Barriers and Facilitators to Long-Acting Injectable HIV Pre-Exposure Prophylaxis Implementation in Primary Care Since Its Approval in the United States

BACKGROUND

HIV pre-exposure prophylaxis (PrEP) is a highly effective method to mitigate the HIV epidemic, but uptake of PrEP has been slow and is associated with racial and gender disparities. Oral PrEP requires high levels of adherence to be effective, which may disadvantage certain high-risk groups. The first injectable HIV PrEP, a drug given every 2 months rather than as a daily pill, was approved by the US Food & Drug Administration in December 2021.

SETTING

A Family Medicine practice in a single health organization in the United States (November 2022 to February 2023).

METHODS

We conducted interviews with patients and key stakeholders to characterize factors affecting long-acting injectable (LAI) PrEP implementation. Data collection and analysis were guided by the Consolidated Framework for Implementation Research. Interviews were transcribed and analyzed using guided content analysis.

RESULTS

Twenty-five patients (n = 13) and practice stakeholders (n = 12) were interviewed. Overall, stakeholders described a very low uptake of LAI PrEP. Barriers to LAI PrEP included a lack of awareness, insurance and access issues, a lack of streamlined workflow, and a trust in pills over injectables. Facilitators to LAI PrEP implementation included the absence of a pill burden, a culture of shared decision making, and pharmacy support.

CONCLUSIONS

Although uptake has been slow, we have identified several promising strategies for improving rollout and implementation of LAI PrEP. Approaches that can bolster rollout of LAI PrEP include having an interdisciplinary care team that is supported by PrEP navigators and pharmacists and are informed by a patient-centered model of care to increase patient engagement and trust.

Care of Patients With HIV Infection: Antiretroviral Drug Regimens

The advent of combination antiretroviral drug regimens has transformed HIV infection from a fatal illness into a manageable chronic condition. All patients with HIV infection should be considered for antiretroviral therapy, regardless of CD4 count or HIV viral load, for individual benefit and to prevent HIV transmission. Antiretroviral drugs affect HIV in several ways: entry inhibitors block HIV entry into CD4 T cells; nucleotide and nucleoside reverse transcriptase inhibitors prevent reverse transcription from RNA to DNA via chain-terminating proteins; nonnucleoside reverse transcriptase inhibitors prevent reverse transcription through enzymatic inhibition; integrase strand transfer inhibitors block integration of viral DNA into cellular DNA; protease inhibitors block maturation and production of the virus. Current guidelines recommend six combination regimens for initial therapy. Five are based on tenofovir and emtricitabine; the other uses abacavir and lamivudine. Five include integrase strand transfer inhibitors. HIV specialists should assist with treating patients with complicated HIV infection, including patients with treatment-resistant HIV infection, coinfection with hepatitis B or C virus, pregnancy, childhood infections, severe opportunistic infections, complex drug interactions, significant drug toxicity, or comorbidities. Family physicians can treat most patients with HIV infection effectively by choosing appropriate treatment regimens, monitoring patients closely, and retaining patients in care.

Care of Patients With HIV Infection: Primary Care

With the advent of antiretroviral therapy and improved access to care, the average life expectancy of patients with HIV infection receiving optimal treatment approaches that of patients in the general population. AIDS-related opportunistic infections and malignancies are no longer the primary issues; instead, traditional age- and lifestyle-related conditions are a growing concern. Patients with HIV infection are at higher risk of cardiovascular disease, diabetes, hypertension, and some non-AIDS-related cancers than patients in the general population. Family physicians need to be knowledgeable about screening for and managing chronic comorbid conditions as this population ages. Health maintenance, including appropriate vaccinations, prophylaxis against opportunistic infections, and routine screening for sexually transmitted infections, remains an important part of care. As HIV infection becomes a chronic condition, emerging strategies in prevention, including preexposure prophylaxis, fall within the scope of practice of the family physician.

Care of Patients With HIV Infection: Medical Complications and Comorbidities

Care of patients with HIV infection starts with diagnosis as soon as possible, preferably at or near the time of acute infection. Opportunistic infections, malignancies, and other conditions develop progressively over time, particularly in untreated patients. The AIDS-defining opportunistic infections most common in the United States include Pneumocystis jirovecii pneumonia, Candida esophagitis, toxoplasmic encephalitis, tuberculosis, disseminated Mycobacterium avium complex, cryptococcal meningitis, and cytomegalovirus retinitis. Specific prophylaxis regimens exist for several opportunistic infections, and effective antiretroviral therapy reduces the risk of most others. Other AIDS-defining conditions include wasting syndrome and HIV encephalopathy. AIDS-defining malignancies include Kaposi sarcoma, systemic non-Hodgkin lymphoma, primary central nervous system lymphoma, and invasive cervical cancer. Although not an AIDS-defining condition, anal cancer is common in patients with HIV infection. Other HIV-related conditions include thrombocytopenia, recurrent bacterial respiratory infections, HIV-associated nephropathy, and HIV-associated neurocognitive disorder.

Care of Patients With HIV Infection: Diagnosis and Monitoring

Appropriate screening for HIV infection is the cornerstone of HIV-related care. There have been several recent changes in testing technology and screening recommendations. The US Preventive Services Task Force recommends universal HIV screening at least once for adolescents and adults ages 15 to 65 years, and additional screening for patients at higher risk, although evidence is insufficient to determine optimum rescreening intervals. All pregnant women should be screened for HIV infection in the first trimester, and pregnant women at high risk should be screened again in the third trimester. The Centers for Disease Control and Prevention recommends use of an algorithm using fourth-generation tests for screening; this decreases the window period between infection and detection to as few as 14 days, thereby reducing the number of false-negative results. Home HIV testing kits, which require follow-up confirmatory testing, also are available. Clinicians should be aware of HIV-specific laws in their states, including those criminalizing HIV exposure and transmission. Thorough medical and laboratory evaluations are essential at initiation of care for patients with HIV infection, along with appropriate follow-up monitoring, as recommended in various guidelines.

MMP-13 In-Vivo Molecular Imaging Reveals Early Expression in Lung Adenocarcinoma

Introduction

Several matrix metalloproteinases (MMPs) are overexpressed in lung cancer and may serve as potential targets for the development of bioactivable probes for molecular imaging.

Objective

To characterize and monitor the activity of MMPs during the progression of lung adenocarcinoma.

Methods

K-ras^LSL-G12D mice were imaged serially during the development of adenocarcinomas using fluorescence molecular tomography (FMT) and a probe specific for MMP-2, -3, -9 and -13. Lung tumors were identified using FMT and MRI co-registration, and the probe concentration in each tumor was assessed at each time-point. The expression of Mmp2, -3, -9, -13 was quantified by qRT-PCR using RNA isolated from microdissected tumor cells. Immunohistochemical staining of overexpressed MMPs in animals was assessed on human lung tumors.

Results

In mice, 7 adenomas and 5 adenocarcinomas showed an increase in fluorescent signal on successive FMT scans, starting between weeks 4 and 8. qRT-PCR assays revealed significant overexpression of only Mmp-13 in mice lung tumors. In human tumors, a high MMP-13 immunostaining index was found in tumor cells from invasive lesions (24/27), but in none of the non-invasive (0/4) (p=0.001).

Conclusion

MMP-13 is detected in early pulmonary invasive adenocarcinomas and may be a potential target for molecular imaging of lung cancer.