U.S. Prescription Drug Market Weekly Growth Rebounds, While New-Product Uptake and Biosimilar Substitution Remain Key Differentiators
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U.S. Prescription Drug Market Weekly Growth Rebounds, While New-Product Uptake and Biosimilar Substitution Remain Key Differentiators
For the week ended August 7, U.S. market TRx grew 2.3% year over year, above the prior week and the 12-week average; the report uses IQVIA prescription and sales data to track new-product execution, therapeutic-area competition, and biosimilar penetration.
- Total U.S. market weekly TRx grew 2.3% year over year, improving from 1.5% in the prior week; 4-week and 12-week rolling year-over-year growth were 1.7% and 1.3%, respectively.
- GILD's Yeztugo prescriptions continue to grow, with payer coverage and PrEP market growth supporting 2026 expectations, although visibility remains limited in the early launch phase.
- VRTX's Journavx and JNJ's Icotyde are both in early launch stages, with prescription ramp-up, hospital-channel data coverage, and net-price assumptions determining the pace of revenue realization.
- Biosimilar penetration continues to reshape the competitive landscape for originator drugs; in the latest week, biosimilars related to Stelara and Prolia have already captured meaningful prescription shares.
Report interpretation
Overview
This report is Morgan Stanley's weekly chart update for the North American biopharmaceutical industry. Based on IQVIA prescription and sales databases, it systematically tracks overall U.S. drug-market volumes, prescription momentum for key products, new-product launch progress, therapeutic-area competition, and biosimilar adoption. The report focuses on comparing the latest prescription trends with 2026 consensus expectations.
Core views
Overall U.S. drug demand is improving moderately, with weekly TRx year-over-year growth rebounding, though differences across companies and products remain substantial. Among new products, Yeztugo's payer coverage and PrEP demand have been relatively positive; whether Cobenfy, Journavx, and Icotyde can meet market expectations still depends on prescription ramp-up, realized net pricing, and completeness of data coverage. For mature products, biosimilars are increasingly affecting originator product share and price realization. In areas such as immunology, diabetes, and obesity, prescription volumes and revenue per prescription must continue to be assessed together.
Analysis framework
The report uses IQVIA weekly TRx, NRx, extended-unit prescriptions, and monthly sales data to calculate year-over-year growth, rolling year-over-year growth, market share, and new-product launch trajectories. It also cross-validates prescription trends against management disclosures, payer coverage, net-price assumptions, and consensus revenue expectations.
Methodology notes
Total prescriptions and new prescriptions
TRx includes all dispensed prescriptions, including refills; NRx represents new prescriptions excluding refills, though it may also include prescriptions rewritten after patients have exhausted refills.
EUTRx/EUNRx
Extended-unit prescriptions adjust for prescriptions with larger doses or longer treatment durations and may therefore better reflect demand than standard TRx/NRx when the mix of 90-day prescriptions changes.
Revenue per prescription and net-price assumptions
Revenue per prescription is estimated by dividing reported quarterly sales by quarterly TRx. Combined with gross-to-net discounts, treatment duration, and prescriptions not covered in hospital-channel data, this is used to infer the prescription trajectory required to meet consensus expectations.
Prescription share and sales share
TRx share is tracked primarily for subcutaneous products, while monthly sales share is used more often for intravenous products; payer coverage, rebates, and price differentials are important determinants of adoption speed.
Asset mapping & comparison
Structured mapping from thesis to named assets (strengths, weaknesses, peers, risks).
- GILD / YeztugoPrEP New-Product Launch Tracking
- Strengths
- Prescriptions are growing sequentially, persistence exceeds 70%, payer coverage is approximately 95%, and the PrEP market is growing 14% year over year.
- Weaknesses
- The product remains in the early launch stage, with limited prescription and revenue visibility.
- Comparison
- The report compares it with the launch trajectories of Descovy and Apretude.
- Risks
- Actual net pricing, prescription conversion, and long-term share below assumptions could affect 2026 revenue realization.
- VRTX / JournavxAcute Pain New-Product Launch Tracking
- Strengths
- Latest weekly prescription volume continued to grow sequentially.
- Weaknesses
- IQVIA data do not cover all hospital-channel prescriptions, creating a gap in assessing actual demand.
- Comparison
- The report estimates the TRx required to meet 2026 consensus expectations using a net-price range after 70% to 80% gross-to-net discounts.
- Risks
- Changes in treatment duration, net pricing, and hospital-channel prescription estimates could materially affect revenue calculations.
- BMY / CobenfySchizophrenia New-Product Launch Tracking
- Strengths
- Early launch prescription data and a peer-product comparison framework are available.
- Weaknesses
- Latest weekly prescription volume declined slightly from the prior week, and the scale required to meet consensus expectations still needs ongoing validation.
- Comparison
- Compared with recent antipsychotic launches including Rexulti, Caplyta, and Lybalvi.
- Risks
- If prescription ramp-up does not reach the multiples required versus comparable products, 2026 consensus expectations face downside risk.
- JNJ / Icotyde and StelaraImmunology New Product and Biosimilar Competition Tracking
- Strengths
- Icotyde has early prescription activity, expanding prescriber adoption, and improving commercial payer coverage; Stelara has relatively comprehensive biosimilar share tracking.
- Weaknesses
- Early IQVIA data for Icotyde may not fully reflect actual prescribing; Stelara faces biosimilar penetration.
- Comparison
- Icotyde is compared with the launch trajectories of Otezla, Rinvoq, and recently launched psoriasis products.
- Risks
- Payer access, prescription persistence, and biosimilar substitution could all affect immunology business performance.
- AMGN / ProliaBiosimilar Competition Tracking
- Strengths
- Originator Prolia still retains approximately 53% of latest weekly prescription share.
- Weaknesses
- Jubbonti and Stoboclo have already reached meaningful combined share.
- Comparison
- The report tracks changes in originator and biosimilar products using 52-week TRx share.
- Risks
- Continued expansion of biosimilar access and share could reduce originator volume and price realization.
Key data
- U.S. Total Market Weekly TRx Year-over-Year Growth+2.3%For the week ended August 7, 2026; +2.7% in the comparable prior-year period.
- U.S. Total Market 4-Week Rolling TRx Year-over-Year Growth+1.7%For the week ended August 7, 2026.
- U.S. Total Market 12-Week Rolling TRx Year-over-Year Growth+1.3%For the week ended August 7, 2026.
- Extended-Unit Weekly TRx Year-over-Year Growth+2.1%Below standard TRx year-over-year growth.
- Cobenfy Latest Weekly Prescription VolumeApproximately 3,310 prescriptionsBelow approximately 3,370 in the prior week; the report estimates that approximately 186,000 TRx would be required to achieve 2026 consensus expectations of approximately $271 million.
- Yeztugo Latest Weekly Total TRxApproximately 1,920 prescriptionsOf which injections accounted for approximately 1,180 prescriptions; the report notes persistence above 70% and approximately 95% payer coverage.
- Journavx Latest Weekly Prescription VolumeApproximately 27,530 prescriptionsAbove approximately 26,970 in the prior week; IQVIA does not fully cover hospital-channel prescriptions.
- Icotyde Latest Weekly Prescription VolumeApproximately 920 prescriptionsAbove approximately 880 in the prior week; the report estimates that approximately 31,000 to 41,000 TRx would be needed to achieve 2026 U.S. consensus expectations of $255 million.
- Stelara Biosimilar Latest Weekly ShareYesintek approximately 78%, Wezlana approximately 18%Latest weekly prescription shares listed in the report.
- Prolia Biosimilar Latest Weekly ShareJubbonti approximately 27%, Stoboclo approximately 13%Originator Prolia share was approximately 53%.
Impact & implications
For pharmaceutical equities, near-term valuation catalysts are more likely to come from deviations of prescription trends relative to consensus expectations than from overall market growth itself. Payer access, prescription persistence, and net-price realization for new products are key validation points for revenue upside; originator drugs, meanwhile, must contend with pressure from rising biosimilar share, rebate dynamics, and data limitations when assessing volume and net pricing.
Risks
- IQVIA sales reflect drug list prices and exclude rebates and discounts; they therefore cannot directly represent net sales.
- Certain products are subject to mail-order channel or contractual data limitations, and prescription and sales data may be incomplete.
- TRx, NRx, and extended-unit prescriptions have different definitions; prescription trends should not be directly equated with true patient demand without adjusting for treatment duration.
- New-product revenue estimates depend on assumptions regarding net pricing, treatment duration, hospital-channel prescriptions, and consensus expectations; actual outcomes may differ materially.
- The pace of biosimilar adoption is affected by payer rebates, price differentials, indication labels, and channel factors, and historical share trends may not continue linearly.
What to watch
- Whether year-over-year growth in U.S. total-market TRx and EUTRx can continue to improve.
- Yeztugo injection prescriptions, payer coverage, persistence, and PrEP market growth.
- Whether weekly prescription ramps for Cobenfy, Journavx, and Icotyde approach the paths required to achieve 2026 consensus expectations.
- Prescription share and year-over-year trends for GLP-1, immunology, and Alzheimer's disease products.
- Changes in biosimilar prescription and sales shares for Stelara, Prolia, and other key originator drugs.
- Changes in quarterly sales relative to TRx to assess the effects of net pricing, indication expansion, and channel mix.