Why Pharmaceutical Market Access is Dependent on Risk Sharing and Persistency Modeling

In our case study for an injectable migraine medication, the higher patient persistency curve for patients with a lower co-pay increased drug utilization by 20%, while lowering payor price by 26% and payor total cost by 11%.

What is Market Access?

Market access is the process that ensures all patients who would benefit from a drug therapy are provided with rapid and sustained access to that therapy at an affordable price or co-payment. On the surface, it seems straightforward: for both pharmaceutical companies and payors, providing patients who suffer from a specific condition with access to effective treatments and cures should be the primary objective.

In practice, supplying and maintaining access to therapies for all eligible patients at a fair price that does not disadvantage the patient, the payor, or the pharmaceutical manufacturer is much harder to execute. At its core, market access is a continuous negotiation.

So how is it done? How can manufacturers and payors work together to optimize market access, and what makes balancing these interests so difficult?

The Traditional Approach: High Co-Pays and Prior Authorization

As a case study, consider a newly approved $600/month injectable migraine medication entering a market where a much less expensive generic drug is already available as a substitute.

A traditional approach to market access is for the pharmaceutical company and the insurance company to agree upon a relatively high patient co-payment for the branded injection. That high co-payment acts not only as a filter based on how well the therapy works for a given patient, but also as a direct financial barrier to treatment.

Within any real-world patient population, there are distinct segments of patients. Not every patient who starts a therapy will experience the exact same clinical benefit; there are degrees of efficacy. And unlike clinical trials where medication is provided free of charge, patients in the real world do not all share the same household income or prescription budget.

A large and growing share of prescription drug spending in the United States is concentrated in a small minority of medications classified as Specialty Pharmacy drugs, which typically cost at least $600 per month. When market access for a specialty therapy is managed through a traditional high co-payment structure, clear disparities emerge across income brackets:

• High-income patients: If the co-payment is around $100/month and the therapy provides any meaningful relief, these patients will generally stay on therapy regardless of the exact degree of efficacy.
• Middle-income patients: For middle-income patients who suffer from migraines, the preventative injection must deliver a substantial reduction in migraine pain; otherwise, the $100/month co-payment acts as a gatekeeper and those patients will revert to the less effective generic.
• Low-income patients: For lower-income patients, the injection has to be a complete game-changer, delivering a night-and-day difference in daily function, for them to justify continuing therapy at that out-of-pocket cost.

This traditional approach leaves serious gaps in market access because the co-pay threshold prices out a large share of the patients who would clinically benefit from the medication.

A second traditional lever used to restrict market access is requiring prior authorization (PA) from the prescribing physician before a pharmacy can dispense the drug. To obtain prior authorization, the physician typically must document that the patient has already tried a generic medication for a specified period and experienced treatment failure or drug intolerance.

How Risk Sharing Changes the Access Equation

Risk sharing is an alternative model that forward-looking pharmaceutical companies and payors adopt to expand market access while lowering overall costs for patients and health plans. Risk-sharing programs typically combine two mechanisms:

1. Prescribed starter samples: Distribution of free medication samples by physician prescription so patients and doctors can evaluate real-world clinical response upfront.
2. Co-payment assistance: Co-pay support that reduces the patient’s out-of-pocket cost from around $100/month down to a manageable $5 to $30/month.

Together, these two steps remove the initial high co-payment barrier and spare patients from waiting months to clear prior authorization hurdles for a second-line therapy.

However, risk sharing is not automatic. It is called risk sharing for a reason. How do you balance the financial and utilization risk across the insurance company, the patient, and the pharmaceutical manufacturer? How can you be confident that lowering the co-pay by a specific dollar amount or distributing a specific volume of starter samples will optimize utilization and maximize market access without overspending?

The answer is patient persistency modeling.

What is Patient Persistency Modeling?

Determining the optimal combination of Patient Co-Pay, Payor Total Cost, Payor Price Per Rx, and Drug Utilization is the key to maximizing market access. Patient persistency modeling quantifies how many prescriptions and how much co-pay assistance are required to reach as many eligible patients as possible while keeping the economics sustainable for every stakeholder.

A practical definition of patient persistency is the percentage of an initial patient cohort that continues to refill a given prescription on a timely basis over time.

In real-world claims data, some patients refill a prescription late because they are waiting on a reauthorization, or because their adherence fluctuates with seasonal symptoms. If a patient eventually refills, even a week or a month past their target date, they remain part of the active patient population. Once a patient goes more than a month past their expected refill date without a subsequent fill, they are classified as discontinued.

The persistency curve tracks the percentage of patients who remain on therapy at 1 month, 6 months, 12 months, and beyond. For any given patient cohort, that curve sits significantly lower when patients face a $100 co-pay than when they face a $5 co-pay.

Because remaining on therapy over time determines cumulative prescription volume and clinical outcomes, the persistency curve is what ultimately drives the payback of a risk-sharing arrangement. In our injectable migraine case study, shifting patients to the higher persistency curve associated with a lower co-pay:

• Increased drug utilization by 20%
• Lowered payor price per prescription by 26%
• Lowered payor total cost by 11%

Persistency curves are built using econometric and survival modeling across millions of anonymized prescription records and hundreds of thousands of patient journeys to isolate the demographic, economic, and clinical drivers of adherence.

High prices for specialty medications and barriers to patient access remain two of the toughest challenges in healthcare. Data-driven risk-sharing arrangements between life science manufacturers, payors, and patients offer a practical path to lowering total costs while expanding patient access.