Viral Load: New Confirmation from Major Delavirdine Studies

Two clinical trials of delavirdine with a total of about 1900 patients have strongly confirmed the value of viral load (both baseline, and response to treatment) in predicting clinical outcome. Pharmacia & Upjohn first announced this result on January 17, and will summarize the data on February 1 at the Third Conference on Retroviruses and Opportunistic Infection.

Both baseline viral load, and change in viral load in response to therapy, predicted clinical outcome to a very high statistical significance, p<.0001 in each case. Change in response to therapy was somewhat better than baseline as a predictor; if the viral load dropped 70% or more with treatment and the improvement was sustained, the risk of clinical progression was reduced 55%. Viral load was more effective than CD4 count in predicting clinical outcome.

The trials of delavirdine are continuing; there was only a partial unblinding for the study. Pharmacia & Upjohn will be able to apply for accelerated approval for the drug this year, based on viral load and other surrogate marker data, while the trial still continues to collect clinical-outcome information. The viral load analysis above will strengthen their application for accelerated approval, by providing additional information that viral load is a useful measurement.

Delavirdine Expanded Access, Clinical Trials: For More Information

Pharmacia & Upjohn will offer an expanded-access program for delavirdine in the U.S. and Canada, and later in Europe and Australia; they do not plan to do a lottery. The program is currently being designed; a starting date has not been announced, but it is targeted for March 1996.

For more information about the expanded access program, call 800/779-0070. Physicians may want to call to be listed on a database of those interested. Patients can also call this number, but only general information is available at this time.

A major clinical trial of delavirdine by Pharmacia & Upjohn, protocol 0021, which is running at 105 sites in North America, is still recruiting persons with CD4 counts between 200 and 500, both antiretroviral experienced and naive. This is one of the trials that was partially unblinded to produce the results above. It has been modified, so that it no longer has an AZT-only arm; instead, the control arm is now AZT plus 3TC. Also, the lower doses of delavirdine have been dropped. For more information about this trial (or about other AIDS research at Pharmacia & Upjohn), patients and physicians can call 800/432-4702.