Efficacy and Mechanism Evaluation (Jun 2023)
Gefitinib and methotrexate to resolve tubal ectopic pregnancy: the GEM3 RCT
Abstract
Background Tubal ectopic pregnancies can cause significant morbidity or even death. Current treatment is with methotrexate or surgery. However, methotrexate treatment can fail in approximately 30% of women. Gefitinib, an epidermal growth factor receptor inhibitor, may improve the effects of methotrexate. We assessed the efficacy of administering oral gefitinib with methotrexate, versus methotrexate alone, to treat a tubal ectopic pregnancy. Objectives To test the hypothesis a combination of gefitinib with methotrexate can increase resolution of stable tubal ectopic pregnancy without the need for surgery, compared with methotrexate alone. Design A randomised, double-blind, placebo-controlled, multicentre, superiority trial. Setting Fifty UK hospitals. Participants A target of 328 women with a stable, tubal ectopic pregnancy. Intervention Women were randomised to combination of methotrexate and gefitinib or methotrexate and placebo. All participants received a single intramuscular dose of methotrexate 50 mg/m2 and were randomised in a 1:1 ratio of oral gefitinib (250 mg daily for 7 days) or placebo. Main outcome measures The primary outcome was surgical intervention for resolution of ectopic pregnancy. Secondary outcomes were the need for an additional dose of methotrexate, time to resolution of the ectopic pregnancy, number of treatment-associated hospital visits, safety and tolerability, acceptability of treatment and return to menses. Results Between 2 November 2016 and 6 October 2021, 328 women were randomly allocated to methotrexate and gefitinib (n = 165) or methotrexate and placebo (n = 163). Three women in the placebo group withdrew. Surgical intervention occurred in 30% (50/165) of the gefitinib group and in 29% (47/160) of the placebo group (adjusted risk ratio 1.15, 95% confidence interval 0.85 to 1.58; adjusted risk difference −0.01, 95% confidence interval −0.10 to 0.09; p = 0.37). Without surgical intervention, median time to resolution was 28.0 days in the gefitinib group and 28.0 days in the placebo group (subdistribution hazard ratio 1.03, 95% confidence interval 0.75 to 1.40). The need for additional methotrexate doses, number of additional hospital visits, participant acceptability, time to return of menses and serious adverse events were similar in both groups. Diarrhoea and rash were more common in the gefitinib group. Conclusions The addition of gefitinib to standard medical management with methotrexate to treat tubal ectopic pregnancy is not clinically effective as it does not reduce subsequent surgical intervention and is associated with higher rates of reported symptoms than placebo. Limitations We were unable to investigate how different gefitinib doses or modes of delivery would impact on the results. Future work Questions that remain unaddressed relate to the use of methotrexate and gefitinib combination treatment for other extrauterine and uterine ectopic pregnancy, such as caesarean scar pregnancies, or in the management of choriocarcinoma. Trial registration This trial is registered as ISRCTN 67795930 and EudraCT 2015-005013-76. Funding This project was funded by the National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation (EME) programme and will be published in full in Efficacy and Mechanistic Evaluation; Vol. 10, No. 1. The gefitinib and placebo were supplied by Astra Zeneca. See the NIHR Journals Library website for further project information. Plain language summary What was the question? A tubal ectopic pregnancy is where a fertilised egg is not growing in the womb. The pregnancy cannot be saved and the woman is at risk of losing her fallopian tube and if this pregnancy is left to grow can even die. Current treatment is with methotrexate or surgery. An operation can happen because either the ectopic pregnancy has ruptured and caused internal bleeding, the medical treatment has not worked and the ectopic pregnancy needs to be removed or the patient can chose to have an operation. However, methotrexate treatment can fail in approximately 30% of women. We carried out research to see if the addition of a new drug (gefitinib, a drug used for lung cancer) to methotrexate could lower the number of women needing an operation to remove their ectopic pregnancy. What did we do? We involved 328 women with a stable tubal ectopic pregnancy, who were being treated medically with methotrexate, and randomly assigned them to have methotrexate alone or a combination of methotrexate and gefitinib. The gefitinib was taken in tablet form for 7 days, and the methotrexate was given as an injection. We followed the women up in line with their clinical care until their ectopic pregnancy resolved or they had surgery to remove the ectopic pregnancy. What did we find? The addition of gefitinib to methotrexate did not reduce the number of women who required surgery to remove their ectopic pregnancy. More women taking gefitinib experienced side effects, such as a facial rash or diarrhoea. What does this mean? Treatment with methotrexate remains the only drug treatment option for ectopic pregnancy. More research is needed. Scientific summary Background Tubal ectopic pregnancy (EP) can cause significant morbidity or even death. Current treatment is with methotrexate (MTX) or surgery. However, MTX treatment can fail in approximately 30% of women. Preclinical studies have shown that tubal implantation sites express high levels of epidermal growth factor receptor (EGFR) and that gefitinib (an EGFR antagonist) augments MTX-induced regression of pregnancy-like tissue. Clinical evidence from uncontrolled phase I and II trials has raised the possibility that a combination of MTX and gefitinib could be a more effective medical treatment than MTX alone to treat stable tubal EP. Objectives To test the hypothesis, a combination of gefitinib with MTX can increase resolution of stable tubal EP without the need for surgery, compared with MTX alone. Design A randomised, double-blind, placebo-controlled, multicentre, superiority trial. Setting This trial took place in 50 hospitals in the UK. Participants A target of 328 women with a stable, tubal EP. Intervention Participants were randomly assigned in a 1:1 ratio to receive either gefitinib and MTX or matched placebo and MTX with the use of minimisation to balance trial-group assignments according to baseline human chorionic gonadotropin levels (<1500 IU/l, ≥1500 to <2500 IU/l, ≥2500 IU/l), body mass index (<25 kg/m2, ≥25 kg/m2), ectopic size (<2 cm, ≥2 cm) and by hospital centre. Main outcome measures The primary outcome, analysed by intention to treat, was surgical intervention for removal of the EP. Secondary outcomes included additional MTX doses, time to resolution of EP, number of treatment-associated hospital visits until resolution or scheduled/emergency surgery, safety/tolerability, acceptability of treatment, return to menses, adverse events and serious adverse events. Results Between 2 November 2016 and 6 October 2021, 328 women were randomly allocated to MTX and gefitinib (n = 165) or MTX and placebo (n = 163). Three women in the placebo group withdrew. Surgical intervention occurred in 30% (50/165) of the gefitinib group and in 29% (47/160) of the placebo group [adjusted risk ratio 1.15, 95% confidence interval (CI) 0.85 to 1.58; adjusted risk difference −0.01, 95% CI −0.10 to 0.09; p = 0.37]. Without surgical intervention, median time to resolution was 28.0 days in the gefitinib group and 28.0 days in the placebo group (subdistribution hazard ratio 1.03, 95% CI 0.75 to 1.40). The need for additional MTX doses and serious adverse events were similar in both groups. The proportion of women who experienced diarrhoea (75/160 vs. 39/161) and rash (97/159 vs. 36/160) were more common in the MTX and gefitinib group compared with the MTX and placebo group. Conclusions In women with a tubal EP, adding oral gefitinib to parental MTX does not offer clinical benefit over MTX alone and increases reported symptoms. Limitations We were unable to investigate how different gefitinib doses or modes of delivery would impact on the results. Future work Questions that remain unaddressed relate to the use of combination treatment for other extrauterine and uterine EP, such as caesarean scar pregnancies, or in the management of choriocarcinoma. Trial registration Current Controlled Trials ISRCTN 67795930 and EudraCT 2015-005013-76. Funding This project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a Medical Research Council (MRC) and National Institute for Health and Care Research partnership. Gefitinib and placebo were supplied by Astra Zeneca. This will be published in full in Efficacy and Mechanistic Evaluation; Vol. 10, No. 1. See the NIHR Journals Library website for further project information.
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