Healthcare Stocks Update: Concord Medical Services Leads Gainers, XORTX Therapeutics Declines

Several health care stocks moved significantly in the after-market session on Friday. Concord Medical Services increased by 24.9% to $6.63, while Tempest Therapeutics rose by 10.54% to $11.21. Atara Biotherapeutics stock increased by 9.92% to $16.28. However, XORTX Therapeutics decreased by 20% to $0.88, and Synlogic declined by 12.57% to $1.6.

Several health care stocks experienced significant movements in the after-market session on Friday, September 12, 2025. Among the notable performers, Concord Medical Services increased by 24.9% to $6.63, Tempest Therapeutics rose by 10.54% to $11.21, and Atara Biotherapeutics stock increased by 9.92% to $16.28. However, XORTX Therapeutics decreased by 20% to $0.88, and Synlogic declined by 12.57% to $1.6.

The most significant movement was seen in XORTX Therapeutics, which surged by 40% intraday on October 17, 2025, peaking just above $1.20 before closing up ~21% for the day around the mid-$1 range, according to a TS2 Tech article. This surge came on unusually heavy trading volume of about 7 million shares, far above its ~44,000 three-month daily average . Despite the rally, XRTX remains down ~25% year-to-date and ~55% over the past 12 months . The stock jump was triggered by XORTX’s announcement of a deal to acquire a new kidney disease drug program . The company is buying the renal anti-fibrotic therapeutic program “VB4-P5” from Australia’s Vectus Biosystems for $3 million, to be paid in XRTX shares (at a deemed price of ~$0.86 each) .

The acquisition of VB4-P5, which aims to treat kidney fibrosis (organ scarring) in both rare and common kidney diseases, was hailed as a highly compelling opportunity by XORTX’s CEO, Dr. Allen Davidoff . Kidney fibrosis is a key driver of chronic kidney disease progression, and currently, no approved therapies exist to reverse or directly treat such scarring . Early preclinical data for VB4-P5 show promise in inhibiting and potentially reversing kidney fibrosis, and the compound has broad patent protection across 30+ countries . The acquisition sparked optimism that XORTX could tap into a multi-billion-dollar kidney disease market if the drug succeeds .

However, experts caution that VB4-P5 is still at an early stage and will require clinical trials and regulatory approvals before any potential FDA green light . The $3M stock-based payment will also dilute shareholders, a common risk as the company raises funds for R&D. In short, while the news is encouraging, investors should temper excitement with the understanding that significant hurdles remain.

XORTX’s surge comes amid a mixed backdrop for biotech stocks. U.S. biopharma shares have struggled in recent months and are trading at historically low valuations , as rising interest rates and risk-off sentiment made funding harder for small caps. This means positive catalysts now stand out even more – in fact, several small biotechs saw outsized gains in the same week on favorable news .