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1.
EClinicalMedicine ; 44: 101273, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35128365

RESUMO

BACKGROUND: Sayana Press® is a 3-monthly contraceptive injection approved by regulatory agencies in more than 40 countries worldwide. Existing effectiveness and pharmacokinetics (PK) data suggest that high contraceptive efficacy may be maintained if the reinjection interval of Sayana Press is extended from 3 to 4 months. METHODS: We conducted a phase 3 trial at three sites in the Dominican Republic, Brazil, and Chile from September 2017 through April 2020. We enrolled 750 women at risk of pregnancy who agreed to use Sayana Press off-label every 4 months (3 treatment cycles) for 12 months. The effectiveness cohort included 710 participants randomized equally to receive injections in the abdomen or thigh. Forty additional participants received injections in the back of the upper arm for comparative PK analyses. The primary outcome was pregnancy, defined by a positive urine pregnancy test confirmed by ultrasound and/or serum human chorionic gonadotropin. Secondary outcomes included PK, safety, and acceptability. Laboratory and trial Sponsor staff were blind to injection site. This study is registered with ClinicalTrials.gov, number NCT03154125. FINDINGS: There were no pregnancies during follow-up; the Pearl Index during 629.3 woman-years (WY) of follow-up in the primary effectiveness analysis was 0.00 (95% CI 0.00, 0.59). Pharmacokinetic profiles differed by injection site, with higher geometric mean (GM) medroxyprogesterone acetate concentrations for the abdomen than the thigh and arm. At month 8, significantly higher GM concentrations were observed in the abdomen and the thigh as compared to the arm, as well as at month 12 in the abdomen as compared to the arm. Injection site reactions were reported by 10.7% of participants. INTERPRETATION: Both pregnancy and PK results confirm that Sayana Press is a highly effective contraceptive method when administered every 4 months. These findings may inform modification of the dosing schedule, or duration of the grace period for reinjection, or both, to reduce overall drug exposure while maintaining contraceptive efficacy. FUNDING: This work is made possible by the generous support of the American people through the U.S. Agency for International Development (USAID), provided to FHI 360 through Cooperative Agreement AID-OAA-A-15-00,045, and a grant from the Gates Foundation. The contents are the responsibility of FHI 360 and do not necessarily reflect the views of USAID, the United States Government, or the Gates Foundation, nor does any mention of trade names, commercial products, or organizations imply endorsement by FHI 360, USAID, the United States Government, or the Gates Foundation.

2.
Nat Med ; 28(3): 481-485, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35051990

RESUMO

The recent emergence of the SARS-CoV-2 Omicron variant is raising concerns because of its increased transmissibility and its numerous spike mutations, which have the potential to evade neutralizing antibodies elicited by COVID-19 vaccines. Here we evaluated the effects of a heterologous BNT162b2 mRNA vaccine booster on the humoral immunity of participants who had received a two-dose regimen of CoronaVac, an inactivated vaccine used globally. We found that a heterologous CoronaVac prime vaccination of two doses followed by a BNT162b2 booster induces elevated virus-specific antibody levels and potent neutralization activity against the ancestral virus and the Delta variant, resembling the titers obtained after two doses of mRNA vaccines. Although neutralization of Omicron was undetectable in participants who had received a two-dose regimen of CoronaVac, the BNT162b2 booster resulted in a 1.4-fold increase in neutralization activity against Omicron compared with the two-dose mRNA vaccine. Despite this increase, neutralizing antibody titers were reduced by 7.1-fold and 3.6-fold for Omicron compared with the ancestral strain and the Delta variant, respectively. These findings have immediate implications for multiple countries that previously used a CoronaVac regimen and reinforce the idea that the Omicron variant is associated with immune escape from vaccines or infection-induced immunity, highlighting the global need for vaccine boosters to combat the impact of emerging variants.


Assuntos
Vacina BNT162 , COVID-19 , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , SARS-CoV-2/genética , Vacinação , Vacinas Sintéticas , Vacinas de mRNA
3.
Contraception ; 92(4): 289-97, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26032952

RESUMO

OBJECTIVE: This study aims to determine the lowest effective of three Nestorone (NES)/estradiol (E2) transdermal gel doses to ensure ovulation suppression in 90-95% of cycles. METHODS: This was a randomized, open-label, three-treatment-period cross-over study to evaluate the effects of NES/E2 transdermal gel on ovulation inhibition, suppression of follicular growth and pharmacokinetic parameters. The doses were low (1.5 mg NES/0.5 mg E2), medium (3.0 mg NES/1.0 mg E2) and high (4.5 mg NES/1.5 mg E2). Participants applied gel daily to a fixed area on the abdomen for 21 consecutive days. They were interviewed regarding their experiences using the gel. RESULTS: Eighteen participants were randomized; 16 completed the study. Median NES C(max) values for low, medium and high dose groups at day 21 were 318.6 pmol/L, 783.0 pmol/L and 1063.8 pmol/L, respectively. Median maximum follicular diameter was higher with the lowest dose with 16.2 mm versus 10.0 and 10.4 mm with the medium and high doses, respectively. Among adherent participants, ovulation was inhibited in all dose groups, except for one participant in the medium dose (6.7%) that had luteal activity and an ultrasound image suggestive of a luteinized unruptured follicle. There were few reports of unscheduled bleeding, with more episodes reported for the lower dose. Adverse events were mild, and no skin irritation was reported from gel application. CONCLUSION: While all three doses blocked ovulation effectively and were evaluated as safe and acceptable, the medium dose was considered the lowest effective dose based on a more adequate suppression of follicular development. Further development of this novel contraceptive delivering NES and E2 is warranted and has potential for improved safety compared to ethinyl-estradiol-based methods.


Assuntos
Anticoncepcionais Femininos/administração & dosagem , Norprogesteronas/administração & dosagem , Ovulação/efeitos dos fármacos , Administração Cutânea , Adulto , Anticoncepcionais Femininos/farmacocinética , Estudos Cross-Over , Combinação de Medicamentos , Endométrio/efeitos dos fármacos , Estradiol/administração & dosagem , Estrogênios/administração & dosagem , Feminino , Géis , Humanos , Adesão à Medicação , Ciclo Menstrual/efeitos dos fármacos , Norprogesteronas/farmacocinética , Globulina de Ligação a Hormônio Sexual/metabolismo
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