Sun Pharma's Fibromun and Nidlegy Face Mixed Clinical Trial Results in Cancer Studies
Key Insights
Sun Pharma's partner Philogen (search) reported that Phase II trials for Fibromun in soft tissue sarcoma and glioblastoma failed to meet primary endpoints, though survival improvements were observed in select patient subgroups.
Despite setbacks, the company is advancing toward Phase III registrational trials for Fibromun, with FIBROSARC-2 study design being finalized through FDA and EMA scientific advice.
Nidlegy demonstrated stronger clinical progress in skin cancers, with 52.60% complete pathological response rates in basal cell carcinoma and multiple registrational studies planned for 2026.
Sun Pharmaceutical Industries has encountered significant challenges in its oncology pipeline as two key drug candidates, Fibromun and Nidlegy, delivered mixed results across multiple Phase II clinical trials. The updates, disclosed through partner Philogen (search)'s financial results, reveal both setbacks and opportunities as the company navigates complex cancer indications with high unmet medical needs.
Fibromun Trials Miss Primary Endpoints
The Phase II FLASH study in advanced soft tissue sarcoma failed to demonstrate efficacy for Fibromun combined with dacarbazine. The randomized trial enrolled 94 patients who received either the combination therapy or dacarbazine alone, but did not meet its primary endpoint of progression-free survival. Sun Pharma acknowledged that pretreated soft tissue sarcoma remains a highly challenging disease area.
Similarly, the Phase II GLIOSTAR trial in second-line glioblastoma patients fell short of expectations. The study, which enrolled 163 patients, did not achieve its primary endpoint. However, researchers observed survival improvements in a subgroup of patients with limited prior exposure to alkylating agents, providing insights for future study designs.
Despite these disappointing results, Sun Pharma emphasized ongoing progress in glioblastoma research. The GLIOSUN trial in treatment-naïve patients has completed its dose escalation phase and is advancing into dose expansion. The GLIOSTELLA study targeting late-line glioblastoma patients in the United States has completed enrollment and is expected to report survival data by September 2026.
Path Forward for Fibromun Development
Encouraging survival signals from the FIBROSARC study in first-line soft tissue sarcoma, particularly in patients with liposarcoma and other sarcoma types, have prompted plans for a new Phase III registrational trial. The company has submitted requests for parallel scientific advice from both the US FDA and European Medicines Agency to finalize the design of FIBROSARC-2, with overall survival as the primary endpoint.
The conclusion of this regulatory guidance process is expected in the second quarter of 2026, setting the stage for what could be a pivotal registration-enabling study for Fibromun in soft tissue sarcoma.
Nidlegy Shows Promise in Skin Cancer Applications
In contrast to Fibromun's challenges, Nidlegy has demonstrated more encouraging clinical progress across multiple skin cancer indications. Following the withdrawal of its earlier melanoma application in Europe, Sun Pharma is preparing a fresh regulatory submission to the EMA in 2026.
The Phase II Duncan study in basal cell carcinoma and cutaneous squamous cell carcinoma has generated particularly compelling results. Data presented at the European Society for Medical Oncology 2025 conference showed complete pathological responses in 52.60% of basal cell carcinoma patients, representing a significant clinical achievement.
The ongoing Phase II Intrinsic study has treated 65 of its target 70 patients across Italy and France, focusing on various forms of non-melanoma skin cancer. These positive results have provided strong rationale for initiating three new registrational studies in basal cell carcinoma and cutaneous squamous cell carcinoma across Europe and the United States.
Regulatory Alignment and Future Studies
A significant milestone was achieved when Sun Pharma held a Type C meeting with the US FDA regarding Nidlegy's melanoma indication. During this meeting, data from European studies were presented, and alignment was reached on the regulatory pathway for obtaining approval in the United States, subject to completion and positive outcomes of ongoing studies.
The company has outlined a comprehensive regulatory strategy with specific timelines. Enrollment of first patients in new registrational studies is expected in the second quarter of 2026. Additionally, scientific advice with the FDA has been completed to define a fourth registrational study in first-line basal cell carcinoma, comparing Nidlegy's performance with Hedgehog pathway inhibitors, with study initiation expected in mid-2026.
Strategic Commitment Despite Challenges
Sun Pharma emphasized its continued commitment to advancing innovative therapies despite the challenges encountered in complex disease areas. The company's approach reflects the inherent difficulties of oncology drug development, where high unmet medical needs often coincide with challenging clinical endpoints and heterogeneous patient populations.
The mixed results from these Phase II studies underscore both the promise and perils of cancer drug development, with Fibromun facing hurdles in its current indications while Nidlegy demonstrates clear potential in skin cancer applications. As both programs advance toward potential registrational studies, the coming years will be critical in determining their ultimate commercial and clinical success.