MannKind Corporation (Nasdaq: MNKD) shares rose sharply after the company disclosed progress on a new inhaled formulation of ralinepag being developed with United Therapeutics Corporation (NASDAQ: UTHR). The announcement expands a long-running pulmonary hypertension Partnership that previously produced the commercially successful Tyvaso DPI Franchise. Investors are now assessing the commercial potential of dry powder inhalation therapies in pulmonary arterial hypertension and fibrotic lung disease markets, alongside the execution and regulatory risks tied to early-stage development programs.

Key Highlights

  • MannKind disclosed six months of development work on ralinepag DPI under its expanded collaboration with United Therapeutics.
  • United Therapeutics paid an additional $5 million in April 2026 to accelerate development activities.
  • MannKind could receive up to $35 million in milestone payments plus 10% royalties on future net sales.
  • Tyvaso DPI, developed through the companies’ earlier partnership, generated $1.3 billion in 2025 Revenue for United Therapeutics.
  • United Therapeutics plans to lead global development, Manufacturing, regulatory filings, and commercialization of the investigational therapy.

MannKind Stock Rally Reflects Investor Focus on Platform Commercialisation

MannKind Corporation (NASDAQ: MNKD) shares climbed nearly 39% after the company revealed details surrounding its ongoing development of ralinepag DPI, a dry powder inhalation formulation designed for pulmonary arterial hypertension and other fibrotic lung diseases. The move marked one of the company’s strongest single-session gains in recent years, despite the stock remaining lower on a year-to-date basis.

The announcement renewed investor attention on MannKind’s inhalation technology platform, particularly following the commercial success of Tyvaso DPI, which emerged from the companies’ earlier 2018 partnership agreement. The market reaction suggests investors are increasingly valuing MannKind’s ability to monetise formulation and drug delivery capabilities through strategic collaborations rather than relying solely on internally commercialised products.

The latest program, internally referred to as MNKD-1501, remains in early-stage development and is expected to support planned non-clinical studies followed by a Phase 1 trial.

United Therapeutics Expands Pulmonary Hypertension Pipeline

United Therapeutics Corporation (NASDAQ: UTHR) has been broadening its pulmonary hypertension portfolio as competitive intensity rises in rare disease therapeutics and specialty respiratory medicine.

Ralinepag is an investigational prostacyclin receptor agonist aimed at treating pulmonary arterial hypertension (PAH), a progressive disease characterised by elevated blood pressure in the pulmonary arteries. The company is also evaluating broader applications across pulmonary hypertension associated with interstitial lung disease, idiopathic pulmonary fibrosis, and progressive pulmonary fibrosis.

In March 2026, United Therapeutics announced that its pivotal Phase 3 ADVANCE OUTCOMES study evaluating extended-release oral ralinepag tablets met its primary endpoint with high statistical significance. That result strengthened the strategic rationale for expanding the drug into inhaled delivery formats, particularly given the commercial success of inhaled therapies in pulmonary hypertension treatment.

The inhaled formulation strategy could potentially improve drug targeting to lung tissue while reducing systemic side effects associated with oral prostacyclin therapies. However, the DPI formulation remains investigational and has not yet received regulatory approval in any Jurisdiction.

Tyvaso DPI Success Shapes Commercial Expectations

Much of the market optimism surrounding the collaboration stems from the historical performance of Tyvaso DPI, the inhaled treprostinil therapy jointly developed under the companies’ earlier agreement.

Tyvaso DPI received US Food and Drug Administration approval in 2022 and generated approximately $1.3 billion in revenue during 2025, according to United Therapeutics. The product has become a significant contributor to United Therapeutics’ revenue base and demonstrated the commercial viability of dry powder inhalation technologies in pulmonary hypertension treatment.

For MannKind Corporation (NASDAQ: MNKD), Tyvaso DPI has also served as validation of its Technosphere inhalation platform and its broader drug-device integration capabilities. The company has increasingly pursued licensing and collaboration structures that allow larger pharmaceutical partners to handle late-stage development and commercialization while MannKind focuses on formulation expertise.

The ralinepag DPI program follows a similar structure, with United Therapeutics expected to serve as the primary manufacturer while overseeing global clinical, regulatory, and commercial operations.

Financial Structure Provides MannKind With Milestone and Royalty Upside

The updated agreement structure provides MannKind with near-term development funding alongside potential long-term royalty Economics.

United Therapeutics paid an additional $5 million in April 2026 to support accelerated development efforts. MannKind also remains eligible for up to $35 million in future milestone payments tied to development progress and regulatory achievements.

Beyond milestone economics, the agreement includes a 10% royalty on net sales of any future commercialised product resulting from the collaboration. While royalty structures offer potentially Recurring Revenue streams, commercial realization remains dependent on successful clinical development, regulatory approval, manufacturing scalability, and eventual physician adoption.

The deal structure reflects a broader trend within biotechnology partnerships where smaller specialty drug delivery companies seek lower-Capital-risk Business models by licensing technologies to larger pharmaceutical operators.

Pulmonary Hypertension Market Remains Strategically Important

The pulmonary arterial hypertension market has attracted sustained pharmaceutical Investment because of high unmet medical need, chronic treatment duration, and premium pricing dynamics associated with rare disease therapies.

Competition has intensified across prostacyclin therapies, endothelin receptor antagonists, and combination treatment strategies as companies seek differentiated delivery methods and expanded patient populations. Inhaled therapies have emerged as a strategically important segment because they can potentially improve tolerability and patient convenience compared with infused or systemic alternatives.

United Therapeutics has been particularly active in expanding its pulmonary hypertension portfolio through inhaled delivery technologies, positioning itself against larger rare disease and specialty pharmaceutical competitors.

For MannKind, continued participation in pulmonary hypertension Drug Development could help diversify revenue generation beyond its existing commercial portfolio while reinforcing the value of its inhaled drug formulation expertise.

Still, the program remains at an early stage, and substantial clinical, regulatory, and manufacturing risks remain before any commercial launch becomes viable.

Outlook Hinges on Clinical Execution and Regulatory Progress

The next major catalysts for investors are likely to include non-clinical study updates, Phase 1 initiation timelines, and further clarity on development pathways for pulmonary fibrosis-related indications.

While the strong precedent established by Tyvaso DPI supports confidence in inhaled pulmonary therapies, ralinepag DPI will require independent clinical validation and regulatory review. Expanding into additional fibrotic lung disease indications could materially increase the commercial opportunity, though it would also require broader clinical programs and higher development spending.

The collaboration nevertheless strengthens MannKind’s position as a specialised inhalation technology partner within respiratory and rare disease drug development markets, while allowing United Therapeutics to deepen its presence in pulmonary hypertension therapeutics.