68% of rectal cancer patients achieve complete response, raising hopes for surgery-free treatment
Jemperli H1 sales rise 30%; SC trials targeting 378 patients scheduled
Alteogen’s (196170) global partner, GSK, has made a strategic breakthrough in the U.S. rectal cancer treatment market with its immuno-oncology drug, Jemperli. The U.S. Food and Drug Administration (FDA) granted approval based on clinical trial results showing complete responses—where all signs of cancer disappear in tests—in select rectal cancer patients without the need for surgery, chemotherapy, or radiotherapy. Next month, GSK is set to initiate global clinical trials applying Alteogen’s proprietary subcutaneous (SC) conversion technology.
On the 19th (local time), GSK announced that the FDA granted accelerated approval to Jemperli (generic name: dostarlimab) for the treatment of adult patients with recurrent or advanced mismatch repair-deficient (dMMR)/microsatellite instability-high (MSI-H) locally advanced rectal cancer. This marks the first time an immuno-oncology treatment has been approved for this specific patient population, whose genetic profile accounts for approximately 5% to 10% of all rectal cancer cases.
68% of Patients Show No Signs of Cancer for Over a Year, Opening Door to Surgery-Free Care
The approval is backed by data from 'AZUR-1,' a global Phase 2 clinical trial involving 154 rectal cancer patients. Participants received intravenous Jemperli every three weeks for roughly six months.
According to investigator assessments, 98 out of 144 evaluable patients (68%) maintained a complete response for 12 months or longer without undergoing surgery. Including patients in whom no cancer cells were detected in post-surgical biopsies, 110 individuals (76%) remained free of cancer evidence for over a year. Among patients responding to the treatment, no recurrences were reported during a median follow-up of 26.3 months.
Independent reviews showed that 54 of 116 patients (47%) maintained a cancer-free status for 12 months. An additional 38 patients also achieved complete responses and remain under ongoing follow-up.
Conventional rectal cancer treatment has historically relied on chemotherapy, radiation, and surgery, which often carry long-term complications such as bowel dysfunction, urinary and sexual issues, and infertility. Jemperli offers a novel alternative that allows select patients to bypass these invasive interventions.
"For decades, treatment has depended on chemotherapy, radiotherapy, and surgery," said Tony Wood, Chief Scientific Officer at GSK, highlighting the approval as a significant stride toward personalized patient care.
Severe adverse events occurred in 20% of patients during the trials, with a permanent treatment discontinuation rate of 3%. The FDA granted accelerated approval under the condition that long-term clinical benefits are further verified.
Jemperli Sales Surge 30%; Alteogen’s SC Trials Awaiting in November
According to GSK, Jemperli sales in the first half of the year reached £480 million, a 30% increase year-on-year. Second-quarter sales also grew 27% to £248 million. Having expanded primarily on the back of endometrial cancer indications, Jemperli’s move into rectal cancer opens additional avenues for revenue growth.
In January, Alteogen entered into an exclusive licensing agreement with GSK subsidiary Tesaro for the development and commercialization of a subcutaneous formulation of Jemperli.
The contract is valued at up to $285 million (approx. 420 billion KRW), comprising an upfront payment of $20 million and up to $265 million in developmental, regulatory, and commercial milestones. Following commercialization, Alteogen will also receive tiered royalties on product sales.
Alteogen’s core technology, 'ALT-B4,' is a proprietary platform designed to convert conventional intravenous (IV) cancer therapies into subcutaneous injections, reducing administration time and significantly enhancing patient convenience.
According to the U.S. clinical trials registry ClinicalTrials.gov, GSK is scheduled to launch 'SAPPHIRE (NCT07860450),' a global clinical trial for the Jemperli SC formulation, on November 12.
[Source: ClinicalTrials.gov, Phase 1b/3 trial design for GSK Jemperli subcutaneous (SC) formulation]
The trial plans to enroll 378 patients with advanced or recurrent endometrial cancer. The Phase 1b portion will determine the optimal dose, while the Phase 3 study will compare drug absorption, therapeutic efficacy, and safety against the conventional intravenous formulation. The primary completion date is projected for November 2030.
The recent FDA approval applies to the existing intravenous formulation and is independent of the authorization for the SC product utilizing Alteogen's technology. Furthermore, the upcoming SC trials are targeting endometrial cancer patients rather than those with rectal cancer.
Alteogen is already supplying its ALT-B4 technology for MSD’s Keytruda SC. With development expanding to include Jemperli, the global reach of its technology platform within the immuno-oncology market continues to broaden.
