The term “multi-purpose prevention technologies” (MPTs) refers to any single technology that simultaneously protects users against sexually transmitted infections (STIs) and unintended pregnancy. As I discussed earlier this month, MPTs have recently garnered substantial attention and devotion from researchers, as well as a major increase in financial backing from donors. MPTs hold a tremendous potential to transform the lives of women everywhere, especially those in low- and middle-income countries (LMICs), where access to family planning and condoms for STI prevention can be a major challenge. Yet, despite innovative research and vast potential, the only MPTs currently on the market are still internal and external condoms. So, why haven’t more MPTs become available?
At first glance, MPTs seem like a pretty simple concept—if a woman is already using a ring that emits drugs to prevent pregnancy, why not add in some prophylactic drugs that prevent HIV transmission as well? Yet, MPT research and development face a multitude of complex hurdles that need to be overcome before any new devices reach the market. These hurdles include lack of political willpower, insufficient and unsustainable funding, undetermined implementation strategies, and scientific barriers. In this post, we’ll focus on the technical and scientific challenges that inhibit rapid development of MPTs.
As the Guttmacher Institute explains, MPTs are unique in that they require the simultaneous delivery of at least two active ingredients, which must be directed at two or more clinical indications (i.e. pregnancy and also HIV, chlamydia, and/or HSV-2, etc.). For the device to work, all the component parts, their release times, duration and efficacy must perfectly align, and the drugs cannot interact. For example, certain anti-retroviral (ARV) products can impact the metabolism of specific hormonal contraceptive agents, resulting in a potentially reduced function of the hormonal contraceptive device. Other studies suggest a potential enhanced risk of HIV infection in women using certain hormonal contraception. Limiting drug interactions will be critical to ensuring the success of MPTs. The optimal mix of indications (i.e. STIs and contraception) to be targeted will vary by the severity of the risks associated with different STIs. For instance, HSV-2 will likely be prioritized since it is both prevalent and can increase the risk of contracting HIV.
The average time for new drug development in the US is 10 to 12 years, and 7 years for device development. Drugs must be developed, go through pre-clinical testing, and then three stages of clinical trials. The clinical trial process alone lasts about 6 to 7 years on average. If proven safe and effective in trials, a drug must then seek Food and Drug Administration (FDA) approval. The FDA regulatory process for an MPT will likely be even slower and more tedious than single indication health technologies since MPTs could qualify as drugs, biological products, devices, or any combination of the three. Beyond the FDA, MPTs must also meet the regulatory requirements in any country in which they are used. Fernández-Romero et al explains some of the challenges gaining regulatory approval just in the US. This process requires review by multiple groups within the Center for Drug Evaluation and Research (CDER) and, if a MPT also involves a drug delivery device, reviews with the Center for Devices and Regulatory Health. The FDA has already approved various drugs that may become components of a MPT (i.e. those currently used to treat HIV), but other contraceptive or prophylactic drugs would need individual approval from regulatory bodies, separate from the MPT device itself.
Hormonal & Acceptability Challenges
Since the MPTs farthest along in development right now mainly use existing ARV treatment drugs, the potential for drug resistance is a major concern if these drugs are used prophylactically on a larger scale. Few new HIV prevention compounds have been created to deal with this problem. Likewise, few new contraceptive compounds, especially non-hormonal, have been created to diversify products and serve the needs of women who cannot take or do not want to take hormonal contraceptives.
For efficacy and acceptability research to advance, target populations must be included to increase knowledge on end-user needs and opinions. In this case, adolescent and young adult women stand to benefit the most from MPT creation. Nonetheless, it remains ethically and technically challenging to conduct trials on these populations, given the sensitive nature of studies regarding sexual health and adolescent pregnancy. Researchers will face the challenges of determining a control group for their trials and deciding if pre-exposure prophylaxis (PreP) will be incorporated as a necessary precaution against HIV for the control group.
It is clear that MPTs have many barriers to overcome before they reach our local markets. The road ahead is long. Nonetheless, these barriers are all surmountable with enough political commitment, financial backing, and dedication to ethical global health principles. Once the scientific and regulatory hurdles are overcome, MPTs are a huge step closer to being available in our markets.
–Emily Nagler, Duke University 2019