C4 Therapeutics is a clinical-stage biotech advancing targeted protein degradation therapies. As multiple programs progressed through development, the medical writing team faced rising narrative volume against a lean headcount. C4 turned to Peer AI, the purpose-built platform for regulatory submissions, to deliver patient narratives at clinical-grade quality, fast enough to keep pace with the pipeline.
Challenge
A growing pipeline outpacing a lean team. Patient narratives sit on the critical path for clinical safety report writing, and volume scales with every additional study. C4's medical writing team needed a partner that could power that growth without expanding headcount.
Per-narrative authoring time as the bottleneck. Each narrative took C4's writers 4 to 6 hours to author. At 50+ events per study, that cumulative time was crowding out higher-value review and strategic work the team needed to focus on.
Quality standards that couldn't slip. Narratives feed directly into safety reporting and regulatory review, leaving no room for shortcuts on accuracy, completeness, or consistency. Any solution had to match the bar C4's writers held themselves to.
The Approach
C4 selected Peer AI because they trusted the company to deliver to their standards. Peer AI's human-in-the-loop model is staffed by medical and regulatory writers who have sat in C4's seat: people who have written the same narratives, know the conventions, and understand what "good" looks like to a medical writing team.
The engagement was structured to earn that trust in practice:
Sample narratives first. Peer AI's platform delivered an initial batch of narratives utilizing C4's templates and style conventions.
Template flexibility. Peer AI works with sponsor-provided templates or develops one from scratch as part of the engagement. Either way, the template is configured to the customer’s specific style conventions, regulatory requirements, and document standards.
Targeted feedback loop. C4's medical writing team reviewed the samples and provided feedback on style and structure.
Scaled delivery. With the feedback incorporated, Peer AI completed the remaining narratives across the study, freeing C4's team to focus on review rather than first-draft generation.
Results
Peer AI delivered 54 narratives, saving C4 over 200 hours of total drafting time.
Efficiency
~85% time savings per narrative. Authoring dropped from 4 to 6 hours per narrative under C4's prior process to roughly 45 minutes per narrative with Peer AI.
~85% reduction in total project time. The full set of 54 narratives that would have consumed an estimated 270 writer-hours under the prior process was completed in roughly 40 hours of authoring time, freeing C4's team to focus on review and strategic input rather than first-draft generation.
Quality
Peer AI evaluates every output against a defined quality framework spanning accuracy, completeness, readability, consistency, and source traceability. On the C4 narratives, that framework translated into drafts C4's reviewers could move through quickly, with fewer queries back to the authoring team and less downstream rework. C4's team described the delivery as exceeding expectations on quality and ready for internal review.
Customer Quote
"What stood out wasn't just the speed. It was that the team behind the work clearly understood what a narrative needs to do. I was very impressed: the drafts arrived in a state our reviewers could engage with immediately, which meant fewer queries and faster turnaround on our side."
Leah Case, PhD
Senior Director, Medical Writing, C4 Therapeutics
Looking Ahead
Following the narratives engagement, C4 is expanding its work with Peer AI to additional regulatory document types, including Clinical Study Reports and non-clinical content. The expanded scope positions C4 to keep pace with growing regulatory writing demand across its pipeline without proportional headcount growth, while keeping its medical writing team focused on the review, strategy, and scientific judgment that only they can provide.
