Dolutegravir: clinical and laboratory safety in integrase inhibitor-naive patients

BACKGROUND

The efficacy of dolutegravir (DTG) has been demonstrated in 5 randomized studies in integrase inhibitor (INI)-naive adult populations. To date, a detailed safety review of DTG has not been provided in the literature.

OBJECTIVE

To describe the safety and tolerability profile of DTG in adults based on 5 randomized, controlled trials and comparison with drugs in 3 major antiretroviral (ARV) classes.

METHODS

Safety data from phase IIb/III/IIIb trials in ART-naive and ART-experienced, INI-naive adults were integrated.

RESULTS

In 4 ART-naive (SPRING-1, SPRING-2, SINGLE, FLAMINGO) and 1 ART-experienced, INI-naive study (SAILING), 1,579 individuals received a DTG-containing regimen. The proportion of individuals from DTG treatment arms who withdrew due to adverse events (AEs) was low (≤2%) compared to raltegravir (RAL; 2% SPRING-2, 4% SAILING), efavirenz (EFV)-containing comparator arm (10% SINGLE), and darunavir + ritonavir (DRV/r; 4% FLAMINGO). The most frequently observed AEs (diarrhea, nausea, headache), typically grade 1 or 2 in severity, did not lead to study discontinuation. Psychiatric and nervous system disorders with DTG were comparable to RAL- and DRV/r-containing regimens and favorable to EFV-containing regimens. In hepatitis B and/or C coinfected ART-naive individuals, the incidence of transaminase elevations was lower with DTG versus RAL and EFV comparators, but was similar to DRV/r. In SAILING, transaminase elevations were more commonly observed with DTG, particularly in the setting of inadequate hepatitis B therapy or immune reconstitution. On DTG treatment, mild creatinine elevations occurred and stabilized early. Few cases of hypersensitivity reaction and/or severe rash were seen. Rates of these events were comparable to or lower than with RAL-, EFV-, and DRV/r-containing regimens.

CONCLUSIONS

The safety profile for DTG 50 mg once daily in INI-naive individuals was comparable to RAL- and DRV/r-containing regimens and generally favorable compared with EFV-containing regimens.

Rapid development of genotypic resistance to lamivudine when combined with zidovudine in pregnancy

The prevention of mother to child transmission of HIV-1 by zidovudine monotherapy is well known, but increasingly combination anti-retroviral therapy is prescribed during pregnancy. In this prospective study, 19 pregnant women with human immunodeficiency virus-1 (HIV-1) infection who elected to take anti-retroviral therapy during the second and third trimesters were treated with zidovudine or zidovudine plus lamivudine. Fourteen women treated with zidovudine monotherapy had a mean 0.3 log(10) reduction in viral load and a mean 52 x 10(6)/L (17%) increase in CD4+ lymphocytes at delivery compared with pre-treatment samples. Genotypic mutations associated with decreased susceptibility to zidovudine were detected in 2 of 10 women at delivery. Five women with more advanced HIV-1 infection were treated with zidovudine plus lamivudine and a mean 1.5 log(10) reduction in viral load together with a mean 30 x 10(6)/L (33%) increase in CD4+ lymphocytes was observed in this group. However, four of five women in the dual therapy arm had the M184V mutation in the reverse transcriptase gene associated with decreased susceptibility to lamivudine at delivery. We conclude that zidovudine plus lamivudine reduced HIV-1 plasma viraemia to low levels in pregnant women with advanced HIV-1 disease but the rapid development of genotypic resistance to lamivudine indicates that additional therapy is required both for the long-term benefit of the mothers and to prevent the development of resistant virus that may be transmitted to the infant.

The rabbit study: ritonavir and saquinavir in combination in saquinavir-experienced and previously untreated patients

Thirteen protease inhibitor-naive patients with HIV-1 infection, and 12 patients with a median of 58 months prior treatment with saquinavir (SQV) monotherapy, were treated with SQV (400 mg twice daily) and ritonavir (RIT, 500 mg twice daily) in a study designed to assess the effect of prior treatment with SQV monotherapy on the antiretroviral activity of RIT-SQV combination therapy. Median baseline viral load and CD4+ cell counts were 155,000 and 262,000 copies/ml and 333 and 225 cells/mm3 in the naive and experienced groups, respectively. Mean viral load changes at 24 weeks were -1.63 and -0.27 log copies/ml in the naive and SQV-experienced groups, respectively (intent-to-treat analysis). Baseline genotype by point mutation assay and sequencing in the SQV-experienced group was highly predictive of virological response. Eight of 11 SQV-experienced patients had evidence of phenotypic resistance to RIT at baseline, despite previous treatment with SQV only. There was strong correlation between phenotypic resistance to RIT and the presence of the L90M mutation. We conclude that prolonged prior treatment with saquinavir monotherapy may produce cross-resistance to ritonavir and reduce the subsequent response to ritonavir-saquinavir in combination. In this study, both phenotypic resistance to ritonavir and presence of the L90M mutation predicted the viral load response to ritonavir-saquinavir.

Evidence for horizontal and not vertical transmission of human herpesvirus 8 in children born to human immunodeficiency virus-infected mothers

A survey of antibody responses to human herpesvirus 8 (HHV-8) was undertaken to examine the mode of transmission of this virus to children born to mothers with HIV. Methods. Serum samples from a cohort of 92 mother-infant pairs and a cross-sectional cohort of 100 children (median age, 4 years) were tested. In the cohort of mother-infant pairs, 14 infants were HIV-infected, 72 were not and the HIV status was unknown for 6. In the cohort of children 70 were HIV-infected and 30 were vertically exposed but uninfected. Serologic responses to two HHV-8 antigens, latency-associated nuclear antigen and the structural antigen encoded by open reading frame 65 were detected by immunofluorescent antibody test and enzyme-linked immunoassay. Results were confirmed by Western blot. Results. All HHV-8-seropositive mothers were African (17 of 92, 18.5%). Six of their infants were HHV-8-seronegative and 11 had at least 1 HHV-8-seropositive sample. One of the 11 infants tested only at birth had a lower antibody titer than the mother; the remaining 10 infants had decreasing titers up to 7 months of age and 6 became seronegative. No infants born to HHV-8-seronegative mothers had antibodies to the virus. The seroprevalence to HHV-8 was 6% in the cohort of children. All had African mothers and their median age was greater than that of the cohort (8.4 vs. 4.0 years). Five were coinfected with HIV. Conclusions. HHV-8 was not vertically transmitted by any of the HIV-coinfected mothers. Acquisition of antibody to HHV-8 occurred in older children, implying a horizontal route of transmission.

Intrapartum mucosal exposure to human immunodeficiency virus type 1 (HIV-1) of infants born to HIV-1-infected mothers correlates with maternal plasma virus burden

The majority of vertical infections with human immunodeficiency virus type 1 (HIV-1) occur at or near delivery, strongly suggesting a mucosal route of transmission. The frequency and level of intrapartum mucosal exposure to HIV-1 of 22 infants born to infected mothers was investigated. Maternal plasma HIV-1 RNA and CD4 cell count were measured at delivery. Infant oropharyngeal aspirates obtained at birth were examined for HIV-1 RNA by reverse transcription-polymerase chain reaction and qualitative nucleic acid sequence-based amplification. Nine infants (41%) had detectable levels of HIV-1 RNA, 3 of which were quantifiable (mean, 3000 copies/mL). This mucosal exposure to HIV-1 during delivery did not lead to infection of any infant. Cesarian delivery did not reduce mucosal exposure to HIV-1. Mucosal exposure did not correlate with maternal CD4 cell count but did correlate with maternal plasma virus load and was reduced by antiretroviral therapy.

Review of uptake of interventions to reduce mother to child transmission of HIV by women aware of their HIV status

OBJECTIVES

To examine the change in uptake of interventions to reduce transmission of HIV from mothers to infants from January 1994 to July 1997.

DESIGN

Review of mother-infant pairs who presented for infant diagnosis of HIV infection.

SETTING

Central London hospital with facilities for diagnosis of infant HIV infection.

SUBJECTS

57 consecutive mother-infant pairs, mainly from central London but also referred from surrounding hospitals.

INTERVENTIONS

Data were collected on mother's country of origin; CD4 count at delivery; plasma HIV RNA copies/ml; mode of delivery; antiretroviral therapy; infant feeding; and HIV infection in infants.

MAIN OUTCOME MEASURES

HIV infection of infants.

RESULTS

The vertical transmission rate was 12% (7 pairs; 95% confidence interval 3% to 22%). All mothers chose not to breast feed. The caesarean section rate was 53% (30/57). Antiretroviral therapy was taken by 68.5% (39/57) of mother-infant pairs. With antiretroviral therapy or caesarean section, or both, transmission occurred in 6% (0% to 13%) of pairs (3/50). During the 24 months of 1994 and 1995, 21% (4/19) of infants were infected with HIV; 7.9% (3/38) were infected over the 19 months January 1996 to July 1997. The caesarean section rate did not change over these periods. Use of antiretroviral therapy increased from 31.5% (6/19) to 86.8% (33/38) (P < 0.0001).

CONCLUSION

Women with a diagnosis of HIV infection acted to reduce the risk of transmission to their infants. Uptake of antiretroviral therapy increased significantly over time, and the caesarean section rate was persistently high.