What Rein Therapeutics does

Rein Therapeutics is a clinical-stage biopharmaceutical company headquartered in Austin, Texas, publicly traded on NASDAQ under ticker RNTX. The company develops first-in-class peptide therapeutics for orphan pulmonary and fibrosis indications, with its lead candidate LTI-03 targeting idiopathic pulmonary fibrosis (IPF) — a progressive, fatal lung disease with median survival of 2–4 years and limited therapeutic options. The company originated as Lung Therapeutics in 2013, was acquired by Aileron Therapeutics in October 2023 (transitioning to public listing), and rebranded to Rein Therapeutics in 2025 to reflect its focus on controlling fibrosis.

The core technology centers on a synthetic peptide derived from the Caveolin-1 scaffolding domain (CSD) — a seven-amino-acid sequence that regulates lung repair and cellular movement. LTI-03, the lead asset, employs a dual mechanism of action: anti-fibrotic activity (modulating signaling pathways to inhibit fibroblast activation and tissue scarring) and regenerative activity (protecting alveolar epithelial cells essential for lung function). It is delivered via a dry powder inhaler for direct-to-lung treatment, offering localized delivery with reduced systemic side effects. Two earlier-stage assets round out the pipeline: LTI-01, a proenzyme (zymogen) for loculated pleural effusion that enzymatically breaks down fibrous scar tissue, and LTI-05 for cystic fibrosis.

As a pre-revenue company, Rein Therapeutics has no commercially approved products and generates no operating revenue; its enterprise value is entirely contingent on clinical milestones and pipeline progression. The company funds operations through equity raises, most recently completing a $57.5 million underwritten public offering in May 2026 expected to fund operations into Q1 2028. Its GTM strategy centers on generating clinical data from the Phase 2 RENEW trial (approximately 120 patients across up to 50 sites in five countries) to support FDA and EMA approvals. Upon regulatory approval, the company would distribute through specialty pharmacy and hospital formulary channels.

Name

Rein Therapeutics

Legal name

Rein Therapeutics, Inc.

Website

https://reintx.com

Company type

Public

Founded year

2013

Operating status

Operating

Headcount range

11–50 employees

Short description

Rein Therapeutics is a clinical-stage biopharmaceutical company developing first-in-class Caveolin-1-derived peptide therapeutics for orphan pulmonary and fibrosis indications, with lead candidate LTI-03 in Phase 2 for idiopathic pulmonary fibrosis and earlier-stage pipeline assets for pleural effusion and cystic fibrosis.

Ownership category

akta.pro rank

Product category

Pulmonary Fibrosis Therapeutics

NAICS

Biological Product (except Diagnostic) Manufacturing (325414)

SIC

Biological Products, (No Disgnostic Substances) (2836)

akta.pro primary industry

Pulmonary Hypertension & Rare Pulmonary Disease Therapies (HLAIAIAG)

akta.pro secondary industry

Therapeutic Peptides & Protein/Peptide Biologics (HLAAAAAH)

Keywords

• Pulmonary fibrosis treatments
• Orphan pulmonary disease
• Fibrosis drug development
• Respiratory therapeutics
• Inhaled peptide therapy

Headquarters

HQ city

Austin

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Marketing or Sales

Revenue model

1. Drug Development and Commercialization: Pre-revenue clinical-stage biopharmaceutical company developing first-in-class medicines for orphan pulmonary and fibrosis indications. Revenue will come from product sales upon regulatory approval of LTI-03 (IPF), LTI-01 (LPE), and LTI-05 (Cystic fibrosis).

Go-to-market motion1 record

Distribution channels1 record

Marketing channels5 records

Core offering

Rein Therapeutics is a clinical-stage biopharmaceutical company developing first-in-class synthetic peptide drug candidates for orphan pulmonary and fibrosis indications. Its lead product, LTI-03, is a synthetic peptide derived from Caveolin-1 delivered via dry powder inhaler for the treatment of idiopathic pulmonary fibrosis (IPF), combining anti-fibrotic and regenerative mechanisms of action. The pipeline also includes LTI-01 for loculated pleural effusion and LTI-05 for cystic fibrosis.

Product overview

Rein Therapeutics is a clinical-stage biopharmaceutical company developing a pipeline of first-in-class multi-pathway treatments for orphan pulmonary and fibrosis indications. The portfolio consists of three main products: LTI-03 (lead product, Phase 2 for idiopathic pulmonary fibrosis via dry powder inhaler), LTI-01 (preclinical/Phase 1 for loculated pleural effusion), and LTI-05 (preclinical for cystic fibrosis). LTI-03 is the primary focus, targeting both anti-fibrotic and regenerative pathways through a novel Caveolin-1 derived peptide mechanism.

Differentiator

Problem solved

Functional benefit

Products and services

• LTI-03 First-in-class synthetic peptide derived from Caveolin-1 for the treatment of idiopathic pulmonary fibrosis (IPF). Delivered via dry powder inhaler with dual mechanism of action combining anti-fibrotic effects (inhibiting fibroblast activation and tissue scarring) and regenerative effects (protecting epithelial cells essential for lung function). Currently in Phase 2 RENEW clinical trial.
• LTI-01 Proenzyme (zymogen) treatment candidate for loculated pleural effusion (LPE), positioned as the first therapy specifically developed for non-draining LPE. Breaks down fibrous tissue, clearing scarred areas and promoting fluid drainage. Currently in preclinical/Phase 1 development.
• LTI-05 Treatment candidate for cystic fibrosis as part of Rein's multi-pathway fibrotic treatments pipeline addressing orphan pulmonary indications. Currently in preclinical development.

Quantifiable outcome

• LTI-03 was well tolerated and showed biological activity including reductions in fibrosis biomarkers and preservation of lung repair cells in Phase 1 dose-escalation study
• +2 more outcomes

Segments3 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Scale indicators6 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Pliant Therapeutics: Clinical-stage biopharma developing integrin-targeting therapies for IPF (bexotegrast/PLN-74809) and other fibrotic diseases. Closest direct peer — same indication, similar Phase 2/3 stage, comparable size and orphan-pulmonary focus.
• FibroGen: Developed pamrevlumab (anti-CTGF) for IPF. Direct comparator in IPF fibrosis drug development with similar clinical-stage positioning and biology-driven approach to fibrotic disease.
• Avalo Therapeutics: Small clinical-stage biopharma with an inflammation/fibrosis pipeline (formerly Cerecor). Comparable in scale and stage to Rein, focused on immunology and rare pulmonary indications.

Broad incumbents

• United Therapeutics: Commercial-stage respiratory biopharma with Tyvaso DPI approved for PAH and PH-ILD, adjacent to IPF. A potential strategic acquirer or commercial partner given its established inhaled pulmonary franchise.
• Boehringer Ingelheim: Markets Ofev (nintedanib), one of two FDA-approved IPF therapies. Sets the standard-of-care bar Rein must clear and is a likely strategic acquirer given its deep respiratory/fibrosis commercial footprint.
• Roche / Genentech: Markets Esbriet (pirfenidone), the other FDA-approved IPF therapy. Like Boehringer, defines the incumbent treatment paradigm and is a credible strategic acquirer for novel fibrosis mechanisms.
• Galapagos NV: Had an IPF program (ziritaxestat) discontinued in Phase 3, illustrating both the strategic interest and the high failure rate in fibrosis drug development. Mid-cap European biopharma with adjacent inflammation/fibrosis R&D.
• Bristol-Myers Squibb: Large biopharma that has invested in IPF/fibrosis through pipeline deals and is a potential strategic acquirer for novel inhaled fibrosis therapies. Sets competitive benchmark for late-stage clinical and commercial resources.

Emerging players

• PureTech Health: Clinical-stage biopharma with fibrosis and inflammation pipeline programs. Comparable in scale and clinical-stage orphan disease focus, with similar platform-based approach to novel mechanisms.
• Atea Pharmaceuticals: Small-cap clinical-stage biopharma of similar size, employee count, and NASDAQ-listed profile to Rein Therapeutics, providing a useful comparable for valuation, capital structure, and clinical-stage biotech dynamics.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat3 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/Rein_Tx
• LinkedInlinkedin.com/company/rein-therapeutics

Revenue estimate

Valuation estimate

Number of profiles

Profiles7 records

Funding overview

Funding rounds13 records

Investors17 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A1 record

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Rein Therapeutics