FIBROSARC (NCT04650984) is a Phase III trial evaluating Onfekafusp alfa (L19TNF, also known as Fibromun) plus doxorubicin versus doxorubicin alone as front-line therapy for patients with advanced or metastatic Soft Tissue Sarcoma

An Independent Data and Safety Monitoring Board reviewed safety and efficacy data of the pre-planned interim analysis and recommended continuing the study as planned by the protocol

L19TNF is also currently studied in pivotal trials for the treatment of newly diagnosed and recurrent Glioblastoma, for which very encouraging data have recently been published

SIENA, Italy I February 20, 2024 I Philogen S.p.A. (BIT:PHIL) is pleased to announce that the Phase III FIBROSARC trial (NCT04650984) will continue as planned by the protocol. The decision was made by an Independent Data and Safety Monitoring Board (DSMB) following the review of efficacy and safety data in the pre-planned interim analysis.

FIBROSARC is a Phase III 1:1 randomized trial (NCT04650984) which studies L19TNF in combination with doxorubicin (Experimental Arm) versus doxorubicin alone (Control Arm) in 118 patients as first-line therapy for advanced or metastatic Soft Tissue Sarcoma (STS). The primary objective of the study is Progression Free Survival (PFS), with an estimated 45% reduction in the risk of progression in the Experimental Arm (Hazard Ratio 0.55). The pre-planned interim analysis was carried out at 50% of the expected events (i.e., one event corresponds to a disease progression or death) necessary for the primary outcome.

The 46 events required to trigger the interim analysis were reached on 9th November 2023, and at the time of this Press Release the study has enrolled 97 out of 118 patients across 24 clinical centers in Germany, Italy, France, Poland, and Spain. The enrolment of 118 patients is expected to be completed in 2024.

Prof. Dario Neri, co-founder, CEO and CSO of Philogen, commented: “We are very pleased with the recommendation of the DSMB to continue the study as planned by the protocol. The Phase III FIBROSARC trial was designed to demonstrate a significant clinical benefit of L19TNF plus doxorubicin compared to doxorubicin alone. If the final analysis is successful, the study is expected to provide an innovative treatment option for patients with advanced or metastatic STS, for whom no new paradigm-shifting therapies have been available in the last decades.”

Alfredo Covelli, MD, Chief Medical Officer of Philogen, commented: “Advanced or metastatic STS are aggressive tumors still treated with chemotherapy-based regimens that were approved in the 1970s. Most innovative therapies, such as immune checkpoint inhibitors, failed to provide a significant benefit to this patient population. We are excited to record the outcome of the interim analysis of FIBROSARC and look forward to seeing the final analysis.”

L19TNF is also being evaluated in (i) a Phase IIb randomized trial in first-line metastatic Leiomyosarcoma in the United States (NCT03420014), (ii) a Phase II randomized trial in pre-treated advanced or metastatic Soft Tissue Sarcoma in Europe (NCT04733183), (iii) a Phase II randomized trial in Glioblastoma at first progression in Europe (NCT04573192), and (iv) a Phase I/II/IIb trial in newly diagnosed Glioblastoma in Europe (NCT04443010). Philogen is currently launching a new Phase II study in Glioblastoma at first or later progression in the United States, based on the very encouraging preliminary data observed in the European study. These results have already been published in the journal Science Translational Medicine in 2023 (Look at al. Sci. Trans. Med. 2023, 15:eadf2281).

For more information about Onfekafusp alfa (also known as Fibromun), FIBROSARC Phase III study (NCT04650984), Soft Tissue Sarcoma, and Philogen, please visit

SOURCE: Philogen