U.S. prescription growth rebounds as new-product uptake and biosimilar substitution advance in parallel

Overview

Based on IQVIA prescription and sales data, this report provides weekly tracking of major U.S. pharmaceutical markets, covering large-cap pharmaceuticals, biotech, biosimilars, cardiovascular, diabetes, immunology, infectious disease, neuroscience, obesity, and respiratory areas. Core focus areas are prescription trends, commercialization progress of launched products, market-share changes, and the extent to which prescription trajectories support 2026 consensus revenue expectations.

Core views

U.S. pharmaceutical-market demand improved modestly: total TRx grew 2.3% year over year and 0.8% week over week for the week ended August 7, although medium-term rolling growth remains in the low single digits.Yeztugo’s payer access and PrEP-market expansion are positive signals; the report believes continued prescription growth supports confidence in PrEP revenue expectations beyond 2026.Cobenfy, Journavx, and Icotyde remain in early launch stages. Whether their commercialization meets targets depends on prescription-ramp speed, net price realization, channel coverage, and IQVIA data representativeness.In immunology, products such as Skyrizi and Rinvoq retain growth momentum, while biosimilar penetration and prescription declines for mature brands continue to reshape the competitive landscape.Biosimilar adoption varies materially across products; payer incentives, brand rebates, indication labels, and data limitations can all affect the pace of substitution.

Analysis framework

The report compares IQVIA weekly and rolling prescription data with historical launch cases, disclosed sales, and consensus expectations. For new products, it back-solves the prescription trajectory needed to achieve revenue targets based on implied revenue per prescription, net price realization, and treatment-duration assumptions, while tracking TRx or sales-value shares for branded drugs and biosimilars.

Methodology notes

• Prescription demand trackingTRx/NRx/EUTRx trend analysis

  Total prescriptions, new prescriptions, and extended-unit prescriptions

  TRx includes refills, while NRx primarily reflects new prescriptions and refill renewals. EUTRx adjusts units for long-duration prescriptions and can supplement traditional prescription counts, which may inadequately identify 90-day prescriptions.

• Revenue realization analysisPrescription-based revenue back-solve

  Prescription volume required for consensus expectations

  Using consensus revenue expectations, implied revenue per prescription, net price realization, and average treatment duration, this estimates the weekly prescription trajectory required for a product to meet annual or quarterly revenue expectations.

• Competitive landscape analysisBiosimilar penetration tracking

  Branded-drug and biosimilar shares

  For subcutaneous products, the analysis tracks TRx share; for intravenous products, it primarily tracks IQVIA sales-value share to assess biosimilar substitution progress.

• Pricing analysisSales value/prescription count analysis

  Sales value per prescription

  Quarterly disclosed sales are divided by IQVIA TRx for the same period to estimate sales value per prescription, helping assess the effects of indication expansion, mix shifts, and price realization.

Asset mapping & comparison

Structured mapping from thesis to named assets (strengths, weaknesses, peers, risks).

• GILD

  Yeztugo and Descovy are core products to monitor in the PrEP business

  Strengths

  Yeztugo has obtained broad payer coverage, the PrEP market grew 14% year over year, and Descovy’s share remains in the mid-40% range.

  Weaknesses

  Yeztugo remains at an early stage of launch, with limited prescription and revenue visibility.

  Comparison

  Launch-prescription comparison with Descovy and GSK’s Apretude.

  Risks

  Changes in payer policy, actual net pricing below expectations, expansion by competing products, and slowing prescription growth.

• BMY

  Cobenfy launch progress affects expectations for the schizophrenia business

  Strengths

  Approved for schizophrenia, with the report providing launch comparisons with Rexulti, Caplyta, and Lybalvi.

  Weaknesses

  Current weekly prescriptions remain low, and meeting 2026 consensus expectations requires significant acceleration.

  Comparison

  Would need to reach prescription volumes roughly 2 to 5 times those of recent schizophrenia-launch cases.

  Risks

  Insufficient prescription ramp, slow physician adoption, and downward revisions to market expectations.

• VRTX

  Journavx commercialization progress affects expectations for the acute-pain business

  Strengths

  Weekly prescriptions continue to grow, and the product is positioned as a non-opioid treatment for acute pain.

  Weaknesses

  Hospital prescription coverage is incomplete, creating uncertainty in the conversion of prescriptions to revenue.

  Comparison

  The report estimates prescription volume required to meet consensus expectations based on a 70% to 80% net price realization rate and an 11-day treatment duration.

  Risks

  Lower net price realization, actual treatment duration diverging from assumptions, and hospital-channel performance below expectations.

• JNJ

  Icotyde’s launch and Stelara biosimilar substitution jointly affect the immunology business

  Strengths

  Icotyde’s early prescriptions and number of prescribing physicians are increasing, while commercial payer coverage exceeds 50%.

  Weaknesses

  Stelara faces biosimilar penetration, and early Icotyde data have limited representativeness.

  Comparison

  Comparison of Icotyde’s launch trajectory with psoriasis products such as Otezla and Rinvoq.

  Risks

  Expanding biosimilar share, payer access below expectations, and a slowing product launch ramp.

• ABBV

  Skyrizi and Rinvoq are growth pillars in immunology

  Strengths

  The report shows that prescriptions for Rinvoq and Skyrizi continue to grow year over year.

  Weaknesses

  Immunology competition is intensifying, and indication mix affects revenue per prescription.

  Comparison

  The 52-week NRx trends of Skyrizi and Tremfya are a key comparison.

  Risks

  Share losses to competing drugs, pricing pressure, and prescription-data limitations.

Key data

• U.S. total-market weekly TRx year-over-year growth (week ended August 7, 2026)+2.3%The prior week was +1.5%, versus +2.7% in the prior-year period.
• U.S. total-market 4-week rolling TRx year-over-year growth+1.7%Reflects modest recent demand growth.
• U.S. total-market 12-week rolling TRx year-over-year growth+1.3%Medium-term growth remains in the low single digits.
• Weekly EUTRx year-over-year growth+2.1%Below the year-over-year growth rate of TRx for the same period.
• Cobenfy weekly prescription volumeApproximately 3,310 prescriptionsApproximately 3,370 in the prior week; an estimated approximately 186,000 TRx would be required to achieve 2026 consensus expectations.
• Yeztugo total weekly prescription volumeApproximately 1,920 prescriptionsOf which injections accounted for approximately 1,800; total prescriptions were approximately 1,890 in the prior week.
• Yeztugo payer coverage rate95%The report states that most payers do not require copays and that prior authorization or step-therapy requirements are limited.
• Journavx weekly prescription volumeApproximately 27,530 prescriptionsApproximately 26,970 in the prior week; IQVIA does not fully cover hospital prescriptions.
• Icotyde weekly prescription volumeApproximately 920 prescriptionsApproximately 880 in the prior week; the report notes that early IQVIA data may not fully reflect actual prescription dynamics.
• Latest weekly share of Stelara biosimilarsYesintek approximately 78%, Wezlana approximately 18%Based on the TRx shares listed in the report.
• Latest weekly TRx share of Prolia biosimilarsJubbonti approximately 27%, Stoboclo approximately 3%Branded Prolia share was approximately 53%.

Impact & implications

For pharmaceutical-equity investors, weekly prescription data can serve as a high-frequency indicator of near-term sales trends and revisions to market expectations. Yeztugo’s market access and PrEP expansion support GILD; however, the valuations and revenue realization of Cobenfy, Journavx, and Icotyde remain highly dependent on accelerating prescriptions. In immunology and biosimilars, investors should monitor volume, net price, payer policies, and brand rebates concurrently, because changes in prescription share do not necessarily equal changes in revenue share.

Risks

• IQVIA sales values reflect list prices and exclude rebates and discounts, so they cannot be directly equated with net sales.
• Certain products have mail-order channels or contractual data restrictions, and prescription and sales shares may be incomplete.
• Hospital prescriptions are not sufficiently captured by IQVIA for certain products, potentially understating actual utilization.
• Revenue back-solves based on linear prescription trajectories, net price realization, and treatment-duration assumptions may diverge materially from actual commercialization paths.
• Drugs may be used in combination, so a share change in one treatment class does not necessarily indicate patients switching between classes.
• Biosimilar substitution is affected by payer rebates, pricing, indication labels, and channel policies, creating uncertainty regarding adoption speed.

What to watch

• Whether weekly, 4-week, and 12-week rolling growth in U.S. total-market TRx and EUTRx continues to improve.
• Whether Yeztugo injection prescriptions, payer coverage, and PrEP-market growth can support 2026 revenue expectations.
• The gap between actual prescription trajectories for Cobenfy, Journavx, and Icotyde and the trajectories required to achieve consensus expectations.
• Prescription-growth rates and market-share changes for Skyrizi, Rinvoq, Tremfya, GLP-1 drugs, and obesity drugs.
• Biosimilar-share changes for Stelara, Prolia, and other branded drugs, and their effects on pricing and revenue.
• Changes in revenue per prescription between quarterly disclosed sales and IQVIA prescription data.