Most people on dolutegravir resuppress viral load after a detectable result

The majority of people who develop low-level viral load on dolutegravir resuppress viral load without needing to change treatment, a large Nigerian study has found, confirming observations regarding the frequency of viral load resuppression from the ADVANCE study of first-line antiretroviral treatment in South Africa.

The findings are published this month in the journal AIDS.

The study looked at viral load suppression in people with HIV receiving antiretroviral treatment with dolutegravir, tenofovir and lamivudine between 2017 and 2023 in Nigeria's Federal Capital Territory. People taking this regimen were eligible for inclusion in the analysis if they had at least one viral load measurement during the study period. The study included 63,521 people, of whom 47,979 had at least one follow-up viral load after an initial viral load measurement when taking dolutegravir, tenofovir and lamivudine.

Seventy per cent of the cohort were female, the median age was 35 years and 56% had started antiretroviral treatment in 2020 or later. The majority (61%) had started treatment on a dolutegravir-based regimen; the remainder had transitioned to dolutegravir-based treatment.

Participants could contribute multiple follow-up viral loads to the analysis and 80% contributed more than one measurement (13% contributed six or more). A total of 192,820 viral load results from 63,521 cohort members were analysed. The analysis focussed on changes between consecutive viral load measurements.

The median time between viral load tests was just under a year (344 days) but less in people with viral load above 1000 (196 days).

In those with an undetectable viral load (below 50) (n=62,604), 85% had an undetectable viral load at their next test, 8% a viral load between 51 and 199 (lower low-level viremia), 3% a viral load between 200 and 999 (higher low-level viremia) and 4% a viral load of 1,000 or more (virologic non-suppression).

Of those with lower low-level viremia (51-199), 66% resuppressed viral load below 50 at their next test, 20% still had lower low-level viremia, 6% had a viral load between 200 and 999 and 6% had virologic non-suppression.

Of those with higher low-level viremia (200-999), 59% resuppressed viral load below 50, 14% had viral load between 51 and 199, 18% had viral load between 200 and 999 and 9% had virologic non-suppression.

Among those with virologic non-suppression, 49% had resuppressed viral load below 50 on their next test, 13% had viral load between 51 and 199, 9% had viral load between 200 and 999 and 28% had virologic non-suppression.

When the researchers looked at people who had experienced virologic failure but had remained on tenofovir, lamivudine and dolutegravir (n=621), 57% regained viral suppression below 50, and 92% had viral load below 1000 on their next viral load test. Six percent switched to another regimen after virologic failure; 32 of 41 to a protease inhibitor. Just under half (48) had a viral load below 1000 on their next test and of these, 13 had viral load below 50.

Younger people aged 15-24 had higher odds of virologic non-suppression (adjusted odds ratio 2.8 for males and 2.1 for females) compared to females aged 55 and over. Being a member of a key population (chiefly female sex workers or gay and bisexual men) reduced the risk of virologic non-suppression by 37%.

"Viral load monitoring may point to a need for more intensive adherence interventions instead of a regimen change."

A previously detectable viral load when taking dolutegravir was associated with ascending odds of virologic non-suppression on the next test, ranging from an adjusted odds ratio of 1.7 for people with viral load between 51 and 199 to an adjusted odds ratio of 7.5 for people with virologic non-suppression, compared to people with undetectable viral load.

The researchers say that, like the findings of the ADVANCE study, their findings show that a large proportion of people with detectable viral load on dolutegravir can resuppress viral load. “Viral load monitoring may point to a need for more intensive adherence interventions instead of a regimen change, and only a small proportion may require cost-intensive genotyping to identify drug resistance,” they conclude.