Drug Update · Pulmonology

FDA Approves Trimbow for Asthma: Trough FEV1 Gains 57–73 mL

August 29, 2026

Approval date

05/14/2026

Indication

Maintenance treatment of asthma in adult patients aged 18 years and older

Primary efficacy (TRIMARAN)

57 mL difference in LS mean trough FEV1 versus BDP/FF (95% CI: 15, 99)

Primary efficacy (TRIGGER)

73 mL difference in LS mean trough FEV1 versus BDP/FF (95% CI: 26, 120)

Recommended doses

172 mcg/9.8 mcg/21.2 mcg and 344 mcg/9.8 mcg/21.2 mcg twice daily

Clinical Perspective

Pulmonologists, generalist clinicians, advanced practice providers, and pharmacists treating adult patients (aged 18 years and older) with asthma now have an FDA-approved single-inhaler triple combination option combining an ICS, LABA, and LAMA for maintenance therapy ^[1]^[2]. The approval is supported by TRIMARAN and TRIGGER, which demonstrated LS mean trough FEV1 advantages of 57 mL and 73 mL versus beclomethasone/formoterol at Week 26 and ACQ-7 responder data at Week 52 reported in labeling ^[3]^[1]. How these lung-function advantages will translate into long-term exacerbation outcomes and real-world effectiveness across broader populations remains to be determined?

Dr. Nikhil Chatterjee, MBBS, MD (Respiratory Medicine) · Pulmonology

The FDA approved TRIMBOW (beclomethasone dipropionate/formoterol fumarate/glycopyrrolate) inhalation aerosol for the maintenance treatment of asthma in adult patients aged 18 years and older, effective 05/14/2026 ^[2]^[3]. Approval was granted with labeling that cites two randomized, double-blind, active-controlled trials (TRIMARAN and TRIGGER) in which TRIMBOW produced LS mean trough FEV1 advantages of 57 mL (95% CI: 15, 99) and 73 mL (95% CI: 26, 120) versus beclomethasone/formoterol (BDP/FF) at Week 26 ^[1]^[3].

Clinical Context

TRIMBOW is a fixed-dose combination inhalation aerosol containing an inhaled corticosteroid (beclomethasone dipropionate), a long-acting beta2-adrenergic agonist (formoterol fumarate), and an anticholinergic (glycopyrrolate) developed by Chiesi, and is indicated for maintenance treatment of asthma in adults aged 18 years and older ^[1]^[2]. The label specifies that TRIMBOW is not indicated for relief of acute bronchospasm and includes priming and mouth-rinse instructions for inhalation use ^[1]. The FDA approval letter records the application pathway (section 505(b)(2)) and sets postmarketing pediatric study requirements and stability/dating conditions for the product ^[2].

Key Findings

In two pivotal randomized, double-blind, parallel-group, active-controlled 52-week trials (TRIMARAN and TRIGGER), the prespecified primary efficacy measure reported in labeling was the mean change from baseline in trough FEV1 at Week 26; TRIMBOW showed LS mean differences in trough FEV1 versus BDP/FF of 57 mL (95% CI: 15, 99) in TRIMARAN and 73 mL (95% CI: 26, 120) in TRIGGER ^[1]^[3].
The efficacy population across TRIMARAN and TRIGGER included 2,291 patients with at least one post-baseline efficacy evaluation; trials enrolled adults with ACQ-7 scores ≥1.5 after run-in on medium- or high-dose ICS plus a LABA, and randomization in each trial was 1:1 to TRIMBOW versus the corresponding BDP/FF dose ^[3]^[1].
At Week 52, ACQ-7 responder rates (≥0.5 decrease) were 61% and 62% for TRIMBOW 172/9.8/21.2 mcg and 344/9.8/21.2 mcg, respectively, versus 59% and 58% for BDP/FF at the matching beclomethasone/formoterol doses, with odds ratios of 1.07 (95% CI: 0.84, 1.36) and 1.12 (95% CI: 0.94, 1.32), respectively, as reported in labeling ^[3]^[1].
Clinicians should consult current prescribing information for full dosing guidance.

Safety & Tolerability

The prescribing information lists the most common adverse reactions (incidence ≥ 1%): bronchitis, hypertension, back pain, blood pressure increased, dysphonia, upper respiratory tract infection, influenza, anemia, muscle spasms, laryngitis, oropharyngeal pain, and sinusitis ^[1].
Warnings and precautions named in the labeling include risk statements and monitoring considerations for LABA monotherapy risk of serious asthma-related events, oral candidiasis, potential worsening of infections, adrenal suppression when transferring from systemic corticosteroids, paradoxical bronchospasm, cardiovascular effects related to beta-adrenergic stimulation, reduction in bone mineral density, glaucoma and cataracts, worsening urinary retention, and the potential for hypokalemia and hyperglycemia ^[1].

Study Design

The FDA labeling describes two randomized, double-blind, parallel-group, active-controlled trials named TRIMARAN and TRIGGER of 52 weeks duration conducted in adults with asthma inadequately controlled (ACQ-7 ≥1.5) on medium- or high-dose ICS plus a LABA; eligible patients entered a run-in on beclomethasone/formoterol and those remaining uncontrolled were randomized 1:1 to TRIMBOW versus matching-dose BDP/FF in each trial ^[3]^[1]. The combined efficacy population for the two trials was 2,291 patients with at least one post-baseline efficacy evaluation; the primary efficacy endpoint in labeling was change from baseline in trough FEV1 at Week 26 ^[3]^[1]. Regulatory approval (NDA 219622) was granted under section 505(b)(2) with required pediatric studies deferred and listed in the approval letter ^[2].

FAQ

What is TRIMBOW approved for?

TRIMBOW (beclomethasone dipropionate/formoterol fumarate/glycopyrrolate) is approved by the FDA for the maintenance treatment of asthma in adult patients aged 18 years and older. The label specifies that TRIMBOW is not indicated for relief of acute bronchospasm. The approval and labeling, including indications and usage, are provided in the FDA-approved prescribing information and approval letter.

How does TRIMBOW work?

TRIMBOW combines three pharmacologic classes: beclomethasone dipropionate, an inhaled corticosteroid with anti-inflammatory effects; formoterol fumarate, a long-acting selective beta2-adrenergic agonist that produces bronchodilation; and glycopyrrolate, a long-acting antimuscarinic agent that inhibits M3 receptors in airway smooth muscle leading to bronchodilation. The prescribing information describes these mechanisms as applying to the fixed-dose combination.

What is the recommended dose of TRIMBOW?

The recommended dosing options in the prescribing information are TRIMBOW 172 mcg/9.8 mcg/21.2 mcg (administered as 2 actuations of TRIMBOW 86 mcg/4.9 mcg/10.6 mcg) twice daily, or TRIMBOW 344 mcg/9.8 mcg/21.2 mcg (administered as 2 actuations of TRIMBOW 172 mcg/4.9 mcg/10.6 mcg) twice daily, with the recommended starting dose based on asthma severity or control on prior inhaled corticosteroids. Priming and re-priming instructions, dose counter guidance, and maximum recommended dosing are specified in the label.

What are the most common side effects of TRIMBOW?

The prescribing information lists the most common adverse reactions (incidence ≥1%) as bronchitis, hypertension, back pain, blood pressure increased, dysphonia, upper respiratory tract infection, influenza, anemia, muscle spasms, laryngitis, oropharyngeal pain, and sinusitis. The label also includes warnings and precautions such as risks associated with LABA monotherapy, oropharyngeal candidiasis, potential worsening of infections, adrenal suppression with corticosteroid withdrawal, paradoxical bronchospasm, cardiovascular effects, bone mineral density considerations, ocular effects (glaucoma/cataracts), urinary retention, hypokalemia, and hyperglycemia.

Clinicians should consult current prescribing information for complete dosing guidance.

FDA Approves Trimbow for Asthma: Trough FEV1 Gains 57–73 mL

Direct Clinical Takeaway & Evidence Summary

FDA Approves Trimbow for Asthma: Trough FEV1 Gains 57–73 mL

Clinical Perspective

Clinical Context

Key Findings

Safety & Tolerability

Study Design

FAQ

References

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