Chronic radiation proctitis refractory to steroid enema was successfully treated by metformin and sodium butyrate: a case report.

BACKGROUND: Radiation proctitis (RP) is a significant complication of pelvic radiation. Effective treatments for chronic RP are currently lacking. We report a case where chronic RP was successfully managed by metformin and butyrate (M-B) enema and suppository therapy. CASE PRESENTATION: A 70-year-old Asian male was diagnosed with prostate cancer of bilateral lobes, underwent definitive radiotherapy to the prostate of 76 Gy in 38 fractions and six months of androgen deprivation therapy. Despite a stable PSA nadir of 0.2 ng/mL for 10 months post-radiotherapy, he developed intermittent rectal bleeding, and was diagnosed as chronic RP. Symptoms persisted despite two months of oral mesalamine, mesalamine enema and hydrocortisone enema treatment. Transition to daily 2% metformin and butyrate (M-B) enema for one week led to significant improvement, followed by maintenance therapy with daily 2.0% M-B suppository for three weeks, resulting in continued reduction of rectal bleeding. Endoscopic examination and biopsy demonstrated a good therapeutic effect. CONCLUSIONS: M-B enema and suppository may be an effective treatment for chronic RP.

Risk of acute pancreatitis among new users of empagliflozin compared to sulfonylureas in patients with type 2 diabetes: A post-authorization safety study.

PURPOSE: This study was undertaken to evaluate the potential risk of acute pancreatitis with empagliflozin in patients with type 2 diabetes (T2D) newly initiating empagliflozin. METHODS: Data from two large US claims databases were analyzed in an observational study of patients with T2D receiving metformin who were newly prescribed empagliflozin versus sulfonylurea (SU). Because dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists have been associated with the risk of acute pancreatitis in some studies, patients on these agents were excluded. Using pooled analyses of data from the two databases (2014-2021), patients initiating empagliflozin were matched 1:1 within database to patients initiating SU using propensity scores (PS) that incorporated relevant demographic and clinical characteristics. Prespecified sensitivity analyses were performed for design parameters. RESULTS: The analyses identified 72 661 new users of empagliflozin and 422 018 new users of SUs, with both patient groups on concurrent metformin therapy. Baseline characteristics within treatment groups appeared to be similar across the 72 621 matched pairs. After mean follow-up of ~6 months, incidence rates of acute pancreatitis in the pooled matched cohort were 10.30 (95% confidence interval [CI] 9.29-11.39) events per 1000 patient-years (PY) for empagliflozin and 11.65 (95% CI 10.59-12.77) events per 1000 PY for SUs. On a background of metformin, patients newly initiating empagliflozin did not have an increased risk of acute pancreatitis compared with those initiating an SU (pooled PS matched hazard ratio 0.88 [0.76-1.02]) across 75621.42 PY of follow-up. CONCLUSIONS: The results of this voluntary post-approval safety study provide additional evidence that the use of empagliflozin for the treatment of T2D is not associated with an increased risk of acute pancreatitis.

Factors contributing to variability in metformin concentration in polycystic ovary syndrome.

AIM: To investigate the factors affecting metformin concentrations after chronic administration in patients with polycystic ovary syndrome (PCOS), focusing on the pharmacokinetic variability and its implications for personalized therapy. METHODS: This study enrolled 53 PCOS patients undergoing long-term metformin treatment at the Clinic for Gynecology and Obstetrics in Nis, Serbia, from February to December 2019. Pharmacokinetic parameters were measured from blood samples, and metformin concentrations were determined with validated analytical techniques. RESULTS: There was a significant variability in metformin concentrations among PCOS patients, with body mass index (BMI) identified as a major influencing factor. Higher BMI was associated with lower plasma metformin levels, a finding suggesting an altered pharmacokinetic profile in obese patients. CONCLUSIONS: This study highlights the critical role of BMI in influencing metformin pharmacokinetics in PCOS patients and underscores the need for personalized treatment strategies in patients with PCOS.

Randomized, Double-blind, Phase III Trial of Lobeglitazone Add-on to Metformin in Type 2 Diabetes (SENSITIZE INDIA).

BACKGROUND: The efficacy and safety of lobeglitazone sulfate has been reported only in the Korean population, and no study has been conducted in India. MATERIALS AND METHODS: In this 16-week randomized, double-blind, and multicenter study, the efficacy and safety of lobeglitazone sulfate 0.5 mg were evaluated with pioglitazone 15 mg. Type 2 diabetes mellitus (T2DM) patients with ≥7.5% glycated hemoglobin (HbA1c) ≤10.5% and on stable metformin dose were assigned to both treatment arms. The primary outcome was a mean change in HbA1c. Safety assessments included adverse events (AE), home-based glucose monitoring, vital parameters, electrocardiogram (ECG), and laboratory assessments. RESULTS: A total of 328 subjects were randomized equally in two groups. A statistically significant reduction in HbA1c at week 16 in the lobeglitazone group with the least square (LS) mean change: 1.01 [standard error (SE): 0.09] (p < 0.0001) was seen. The LS mean difference between the two groups was 0.05 (SE: 0.12) [95% confidence interval (CI): -0.18, 0.27], which was statistically significant (p = 0.0013). Statistically significant reductions were also observed in fasting and postprandial glucose. Treatment-emergent Aes (TEAE) were comparable between both groups. CONCLUSION: Lobeglitazone 0.5 mg once daily was found to be efficacious and safe in the treatment of T2DM in the Indian population. Lobeglitazone significantly improved glycemic parameters and was noninferior to pioglitazone; hence, it could be a promising insulin sensitizer in T2DM management in India.

Comparative effectiveness of second line oral antidiabetic treatments among people with type 2 diabetes mellitus: emulation of a target trial using routinely collected health data.

OBJECTIVE: To compare the effectiveness of three commonly prescribed oral antidiabetic drugs added to metformin for people with type 2 diabetes mellitus requiring second line treatment in routine clinical practice. DESIGN: Cohort study emulating a comparative effectiveness trial (target trial). SETTING: Linked primary care, hospital, and death data in England, 2015-21. PARTICIPANTS: 75 739 adults with type 2 diabetes mellitus who initiated second line oral antidiabetic treatment with a sulfonylurea, DPP-4 inhibitor, or SGLT-2 inhibitor added to metformin. MAIN OUTCOME MEASURES: Primary outcome was absolute change in glycated haemoglobin A1c (HbA1c) between baseline and one year follow-up. Secondary outcomes were change in body mass index (BMI), systolic blood pressure, and estimated glomerular filtration rate (eGFR) at one year and two years, change in HbA1c at two years, and time to ≥40% decline in eGFR, major adverse kidney event, hospital admission for heart failure, major adverse cardiovascular event (MACE), and all cause mortality. Instrumental variable analysis was used to reduce the risk of confounding due to unobserved baseline measures. RESULTS: 75 739 people initiated second line oral antidiabetic treatment with sulfonylureas (n=25 693, 33.9%), DPP-4 inhibitors (n=34 464 ,45.5%), or SGLT-2 inhibitors (n=15 582, 20.6%). SGLT-2 inhibitors were more effective than DPP-4 inhibitors or sulfonylureas in reducing mean HbA1c values between baseline and one year. After the instrumental variable analysis, the mean differences in HbA1c change between baseline and one year were -2.5 mmol/mol (95% confidence interval (CI) -3.7 to -1.3) for SGLT-2 inhibitors versus sulfonylureas and -3.2 mmol/mol (-4.6 to -1.8) for SGLT-2 inhibitors versus DPP-4 inhibitors. SGLT-2 inhibitors were more effective than sulfonylureas or DPP-4 inhibitors in reducing BMI and systolic blood pressure. For some secondary endpoints, evidence for SGLT-2 inhibitors being more effective was lacking-the hazard ratio for MACE, for example, was 0.99 (95% CI 0.61 to 1.62) versus sulfonylureas and 0.91 (0.51 to 1.63) versus DPP-4 inhibitors. SGLT-2 inhibitors had reduced hazards of hospital admission for heart failure compared with DPP-4 inhibitors (0.32, 0.12 to 0.90) and sulfonylureas (0.46, 0.20 to 1.05). The hazard ratio for a ≥40% decline in eGFR indicated a protective effect versus sulfonylureas (0.42, 0.22 to 0.82), with high uncertainty in the estimated hazard ratio versus DPP-4 inhibitors (0.64, 0.29 to 1.43). CONCLUSIONS: This emulation study of a target trial found that SGLT-2 inhibitors were more effective than sulfonylureas or DPP-4 inhibitors in lowering mean HbA1c, BMI, and systolic blood pressure and in reducing the hazards of hospital admission for heart failure (v DPP-4 inhibitors) and kidney disease progression (v sulfonylureas), with no evidence of differences in other clinical endpoints.

The role of the cholinergic system in the memory-protecting effects of metformin in a model of scopolamine-induced memory impairment in aged rats.

PURPOSE: As the elderly population grows, the prevalence of dementia is also rapidly increasing worldwide. Metformin, an antidiabetic drug, has been shown to have ameliorative effects on impaired cognitive functions in experimental models. However, studies have generally used young animals. Additionally, although it has a major role in Alzheimer's disease (AD) and memory, literature information about the effects of metformin on the cholinergic system is limited. In this study, we investigated the effects of metformin on memory in a model of scopolamine-induced memory impairment in aged rats. We also examined the effects of metformin on the cholinergic system, which is very important in cognitive functions. METHODS: Metformin was administered orally to male Wistar rats (20-22 months old) at 100 mg/kg/day for three weeks. Morris water maze (MWM) tests were performed to assess spatial memory. Before the probe test of the MWM test, scopolamine was injected intraperitoneally at a dose of 1 mg/kg. After testing, animals were sacrificed, whole brains were removed, and hippocampus samples were separated for biochemical analysis. RESULTS: Impaired memory associated with scopolamine administration was reversed by metformin. In addition, metformin administration ameliorated scopolamine-induced changes in acetylcholine (ACh) levels, acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), and choline acetyltransferase (ChAT) activity. CONCLUSION: Our results show that metformin may have protective effects in a scopolamine-induced memory impairment model in aged animals by improving cholinergic function. Metformin shows promise in preventing dementia with its dual cholinesterase inhibition and ChAT activation effect.

The maintenance of long-term weight loss after semaglutide withdrawal in obese women with PCOS treated with metformin: a 2-year observational study.

Background: Withdrawal of semaglutide is frequently followed by weight regain due to compensatory biological changes that prevent the maintenance of long-term weight loss. There are some studies implying that metformin might attenuate weight regain. The weight trajectory after discontinuation of short-term semaglutide treatment in obese women with PCOS who continued metformin treatment has not yet been evaluated. Aims: We explored changes in body weight, cardiometabolic and endocrine parameters in obese women with PCOS who continued treatment with metformin 2 years after discontinuation of short-term intervention with semaglutide. Methods: 25 women with PCOS and obesity, aged 33.7 ± 5.3 years (mean ± SD), were treated with once-weekly subcutaneous semaglutide 1.0 mg as an adjunct to metformin 2000 mg/day and lifestyle intervention for 16 weeks. At week 16, semaglutide was discontinued. Treatment with metformin 2000 mg/day and promotion of lifestyle intervention were continued during the 2-year follow-up period. Weight change, cardiometabolic, and endocrine parameters were assessed 2 years after semaglutide discontinuation. Results: During semaglutide treatment phase, weight decreased from 101 (90-106.8) kg to 92 (83.3-100.8) kg. Two years after semaglutide withdrawal, weight was 95 (77-104) kg. The net weight loss 2 years after discontinuation of semaglutide remained significant when compared to baseline (p=0.003). At the end of the study, 21 out of 25 subjects had lower body weight compared to baseline. Improvements in cardiometabolic parameters including decrease in total and LDL cholesterol, fasting glucose, and glucose after OGTT that had been seen during semaglutide-treatment phase reverted towards baseline two years after semaglutide cessation. Free testosterone levels significantly decreased during semaglutide treatment from 6.16 (4.07-9.71) to 4.12 (2.98-6.93) nmol/l, (p= 0.012) and did not significantly deteriorate after semaglutide discontinuation. Conclusion: Two years after semaglutide withdrawal, women with PCOS who continued with metformin regained about one-third of the semaglutide-induced weight loss. At the end of the follow up, 84% of women had a lower body weight than at baseline.

Integration of metformin-loaded MIL-100(Fe) into hydrogel microneedles for prolonged regulation of blood glucose levels.

The transdermal drug delivery based on microneedles (MNs) provides a suitable and painless self-administration for diabetic patients. In this work, the hydrogel-forming MNs were firstly fabricated using poly(vinyl alcohol) (PVA) and chitosan (CS) as matrix. A hypoglycemic drug, metformin (Met), had been loaded into MIL-100(Fe). Then, both of free Met and Met-loaded MIL-100(Fe) were integrated into hydrogel-forming MNs for regulation of blood glucose levels (BGLs) on diabetic rats. After penetrated into the skin, the free Met could be firstly released from MNs. Due to the absorption of interstitial fluid and subsequent release of loaded Met from MIL-100(Fe), leading to a sustainable and long-term drug release behaviors. A notable hypoglycemic effect and low risk of hypoglycemia could be obtained on diabetic rat modelsin vivo. The as-fabricated hydrogel-forming MNs expected to become a new type of transdermal drug delivery platform for transdermal delivery of high-dose drugs to form a long-term hypoglycemic effect.

A 52-week efficacy and safety study of enavogliflozin versus dapagliflozin as an add-on to metformin in patients with type 2 diabetes mellitus: ENHANCE-M extension study.

AIM: To evaluate the long-term safety and efficacy of enavogliflozin 0.3 mg/day added to metformin in patients with type 2 diabetes mellitus. MATERIALS AND METHODS: After 24 weeks of a randomized, double-blind treatment period with enavogliflozin 0.3 mg/day (n = 101) or dapagliflozin 10 mg/day (n = 99) added to metformin, all patients received enavogliflozin 0.3 mg/day plus metformin for an additional 28 weeks during the open-label extension period. RESULTS: Eighty-two patients continued enavogliflozin (maintenance group), and 77 were switched from dapagliflozin to enavogliflozin (switch group). All adverse drug reactions (ADR) were mild in severity. In the maintenance group, ADRs (cystitis and vaginal infection) were reported in two patients (2.44%) during 52 weeks. In the switch group, ADR (hypoglycaemia) was reported in one patient (1.30%) during a 28-week open-label extension period. At week 52, glycated haemoglobin and fasting plasma glucose were significantly lower than at the baseline, by 0.85% and 29.08 mg/dl, respectively, in the maintenance group (p < .0001 for both), and by 0.81% and 32.77 mg/dl, respectively, in the switch group (p < .0001 for both). At week 52, 68.92% of patients from the maintenance group and 64.29% from the switch group achieved glycated haemoglobin <7%. A significant increase in the urine glucose-creatinine ratio was observed at week 52, by 58.81 g/g and 63.77 g/g in the maintenance and switch groups, respectively (p < .0001). CONCLUSIONS: Enavogliflozin added to metformin was tolerated well for up to 52 weeks and provided continual glycaemic control in type 2 diabetes mellitus, along with a significant increase in the urine glucose-creatinine ratio.

Co-delivery of artemisinin and metformin via PEGylated niosomal nanoparticles: potential anti-cancer effect in treatment of lung cancer cells.

PURPOSE: Despite the advances in treatment, lung cancer is a global concern and necessitates the development of new treatments. Biguanides like metformin (MET) and artemisinin (ART) have recently been discovered to have anti-cancer properties. As a consequence, in the current study, the anti-cancer effect of MET and ART co-encapsulated in niosomal nanoparticles on lung cancer cells was examined to establish an innovative therapy technique. METHODS: Niosomal nanoparticles (Nio-NPs) were synthesized by thin-film hydration method, and their physicochemical properties were assessed by FTIR. The morphology of Nio-NPs was evaluated with FE-SEM and AFM. The MTT assay was applied to evaluate the cytotoxic effects of free MET, free ART, their encapsulated form with Nio-NPs, as well as their combination, on A549 cells. Apoptosis assay was utilized to detect the biological processes involved with programmed cell death. The arrest of cell cycle in response to drugs was assessed using a cell cycle assay. Following a 48-h drug treatment, the expression level of hTERT, Cyclin D1, BAX, BCL-2, Caspase 3, and 7 genes were assessed using the qRT-PCR method. RESULTS: Both MET and ART reduced the survival rate of lung cancer cells in the dose-dependent manner. The IC50 values of pure ART and MET were 195.2 µM and 14.6 mM, respectively while in nano formulated form their IC50 values decreased to 56.7 µM and 78.3 µM, respectively. The combination of MET and ART synergistically decreased the proliferation of lung cancer cells, compared to the single treatments. Importantly, the combination of MET and ART had a higher anti-proliferative impact against A549 lung cancer cells, with lower IC50 values. According to the result of Real-time PCR, hTERT, Cyclin D1, BAX, BCL-2, Caspase 3, and Caspase 7 genes expression were considerably altered in treated with combination of nano formulated MET and ART compared to single therapies. CONCLUSION: The results of this study showed that the combination of MET and ART encapsulated in Nio-NPs could be useful for the treatment of lung cancer and can increase the efficiency of lung cancer treatment.

An Open-Label Phase I Study of Metformin and Nelfinavir in Combination With Bortezomib in Patients With Relapsed and Refractory Multiple Myeloma.

BACKGROUND: In preclinical models, combining a GLUT4 inhibitor with an oxidative phosphorylation inhibitor shows synergistic therapeutic potential against multiple myeloma (MM). Thus, this study evaluated the safety and tolerability of repurposing metformin, a complex I inhibitor, and nelfinavir, a GLUT4 inhibitor, in combination with bortezomib for the treatment of relapsed/refractory MM that had progressed on all standard of care therapies. MATERIALS AND METHODS: This trial utilized a 3 + 3 dose escalation design with 3 dose levels planned for up to a maximum of 6 (21-day) cycles. Metformin and nelfinavir were administered for 14 of 21 days, and subQ bortezomib was administered to a portion of patients on days 1, 8, and 15. The primary objective was to determine the maximal tolerated dose, and the secondary objective was to evaluate the safety and overall response rate (ORR) of this combination. RESULTS: Nine patients were accrued with a median age of 65 (range: 42-81) and received a median of 7 prior lines of therapy (Range: 5-12). The first 3 patients received only metformin (500 mg BID) and nelfinavir (1250 mg BID) at the first dose level, with 1 patient experiencing an unconfirmed minimal response (MR) in the first cycle, 1 experiencing progressive disease after 1 cycle of treatment and 1 patient going off treatment prior to assessing response but with signs of progressive disease. Given the limited therapeutic activity, the upfront addition of bortezomib (1.3 mg/m2) was utilized for the subsequent 6 patients accrued. Three of these 6 patients went off study due to progressive disease, 1 patient achieved an unconfirmed partial response after 1 cycle of treatment but reported progressive disease in the subsequent cycle, 1 patient went off study to enter hospice, and the remaining patient experienced stable disease (SD) after receiving 6 cycles of clinical trial treatment. The study was closed before accrual to the next dose level was started. CONCLUSION: This is the first study to evaluate the safety and efficacy of this repurposed drug combination in this very difficult-to-treat population of relapsed and refractory MM. This was an overall negative study with no ORR observed. Fortunately, 1 patient experienced an SD response, allowing this combination to stabilize their disease until another novel therapy on a clinical trial was available.

A Drug-Drug Interaction Study to Evaluate the Impact of Rimegepant on OCT2- and MATE1-Mediated Transport of Metformin in Healthy Participants.

Rimegepant is a calcitonin gene-related peptide receptor antagonist approved for migraine treatment. This phase 1, open-label, single-center, fixed-sequence study evaluated the effect of rimegepant on the pharmacokinetics (PK) of metformin. Twenty-eight healthy participants received metformin 500 mg twice daily from Days 1 to 4 and Days 7 to 10, and once daily on Days 5 and 11. Rimegepant, 75 mg tablet, was administered once daily from Days 9 to 12. At pre-specified time points, plasma metformin concentration, serum glucose levels, and safety and tolerability were evaluated. A 16% increase in the area under the plasma metformin concentration-time curve (AUC) for 1 dosing interval (AUC0-τ,ss), a statistically insignificant increase in maximum and minimum steady-state metformin concentration (Cmax,ss and Cmin,ss), and a decrease in metformin renal clearance were observed on Day 11 following metformin-rimegepant coadministration compared with metformin alone; however, the changes were not clinically relevant. Additionally, coadministration of rimegepant with metformin did not induce clinically meaningful change in the maximum observed glucose concentration (Gmax) or AUCgluc compared with metformin alone. Overall, rimegepant and metformin coadministration did not result in clinically relevant changes in metformin PK, renal clearance, or the antihyperglycemic effects of metformin. Rimegepant is considered safe for use with metformin.

A Multicenter, Randomized, Open-Label Study to Compare the Effects of Gemigliptin Add-on or Escalation of Metformin Dose on Glycemic Control and Safety in Patients with Inadequately Controlled Type 2 Diabetes Mellitus Treated with Metformin and SGLT-2 Inhibitors (SO GOOD Study).

Background: We aimed to compare efficacy and safety between gemigliptin add-on and escalation of the metformin dose in patients with inadequately controlled type 2 diabetes mellitus (T2DM) despite treatment with metformin and SGLT2 inhibitors. Methods: This study was a multicenter, randomized, open-label, active-controlled, parallel-group comparative study. Patients with T2DM uncontrolled on metformin and SGLT2 inhibitors were randomized to receive gemigliptin 50 mg as an add-on (GEM group, n = 37) or escalation of the metformin dose (500 mg, MET group, n = 38) for 24 weeks. The primary endpoint was the change in glycosylated hemoglobin (HbA1c) from baseline to week 24. Results: At weeks 12 and 24, the reduction in HbA1c levels was significantly greater in the GEM group than in the MET group (GEM vs. MET = -0.64% ± 0.34% vs. -0.36% ± 0.50%, p = 0.009 at week 12; -0.61% ± 0.35% vs. -0.33% ± 0.70%, p = 0.045 at week 24). The proportions of patients who achieved target HbA1c levels of <7.0% at weeks 12 and 24 and <6.5% at week 12 were greater in the GEM group than in the MET group. An index of ß-cell function was also significantly improved in the GEM group. The safety profiles were similar between the two groups. Conclusions: Gemigliptin add-on therapy may be more effective than metformin dose escalation in patients with T2DM insufficiently controlled using metformin and SGLT2 inhibitors, without safety concerns. This trial is registered with CRIS_number: KCT0003520.

Metformin Plus Insulin for Preexisting Diabetes or Gestational Diabetes in Early Pregnancy: The MOMPOD Randomized Clinical Trial.

Importance: Insulin is recommended for pregnant persons with preexisting type 2 diabetes or diabetes diagnosed early in pregnancy. The addition of metformin to insulin may improve neonatal outcomes. Objective: To estimate the effect of metformin added to insulin for preexisting type 2 or diabetes diagnosed early in pregnancy on a composite adverse neonatal outcome. Design, Setting, and Participants: This randomized clinical trial in 17 US centers enrolled pregnant adults aged 18 to 45 years with preexisting type 2 diabetes or diabetes diagnosed prior to 23 weeks' gestation between April 2019 and November 2021. Each participant was treated with insulin and was assigned to add either metformin or placebo. Follow-up was completed in May 2022. Intervention: Metformin 1000 mg or placebo orally twice per day from enrollment (11 weeks -<23 weeks) through delivery. Main Outcome and Measures: The primary outcome was a composite of neonatal complications including perinatal death, preterm birth, large or small for gestational age, and hyperbilirubinemia requiring phototherapy. Prespecified secondary outcomes included maternal hypoglycemia and neonatal fat mass at birth, and prespecified subgroup analyses by maternal body mass index less than 30 vs 30 or greater and those with preexisting vs diabetes early in pregnancy. Results: Of the 831 participants randomized, 794 took at least 1 dose of the study agent and were included in the primary analysis (397 in the placebo group and 397 in the metformin group). Participants' mean (SD) age was 32.9 (5.6) years; 234 (29%) were Black, and 412 (52%) were Hispanic. The composite adverse neonatal outcome occurred in 280 (71%) of the metformin group and in 292 (74%) of the placebo group (adjusted odds ratio, 0.86 [95% CI 0.63-1.19]). The most commonly occurring events in the primary outcome in both groups were preterm birth, neonatal hypoglycemia, and delivery of a large-for-gestational-age infant. The study was halted at 75% accrual for futility in detecting a significant difference in the primary outcome. Prespecified secondary outcomes and subgroup analyses were similar between groups. Of individual components of the composite adverse neonatal outcome, metformin-exposed neonates had lower odds to be large for gestational age (adjusted odds ratio, 0.63 [95% CI, 0.46-0.86]) when compared with the placebo group. Conclusions and Relevance: Using metformin plus insulin to treat preexisting type 2 or gestational diabetes diagnosed early in pregnancy did not reduce a composite neonatal adverse outcome. The effect of reduction in odds of a large-for-gestational-age infant observed after adding metformin to insulin warrants further investigation. Trial Registration: ClinicalTrials.gov Identifier: NCT02932475.