Investing.com -- China's healthcare sector declined 1.3% this week, underperforming the Hang Seng Index which fell 1.7%, as regulators in both the U.S. and China announced plans to increase oversight of licensing agreements.

The sector is down 8.1% year-to-date, compared to a 1.7% decline in the Hang Seng Index. Contract development and manufacturing organizations and biotechnology companies have outperformed, rising 7.0% and 6.7% respectively.

The ASCO conference is scheduled to run from Friday through June 2.

Chinese regulators have tightened rules governing online prescription drug sales, now requiring licensed pharmacist-led reviews of artificial intelligence systems and real-name authentication of buyers.

Hengrui's HRS-7535, an oral GLP-1 agonist for type 2 diabetes co-developed with Kailera, achieved HbA1c reductions of up to 1.68% at week 32 in a phase III trial in China.

Sentiment weakened following U.S. proposals to include biotechnology in the COINS Act. If passed, the legislation could prohibit or require review of U.S. investments in Chinese biotechnology companies, potentially affecting equity, mergers and acquisitions, and new company deals.

Despite regulatory concerns, Chinese biopharmaceutical companies continued securing deals with multinational corporations. Innovent and Pfizer signed a $10.5 billion collaboration agreement, including $650 million upfront and milestone payments up to $9.85 billion. The deal covers 12 oncology programs, with eight Innovent-originated early stage assets licensed to Pfizer and four programs in a co-development structure.

WuXi Bio secured a five-year commercial supply contract with U.S. biotechnology company Viridan Therapeutics (NASDAQ: VRDN) as a major non-exclusive supplier for veligrotug, an IF-1R antibody for thyroid eye disease.

Pharmaron committed approximately 3.0 billion yuan to construct a facility in Shaoxing to expand its intermediates and active pharmaceutical ingredients capacity.

Medtide's subsidiary Zhongtai Biochem received an FDA acknowledgment letter for DMF registration of the tirzepatide active pharmaceutical ingredient.