Taking an HCP Buy Off the Open Exchange
Supply path optimization is usually sold as a fee story. This is what happened when a Sanofi Rx HCP video buy was consolidated into curated supply and measured on delivery quality, and what happened to prescriptions per impression when two brands in the same portfolio migrated off the open exchange entirely. Completion rate rose 15.5% and held every single day. The Rx read is more interesting, and more complicated.
The short answer
Moving an HCP video buy off broad open exchange inventory and into a single curated supply partner lifted average video completion rate from 51.95% to 59.97%, an 8 point gain, or 15.5%. Every day of the curated flight beat the entire prior-period average. On a separate portfolio read, the campaign where delivery concentrated also improved per-impression Rx efficiency: TRx per 1,000 impressions rose 41% and new patient starts per 1,000 impressions rose 42%. Neither read is a randomized test, and the Rx figures sit inside a claims lag.
The question worth answering
Supply path optimization is usually sold as a cost story. Fewer hops, less fee leakage, a cleaner auction. That is a real benefit, and it is also the easiest one to claim, because nobody has to prove the media got better. In pharma, where the actual currency is prescriptions rather than working-media percentage, the harder question is the one worth asking: if you consolidate the buy into curated supply, does anything downstream move?
Two reads inside a Sanofi Rx portfolio gave a chance to test that. The first is a clean before-and-after on an HCP video line. The second is a per-impression Rx efficiency read across two brands that migrated fully off open exchange. They answer different halves of the question, and they carry different levels of confidence.
Read one: the completion rate test
An HCP online video campaign, 30-second branded creative, launched on 23 July 2026 running against broad open exchange inventory through DeepIntent. Nine days in, we consolidated the entire buy into Infolinks curated supply and left everything else alone: same creative, same targeting, same DSP, same daypart logic, CTV excluded from the read.
The daily pattern is what makes this one worth writing down. Consistency, not the average, is the signal:
| Flight | Best day | Worst day | Days above the July average |
|---|---|---|---|
| Open exchange (7/23 to 7/31) | 58.31% | 46.58% | 4 of 9 |
| Curated supply (8/1 to 8/7) | 62.30% | 55.09% | 7 of 7 |
The worst day on curated supply cleared the entire open exchange average. That matters more than the headline lift, because a two-point average gain driven by one outlier day is noise, and a floor that rises above the old ceiling is a supply quality change. Seven of seven is a small sample, but it is a clean one.
Read two: what happened to the scripts
The second read is broader and less controlled. On 9 June 2026, a cardiovascular brand and a rare disease brand inside the same portfolio moved from a blend of curated and open exchange supply to Infolinks inventory exclusively. Measuring the month that followed against a monthly-normalized blended baseline from the prior two months, on third-party Rx outcomes data:
| Campaign | TRx / 1K impressions | Change | New patient starts / 1K | Change |
|---|---|---|---|---|
| Cardiovascular HCP | 97.9 → 138.0 | +41% | 7.41 → 10.55 | +42% |
| Rare disease, integrated | 0.75 → 0.66 | -13% | 0.028 → 0.033 | +18% |
| Rare disease, HCP | 2.13 → 1.68 | -21% | 0.078 → 0.085 | +8% |
The cardiovascular result is the one to sit with, and it needs its context stated plainly. Impression volume on that brand was cut 52%, and the brand still delivered 68% of its prior monthly TRx: 37,934 against a 55,499 baseline. Absolute scripts went down. Scripts per impression went up 41%. Those are both true, and reporting only the second one would be the kind of case study that gets a media plan into trouble.
On the rare disease brand, where impression levels stayed close to flat, the leading indicator improved on both lines while TRx dipped. That pattern is what you would expect from a claims lag, not a collapse: new patient starts are the forward signal, and refill-driven TRx reports four to eight weeks behind. Front-end quality held across the portfolio, with a 0.26% CTR on curated-only supply against 0.27% on the blended baseline, so nothing about the migration bought engagement at the expense of delivery.
How to read this honestly
Neither read is a randomized or holdout-controlled test. Both are before-and-after comparisons, which means seasonality, competitive activity, creative fatigue, and normal week-to-week Rx variance are all sitting inside the numbers alongside the supply change. The video read covers 16 days total, seven of them post-change. The Rx read closed on 9 July, and because claims report on a four to eight week lag, the curated-period TRx figures are a floor that will rise as the data matures, which also means they are not final. Two of the three lines show TRx per impression down. The defensible claim is that a full migration to curated supply held prescription outcomes and improved per-impression efficiency where delivery concentrated, with a consistent and immediate improvement in video completion. The claim it does not support is that curated supply caused a 41% script lift.
What I would take to the next plan
Design the read before the switch, not after it. The completion rate test is trustworthy because everything except supply was held constant and the baseline was already running. If the creative had rotated in the same week, there would be nothing to say. Supply path decisions get made quickly and quietly, which is exactly why the measurement scaffolding has to exist beforehand.
Judge supply on the floor, not the average. Curated inventory should show up as a rising worst day. Averages hide the days when open exchange delivered against inventory nobody would have bought on purpose, and those days are the actual cost of an unconstrained supply path.
Report per-impression efficiency next to absolute volume, always. Efficiency gains on a shrinking impression base are real and useful, and they are also the easiest metric in pharma media to accidentally oversell. If volume fell 52%, that belongs in the same sentence as the 41%.
Let the leading indicator lead. New patient starts move before TRx does. On a 30-day post-period read, weighting refill-driven TRx equally with new starts will systematically understate anything that just launched. The broader architecture behind reads like this is in the Pharma Programmatic Measurement Framework, and the delivery benchmarks it feeds are in Pharma Programmatic Benchmarks.
Key takeaways
- Consolidating an HCP video buy into curated supply lifted completion rate from 51.95% to 59.97%, with all seven post-change days above the prior average and the worst new day above the old mean.
- On a full portfolio migration, the campaign where delivery concentrated improved TRx per 1,000 impressions by 41% and new patient starts per 1,000 by 42%.
- Impression volume on that campaign fell 52% and absolute TRx fell to 68% of baseline, which is the context the efficiency number needs.
- Rare disease lines showed the classic lag signature: new patient starts up on both lines, TRx down, with claims reporting four to eight weeks behind.
- Both reads are before-and-after comparisons, not controlled tests, and the write-up is scoped to what that design can actually support.
Frequently asked questions
Does curated supply always beat the open exchange?
No. This read shows one HCP video buy where completion rate improved immediately and stayed improved for every day of the new flight, and one portfolio migration where per-impression Rx efficiency improved on the campaign that concentrated delivery. Curated supply narrows the inventory pool, which helps quality and can hurt scale. The right answer depends on whether the campaign is reach-constrained or quality-constrained, and it should be tested rather than assumed.
Why does the case study report a TRx decline alongside a 41% efficiency gain?
Because both happened. Impression volume on the cardiovascular campaign was cut 52% during the curated period, so absolute TRx fell to 68% of the baseline while scripts per 1,000 impressions rose 41%. Reporting the efficiency gain without the volume context would misrepresent what the media actually did.
How reliable are Rx outcomes measured over a single 30-day window?
Directionally useful, not conclusive. Rx claims report on a four to eight week lag, so figures inside a just-closed window are a floor rather than a final number. New patient starts are the leading indicator and move first; refill-driven TRx follows. A single before-and-after month also carries seasonality and competitive noise, which is why the honest read is stated as efficiency improvement rather than causal lift.
About the author
Christian Guerrero is an Associate Director of Programmatic Media at Havas Media Network in New York, where he leads programmatic strategy and activation for pharmaceutical brands across HCP and DTC channels. He holds an MS in Marketing from Baruch College's Zicklin School of Business and writes about connecting media investment to verified Rx outcomes. Connect on LinkedIn or get in touch.
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Thinking about consolidating your supply path?
I design supply tests that hold everything else constant, so the read reflects the inventory rather than whatever else changed that week. Happy to walk a recruiter or brand lead through how this structure applies to a specific portfolio.