Sun Pharma’s $416 Million Oncology Bet: UNLOXCYT, Checkpoint Therapeutics, and the Building of India’s First Immuno-Oncology Multinational

In December 2024, a small Nasdaq-listed oncology company called Checkpoint Therapeutics received FDA approval for UNLOXCYT, a drug for patients with advanced skin cancer who cannot have surgery or radiation. It was Checkpoint’s first-ever drug approval. Three months later, Sun Pharma, India’s largest pharmaceutical company, agreed to buy the entire company for $355 million upfront with an additional contingent payment of up to $0.70 per share (maximum $416 million total) if UNLOXCYT secures regulatory approval in Europe.

The Beginning: 1983, Kolkata, Rs 10,000

Dilip Shantilal Shanghvi grew up in Amreli, Gujarat, but spent his formative years in Kolkata, where his father Shantilal Shanghvi ran a wholesale medicine distribution business. While working in his father’s distribution business, the younger Shanghvi identified a gap in India’s eastern markets: Lithosan, a widely used drug for the treatment of manic-depressive disorders, was unavailable in the region. The drug was not difficult to manufacture, and a friend owned the necessary equipment.

In 1983, Shanghvi borrowed Rs 10,000 from his father, used his friend’s equipment and factory in Vapi, Gujarat, and started Sun Pharmaceutical Industries with a two-person marketing team and five psychiatry products. Year one turnover was Rs 1 million. The company’s sales were initially limited to the Calcutta market.

Key Milestones: From Generic Pharma to Specialty

Why Sun Pharma Chose Dermatology and Oncology

Sun Pharma’s US business had historically been built on generics, a high-volume, low-margin business increasingly pressured by competition, pricing erosion, and FDA inspection risks. By the late 2010s, it was clear that generics alone would not sustain the kind of value creation Shanghvi had delivered through acquisition. The answer was Global Specialty: a portfolio of branded products targeting dermatology, ophthalmology, and oncology where Sun Pharma could leverage its manufacturing and commercial infrastructure to sell differentiated drugs at significantly higher margins.

Dermatology was a natural entry because Sun Pharma already led India’s generics dermatology market. Oncology, specifically oncology with a dermatology connection (onco-derm), allowed the company to extend its salesforce relationships with dermatologists into a therapeutic area with high unmet need and premium pricing. UNLOXCYT sits exactly at this intersection: it is an immuno-oncology drug used by oncologists and dermatologists alike for a skin cancer indication.

The Global Specialty Portfolio Today

What Is Cutaneous Squamous Cell Carcinoma?

Cutaneous squamous cell carcinoma (cSCC) is one of the most common forms of skin cancer globally. It arises from the squamous cells that make up most of the skin’s outer layer. In the United States, over one million people are estimated to be diagnosed with cSCC each year, according to the National Library of Medicine. While most cSCC cases are detected early and are curable through surgery or radiation, approximately 1.5% to 5.2% of cases are metastatic, meaning the cancer has spread from the skin to lymph nodes or other organs. These advanced cases carry a significantly worse prognosis and historically had very limited treatment options.

For patients who cannot undergo curative surgery or curative radiation (due to disease location, patient health, or disease spread), the treatment landscape before checkpoint inhibitor approvals was limited to chemotherapy with poor response rates and high toxicity. The advent of PD-1 and PD-L1 inhibitors transformed this segment.

What Is Cosibelimab?

UNLOXCYT is the brand name for cosibelimab-ipdl (INN: cosibelimab). It is a programmed death ligand-1 (PD-L1) blocking antibody. PD-L1 is a protein expressed on the surface of tumour cells that interacts with PD-1 on T-cells, sending a signal that tells the immune system to stand down and ignore the cancer. By blocking PD-L1, cosibelimab removes this immune suppression signal, allowing T-cells to recognise and attack the tumour.

Compared with PD-1 inhibition (the mechanism of cemiplimab and pembrolizumab), PD-L1 inhibition has been shown in studies to cause fewer high-grade immune-related adverse events. Additionally, cosibelimab has demonstrated the ability to induce antibody-dependent cell-mediated cytotoxicity (ADCC), a process by which immune effector cells directly kill antibody-coated tumour cells. This ADCC activity is considered a potential differentiating feature of cosibelimab versus existing approved therapies.

Study CK-301-101: The Pivotal Clinical Data

FDA approval was based on results from Study CK-301-101 (ClinicalTrials.gov identifier: NCT03212404). This was a multicenter, multicohort, open-label Phase 1 trial in 109 patients with metastatic or locally advanced cSCC who were not candidates for curative surgery or curative radiation. In the Phase 1 study, patients received cosibelimab at 800 mg administered intravenously every two weeks until disease progression or unacceptable toxicity. Based on this data, the FDA approved UNLOXCYT at a commercial dose of 1,200 mg administered as an intravenous infusion over 60 minutes every three weeks, as specified in the approved prescribing information.

The Regulatory Path: Complete Response Letter and Resubmission

Checkpoint Therapeutics originally filed a Biologics Licence Application (BLA) for cosibelimab with the FDA. The FDA initially issued a Complete Response Letter (CRL), requesting additional information. Checkpoint resubmitted the BLA, which the FDA accepted in July 2024 with a Prescription Drug User Fee Act (PDUFA) action date of December 28, 2024. The FDA acted ahead of the PDUFA date, granting approval on December 13, 2024. Checkpoint’s CEO James Oliviero described the approval as “a significant milestone both for Checkpoint and for patients with advanced cSCC” and noted it marked Checkpoint’s “transformation to a commercial-stage company.”

Following the May 30, 2025 acquisition, Sun Pharma pursued a label update. On November 25, 2025, the FDA approved an updated label for UNLOXCYT based on longer-term follow-up data from Study CK-301-101. With a median follow-up of 29.3 months in the metastatic cohort and 24.1 months in the locally advanced cohort, the updated analysis showed an improved ORR of 50.0% (95% CI: 38.5% to 61.5%) in metastatic cSCC and 54.8% (95% CI: 36.0% to 72.7%) in locally advanced cSCC, with more complete responses than in the primary analysis. Sun Pharma stated it intends to commercially launch UNLOXCYT in early 2026.

The Fortress Biotech Connection

Checkpoint Therapeutics, Inc. was a Nasdaq-listed (ticker: CKPT) commercial-stage immunotherapy and targeted oncology company headquartered in Waltham, Massachusetts. It was founded and incubated by Fortress Biotech, Inc. (Nasdaq: FBIO), an innovative biopharmaceutical company that creates and develops biopharmaceutical products through a portfolio of subsidiary companies. Fortress held the majority of Checkpoint’s outstanding voting power at the time of the Sun Pharma acquisition.

Because of Fortress’s role in founding Checkpoint and funding its early development, Checkpoint had granted Fortress royalty rights on future sales of cosibelimab. As part of the Sun Pharma transaction, a royalty agreement was negotiated among Sun Pharma, Checkpoint, and Fortress. Under this agreement, Fortress receives approximately $28 million from the deal proceeds and is entitled to a 2.5% royalty on net sales of UNLOXCYT for a specified term, in lieu of the earlier royalty rights. Fortress also holds the right to receive additional payments based on regulatory milestones.

Checkpoint’s Pipeline Beyond UNLOXCYT

Checkpoint’s Financial State at the Time of Acquisition

Checkpoint’s financial position made the timing of the Sun Pharma acquisition critical. For the nine months ending September 30, 2024, Checkpoint reported revenues of just $0.04 million against a net loss of $27.3 million, with R&D expenses of $19.3 million. Its cash balance stood at $4.7 million against total liabilities of $17.6 million (accounts payable and accrued expenses of $15.6 million, plus related party payables of $2.0 million). The company had received its FDA approval in December 2024 but had minimal funds to build a commercial sales force or launch the drug at meaningful scale. Without a partner or acquirer, Checkpoint would have required substantial dilutive financing to commercialise UNLOXCYT independently.

Structure: Merger Agreement and CVR

Why the CVR Is Tied to Europe

The contingent value right of up to $0.70 per share is payable upon regulatory approval of UNLOXCYT in select European markets. European approval would substantially expand the commercial opportunity for the drug beyond the US. The European Medicines Agency (EMA) approval process is separate from the FDA and requires its own regulatory submission and review. By tying the CVR to European approval, Sun Pharma aligns former Checkpoint shareholders’ residual economic interest with the global regulatory success of the drug, while capping its own upfront obligation at $355 million.

Deuruxolitinib: A Second Specialty Launch in the Same Period

The Checkpoint acquisition did not happen in isolation. Simultaneously, Sun Pharma was navigating a complex patent battle around its other major dermatology product: Leqselvi (deuruxolitinib). Deuruxolitinib is an oral selective inhibitor of Janus kinases JAK1 and JAK2. It was FDA-approved in July 2024 for adults with severe alopecia areata, becoming the third FDA-approved treatment for this autoimmune condition that causes hair loss. Sun Pharma had obtained the drug through its acquisition of Concert Pharmaceuticals.

Full Year Performance (FY2025: April 2024 to March 2025)

What the Numbers Tell Us

The FY2025 financials tell a story of a company in confident transition. The Global Specialty segment, which is the home of Ilumya, Cequa, Winlevi, and now UNLOXCYT and Leqselvi, grew 17.1% to USD 1,216 million. It accounted for approximately 20% of total revenues in FY2025. The EBITDA margin expanded to 29%, which is high by global pharma standards for a company of this size. The adjusted net profit growth of 19% demonstrates that the specialty strategy is improving profitability, not just revenues. Sun Pharma enters the UNLOXCYT commercialisation phase from a position of financial strength, with the balance sheet and margins to absorb the investment required to build the drug’s commercial footprint.

The Strategic Logic: India’s First Immuno-Oncology Multinational

No Indian pharmaceutical company has ever built a sustained, profitable business in immuno-oncology. The checkpoint inhibitor market globally is dominated by Merck (pembrolizumab / Keytruda), Bristol-Myers Squibb (nivolumab / Opdivo and ipilimumab / Yervoy), Regeneron and Sanofi (cemiplimab / Libtayo), Roche, and AstraZeneca. These are all Western multinationals with decades of oncology R&D investment. The Checkpoint acquisition places Sun Pharma, through UNLOXCYT, in this field for the first time with an approved product.

The strategic logic has four components. First, UNLOXCYT gives Sun Pharma its first approved oncology-specific checkpoint inhibitor, establishing the commercial and regulatory template for future oncology acquisitions. Second, olafertinib, if successful in NSCLC, will extend Sun Pharma into thoracic oncology, opening relationships with a new class of oncologists in the US and Europe. Third, the combination of Leqselvi (dermatology salesforce), Ilumya (dermatology salesforce), UNLOXCYT (oncology-dermatology interface), and Odomzo (dermatology oncology) creates a coherent portfolio for a single focused commercial organisation serving both dermatologists and oncologists treating skin diseases. Fourth, the European CVR signals explicit intent to pursue global registration of UNLOXCYT beyond the US, a step no Indian company has previously managed for an immuno-oncology asset.

The Risks