Argos Therapeutics (Nasdaq: ARGS) disclosed early Friday that its proposed drug for HIV – a treatment based on personalized immunotherapy – failed to hit its primary target in a Phase 2 clinical trial.

Wall Street did not like the news. Argos shares plummeted some 20 percent in early trading after markets opened and in late afternoon trading was down nearly 30 percent at $6.80 per share. Shares fell $2.81 in heavy trading.

More than 300,000 shares were traded just before 3 p.m., some eight times the annual daily average.

However, the Durham company says the trial produced other promising results and that it therefore will not give up on the government-funded program.

Argos,, which went public last year and recently announced plans to build a new production facility in Durham, said AGS-004 failed to reduce the “median viral load” in patients chronically afflicted with the HIV-1 virus. HIV’s ability to mutate continues to defy scientific efforts to eradicate it.

But, since some 70 percent of the patients receiving AGS-004 rather than a placebo did show a positive response in their immune systems, Argos said it would continue testing in a test focused on eradication of HIV in adults and a planned test focused on young people. 

Argos is developing a number of individually targeted therapies based on proprietary technology known as the Arcelis Technology Platform, which was developed at Duke University. 

Argos also is targeting cancer with the technology. Its most advanced product candidate is AGS-003, which is being tested in a Phase 3 clinical trial as a treatment for metastatic renal cell carcinoma.

Hopeful results

“By demonstrating that AGS-004 induced memory T-cell responses in a majority of patients and that those immune responders had fewer CD4+ T-cells with integrated HIV DNA, these data suggest that induced anti-viral memory T-cell responses may contribute to lower persistent viral reservoirs,” said Dr. Charles Nicolette, chief scientific officer and vice president of research and development at Argos.

“These data support our plans to continue testing AGS-004 in the studies aimed at decreasing or
eliminating the latent HIV reservoir. In addition, based on these data we believe that more frequent dosing of AGS-004 during ART [standard antiretroviral therapy, or ART] may provide further benefit, but also highlight the need to better understand the mechanisms of immune evasion employed by the HIV virus in the absence of ART.”

The principal investigar of of the trial, Dr. David Margolis of the University of North Carolina, also issued a statement in which he sees reasons to continue development.

“The results of the AGS-004 Phase 2b trial allow us to now ask if combining AGS-004 treatment with HDAC inhibitors, part of a new class of latent reservoir mobilizers, will lead to the elimination of HIV-infected cells,” Margolis said. ”We look forward to initiating stage two of the
adult eradication study where patients on ART will receive the HDAC inhibitor vorinostat in addition to AGS-004.”

What is Arcelis?

Here’s how Argos describes the Arcelis platform:

“Arcelis(R) is a fully personalized immunotherapy technology that captures mutated and variant antigens that are specific to each patient’s disease. It is designed to overcome immunosuppression by producing a durable memory T-cell response without adjuvants that may
be associated with toxicity. The technology is potentially applicable to a wide range of different cancers and infectious diseases and is designed to overcome many of the manufacturing and commercialization challenges that have impeded other personalized immunotherapies.

“The Arcelis process uses only a small tumor or blood sample and the patient’s own dendritic cells, which are collected and optimized following a single leukapheresis procedure. The proprietary process uses RNA isolated from the patient’s disease sample to program dendritic cells to target disease antigens. The activated, antigen-loaded dendritic cells are then formulated into the patient’s plasma and administered via intradermal injection.”