Sun Pharmaceutical faces regulatory pause as EMA application for melanoma drug withdrawn

Why Sun Pharmaceutical’s European skin cancer drug launch has been delayed after Philogen’s EMA withdrawal for Nidlegy

Sun Pharmaceutical Industries Limited (NSE: SUNPHARMA, BSE: 524715) confirmed that its partner, the Italian-Swiss oncology-focused drugmaker Philogen S.p.A. (BIT: PHIL), has voluntarily withdrawn the Marketing Authorization Application (MAA) for Nidlegy from the European Medicines Agency (EMA). The investigational therapy was being evaluated for use as a neoadjuvant treatment in adult patients with locally advanced, fully resectable melanoma.

Nidlegy is one of the most advanced immuno-oncology products in Sun Pharmaceutical Industries Limited’s European portfolio, developed through a licensing agreement with Philogen for distribution rights across Europe, New Zealand, and Australia. The setback comes nearly one year after the initial submission of the MAA in June 2024, based on data from a pivotal Phase 3 trial.

Why was the EMA application for Nidlegy withdrawn despite positive Phase 3 clinical trial results?

According to Philogen’s June 24, 2025 statement, the decision to withdraw the application was driven by timing constraints in fulfilling critical regulatory requirements, particularly those involving Chemistry Manufacturing and Controls (CMC) documentation and supplementary clinical datasets. These were deemed essential for EMA to complete its benefit-risk assessment, but would not be ready within the timeframe mandated under current regulatory review processes.

Although the trial results demonstrated a statistically significant and clinically meaningful reduction in risk of relapse or death, Philogen noted that a more robust submission with additional supportive data would improve the drug’s approval prospects. The melanoma therapy was originally supported by data from the PIVOTAL Phase 3 trial (NCT02938299), which showed a 41% reduction in relapse or death risk in the Nidlegy arm compared to standard surgery alone. The results were published in the Journal of Clinical Oncology in 2024 and accepted for publication in Annals of Oncology in 2025.

What kind of drug is Nidlegy and how does its mechanism target skin cancer?

Nidlegy, also known by its development code Daromun, is a biopharmaceutical product that combines two independently manufactured cytokine fusion proteins—L19IL2 and L19TNF—which are mixed before administration and injected directly into tumors. The therapy leverages a proprietary targeting system involving the L19 antibody, which binds to the Extra Domain B of fibronectin, a protein commonly overexpressed in tumor environments but absent in healthy tissue.

The active agents—Interleukin 2 (IL2) and Tumor Necrosis Factor (TNF)—are pro-inflammatory cytokines designed to provoke a strong immune response against the tumor mass. Nidlegy’s intratumoral delivery method is central to its mechanism, allowing the therapeutic payload to concentrate on the tumor site with minimal systemic exposure. This contributes to its tolerability profile, which has been characterized primarily by low-grade, localized side effects.

What did the Phase 3 trial reveal about Nidlegy’s performance in resectable melanoma?

The pivotal study was a multinational, randomized, comparator-controlled trial involving 256 patients with locally advanced, fully resectable cutaneous, subcutaneous, or nodal metastases. Conducted across 22 clinical sites in Germany, Italy, France, and Poland, the trial evaluated the efficacy of up to four weekly intratumoral injections of Nidlegy prior to surgical resection, followed by adjuvant therapy as per standard guidelines.

In comparison to surgery alone, the addition of Nidlegy demonstrated a substantial improvement in disease-free survival, which is particularly notable given the absence of approved neoadjuvant therapies for this specific melanoma subset. Institutional investors and clinical researchers have viewed the study’s outcome as a potential paradigm shift, although regulatory readiness remains a key hurdle.

How does this regulatory delay affect Sun Pharmaceutical’s European oncology strategy?

For Sun Pharmaceutical Industries Limited, the delay represents a significant pause in its specialty pipeline commercialization roadmap for Europe. However, analysts suggest the impact is moderate in the short term due to the therapy’s still-developing regulatory profile and the broader spread of the company’s global dermatology and oncology revenues.

The Indian pharma firm had positioned Nidlegy as a future differentiator in the underpenetrated neoadjuvant melanoma therapy space. Its geographic rights outside Europe, New Zealand, and Australia are unaffected by this development, preserving optionality for additional regulatory pathways in North America or Asia in the future.

Still, the EMA withdrawal halts momentum in a key market where Sun Pharmaceutical Industries Limited has been actively expanding its specialty drug offerings via partnerships and acquisitions.

What is the future outlook for Nidlegy resubmission and regulatory approval?

Philogen CEO and CSO, Prof. Dr. Dario Neri, noted that the withdrawal should be viewed as a proactive regulatory reset rather than a failure. The oncology-focused drugmaker intends to resubmit the MAA with the complete set of requested documentation. No explicit timeline has been provided, but institutional observers expect a re-filing within the next 12 to 18 months, contingent on completion of manufacturing validation and updated trial reporting.

Despite the regulatory delay, Philogen has reiterated its belief in Nidlegy’s clinical utility. The treatment has already been administered to over 450 patients across multiple skin cancer subtypes, including high-risk basal cell carcinoma and other non-melanoma forms currently under Phase 2 evaluation. This broader dataset could support the drug’s profile in future filings.

How are investors reacting to the withdrawal and what does it mean for future filings?

Investor sentiment toward Philogen remained relatively stable in the immediate aftermath of the announcement, reflecting confidence that the drug will eventually return to the EMA review pipeline with a more robust submission. Market participants noted that EMA’s request for additional data, particularly regarding CMC and long-term safety, aligns with current regulatory trends for immunotherapies and biologics.

For Sun Pharmaceutical Industries Limited, the delay may reduce short-term revenue expectations from the Nidlegy collaboration, but is not seen as materially altering the company’s longer-term oncology strategy. Institutional investors will likely monitor updates on the resubmission timeline and manufacturing milestones closely, as these will dictate revised expectations for European market entry.

What are the commercial implications of a delayed melanoma therapy launch in Europe?

Melanoma remains one of the most aggressive and therapeutically complex forms of skin cancer. While adjuvant therapies post-surgery are common, there is no currently approved neoadjuvant agent for fully resectable, locally advanced cases in the EU. This leaves a gap that therapies like Nidlegy aim to fill, especially as tumor-targeted cytokine delivery becomes a more attractive modality in oncology.

Analysts believe that a successful approval for Nidlegy could make it a first-in-class agent for neoadjuvant use, offering Sun Pharmaceutical Industries Limited a strong position in a niche but high-value market. The size of the European melanoma therapy market exceeded EUR 500 million in 2024 and is projected to grow in the mid-single digits annually through 2028. Capturing even a portion of this segment with a differentiated product could yield meaningful upside—particularly as competition in neoadjuvant melanoma care is currently sparse.

What does the EMA withdrawal of Nidlegy mean for stakeholders?

While the withdrawal of the EMA application delays the timeline for Nidlegy’s commercialization in Europe, it does not diminish the product’s clinical promise. Both Sun Pharmaceutical Industries Limited and Philogen remain committed to the therapy’s development, and institutional sentiment has not markedly shifted.

The delay is a regulatory recalibration, not a rejection, and underscores the increasingly rigorous standards applied to biologic therapies in oncology. If Philogen is able to complete its CMC and data requirements in a timely fashion, analysts expect a revised filing to be stronger and more likely to secure approval in a market eager for innovation in melanoma treatment.