As the global oncology community prepares to descend upon Chicago for the American Society of Clinical Oncology (ASCO) annual meeting—running from May 29 to June 2—the release of preliminary abstracts has provided a high-stakes roadmap for the industry. While the most consequential "late-breaking" findings remain under embargo until the moment of their presentation, the initial data dumps have already signaled significant shifts in the competitive landscape for lung cancer, multiple myeloma, and personalized cancer vaccines.
This year’s meeting serves as a critical proving ground for several "next-generation" modalities, including antibody-drug conjugates (ADCs), PD-1/VEGF bispecific antibodies, and in vivo cell therapies. The data released this week offers a window into how these platforms are maturing, providing investors and clinicians with early indicators of which drugs may soon define the new standard of care.
The Landscape: A Shift in Clinical Focus
The current clinical environment is characterized by a rapid transition toward combination therapies and novel delivery mechanisms. Merck & Co., a titan in the oncology space, continues to aggressively expand the footprint of its flagship immunotherapy, Keytruda, while simultaneously hedging its bets with massive investments in ADCs and mRNA-based vaccines. Meanwhile, smaller, agile players—particularly those emerging from China’s biotech sector—are challenging the status quo with bispecific inhibitors that aim to outperform existing monotherapies.
The anticipation surrounding this year’s gathering is underscored by the high stakes involved for shareholders and, more importantly, patients. From the management of non-small cell lung cancer (NSCLC) to the pursuit of curative potential in multiple myeloma, the following snapshots represent the most pivotal developments unveiled ahead of the conference.
Chronology of Clinical Milestones
The trajectory of these clinical trials reflects a multi-year effort to refine treatment efficacy and safety profiles.
- Late 2023: Merck and Kelun Biotech announced that their ADC, sacituzumab tirumotecan (sac-TMT), met its primary endpoint in a Chinese Phase 3 trial for non-small cell lung cancer, though full data remained under wraps.
- December 2024: Kelonia Therapeutics presented initial, albeit small-scale, human data for its in vivo CAR-T therapy, KLN-101, at the American Society of Hematology (ASH) meeting.
- May 2025 (Pre-Conference): ASCO organizers released hundreds of abstracts, allowing for the first public analysis of the "OptiTROP-Lung05" trial and updated five-year survival data for the Moderna-Merck melanoma vaccine partnership.
- May 29 – June 2, 2025: The ASCO Annual Meeting in Chicago will serve as the forum for official presentations, including the highly awaited late-breaking readouts on Revolution Medicines’ daraxonrasib and the Akeso/Summit Therapeutics immunotherapy, ivonescimab.
Supporting Data: Decoding the Abstracted Findings
The Rise of ADCs: Merck’s "OptiTROP-Lung05"
Perhaps the most notable revelation from the pre-conference abstracts is the performance of sac-TMT in first-line NSCLC. In the "OptiTROP-Lung05" trial, the addition of sac-TMT to a Keytruda backbone reduced the risk of disease progression by a striking 65% compared to Keytruda alone. Furthermore, the objective response rate (ORR) climbed to over 70%, a significant jump from the 42% observed in the control group.
Importantly, the safety profile did not show a prohibitive increase in treatment discontinuations, a metric that often plagues more toxic chemotherapy regimens. Analysts have labeled these results "optically very impressive," suggesting that sac-TMT may indeed function as a "bio-better" form of chemotherapy, capable of extending the life of Keytruda’s patent-protected dominance in lung cancer.
The Bispecific Battle: Pumitamig and SSGJ-707
Akeso’s ivonescimab remains the "gold standard" for the current class of PD-1/VEGF bispecifics, but it faces increasing scrutiny from competitors. The abstract data for BioNTech and Bristol Myers Squibb’s pumitamig and Pfizer’s SSGJ-707 provide a baseline for comparison.
- Pumitamig: In a global Phase 2 study, the drug demonstrated a 70% response rate in first-line NSCLC. However, with a 44% rate of Grade 3 or higher adverse events, the path to commercialization remains complex.
- SSGJ-707: Pfizer’s data from a monotherapy trial showed a 68% response rate, with a median progression-free survival (PFS) of 12.4 months. These results are broadly consistent with the class, and observers expect efficacy to climb as the drug is tested in combination with chemotherapy in ongoing pivotal trials.
In Vivo CAR-T: Kelonia’s Breakthrough
Eli Lilly’s investment in Kelonia Therapeutics is beginning to yield tangible results. Unlike traditional "ex vivo" CAR-T therapies, which require expensive, weeks-long laboratory processing of a patient’s own cells, Kelonia’s KLN-101 is designed for "in vivo" delivery—essentially reprogramming cells inside the patient’s body.
Data from six patients with relapsed multiple myeloma showed that all six achieved "minimal residual disease (MRD) negative" status. This is a critical threshold in myeloma treatment, signaling a profound depth of response. With manageable side effects, the potential for outpatient delivery could revolutionize the accessibility of cell therapy.
The Vaccine Paradigm: Moderna and Merck’s Long-Term Data
The melanoma vaccine known as intismeran continues to be a bellwether for the future of mRNA in oncology. Updated five-year follow-up data from a mid-stage trial revealed a 49% reduction in relapse risk and a 53% reduction in the risk of death when combined with Keytruda. Most compellingly, 92% of participants were alive five years post-treatment, providing a strong signal of efficacy ahead of the massive "INTerpath-001" Phase 3 trial.
Official Responses and Expert Analysis
The analyst community has been quick to temper enthusiasm with necessary caution. Daina Graybosch of Leerink Partners noted that while the sac-TMT data is compelling, it is part of a broader, highly competitive environment. "These results support the drug’s positioning," she wrote, "but they must be viewed in the context of the evolving bispecific landscape."
Conversely, Dara Azar of Stifel emphasized that the current data for competitors like pumitamig should not be seen as a direct threat to the market leaders just yet. "The study sizes are small, and the lack of mature survival data limits our ability to predict long-term superiority," Azar noted.
Regarding the Kelonia data, Trung Huynh of RBC Capital Markets was notably optimistic: "The early data from this program continue to get better," reflecting a consensus that in vivo technologies may represent the next great leap in hematology.
Implications for the Future of Oncology
The findings revealed ahead of ASCO 2025 carry significant implications for both drug developers and the medical community:
- The "Keytrudaization" of New Drugs: Almost every successful trial presented this week involves a combination with Merck’s Keytruda. This confirms the drug’s status as the mandatory foundation for any new lung cancer regimen, effectively making Merck the "gatekeeper" of modern oncology.
- The Maturity of ADCs: Antibody-drug conjugates have moved beyond their "experimental" phase. The strong data for sac-TMT proves that these agents can be both potent and tolerable, setting the stage for them to replace traditional platinum-based chemotherapy.
- The Logistics of Cell Therapy: If in vivo CAR-T therapies like KLN-101 continue to demonstrate safety, the logistical nightmare of current cell therapy—which involves specialized hospitals and multi-week wait times—could vanish. This would open the door to treating thousands more patients who currently lack access to advanced immunotherapies.
- Survival as the Ultimate Metric: With five-year survival data for the mRNA melanoma vaccine, the field is clearly shifting away from simple "progression-free" metrics toward genuine curative outcomes. The high bar set by the 92% survival rate in the intismeran trial will likely become the benchmark for all future adjuvant therapies.
As the industry prepares for the formal presentations in Chicago, one thing is clear: the pace of innovation in cancer research is accelerating. While not every drug mentioned in the pre-conference abstracts will succeed in large-scale, late-stage trials, the collective data paints a picture of a field on the verge of providing significantly more options for patients facing terminal diagnoses. The focus now turns to the "late-breaking" sessions, where the true winners and losers of this year’s ASCO meeting will be determined.
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