This section highlights FDA-related milestones and regulatory updates for drugs developed by Xilio Therapeutics (XLO).
Over the past two years, Xilio Therapeutics has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
vilastobart, XTX101, and XTX301. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Select a button below to view the list of FDA events for that drug.
Vilastobart FDA Regulatory Events
Vilastobart is a drug developed by Xilio Therapeutics for the following indication: In Patients with Microsatellite Stable Colorectal Cancer.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- vilastobart
- Announced Date:
- May 31, 2025
- Indication:
- In Patients with Microsatellite Stable Colorectal Cancer
Announcement
Xilio Therapeutics, Inc. announced updated data from its ongoing Phase 2 clinical trial evaluating vilastobart, a tumor-activated, Fc-enhanced, high affinity binding anti-CTLA-4, in combination with atezolizumab (Tecentriq®) in patients with metastatic MSS CRC.
AI Summary
Xilio Therapeutics, Inc. announced new data from its ongoing Phase 2 clinical trial evaluating vilastobart—a tumor-activated, Fc-enhanced, high affinity anti-CTLA-4 antibody—in combination with atezolizumab (Tecentriq®) for patients with metastatic microsatellite stable colorectal cancer (MSS CRC). The trial focuses on heavily pre-treated patients, with notable results observed in those without liver metastases, where a preliminary objective response rate of 26% was reported. Responses were deep and durable, lasting up to 37 weeks, and were supported by significant tumor biomarker decreases and symptom improvements.
The combination treatment also demonstrated a distinct safety and tolerability profile, showing a low incidence of colitis and other immune-related adverse events. These encouraging results highlight the potential of vilastobart paired with PD-(L)1 inhibitors, not only for addressing MSS CRC but also for a broader range of tumor types resistant to current immunotherapy options.
Read Announcement- Drug:
- vilastobart
- Announced Date:
- April 23, 2025
- Indication:
- In Patients with Microsatellite Stable Colorectal Cancer
Announcement
Xilio Therapeutics, Inc. announced plans to present updated data from its ongoing Phase 2 clinical trial investigating vilastobart, a tumor-activated, Fc-enhanced anti-CTLA-4, in combination with atezolizumab (Tecentriq®) in patients with metastatic microsatellite stable colorectal cancer (MSS CRC) at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting.
AI Summary
Xilio Therapeutics, Inc. is preparing to share updated data from its ongoing Phase 2 clinical trial at the 2025 American Society of Clinical Oncology Annual Meeting in Chicago. The trial is investigating vilastobart, a tumor-activated, Fc-enhanced anti-CTLA-4 antibody, combined with atezolizumab (Tecentriq®), in patients with metastatic microsatellite stable colorectal cancer (MSS CRC). Vilastobart is designed to specifically target the tumor environment by blocking CTLA-4 and depleting regulatory T cells, potentially enhancing anti-tumor effects while reducing side effects seen with standard treatments. This presentation will provide insights into how combining these two therapies could offer a new treatment option for advanced colorectal cancer, highlighting progress in efforts to develop more focused and effective immuno-oncology therapies.
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XTX101 FDA Regulatory Events
XTX101 is a drug developed by Xilio Therapeutics for the following indication: Solid Tumor.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- XTX101
- Announced Date:
- January 21, 2025
- Indication:
- Solid Tumor
Announcement
Xilio Therapeutics, Inc announced initial data from its ongoing Phase 2 clinical trial evaluating vilastobart (XTX101), a tumor-activated, Fc-enhanced, high affinity binding anti-CTLA-4, in combination with atezolizumab (Tecentriq®) in patients with metastatic microsatellite stable colorectal cancer (MSS CRC).
AI Summary
Xilio Therapeutics, Inc. announced encouraging initial results from its ongoing Phase 2 trial evaluating vilastobart (XTX101), a tumor-activated, Fc-enhanced anti-CTLA-4 antibody, in combination with atezolizumab (Tecentriq®) for patients with metastatic microsatellite stable colorectal cancer (MSS CRC). In patients without liver metastases, the trial showed a 27% preliminary response rate, with several partial responses that were accompanied by significant decreases in carcinoembryonic antigen (CEA) and circulating tumor DNA (ctDNA) levels and improvements in clinical symptoms. The data also highlighted a differentiated safety and tolerability profile, with a low incidence of immune-related adverse events. These results suggest that adding vilastobart may enhance the efficacy of PD-(L)1 inhibitors in a patient population that has historically shown resistance to immunotherapy. Xilio plans to present further data and follow-up results later this year.
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XTX301 FDA Regulatory Events
XTX301 is a drug developed by Xilio Therapeutics for the following indication: Solid tumors.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- XTX301
- Announced Date:
- December 19, 2024
- Indication:
- Solid tumors
Announcement
Xilio Therapeutics, Inc announced plans to present initial data from its ongoing Phase 2 trial for vilastobart (XTX101), a tumor-activated, Fc-enhanced, high affinity binding anti-CTLA-4, in combination with atezolizumab (Tecentriq®) in patients with metastatic microsatellite stable colorectal cancer (MSS CRC) at the ASCO Gastrointestinal (ASCO GI) Cancers Symposium in San Francisco, California from January 23-25, 2025.
AI Summary
Xilio Therapeutics, Inc. announced that it plans to share initial data from its ongoing Phase 2 trial for vilastobart (XTX101), a tumor-activated, Fc-enhanced, high affinity binding anti-CTLA-4 antibody. The trial is testing the combination of vilastobart with atezolizumab (Tecentriq®) in patients with metastatic microsatellite stable colorectal cancer (MSS CRC). This data will be presented at the ASCO Gastrointestinal (ASCO GI) Cancers Symposium, which will take place in San Francisco, California from January 23-25, 2025.
The presentation is expected to detail the clinical insights and potential benefits of the combination therapy in treating MSS CRC. This move underscores Xilio Therapeutics’ commitment to developing innovative immuno-oncology therapies aimed at improving outcomes for patients with challenging cancer types.
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