Rexahn Pharmaceuticals Inc (NYSEMKT:RNN): Upside Ahead Of Data Presentation

Rexahn Pharmaceuticals, Inc. (NYSEMKT:RNN) is just about to present data from the first stage of its ongoing phase 1/2 oncology trial at ESMO. We already know that the data is indicative of efficacy – the company moved from the first stage of the trial to the second based on this fact – but the degree to which the first stage suggests the drug in question is effective in its target indication could set the tone for the company across the coming quarters.Based on what we know already, we expect the data to be pretty strong, and in turn, we expect to see some upside come presentation day. With this in mind, and ahead of ESMO, here's what we are looking for from the numbers to support our bullish bias.First, let's take a look at the company, and the drug in question.As mentioned, it's an oncology target, and its called RX-3117. The company is investigating it as a potential treatment for metastatic pancreatic cancer; specifically, in patients that have undergone three or more treatments to which they have not yet responded.It's a pretty serious patient population, and one with a poor prognosis.The drug is a next generation nucleoside analog. Some readers may already be familiar with nucleoside analogs – they are used in a wide variety of indications, primarily viral infections. They are also used in cancer treatment, however, and one of the best examples is a drug called gemcitabine. These types of drugs work by replacing one of the key components, or building blocks, of nucleic acids in the the transcription process of DNA in cancer cells. It's technically a faulty version of the nucleic acid, and it stops the transcription process in the DNA in question. No transcription translates to apoptosis, which is the process through which a cell kills itself.There's a problem with gemcitabine, however. It becomes active once it comes across an enzyme called DCK. Cancer cells express DCK, and so when the gemcitabine reaches these cells and becomes active, all is well. Healthy cells also express this enzyme though (or at least, lots of them do) so the drug acts against a large number of healthy cells. This creates a high level of toxicity, and makes it difficult to administer in high doses, limiting its potential therapeutic benefit.RX-3117 is the same as gemcitabine from an MOA perspective, but it is activated by an enzyme called Uridine Cytidine Kinase (UCK). Lots of different types of tumors express high levels of UCK, and very few healthy cells do. This means it's highly selective to cancer cells and can be used at higher doses than gemcitabine without the toxicity.So what are we looking at from the upcoming data?Well, in order to advance from the first to the second stage of the trial, 20% or more of the patients needed to show progression free survival of more than 4 months, or an objective clinical response rate and reduction in tumor size. If this occurred, then an additional 40 pancreatic cancer patients would be enrolled into stage 2.We know this threshold has been hit, as the trial has moved forward, and we know that 40% of patients showed responses beyond 2 months (based on a quote from the company's Chief Medical Officer back mid-September). We don't know what this response refers to, however.We'd like to see the more than 20% progression free number closer to the 40% response rate – the closer the better. Primary from the phase one was dose limiting toxicity, so we'd either like to see no dose limiting toxicity (although this is pretty unlikely) or a DLT at the high end of the multiple dose regimen. Secondary on the first phase is area under the plasma concentration time curve. This is a pretty common secondary in the field of pharmacokinetics, and it helps establish how long a drug remains effective. The higher the AUC, the better.So there we go, if these play out as we think they might, there's a decent upside on the speculative volume that the presentation should draw.For more analyses ahead of clinical data presentations like this, subscribe to our newsletter below 100% free!Disclosure: We have no position in RNN and have not been compensated for this article.