The four weeks after ESMO

ESMO 2026 finished in Madrid on Tuesday. By ESMO’s own numbers, more than 40,000 people were expected, over 6,300 abstracts were submitted and around 230 sessions ran across five days. Third-party trackers counted more than 230 exhibiting companies.

It’s one of the biggest weeks of the year for oncology, and for the pharma companies and agencies who spend months getting ready for it.

But I think the most valuable weeks for pharma aren’t congress week. They’re the four that follow. In my experience, that’s where a lot of the value gets left on the table.

Nobody sees more than a fraction of it

No oncologist can get to 230 sessions. Sessions run in parallel across multiple halls, and industry satellites compete with each other for the same people. ESMO itself says it can’t guarantee that satellites on the same topic won’t clash.

This year, day one opened with a morning of industry satellites before the Opening Session had even started. If your symposium was up against two others in the same tumour type, a lot of the HCPs you wanted never made it into the room.

That isn’t a criticism of ESMO. It’s what happens when 40,000 people try to take in a year of oncology in five days.

The question is what happens to everything they missed.

HCPs expect the conversation to carry on

This year’s Emota and IPCAA report asked 251 HCPs how they experience medical congresses. Its clearest finding was that post-congress engagement is the overlooked opportunity. HCPs don’t just welcome follow-up after a congress, they expect it.

Earlier IPCAA research found the thing HCPs most want from pharma afterwards is simply the slides from the symposium. That’s a very modest ask, and it says a lot about where the bar currently sits.

And interest lasts longer than most plans do. One analysis of ADA found HCPs still discussing specific symposium data four weeks after the congress, well beyond the brand’s content calendar.

Part of the reason is how congress is organised inside companies. Medical affairs tracks scientific exchange, commercial tracks customer interactions, and comms tracks content. Each team measures its own piece, so nobody owns what happens to the HCP after they fly home.

The moment you can’t control, and the one you can

The most anticipated data at ESMO 2026 didn’t get its moment at ESMO.

On the eve of the congress, details of Moderna and MSD’s phase 3 melanoma vaccine trial were posted online before the embargo lifted. ESMO lifted the embargo on the full dataset, the companies released the results two days early, and Moderna’s shares fell sharply that day. For a while, the story was the leak rather than the science.

It’s an extreme case. But it shows something every medical affairs and medcomms team already knows: the congress moment is fragile, crowded and short. You share it with hundreds of other abstracts and dozens of competing sessions, and sometimes you don’t get it at all.

What happens after the congress is different. You choose the date, the faculty, the audience and the questions. It’s the part of the congress you actually own.

Where Adelo fits

ESMO owns congress week, and rightly so. It streams sessions on its own virtual platform, and in past years it has asked companies not to host their satellite webcasts elsewhere while the congress runs. Once that platform closes, companies have been free to publish them.

That’s where we come in. Adelo is the professional video event platform for health, and the weeks after a congress are exactly what it’s built for. A pharma company or agency could run:

• A satellite encore. The same faculty, live again two or three weeks later, for the HCPs who missed it or had a clash. A recording on a website answers the slides request. An encore lets HCPs ask the questions they didn’t get to ask in Madrid.
• Local debriefs. ESMO is global, but prescribing decisions are local. A UK KOL explaining what the data means for NICE and NHS practice is a different conversation from the one in the hall.
• A post-congress ad board. Hear what KOLs really made of your data, and your competitors’, while it’s still fresh, with every comment on the record for medical affairs.
• Field team and MSL briefings. Get your people up to speed on what came out before HCPs start asking them about it.

For agencies, this becomes a product rather than a one-off: a post-congress programme for every oncology client, after ASCO, ESMO and ESMO Asia, every year.

Some things worth doing

1. Write the encore into the speaker contract. When you book faculty for the satellite, book the follow-up date and the rights to record and re-use in the same agreement. KOL diaries fill up fast after a congress, and November is too late to start asking.
2. Keep a list of the questions nobody answered. Have someone log every question from the satellite Q&A that ran out of time. That list is the agenda for your encore, and it shows HCPs you were listening.
3. Invite the people who weren’t there. Your badge scans tell you which target HCPs were in the room. The invite list for the encore is your target list minus those names.
4. Plan for your competitors’ data, not just yours. HCPs leave ESMO trying to work out how all the new readouts fit together and in what order. A medical-led session that helps them make sense of the whole picture is worth more than another look at your own slides.
5. Have a plan for an early release. Decide now what happens if your data goes public before the embargo lifts: who briefs the field, which HCP session moves forward, who is on camera. After this year, someone will ask.
6. Time local debriefs to local moments. Run the UK session when it lines up with something UK HCPs care about, such as a NICE appraisal or a regional network meeting, rather than a fixed two weeks after the congress.
7. Give one person the four weeks. Set one number for the post-congress period before you travel, such as the share of target HCPs who engaged with your data by the end of November. Then make one person accountable for it across medical, commercial and comms.
8. Use ESMO IO in London as a test. It runs 14 to 16 December at the QEII Centre. It’s small enough to try a full post-congress programme and learn from it before ASCO.

If you’re planning something after ESMO or ESMO IO, I’d like to hear how you’re approaching it.

Sources

• ESMO: Congress 2026 opened in Madrid (attendees, abstracts, sessions)
• tnuki: Who’s going to ESMO 2026 and Lensmor: ESMO 2026 exhibitors (exhibitor counts)
• Prezent: ESMO 2026 attendee guide (day one satellites)
• ESMO 2024 programme template (satellite clashes)
• Pharmaceutical Executive: Emota and IPCAA report
• Onomi: The Great Debate on congress investment (IPCAA slides finding)
• Indegene: Congress social listening (ADA four weeks)
• Pharma Marketing Network: Congress coordination
• pharmaphorum: Moderna, MSD reveal data early after leak and EMJ: Moderna shares after ESMO leak
• ESMO 2023 Industry Guidelines Addendum and ESMO 2024 Satellite Symposia Resources Manual (webcast rules)
• ESMO IO & Advanced Therapies Congress 2026