Expanded distribution of an investigational drug in parallel with ongoing controlled clinical trials: the didanosine model

Determinants of access to experimental antiretroviral drugs in an Italian cohort of patients with HIV: a multilevel analysis

Background

Identification of the determinants of access to investigational drugs is important to promote equity and scientific validity in clinical research. We aimed to analyze factors associated with the use of experimental antiretrovirals in Italy.

Methods

We studied participants in the Italian Cohort of Antiretroviral-Naive Patients (ICoNA). All patients 18 years or older who had started cART (≥ 3 drugs including at least two NRTI) after their enrolment and during 1997-2007 were included in this analysis. We performed a random effect logistic regression analysis to take into account clustering observations within clinical units. The outcome variable was the use of an experimental antiretroviral, defined as an antiretroviral started before commercial availability, in any episode of therapy initiation/change. Use of an experimental antiretroviral obtained through a clinical trial or an expanded access program (EAP) was also analyzed separately.

Results

A total of 9,441 episodes of therapy initiation/change were analyzed in 3,752 patients. 392 episodes (360 patients) involved an experimental antiretroviral. In multivariable analysis, factors associated with the overall use of experimental antiretrovirals were: number of experienced drugs (≥ 8 drugs versus "naive": adjusted odds ratio [AOR] = 3.71) or failed antiretrovirals(3-4 drugs and ≥ 5 drugs versus 0-2 drugs: AOR = 1.42 and 2.38 respectively); calendar year (AOR = 0.80 per year) and plasma HIV-RNA copies/ml at therapy change (≥ 4 log versus < 2 log: AOR = 1.55). The probability of taking an experimental antiretroviral through a trial was significantly lower for patients suffering from liver co-morbidity(AOR = 0.65) and for those who experienced 3-4 drugs (vs naive) (AOR = 0.55), while it increased for multi-treated patients(AOR = 2.60). The probability to start an experimental antiretroviral trough an EAP progressively increased with the increasing number of experienced and of failed drugs and also increased for patients with liver co-morbidity (AOR = 1.44; p = 0.053). and for male homosexuals (vs heterosexuals: AOR = 1.67). Variability of the random effect associated to clinical units was statistically significant (p < 0.001) although no association was found with specific characteristics of clinical unit examined.

Conclusions

Among patients with HIV infection in Italy, access to experimental antiretrovirals seems to be influenced mainly by exhaustion of treatment options and not by socio-demographic factors.

Participation in research and access to experimental treatments by HIV-infected patients

BACKGROUND

Although there is concern that minority groups and women are underrepresented in research involving patients with human immunodeficiency virus (HIV) infection, the available data are inconclusive.

METHODS

We used nationally representative data from the HIV Cost and Services Utilization Study to determine the characteristics of the participants and nonparticipants in trials of medications for HIV infection and whether or not patients had access to experimental treatments. A probability sample of 2864 persons, representing all 231,400 adults with known HIV infection who are cared for in the contiguous United States, were interviewed on three occasions between 1996 and 1998. They were asked about participation in clinical research studies of medications and past receipt of experimental medications for HIV.

RESULTS

We estimate that 14 percent of adults receiving care for HIV infection participated in a medication trial or study; 24 percent had received experimental medications; and 8 percent had tried and failed to obtain experimental treatments. According to multivariate models, non-Hispanic blacks and Hispanics were less likely to be participating in trials than non-Hispanic whites (odds ratio for participation among non-Hispanic blacks, 0.50 [95 percent confidence interval, 0.28 to 0.91]; odds ratio among Hispanics, 0.58 [95 percent confidence interval, 0.37 to 0.93]) and to have received experimental medications (odds ratios, 0.41 [95 percent confidence interval, 0.32 to 0.54] and 0.56 [95 percent confidence interval, 0.41 to 0.78], respectively). Patients who were cared for in private health maintenance organizations were less likely to participate in trials than those with fee-for-service insurance (odds ratio, 0.43 [95 percent confidence interval, 0.21 to 0.88]). Women were not underrepresented in research trials and had a similar likelihood of receiving experimental treatments.

CONCLUSIONS

Among patients with HIV infection, participation in research trials and access to experimental treatment is influenced by race or ethnic group and type of health insurance.

Abacavir expanded access program for adult patients infected with human immunodeficiency virus type 1

Expanded access programs (EAPs) provide medication to patients with life-threatening, treatment-refractory illnesses before regulatory approval and allow the acquisition of safety information. A 2-part, multisite EAP to evaluate abacavir, a carbocyclic nucleoside reverse-transcriptase inhibitor for use in combination antiretroviral therapy, was conducted. The EAP involved >13,000 adults infected with human immunodeficiency virus type 1 (HIV-1) who no longer responded to commercially available treatment regimens. Part A (open-label trials) examined the efficacy, safety, and tolerance of abacavir, and part B (provision of abacavir through expanded access) assessed only the occurrence of serious adverse events. By month 2 of abacavir-containing treatment, plasma HIV-1 RNA levels decreased by > or =0.5 log(10) in 31.4% of patients, and 5.6% of the patients had HIV-1 RNA levels decrease to <400 copies/mL. Drug-related serious adverse events were reported by 7.7% of patients, the most common of which were nausea, skin rash, diarrhea, malaise or fatigue, and fever. Approximately 4.6% of patients experienced a hypersensitivity reaction that was possibly drug related. Overall, the types and incidences of adverse events reported in the abacavir EAP were similar to those reported in phase 2 and 3 clinical trials evaluating abacavir.