Xilio Therapeutics Announces Initiation of Phase 2 Trial for Efarindodekin Alfa (XTX301), a Tumor-Activated IL-12, and Achievement of $17.5 Million Development Milestone Under Exclusive License Agreement with Gilead
Xilio Therapeutics (NASDAQ:XLO) has initiated Phase 2 patient dosing for efarindodekin alfa (XTX301), a tumor-activated IL-12 therapy for advanced solid tumors. The company has also achieved a $17.5 million development milestone under its exclusive license agreement with Gilead Sciences.
Phase 1 data showed promising results with two partial responses in late-line patients and a generally well-tolerated safety profile. The company has selected the recommended Phase 2 dose (RP2D) based on these encouraging results. The therapy demonstrated sustained interferon gamma signaling without tachyphylaxis throughout treatment cycles.
Financially, Xilio reported cash and cash equivalents of $121.6 million as of June 30, 2025. With the additional milestone payment, the company expects to fund operations into Q1 2027.
Xilio Therapeutics (NASDAQ:XLO) ha avviato la somministrazione ai pazienti in Fase 2 di efarindodekin alfa (XTX301), una terapia a base di IL-12 attivata nel tumore per neoplasie solide avanzate. L'azienda ha inoltre raggiunto un traguardo di sviluppo da 17,5 milioni di dollari nell'ambito dell'accordo di licenza esclusiva con Gilead Sciences.
I dati di Fase 1 hanno mostrato risultati promettenti, con due risposte parziali in pazienti trattati in linee tardive e un profilo di sicurezza generalmente ben tollerato. Sulla base di questi dati, è stata selezionata la dose raccomandata per la Fase 2 (RP2D). La terapia ha dimostrato una segnalazione sostenuta di interferone gamma senza tachifilassi durante i cicli di trattamento.
Sul piano finanziario, Xilio ha riportato liquidità e mezzi equivalenti per 121,6 milioni di dollari al 30 giugno 2025. Con il pagamento del milestone aggiuntivo, la società prevede di finanziare le operazioni fino al 1° trimestre 2027.
Xilio Therapeutics (NASDAQ:XLO) ha comenzado la dosificación de pacientes en Fase 2 con efarindodekin alfa (XTX301), una terapia de IL-12 activada en el tumor para tumores sólidos avanzados. La compañía también alcanzó un hito de desarrollo de 17,5 millones de dólares en su acuerdo de licencia exclusiva con Gilead Sciences.
Los datos de Fase 1 mostraron resultados prometedores, con dos respuestas parciales en pacientes de líneas tardías y un perfil de seguridad generalmente bien tolerado. Con base en estos resultados, se ha seleccionado la dosis recomendada para Fase 2 (RP2D). La terapia demostró una señalización sostenida de interferón gamma sin taquifilaxia a lo largo de los ciclos de tratamiento.
En cuanto a lo financiero, Xilio informó efectivo y equivalentes por 121,6 millones de dólares al 30 de junio de 2025. Con el pago adicional del hito, la compañía espera financiar sus operaciones hasta el 1er trimestre de 2027.
Xilio Therapeutics (NASDAQ:XLO)는 진행성 고형암을 위한 종양 활성화형 IL-12 치료제 efarindodekin alfa (XTX301)의 2상 환자 투약을 시작했습니다. 또한 Gilead Sciences와의 독점 라이선스 계약에 따라 1,750만 달러 규모의 개발 마일스톤을 달성했습니다.
1상 데이터는 말기 환자에서 2건의 부분 반응과 전반적으로 양호한 내약성을 보여 유망한 결과를 제시했습니다. 이를 바탕으로 권장 2상 용량(RP2D)이 선정되었습니다. 치료 동안 인터페론 감마 신호가 지속되었고 태크피락시(탈감작)는 관찰되지 않았습니다.
재무적으로 Xilio는 2025년 6월 30일 기준으로 현금 및 현금성 자산 1억2,160만 달러를 보고했습니다. 추가 마일스톤 지급으로 회사는 2027년 1분기까지 운영 자금을 확보할 것으로 예상하고 있습니다.
Xilio Therapeutics (NASDAQ:XLO) a lancé la mise en traitement des patients en phase 2 avec efarindodekin alfa (XTX301), une thérapie à base d'IL-12 activée au niveau de la tumeur pour les tumeurs solides avancées. La société a également atteint un jalon de développement de 17,5 millions de dollars dans le cadre de son accord de licence exclusive avec Gilead Sciences.
Les données de phase 1 ont montré des résultats prometteurs, avec deux réponses partielles chez des patients en ligne tardive et un profil de sécurité globalement bien toléré. Sur la base de ces résultats, la dose recommandée pour la phase 2 (RP2D) a été sélectionnée. La thérapie a démontré une signalisation soutenue de l'interféron gamma sans tachyphylaxie au cours des cycles de traitement.
Sur le plan financier, Xilio a déclaré 121,6 millions de dollars en liquidités et équivalents au 30 juin 2025. Avec le paiement supplémentaire du jalon, la société prévoit de financer ses opérations jusqu'au 1er trimestre 2027.
Xilio Therapeutics (NASDAQ:XLO) hat mit der Patientenbehandlung in Phase 2 für efarindodekin alfa (XTX301) begonnen, eine tumoraktivierte IL-12-Therapie für fortgeschrittene solide Tumoren. Das Unternehmen hat außerdem eine Entwicklungsmeilensteinzahlung in Höhe von 17,5 Millionen US-Dollar im Rahmen der exklusiven Lizenzvereinbarung mit Gilead Sciences erreicht.
Die Daten aus Phase 1 zeigten vielversprechende Ergebnisse mit zwei partiellen Remissionen bei Patienten in späten Therapielinien und einem insgesamt gut verträglichen Sicherheitsprofil. Basierend auf diesen Ergebnissen wurde die empfohlene Phase-2-Dosis (RP2D) festgelegt. Die Therapie zeigte während der Behandlungszyklen anhaltende Interferon-gamma-Signalisierung ohne Tachyphylaxe.
Finanziell meldete Xilio Barmittel und Zahlungsmitteläquivalente in Höhe von 121,6 Millionen US-Dollar zum 30. Juni 2025. Mit der zusätzlichen Meilensteinzahlung rechnet das Unternehmen damit, die Geschäftstätigkeit bis ins 1. Quartal 2027 finanzieren zu können.
- Achievement of $17.5 million development milestone from Gilead partnership
- Two partial responses observed in Phase 1 trials for advanced solid tumors
- Generally well-tolerated safety profile with majority of adverse events being Grade 1 or 2
- Extended cash runway into Q1 2027 with current $121.6M cash position
- Successful advancement to Phase 2 clinical trials indicating promising drug development progress
- Phase 1A trial results are still under ongoing evaluation
- Drug efficacy and safety have not been established by regulatory agencies
Insights
Xilio's tumor-activated IL-12 shows promising Phase 1 results, advances to Phase 2, triggering $17.5M milestone from Gilead.
Xilio Therapeutics has reached a significant clinical milestone with efarindodekin alfa (XTX301), their tumor-activated IL-12 therapy, by initiating the Phase 2 portion of their Phase 1/2 trial. The advancement follows promising Phase 1 data that demonstrated encouraging anti-tumor activity, including two partial responses in late-line patients with advanced solid tumors. This progress validates Xilio's proprietary masking technology that aims to activate immunotherapies specifically within tumors while minimizing systemic toxicity.
The preliminary efficacy signals are particularly noteworthy given IL-12's historically challenging safety profile. Xilio reports that at dose levels up to the recommended Phase 2 dose, efarindodekin alfa has been generally well-tolerated with most treatment-related adverse events being Grade 1 or 2 - a significant achievement for an IL-12 therapy. The observed sustained interferon gamma signaling without tachyphylaxis (diminishing response) throughout treatment cycles suggests durable immunologic activity.
From an immunotherapy development perspective, IL-12 represents a compelling cytokine target due to its potential to convert immunologically "cold" tumors to "hot" ones by reprogramming the tumor microenvironment. This approach could address a fundamental limitation of current immunotherapies that often fail in non-inflamed tumors. The progress of efarindodekin alfa provides further validation for tumor-activated approaches that may unlock the potential of potent immunomodulatory agents previously limited by systemic toxicities.
Xilio's achievement of the
The Gilead partnership, initially formed in March 2024, provides Xilio with a strong commercialization pathway for their IL-12 program. This milestone achievement indicates that program development is proceeding according to plan, potentially unlocking additional future milestone payments. The advancement to Phase 2 typically represents a key value inflection point for clinical-stage biotech companies, as it begins to de-risk the clinical development pathway.
For a clinical-stage biotech like Xilio, this milestone is particularly meaningful as it: 1) provides non-dilutive capital, 2) validates their platform technology, and 3) demonstrates productive advancement of their pipeline. While specific terms of additional milestone payments weren't disclosed, development partnerships typically include escalating payments as programs advance through clinical stages and regulatory approval. With cash runway now extending into Q1 2027, Xilio has sufficient capital to potentially reach additional value-creating milestones without immediate financing pressure.
Phase 1 data for efarindodekin alfa (XTX301) demonstrate promising anti-tumor activity in patients with advanced solid tumors
Achievement of milestone extends anticipated cash runway into first quarter of 2027
WALTHAM, Mass., Sept. 09, 2025 (GLOBE NEWSWIRE) -- Xilio Therapeutics, Inc. (Nasdaq: XLO), a clinical-stage biotechnology company discovering and developing tumor-activated immuno-oncology therapies for people living with cancer, today announced the initiation of patient dosing in Phase 2 of an ongoing Phase 1/2 clinical trial evaluating efarindodekin alfa (XTX301), a tumor-activated IL-12, as a monotherapy in patients with certain advanced solid tumors. In addition, today Xilio announced the achievement of a
“We are pleased to announce the initiation of the Phase 2 clinical trial for efarindodekin alfa (XTX301), a tumor-activated IL-12, in patients with advanced solid tumors,” said René Russo, Pharm.D., president and chief executive officer of Xilio. “The achievement of this important milestone highlights the promising Phase 1 data demonstrated for efarindodekin alfa to date, including two partial responses in late-line patients with advanced solid tumors and a generally well-tolerated safety profile. These data also provide further clinical validation for our proprietary masking technology and approach, which we believe is best-in-class and has potential across a wide range of therapies and modalities.”
“We are encouraged by the totality of data observed to date for efarindodekin alfa (XTX301) as a monotherapy in patients with advanced solid tumors, and we are excited for the potential that IL-12 has to treat a broad range of tumor types,” said Bernard Fine, vice president, oncology early development at Gilead. “We look forward to advancing the efarindodekin alfa (XTX301) program in the Phase 2 trial in partnership with Xilio.”
Efarindodekin alfa (XTX301): tumor-activated IL-12
Efarindodekin alfa (XTX301) is an investigational tumor-activated IL-12 designed to potently stimulate anti-tumor immunity and reprogram the tumor microenvironment (TME) of poorly immunogenic “cold” tumors towards an inflamed or “hot” state. In March 2024, Xilio entered into an exclusive license agreement with Gilead related to Xilio’s tumor-activated IL-12 program, including efarindodekin alfa. Xilio is evaluating efarindodekin alfa as a monotherapy in an ongoing Phase 1/2 clinical trial in patients with advanced solid tumors.
- As of a data cutoff date of September 2, 2025, at dose levels up to the recommended Phase 2 dose (RP2D), efarindodekin alfa has been generally well-tolerated in Phase 1, and the majority of treatment-related adverse events were Grade 1 or 2.
- In Phase 1, as of the data cutoff date, efarindodekin alfa has also demonstrated encouraging anti-tumor activity, including two partial responses in patients with advanced solid tumors (one confirmed, one unconfirmed), as well as sustained interferon gamma (IFNɣ) signaling without evidence of tachyphylaxis throughout treatment cycles.
- Based on these promising Phase 1 data, Xilio recently selected an initial RP2D and schedule for efarindodekin alfa and initiated patient dosing in the Phase 2 portion of the trial evaluating efarindodekin alfa as a monotherapy in patients with certain advanced solid tumors. In connection with the initiation of Phase 2, Xilio achieved a development milestone of
$17.5 million .
- Xilio recently completed enrollment in Phase 1A monotherapy dose escalation and evaluation of those patients is ongoing. In addition, Xilio continues to enroll patients in the Phase 1B monotherapy dose expansion portion of the ongoing Phase 1/2 clinical trial of efarindodekin alfa.
Efarindodekin alfa has not been approved by any regulatory agency and its efficacy and safety have not been established.
Financial Guidance
As of June 30, 2025, Xilio had cash and cash equivalents of
About the Gilead License Agreement
In March 2024, Xilio entered into an exclusive global license agreement with Gilead to develop and commercialize efarindodekin alfa (XTX301), a tumor-activated IL-12, and specified other molecules directed to IL-12.
Xilio is responsible for conducting clinical development for efarindodekin alfa through the initial Phase 2 portion of the ongoing Phase 1/2 clinical trial. Following the delivery by Xilio of a specified clinical data package for efarindodekin alfa related to the Phase 1/2 clinical trial, Gilead can elect to transition responsibilities for the development and commercialization of efarindodekin alfa to Gilead, subject to the terms of the license agreement and payment by Gilead of a
If Gilead exercises its option for efarindodekin alfa, Xilio will be eligible to receive up to
About Efarindodekin Alfa (XTX301) and the Phase 1/2 Clinical Trial
Efarindodekin alfa (XTX301) is an investigational masked IL-12 designed to potently stimulate anti-tumor immunity and reprogram the tumor microenvironment (TME) of poorly immunogenic “cold” tumors towards an inflamed or “hot” state. In March 2024, Xilio entered into an exclusive license agreement with Gilead Sciences, Inc. for Xilio’s tumor-activated IL-12 program, including efarindodekin alfa. Xilio is currently evaluating the safety and tolerability of efarindodekin alfa as a monotherapy in patients with advanced solid tumors in the Phase 1 portion of a first-in-human, multi-center, open-label Phase 1/2 clinical trial and the safety and efficacy of efarindodekin alfa as a monotherapy in the Phase 2 portion in patients with advanced solid tumors. The Phase 2 portion of the trial is anticipated to enroll approximately 40 patients in specific tumor types at multiple sites in the United States. Please refer to NCT05684965 on www.clinicaltrials.gov for additional details.
About Xilio Therapeutics
Xilio Therapeutics is a clinical-stage biotechnology company discovering and developing tumor-activated, or masked, immuno-oncology (I-O) therapies with the goal of significantly improving outcomes for people living with cancer without the systemic side effects of current I-O treatments. The company is leveraging its proprietary platform to advance a pipeline of novel, tumor-activated I-O molecules that are designed to optimize the therapeutic index by localizing anti-tumor activity within the tumor microenvironment. Learn more by visiting www.xiliotx.com and follow us on LinkedIn (Xilio Therapeutics, Inc.).
Cautionary Note Regarding Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, without limitation, statements regarding plans, expectations, development timelines and anticipated milestones for Xilio’s programs; the timing of data releases or program updates; the timing and receipt of future payments under Xilio’s collaboration with Gilead; the potential benefits of efarindodekin alfa in any indication; the sufficiency of, and the period in which Xilio expects to have, cash to fund its operations; and Xilio’s strategy, goals and anticipated financial performance, milestones, business plans and focus. The words “aim,” “may,” “will,” “could,” “would,” “should,” “expect,” “plan,” “anticipate,” “intend,” “believe,” “estimate,” “predict,” “project,” “potential,” “continue,” “seek,” “target” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Any forward-looking statements in this press release are based on management’s current expectations and beliefs and are subject to a number of important risks, uncertainties and other factors that may cause actual events or results to differ materially from those expressed or implied by any forward-looking statements contained in this press release, including, without limitation, risks related to general market conditions and geopolitical uncertainties; risks and uncertainties related to ongoing and planned research and development activities, including initiating, conducting or completing preclinical studies and clinical trials and the timing and results of such preclinical studies or clinical trials; the delay of any current or planned preclinical studies or clinical trials or the development of Xilio’s current or future product candidates; Xilio’s ability to obtain and maintain sufficient preclinical and clinical supply of current or future product candidates; Xilio’s ability to advance multiple early stage masked T cell engager programs; initial, preliminary or interim preclinical or clinical data or results may not be replicated in or predictive of future preclinical or clinical data or results; Xilio’s ability to successfully demonstrate the safety and efficacy of its product candidates and gain approval of its product candidates on a timely basis, if at all; results from preclinical studies or clinical trials for Xilio’s product candidates may not support further development of such product candidates; actions of regulatory agencies may affect the initiation, timing and progress of current or future clinical trials; Xilio’s ability to obtain, maintain and enforce patent and other intellectual property protection for current or future product candidates; Xilio’s need to obtain additional cash resources to advance its pipeline of tumor-activated I-O molecules; the impact of international trade policies on Xilio’s business, including U.S. and China trade policies; and Xilio’s ability to maintain its collaboration or partnership agreements with AbbVie, Gilead and Roche. These and other risks and uncertainties are described in greater detail in the sections entitled “Risk Factor Summary” and “Risk Factors” in Xilio’s filings with the U.S. Securities and Exchange Commission (“SEC”), including Xilio’s most recent Quarterly Report on Form 10-Q and any other filings that Xilio has made or may make with the SEC in the future. Any forward-looking statements contained in this press release represent Xilio’s views only as of the date hereof and should not be relied upon as representing its views as of any subsequent date. Except as required by law, Xilio explicitly disclaims any obligation to update any forward-looking statements.
This press release contains hyperlinks to information that is not deemed to be incorporated by reference in this press release.
Investor Contact
investors@xiliotx.com
Media Contact
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1AB
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FAQ
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