The market may be falling today, but that hasn't stopped Biotron Ltd (ASX: BIT) shares from rocketing.

In morning trade, the ASX healthcare stock is up almost 50% to 11 cents.

Investors have been scrambling to buy the antiviral therapies developer's shares this morning after it released an update on its Phase 2 study of BIT225.

BIT225 is Biotron's lead compound. It is in Phase 2 development for the treatment of HIV-1 and Hepatitis C virus infections.

According to the release, preliminary analyses of data from the BIT225-010 Phase 2 clinical trial provide confirmation, and extension, of the results of previous trials in people infected with HIV-1.

The ASX healthcare stock explained that the double-blind placebo-controlled Phase 2 trial was designed to characterise the effect of BIT225 (200 mg, once daily for 24 weeks) added to a standard of care antiretroviral therapy (cART) in 27 treatment naive people infected with HIV-1. This comprises 18 using BIT225 and 9 using a placebo.

Study participants were followed for a one-month period following 24-weeks of BIT225 or placebo dosing, with all individuals continued on cART as per standard treatment guidelines post-study.

Preliminary analysis of the safety data has shown that BIT225 was safe and generally well tolerated at the 200mg once daily dose, with no deaths or drug-related serious adverse events.

As for efficacy, preliminary analyses of the HIV-1 plasma viral load (pVL) data suggest that the addition of BIT225 to cART results in a more rapid reduction in plasma virus levels during the second phase of viral decay, compared to cART alone.

Furthermore, preliminary analyses of blood immune cell populations showed changes in specific immune cell populations in the BIT225 group compared to cART alone.

The ASX 200 healthcare stock's managing director, Dr Michelle Miller, was pleased with the trial results. She said:

The positive outcomes from this trial further our understanding of BIT225. The blood (plasma) viral load data in particular should be highlighted, as it suggests that BIT225 is having an impact on a critical phase of viral decay when latent reservoirs are established. Current cART is efficient at rapidly and durably reducing virus levels in the blood, but this does not translate into clearance of latent reservoirs.

The observed changes to immune markers and cells further the results from the previous 009 trial and suggest the utility of targeting viroporins as a new class of antiviral drugs. The results reported here are preliminary, and ongoing analysis of the BIT225-010 study, as well as its companion study, BIT225-011 in HIV-1 chronically infected individuals, will be reported when complete.