Pfizer Advances Prazosin Manufacturing Shift With New Bioequivalence Study

Pfizer Inc (PFE) announced an update on their ongoing clinical study.

Study Overview
This Pfizer study, officially titled “A 2 CohORT, SINGLE DOSE, OPEN-LABEL, RANDOMIZED, PIVOTAL BIOEQUIVALENCE STUDY TO QUALIFY MANUFACTURING SITE TRANSFER FROM BARCELONETA TO ASCOLI FOR PRAZOSIN HYDROCHLORIDE CAPSULES IN HEALTHY ADULT PARTICIPANTS UNDER FASTED CONDITIONS,” aims to show that prazosin hydrochloride (used to treat high blood pressure and heart failure) made at a new plant in Ascoli, Italy works the same in the body as product from Pfizer’s existing site in Barceloneta, Puerto Rico. The focus is on how the drug is absorbed and cleared from the blood and on basic safety in healthy adults. This type of work is key for ensuring supply chain flexibility and cost efficiency without changing the clinical benefit patients receive.

Intervention/Treatment
The only treatment in the trial is prazosin hydrochloride capsules, taken by mouth. Participants receive either four capsules (cohort 1) or two capsules (cohort 2) under fasting conditions. The goal is not to test a new medicine, but to confirm that the capsules made at two different manufacturing sites behave the same in the body and are similarly safe and tolerated.

Study Design
This is a Phase 1, randomized, crossover study in healthy adults. Each participant receives prazosin capsules from both manufacturing sites at different times, so each person acts as their own control. The trial is open-label, meaning both investigators and participants know which product they are taking. The main purpose is basic science: to compare blood levels and safety data across the two versions to confirm they are equivalent.

Study Timeline
The study was first submitted on November 13, 2025, marking the formal start of regulatory tracking and setup. The trial is currently listed as “recruiting,” so dosing and data collection in healthy volunteers are ongoing. Pfizer reported a last update to the record on January 13, 2026, which signals that the protocol and status were recently reviewed and refreshed. Primary completion and final completion dates are not yet specified but, given the short duration per participant (around 10 weeks including follow-up), top-line bioequivalence data could reasonably be expected within months of full enrollment.

Market Implications
For investors, the key takeaway is that this is a manufacturing-transfer bioequivalence study, not a new drug launch. The direct revenue upside is modest, but successful completion should support uninterrupted global supply of prazosin at potentially lower cost. That helps defend margins in a mature, genericized hypertension market and underpins Pfizer’s reputation for reliable manufacturing. In the wider industry, many large pharma companies are optimizing their plant networks and shifting production to improve efficiency; this trial is one more example of that trend. A smooth site transfer with no safety or bioequivalence issues is neutral to slightly positive for sentiment, reinforcing operational discipline rather than driving major stock re-rating. Any delays, negative safety findings, or failure to show equivalence would not likely be financially material on their own, but could contribute to broader concerns if seen alongside other manufacturing issues. Overall, this update supports the view that Pfizer is actively managing its legacy portfolio and supply chain, while investors should focus price and earnings expectations on larger late-stage and launch assets.

The study is ongoing with recent updates, and further details are available on the ClinicalTrials portal.

To learn more about PFE’s potential, visit the Pfizer Inc drug pipeline page.