell lung cancer (NSCLC) patients. The potential for drug-drug interaction (DDI) was assessed during co-administration of IV onartuzumab with oral erlotinib, by measuring the PK of both drugs. The concentration-time profiles of onartuzumab were adequately described using a two-compartment model with linear clearance (CL) at doses between 4 and 30 mg/kg. The estimates for CL, central compartment volume (V1 ), and median terminal half-life were 0.439 L/day, 2.77 L, and 13.4 days, respectively. Statistically significant covariates included creatinine clearance (CrCL) on clearance, weight and gender on V1 , and weight on peripheral compartment volume (V2 ), but the clinical relevance of these covariates needs to be further evaluated. The current analysis did not indicate obvious DDI between onartuzumab and erlotinib. MET diagnostic status did not impact the exposure of either agent. Despite the slightly faster clearance compared with typical bivalent mAbs, the PK of onartuzumab support dosing regimens of 15 mg/kg every 3 weeks or doses equivalent to achieve the target minimum tumoristatic concentration in patients.

The utility of endocervical curettage: does routine ECC at the time of colposcopy for low-grade cytologic abnormalities improve diagnosis of high-grade disease?

OBJECTIVE: To determine the use of endocervical curettage at the time of colposcopy for low-grade cytologic abnormalities. STUDY DESIGN: We conducted a retrospective chart review of women with low-grade Papanicolaou smears who had undergone satisfactory colposcopic examinations with identifiable lesions. We evaluated results during a 2-year period thereafter to determine whether endocervical curettage increased the diagnosis of high-grade dysplasia. RESULTS: The study group consisted of 374 patients. Of these patients, 16 had endocervical curettages suggestive of high-grade dysplasia. Of these 16 patients, 4 did not have concomitant high-grade dysplasia identified on ectocervical biopsy. Therefore, 93 to 94 endocervical curettages needed to be performed to detect 1 case of high-grade dysplasia that would not have been identified otherwise. CONCLUSION: Routine endocervical curettage at the time of satisfactory colposcopy for low-grade cytologic abnormalities with a visible lesion does not significantly improve the diagnosis of high-grade dysplasia.

Angiomyofibroblastoma of the vulva: a case report of a pedunculated variant and review of the literature.

OBJECTIVE: Angiomyofibroblastoma (AMF) is a benign mesenchymal tumor usually found in the vulva. We reviewed 70 cases of vulvar AMF that have been reported in the English-language literature and report 1 case of a pedunculated variant. Our case brings the total reported to 71 and is only the fourth pedunculated variant reported. METHODS: This 50-year-old woman presented to our gynecology clinic with a 1-year history of a left labial mass. It began as pea-sized, and rapidly grew to 12 cm in diameter. Physical examination demonstrated a 12-cm pedunculated soft mass arising from the left labia majora. The clinical diagnosis was aggressive angiomyxoma, and a simple excision was performed. The final pathology demonstrated AMF. The patient remains free from tumor at 4 years of follow-up. RESULTS: Seventy-one cases were summarized. The mean age at presentation was 45 years. The lesions were equally distributed between the left (52%) and right (48%). The most common clinical diagnosis was a Bartholin gland cyst (46%) or lipoma (15%). The mean duration of the lesion before seeking treatment was 29 months, and the mean diameter at presentation was 5.9 cm. All of the patients were treated with simple excision. The mean duration of follow-up was 37 months. There was 1 report of sarcomatous transformation 2 years after initial treatment. CONCLUSIONS: Angiomyofibroblastoma is a rare benign tumor that most often occurs in the vulva. Differential diagnosis may include aggressive angiomyxoma, Bartholin cyst, or lipoma. The treatment of choice is simple total excision, which is usually curative.

Vulvar lymphangioma circumscriptum: a report of 3 cases, 2 associated with vulvar carcinoma and 1 with hidradenitis suppurativa.

Vulvar lymphangioma circumscriptum is a rare, benign proliferation of the lymphatic system that presents a diagnostic and management challenge. It may be confused with condyloma acuminata, molluscum contagiosum, or other vulvar disorders. Treatment options include observation, surgical excision, laser ablation, or sclerosing therapy. We report 3 cases, 2 associated with vulvar squamous cell carcinoma and 1 with hidradenitis suppurativa.

The effectiveness of endometrial ablation with the Hydro ThermAblator (HTA) for abnormal uterine bleeding.

OBJECTIVE: We sought to determine the overall effectiveness and risk factors for failure of hydrothermal ablation in the management of abnormal uterine bleeding. STUDY DESIGN: We performed a retrospective cohort analysis of patients who underwent hydrothermal ablation for abnormal uterine bleeding at our institution from July 2005 through February 2008. Variables analyzed included patient demographics, insurance status, body mass index, bleeding pattern, obstetric history, prior medical therapy and duration, uterine characteristics, and tobacco use history. RESULTS: In all, 159 patients were identified and 142 charts were eligible for evaluation. A total of 45 patients (31.6%) had return of preablation vaginal bleeding. Menometrorrhagia was a significant predictor for failure (P = .027) and subsequent hysterectomy (P = .0025). Younger age (P = .044), tobacco use (P = .042), and Medicaid/Medicare insurance status (P = .039) were also associated with a higher risk of failure. CONCLUSION: Women who are younger, use tobacco products, and have menometrorrhagia are more likely to fail hydrothermal ablation.

Vaginal bleeding due to an infantile hemangioma in a 3-year-old girl.

BACKGROUND: Infantile hemangiomas may cause vaginal bleeding in prepubescent girls. CASE: A 3-year-old girl was referred for evaluation of painless vaginal bleeding. Her initial evaluation was nondiagnostic. The girl's physical examination was remarkable only for an infantile hemangioma of her right hand. A vaginoscopy was performed and a hemangioma of the anterior vaginal wall was identified. The patient was managed conservatively. Her bleeding has decreased in amount and frequency. SUMMARY AND CONCLUSION: Infantile hemangiomas are a potential cause of vaginal bleeding in young girls and should be suspected if a child has a hemangioma on another part of their body. Most infantile hemangiomas resolve without therapy.

Massive uterovaginal prolapse in a young nulligravida with ascites: a case report.

BACKGROUND: Uterovaginal prolapse commonly affects older, multiparous women. CASE: A 21-year-old nulligravida was referred to us for management of massive uterovaginal prolapse secondary to chronic ascites. Conservative attempts at reducing the patient's prolapse were unsuccessful. She underwent anterior colporraphy, reduction and ligation of an enterocele sac, and sacrospinous cervicopexy for treatment of the prolapse. CONCLUSION: An option for treating women with massive uterovaginal prolapse secondary to chronic ascites is reduction and ligation of the enterocele sac and sacrospinous cervicopexy.