Manage the conditions driving it, instead of chasing another PBM discount.
The short answer. Health plans reduce specialty drug spend by managing the four conditions that drive it: GLP-1s, autoimmune biologics, oncology and rare disease, and cell and gene therapy. Specialty drugs are 54% of pharmacy cost, and 25 years of rebate and discount guarantees have not bent the trend. Condition-level programs sit on top of an existing PBM contract.
Key takeaways
- GLP-1 spend is an adherence problem: two-thirds of non-diabetic users stop within a year, and about half never get past the starting dose.
- Biosimilars listed at parity do not move share; a preferred or biosimilar-only position does.
- For oncology, rare disease and cell and gene therapy, the question that saves money is whether the drug is working, asked early and often.
- None of this requires replacing your PBM. Start by pulling your top drug report.
Why hasn’t a better PBM discount reduced specialty drug spend?
Because a discount changes the unit price and nothing else. Every PBM renewal brings a better rate, and every year pharmacy trend goes up anyway. Specialty drugs are now 54% of pharmacy cost, and the growth is concentrated in four conditions that a price concession cannot touch.
A discount does nothing about whether the right member is on the right drug, at the right dose, with the outcome the plan is paying for. That is a condition management problem, and it needs a different strategy.
Which conditions drive specialty pharmacy trend, and what should health plans do about each?
Four conditions drive most of the growth, and in each one the pattern is the same: plans pay for drugs without anyone confirming the drug is doing its job. The money is lost in utilization, and a discount cannot reach it. Here is MacroHealth’s view on each.
GLP-1s
GLP-1s were the leading driver of a 14.8% rise in plan costs this year, and they touch a large share of the population. Most plans cover them for diabetes only, yet many members on a diabetes-indicated GLP-1 are using it for weight, and studies show two-thirds of members without diabetes stop the drug within a year. Jessica Lea, COO of Stellus Rx, has seen about half of patients stall at the starting dose during her career as a pharmacist, because they are not tolerating the drug and nobody is checking in. The plan pays full price and gets none of the outcome.
What to do: put a clinician or pharmacist alongside the member from the first fill. Set the outcome goal, manage titration, and check at 30 and 90 days whether it is working.
Autoimmune biologics
Biosimilars were supposed to collapse the cost of this class. For many plans they have not, because of formulary structure. When biosimilars sit at parity with the originator and the manufacturer’s follow-on brands, prescribing drifts to the newer, heavily marketed products at several times the price, and copay assistance means the member never feels it. Heather Sundar, CEO of Archimedes, put it plainly:
If you are just adding the biosimilars at parity, you will not get the market share movement, and so you will lose all of that savings opportunity to the follow-on brands.
Heather Sundar, CEO, Archimedes
What to do: move biosimilars to a preferred or biosimilar-only position, pick a partner that will guarantee the share movement, and accept less rebate for a lower net cost. Most plans can make the formulary change with 60 days notice.
Oncology, rare disease, and cell and gene therapy
These are the drugs plans fear most, and the instinct is to control them at the front door with prior authorization, or to exclude them outright. Both miss where the exposure sits. Roughly a quarter of cancers are rare, standard of care runs out with each progression, and decisions get made on thin data under time pressure. The question that matters for a plan is whether the drug is working six months on, and whether a better option exists. Christine Johnston, GM of Pharmacy at MacroHealth, saw the cost of not asking in a former PBM role: a member spent nearly three years on a therapy costing about $2.5 million a year before anyone checked whether it was working. It was not, and a far less expensive transplant resolved the condition.
Better options do exist. Dr. Jennifer Carter, founder and CEO of MedZone, works with plans to place members in clinical trials when standard treatment is no longer an option: the member gets a new option, the trial sponsor covers the drug, and the plan’s cost falls away.
Probably the least valuable medication is the one that’s not producing the intended outcome.
Jessica Lea, COO, Stellus Rx
What to do: review safety and durability, not just efficacy, before approval; set an outcome check after it; and offer trial access where the evidence is thin. Exclusion protects the plan less than any of these.
How can a health plan start managing conditions instead of discounts?
Start with three decisions: which partners to use, who governs each condition, and how many carve-outs the plan can run. None of this requires a new PBM. These programs sit on top of the existing PBM relationship and are typically allowed under the contract, and plans are ready to move: among health plans aware of unbundled PBM models, 49% would pursue a partially unbundled approach today and 11% a fully unbundled one (PSG, 2026).
There are solution out there that you can put on top of your existing PBM relationship that are typically allowed through your contract.
Christine Johnston, GM of Pharmacy, MacroHealth
- Evaluate partners. Look for clinical expertise by condition, independence, and savings measured on net cost rather than rebate.
- Set up governance. Decide who owns each condition, how partners report, and how results roll up to net cost.
- Choose carve-outs. Match the number and type of carve-outs to your plan’s size and needs.
Frequently asked questions
Do we need to replace our PBM to manage specialty drug spend?
No. Condition-level programs for GLP-1s, biosimilars, and high-cost therapies layer on top of the existing PBM relationship and are typically allowed under the contract. Plans may give up some rebate, and net cost is the number to watch.
Should health plans exclude cell and gene therapies from coverage?
No. The panel of pharmacy leaders rejected exclusion unanimously. A clinical review of safety and durability before approval, an outcome check after it, and clinical trial access where evidence is thin protect the plan without denying members treatment.
Should health plans cover GLP-1s for weight loss?
Coverage is the plan’s call, but the spend decision is about adherence, not indication. Members on a diabetes-indicated GLP-1 are often using it for weight, and most stop within a year. Whatever a plan covers, pairing the drug with clinical support at the start and at 30 and 90 days is what turns the spend into an outcome.
Can clinical outcomes be written into value-based pharmacy contracts?
Yes. Plan and vendor agree up front on the clinical markers that count as success for a pathway, then tie shared savings to those markers and to total cost of care over time. For GLP-1s the contract needs a realistic horizon, because the total cost of care reduction takes time to show up.
These ideas came from an ACHP panel, Managing Conditions, Not Discounts, moderated by MacroHealth. If you want a second set of eyes on your top drug report, MacroHealth’s pharmacy team will walk through it with you, show you where the conditions above sit in your spend, and tell you which programs fit under your current PBM contract. Book a top drug report review