This Tiny Biotech Is Beating MRNA, IOVA And SLS — Here's How A Billionaire Fueled Its September Rally

• PDSB surged nearly 68% on Wednesday, lifting its weekly gain to 236% and its September advance to almost 363%.
• Soon-Shiong’s NantWorks also secured a one-year exclusive right to negotiate a license for PDS0101, PDSB’s HPV16-targeted cancer vaccine.
• The funding helped PDSB repay $4.6 million of debt after it ended June with just $5.6 million in cash.

PDS Biotechnology (PDSB) has emerged as one of September’s hottest small-cap biotech stocks, leaving Moderna (MRNA), Iovance Biotherapeutics (IOVA) and Sellas Life Sciences (SLS) behind after billionaire investor Patrick Soon-Shiong made a high-stakes investment in the cancer-drug developer.

PDSB shares soared nearly 68% to $0.99 on Wednesday, extending a rally sparked by a Nant Capital-led financing worth up to $22.3 million and lifting the stock’s weekly gain to 236%. So far this month, PDSB has soared nearly 363%, dwarfing gains of about 21% for IOVA and 4% for MRNA, while SLS has fallen nearly 13%.

Inside Soon-Shiong’s PDSB Power Play 

PDS Biotechnology announced the financing last week and raised $11.3 million at its initial close on Monday. Nant and its affiliates supplied about $10 million. Another $11 million is conditional on PDS Biotechnology submitting a registrational Phase 3 protocol for PDS0301, designed with Nant, to the U.S. Food and Drug Administration (FDA).

Nant also gained two board seats. PDS Biotechnology expanded its board from six to eight members and appointed Soon-Shiong and NantBio CFO James Banaag as non-independent directors. Nant retains the designation rights, while it and its affiliates own at least 15% of PDSB. 

Why PDSB Fits Soon-Shiong’s Cancer Strategy 

NantWorks, Soon-Shiong’s private firm, also paid $25,000 for a one-year exclusive right to negotiate an exclusive license for PDS0101, PDSB’s HPV16-targeted immunotherapy.

The scientific overlap is clear. PDS0301 can deliver the immune-stimulating protein IL-12 to tumors and is being tested in metastatic colorectal cancers that typically resist immunotherapy. ImmunityBio’s FDA-approved Anktiva uses another immune-signaling protein, IL-15, while PDS0101 is a cancer vaccine intended to train the immune system to attack HPV-positive tumors. Together, the programs align with Soon-Shiong’s broader strategy of combining immune activators with cancer vaccines.

PDSB’s Cash Lifeline Carries Strings 

The investment comes as PDS Biotechnology faced intense funding pressure. It held only $5.6 million in cash as of June 30 and had agreed at the end of August to direct proceeds from new equity financings toward repaying a $6 million note held by YA II PN Ltd.

After the PIPE closed, PDSB redeemed $4.6 million of that note. The remaining proceeds will fund working capital and clinical development, including late-stage work on PDS0301. The deal also includes shares and warrants that could substantially expand PDSB’s share count, while only about half of the headline funding has closed.

H.C. Wainwright called the deal a positive that reduced PDSB’s funding overhang, but lowered its price target to $5 from $7 while maintaining a 'Buy’ rating. The firm cited the company’s limited cash and the contingent nature of the remaining financing. 

What Is Driving MRNA, IOVA And SLS? 

Moderna is the second-best-performing S&P 500 stock of 2026 after its personalized cancer vaccine with Merck succeeded in a Phase 3 melanoma trial. MRNA soared 177% on Aug.19, the largest one-day gain by an S&P 500 company in more than two decades.

“It’s a big moment for medicine, a big moment for patients,” Moderna CEO Stéphane Bancel said. However, detailed efficacy and overall-survival data remain pending.

On the other hand, Iovance reported nearly $100 million in second-quarter revenue, a record 56% margin and more than $300 million in liquidity, giving it a cash runway into mid-2028 and a “clear line of sight to profitability.”

The company is expanding its approved Amtagvi cell therapy beyond melanoma and expects a larger non-small cell lung cancer dataset by year-end. Executive Vice President Brian Gastman said the trial was finishing “really very soon.”

Sellas, meanwhile, is approaching the final analysis of its Phase 3 Regal trial of Galinpepimut-S (GPS) in acute myeloid leukemia (AML). The study has recorded 78 of the 80 events needed to trigger the analysis. The trial would succeed if the therapy delivers a median overall survival of 12.6 months, compared with eight months for standard treatment. Sellas also expects initial Phase 2 data for its CDK9 inhibitor SLS009 in the fourth quarter and will present three pancreatic-cancer studies at an AACR conference from Sept.25 through Sept.28.

How Do Retail Traders Feel About Biotech Stocks?

On Stocktwits, retail sentiment around PDSB was ‘extremely bullish’ as message volume surged to ‘extremely high’ levels. IOVA was also ‘bullish’ with ‘high’ activity, while SLS remained ‘neutral’ amid ‘normal’ chatter. MRNA stood apart, with ‘bearish’ sentiment and ‘extremely low’ message volume. 

Despite its recent surge, PDSB is still down 17% over the past year, sharply trailing gains of 598% for SLS, 486% for MRNA and 329% for IOVA.

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