A drug can clear every hurdle, including discovery, trials, regulatory approval, and still take years to reach the patients it was designed for. Not because supply chains fail or physicians refuse to prescribe. Because the patient doesn’t get diagnosed in time.
This is the part of the journey that rarely shows up in pipeline reviews or launch readiness decks. A patient feels something isn’t right. They see a primary care physician who doesn't recognize the pattern. They get referred somewhere that turns out to be a dead end. Specialists consult without the full history. Months pass. Sometimes years. By the time someone finally names what's happening, the window for early intervention has narrowed or closed.
Where the journey stalls
For rare diseases, this delay can stretch to five, eight, even 10 years. But it's not just rare disease. Even conditions that seem common enough, like autoimmune disorders, certain cancers, metabolic syndromes, carry diagnosis timelines that would shock anyone who hasn't lived through them. I've talked to people who spent the better part of a decade bouncing between specialists before someone finally connected the dots.
The therapies exist. The science is there. What breaks is the connection between the patient’s trajectory and the physician who can actually help. That's not a research problem or a manufacturing problem. It's a systems problem, and it sits squarely in the space between development and commercialization.
The pharmaceutical industry has spent decades building commercial infrastructure around one question: how do we reach physicians effectively? Which doctors matter most for a given brand? When should we engage them? Through which channels and with what message? These are the questions that get asked in brand planning sessions, and the machinery built to answer them has become genuinely sophisticated. Data science, behavioral modeling, AI-driven targeting. All of it focused on the healthcare professional as the unit of engagement.
A system built for blockbusters
For the blockbuster era, this made sense. When you're marketing a cardiovascular drug to tens of millions of potential patients, you can afford some inefficiency in the funnel. The population is large enough to absorb a slow, leaky process.
Precision medicine has changed that math. Patient populations are smaller, sometimes dramatically so. The therapies themselves are more targeted, built for specific genetic markers, molecular profiles, disease subtypes. In that world, every patient matters differently. A therapy developed for a population of 50,000 can't tolerate the same diagnostic delays as one developed for 50 million. And yet the commercial apparatus hasn't fully caught up. It's still largely organized around reaching physicians, not around understanding where patients are in their journey before they ever reach the right physician.
Think about what that means in practice. A company spends years developing a therapy for a rare disease. The science is strong. The trial data is compelling. Approval comes through. The commercial team activates: field reps, digital engagement, speaker programs, all the standard plays aimed at the specialists who treat this condition.
But the patients who need this therapy aren't sitting in those specialists' waiting rooms yet. They're still cycling through primary care. They're seeing rheumatologists when they need neurologists, or oncologists when the real issue is metabolic. They're collecting partial diagnoses that don't quite fit. Some of them have been at this for years. The commercial model reaches the physician. It doesn't see the patient who hasn't arrived yet.
This is what I think of as the last mile problem, not in logistics, but in diagnosis. The gap between a patient's need emerging and that need being recognized by someone who can act on it. It's not a new observation exactly. People with rare diseases have been talking about diagnostic odysseys for a long time. What's newer is the recognition that commercial operations might have a role to play in shortening them.
The blind spot between clinical and commercial
The instinct might be to assume this is a clinical problem, not a commercial one. Diagnosis is medicine. Commercial teams get medicines to the right doctors treating the right patients. The two operate in different domains, separated by regulation and tradition and a healthy wariness about mixing them. That separation exists for good reasons. But it has also created a blind spot.
The commercial side of biopharma has become genuinely skilled at understanding physicians, their prescribing patterns, their responsiveness to different messages, their likelihood to try a new therapy. What it doesn't understand nearly as well is the patient journey that precedes the prescription. And the data to start understanding that journey does exist, even if it's scattered and imperfect. Claims records, lab results, referral patterns, procedure codes, fragments of the path patients travel before they reach a diagnosis. No single data point tells the story. But seen in aggregate, patterns emerge. You can start to identify patients who are cycling through the system in ways that suggest an unrecognized condition. You can see where journeys are stalling.
This isn't about predicting individual diagnoses or substituting for clinical judgment. It's about recognizing that commercial engagement could be informed by patient trajectories, not just physician profiles. If you know which physicians are likely to encounter patients on a certain diagnostic path, you can get relevant information in front of them earlier, not to push a product, but to shorten the time between suspicion and recognition.
The blockbuster model tolerated long diagnosis windows because the numbers worked anyway. Precision medicine doesn't have that luxury. When patient populations are measured in thousands rather than millions, every delayed diagnosis represents a meaningful share of the people your therapy was built for. Every year someone spends undiagnosed is a year of disease progression, diminished quality of life, and narrowing treatment options. This is where drug development and commercial execution share a stake, even though they operate on different timelines and answer to different pressures.
The work that goes into developing a precision therapy, the years of research, the careful trial design, the regulatory navigation, all of it assumes that patients will eventually be identified and treated. But that assumption depends on a commercial and healthcare system that can actually find them. Right now, finding them is harder than it should be. The systems that track physician behavior are mature. The systems that track patient journeys before diagnosis are not.
Closing the gap
I'm not a clinical scientist. I don't work on the development side. My perspective comes from commercial operations, watching how brands launch, how field teams engage, how data flows through the systems that are supposed to connect therapies to the people who need them. What I've seen over the past several years is a commercial apparatus that has gotten good at reaching physicians faster and more precisely than ever before. And I've seen that same apparatus struggle to account for the patient who hasn't yet arrived, the person still caught in a diagnostic maze, invisible to a system built around prescribers rather than patients.
The technology to start closing that gap is emerging. Machine learning can surface patterns in patient data that suggest undiagnosed conditions. Aggregated, de-identified signals can inform when and how commercial teams engage with physicians. None of this replaces clinical expertise. It just means the commercial side could start operating with some awareness of patient trajectories, not just physician targets.
For those working on the development side, formulating therapies, running trials, navigating regulatory pathways, the commercial handoff can feel like someone else's problem. You build the therapy. You prove it works. Then it's over the wall to the teams responsible for getting it into the market. But the mission doesn't end at approval. It ends when patients benefit. And right now, too many patients are waiting too long because the systems designed to connect them to care weren't built with their journey in mind.
The next advance in commercial biopharma won't come from better physician targeting. That's already improving steadily, and honestly, the gains from further optimization there are incremental at this point. The real leap will come from finally paying attention to the patient's path, the diagnostic wandering, the missed signals, the years lost before someone puts the pieces together. That's the last mile. And for precision medicine to deliver on its promise, someone has to close it.
