Prelude Therapeutics And Lilly Agree To Supply Drugs For Combination Trial
By Elizabeth Urbanek, Executive Editor
Prelude Therapeutics has entered a clinical trial collaboration and supply agreement with Eli Lilly and Company for two medicines to be used alongside Prelude’s investigational cancer drug in a Phase 1 breast cancer trial. Under the agreement, Lilly will supply abemaciclib (Verzenio) and imlunestrant (Inluriyo) for combination cohorts evaluating Prelude’s investigational KAT6A degrader, PRT13722.
The study will evaluate the drug combinations in patients with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer. The U.S. Food and Drug Administration recently cleared Prelude to proceed with the Phase 1 study under and Investigational New Drug (IND) application. Prelude expects enrollment to begin in the fourth quarter of 2026, starting with dose escalation of PRT13722 as a single agent before advancing to combination cohorts.
The agreement gives Prelude access to Lilly’s two medicines for the planned combination studies while Prelude retains full global development and commercial rights to PRT13722. The announcement does not detail supply quantities, delivery arrangements, packaging responsibilities, or how the companies will coordinate product availability across the study.
Why Supply Should Care
Combination trials introduce supply dependencies beyond the investigational product being developed by the sponsor. When a study requires medicines supplied by another company, teams must account for the availability of each product as they prepare for cohort initiation and enrollment.
In this case, the study will begin with PRT13722 monotherapy dose escalation before progressing to combination cohorts involving Lilly’s medicines. That sequence makes coordination between the clinical development plan and the availability of the additional products an important consideration as the trial advances.
The transition between study stages is where supply planning can become more complicated. Teams need to align product availability with cohort readiness, anticipated enrollment, and protocol requirements. If the timing of a combination cohort changes, supply teams may need to reassess when products are required and how much inventory should be positioned to support the revised schedule.
External supply agreements also introduce coordination across organizational boundaries. Sponsors need clarity on responsibilities, forecasts, lead times, and communication when study plans change. When two companies are responsible for products used in the same trial, forecasting and timing become interdependent. A change in enrollment or cohort timing may affect when each product is needed, making early communication between the sponsor and supplying company important to keeping study activities aligned.
The announcement does not indicate that Prelude or Lilly has encountered a supply issue. It does, however, illustrate a recurring challenge in clinical trial supply: a study can be ready to advance scientifically before every product and supply requirement is aligned to support the next stage.
The Supply Question
How should sponsors coordinate investigational product and externally supplied medicines when a Phase 1 trial moves from monotherapy dose escalation into combination cohorts?
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About The Author:
Elizabeth Urbanek is the Executive Editor for Clinical Supply Leader, where she works with clinical trial supply and logistics professionals across pharma and biotech to bring real-world perspectives, operational challenges, trends, scientific insights and regulatory strategy to the field.
Before joining life sciences media, Elizabeth spent more than 15 years in broadcast, digital and live-event storytelling, helping highly technical teams communicate complex ideas with clarity and impact. She brings that same approach to clinical supply, creating editorial space for experts to share what is happening across clinical trial operations.
Elizabeth is passionate about connecting people and ideas, identifying emerging themes and showcasing work that can move the clinical supply field forward.