September WAC-based sales reach $324 million (approx. KRW 434.1 billion); SC formulation accounts for 15.7% of total Keytruda franchise
Global market expansion follows regulatory approvals in China and Japan; Alteogen eyes additional milestone payments
Sales of 'Keytruda SC,' which utilizes Alteogen’s proprietary subcutaneous (SC) formulation technology, surpassed KRW 430 billion in September. The SC version's share of total Keytruda prescriptions has now climbed above 15%. While recent patent litigation in Europe has weighed on Alteogen’s stock price, real-world sales metrics indicate robust growth.
According to Bloomberg data shared by Alteogen (196170) on the 12th, prescription sales of Keytruda SC—calculated by Wholesale Acquisition Cost (WAC)—reached $324 million (approximately KRW 434.1 billion) in September, a 34% increase from the previous month. The SC formulation’s share within the total Keytruda franchise rose by 3.3 percentage points, from 12.4% in August to 15.7% in September.
Keytruda SC incorporates Alteogen's human hyaluronidase technology, ALT-B4, into MSD’s blockbuster immunotherapy, Keytruda. Since receiving U.S. Food and Drug Administration (FDA) approval last September, the product has gained significant market traction by offering a much shorter administration time compared to the traditional intravenous (IV) method.
Monthly WAC-based sales have shown a steady upward trajectory, growing from $168 million in June to $203 million in July and $241 million in August, before reaching $324 million in September.
MSD officially reported Keytruda SC sales of approximately $590 million for the first half of this year. Adding the $768 million in estimated WAC-based sales from July to September brings the cumulative total for the first nine months of the year to approximately $1.358 billion (about KRW 1.82 trillion). Note that this figure combines official sales and WAC estimates and may differ from official cumulative accounting revenue.
MSD has set a goal to increase the adoption rate of the SC formulation in the U.S. market to 30–40% by the end of 2027. During their second-quarter earnings call, the company noted that clinician and patient adoption has been increasing following the implementation of a U.S. insurance billing code (J-code).
The international expansion is also accelerating. On the 29th of last month, China’s National Medical Products Administration (NMPA) approved Keytruda SC for 19 solid tumor indications, and it has also received approval for all indications currently covered by the existing Keytruda in Japan. In South Korea, distribution of the product began on the 1st of this month.
The expansion of Keytruda SC sales directly correlates to additional licensing revenue for Alteogen. Alteogen has already received an initial $25 million sales milestone payment from MSD and stands to gain further milestone payments and royalties based on future sales performance.
Meanwhile, uncertainty surrounding the European patent dispute persists. A Dutch court recently granted Halozyme’s request for a preliminary injunction, restricting the manufacturing, sale, and import of Keytruda SC in eight European countries. Alteogen estimates the impact on its actual business in these regions to be approximately 3%, and notes that related patents have faced successive invalidation rulings in the United States.
The growth in Keytruda SC sales underscores the successful transition of Alteogen’s technology transfers into tangible financial returns. MSD’s official third-quarter earnings report is expected to provide further clarity on actual SC revenue and the pace of conversion from the traditional IV formulation.
