Why enrollment stalls
Four in five trials miss their enrollment timeline. The patients exist. The physicians who see them are twenty minutes from the site and have never heard of the study.
Ads find strangers. Patients say they would hear about a trial from their own doctor, not a banner. A screener full of strangers is not enrollment.
So we mapped every US physician: what they treat, where they send patients, where those patients live. Then we do the asking, in your name.
We are building the layer between a protocol and the doctors who already see its patients, so that no trial waits on people who were never told.
01
Share the trial protocol.
Protocol, site addresses, target enrollment. A PDF is enough. The surfacing agent returns the ranked physicians for each site, with the reason each one is on the list.
02
We find physicians who have your patients.
The outreach agent reaches them by email and phone, in your name. The ask is specific: which of their patients likely qualify and why. Your coordinator joins when a physician is ready.
03
Patients start enrolling.
Patients arrive at the site the way they always have, with a heads-up before each one. A new list every day: who was reached, who replied, who sent patients, which site needs help next.
No PHI leaves the practice. Spellbinder works at the physician level.
HIPAA compliant. Outreach copy MLR approved.
Nothing to install. Exports to your CTMS on request.
What we built
A map of every US physician and two agents that work it. Nobody on your team builds a list, writes an email or chases a reply.
The healthcare map
Every US physician, resolved from 400+ public sources to one profile: what they treat, whom they send patients to, where those patients live, and which trials they have enrolled into before. Public data is the floor; what comes back from the field keeps it true.
↳ Read more
Surfacing agent · 14 physicians near site 03 see patients who likely qualify
Outreach agent · Emailed Dr. Mahoney in your name · replied Tue 9:12
Handoff ✓ · Ready for your coordinator · call booked Thu
Agents
Two agents work the map. The surfacing agent reads your protocol and sites and delivers a ranked list per site every morning, with the reason each physician is on it. The outreach agent runs the conversation in your name, follows up, logs every reply and hands the physician to your coordinator when they say yes.
↳ Read more
A daily brief of physicians
Every morning, per site: the physicians to reach today, how many eligible patients each one sees, and why they are on the list.
What is on the map
Neurology
18,400 physicians
Psychiatry
41,000 physicians
Oncology
21,700 physicians
Counts as of September 2026, from the Spellbinder map.
lift in randomization at Alto Neuroscience after Spellbinder took over physician outreach for a CNS trial. The case study
Trusted by experts at pharmaceutical companies
“Our coordinators had spent a month finding one physician. Spellbinder gave us three in forty-eight hours. We signed before the contract was drafted.”
Clinical Operations Lead
Clinical-stage biopharma
01 / 04
Hit rate
Ads to strangers
~20
of 100 who pass an ad pre-screen go on to enroll, once no-shows and site screen-fails are counted.
Patient databases
—
No published figure. Records go stale; eligibility is self-reported.
Physicians who have your patients
65
of 100 who randomized after physicians referred.
One healthcare map for biopharma
For clinical
Physicians who have your patients, near every site, reached in your name.
For commercial
Untapped prescribers, the paths into a territory and the KOLs whose behavior is shifting.