MannKind's inhaled nintedanib clears Cohort 1 safely, awaits IPF efficacy data
Cohort 1 of the Phase 1b INFLO-1 study finished enrollment with no discontinuations or serious adverse events, leaving lung-function and tolerability data as the test of whether an inhaled version of nintedanib can match the oral drug's profile.
Executive Summary
- The first patient cohort in MannKind's early-stage trial of an inhaled nintedanib formulation completed enrollment without any drug discontinuations or serious safety events, a tolerability signal that clears the way to the pending efficacy and lung-function readout.
- Nintedanib is an approved, mechanistically validated therapy for pulmonary fibrosis; the open question is whether an inhaled version can preserve that effect while sidestepping the gastrointestinal side effects that limit long-term use of the oral drug.
- Because this is a small, non-registrational safety and pharmacokinetics study, the informative result is tolerability and pulmonary safety data, not a proof of superior efficacy over the oral formulation.
- The sponsor's own guidance for when data will post has moved from a broad second-half window toward a third-quarter target, a narrowing rather than a slip.
The catalyst
MannKind Corporation said topline data from the Phase 1b INFLO-1 study of its inhaled nintedanib formulation, MNKD-201, are expected in the second half of 2026. The trial, registered as NCT07344558, is a Phase 1 study testing safety, tolerability and pharmacokinetics of the dry-powder inhaler in adults with idiopathic pulmonary fibrosis. It targets an anticipated enrollment of 24 patients across two cohorts, evaluated against a placebo comparator. CEO Michael Castagna called 2026 a catalyst-rich year that includes the INFLO-1 topline data alongside two FDA decisions on other MannKind products. MannKind+1MannKind Reports Fourth Quarter and Full Year 2025 Financial Results and Provides Business UpdateFeb 26, 2026A Study to Evaluate Safety, Tolerability and Pharmacokinetics of MNKD-201 in Patients With Idiopathic Pulmonary FibrosisNCT07344558
Probability of SuccessBased on the AppliedXL Probability of Success model. For more information about the methodology, read the research here.
What the readout will test
The registered primary endpoints are not an antifibrotic efficacy measure like forced vital capacity decline. They are pulmonary function and safety metrics: change in FEV1 (a measure of exhaled air volume) and the FEV1/FVC ratio from pre-dose to post-dose, along with rates of bronchospasm, serious adverse events, treatment discontinuations, dose reductions, and treatment-emergent and treatment-related adverse events, tracked separately in each of the trial's two cohorts. A secondary endpoint defines the maximum tolerated dose. The trial randomizes patients across two experimental arms and one placebo arm. This is a tolerability and dose-finding study, not a test of whether inhaled nintedanib slows lung-function decline over time. NCT07344558A Study to Evaluate Safety, Tolerability and Pharmacokinetics of MNKD-201 in Patients With Idiopathic Pulmonary FibrosisNCT07344558
Interim safety signal
MannKind reported in May 2026 that Cohort 1 completed enrollment and recorded no study drug discontinuations and no serious adverse events. That is an early, favorable tolerability signal for a drug whose oral form is associated with gastrointestinal side effects that drive some patients to stop treatment. No endpoint results for FEV1 change or bronchospasm rates have posted yet; those pharmacodynamic and dose-finding results are what the pending topline readout will supply. MannKindMannKind Reports Fourth Quarter and Full Year 2025 Financial Results and Provides Business UpdateFeb 26, 2026
The competitive frame
Idiopathic pulmonary fibrosis carries an active late-stage pipeline of oral small-molecule antifibrotics, including deupirfenidone (NCT07284602), HEC585 (NCT07082842), and rentosertib (NCT07687459), each in Phase 3 testing against forced vital capacity decline over 52 weeks. None of these shares nintedanib's mechanism or MannKind's inhaled delivery approach; they compete on indication and modality, not on target. No trial in this indication currently shares MNKD-201's specific combination of an approved oral antifibrotic reformulated for inhaled delivery, which places the tolerability question this trial answers in a position with no direct precedent to benchmark against within the current competitive field. MannKind has already moved a Phase 2 trial, INFLO-2, into the same indication, with first-patient enrollment targeted for the second quarter of 2026. MannKindMannKind Reports Fourth Quarter and Full Year 2025 Financial Results and Provides Business UpdateFeb 26, 2026
Trial conduct
The trial's primary completion date moved from April 1, 2026 to June 15, 2026, a roughly two-month shift logged in April 2026. That is the only protocol change on record, and the trial's amendment frequency reads as stable under the registry's own churn measure. Enrollment held flat at the original 24-patient target, a routine hold rather than a change for a Phase 1 study. MannKind's own guidance on when topline data will post has since narrowed from a second-half-2026 window to a third-quarter target across two more recent updates. NCT07344558+1A Study to Evaluate Safety, Tolerability and Pharmacokinetics of MNKD-201 in Patients With Idiopathic Pulmonary FibrosisNCT07344558MannKind Reports Fourth Quarter and Full Year 2025 Financial Results and Provides Business UpdateFeb 26, 2026
This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.