NEW YORK – Measuring the presence of antipsychotic drugs in a patient's system is currently a time-consuming and unwieldy process, but therapeutic drug monitoring firm Saladax Biomedical is looking to change that with an agreement announced last month with Danaher subsidiary Beckman Coulter.
The deal, according to Saladax CEO and Founder Sal Salamone, will allow Saladax to have a "global footprint" with its drug tests. Added the firm's Chief Commercial Officer Maria Foster, its nanoparticle-based immunoassays can help change the standard of care in the antipsychotic drug monitoring field.
Currently, the testing standard for measuring these drugs in patients is liquid chromatography-mass spectrometry — a nonautomated process that can take days to return results and requires specialized expertise and a highly complex laboratory.
Because of the time lag, which can be anywhere from three days to three weeks, many clinicians don't actually end up ordering tests for patients, Salamone said. "By the time the psychiatrist gets the results back, it's worthless." That turnaround time "diminishes the clinical utility" of testing for the drugs in the first place, Foster added.
Saladax decided to apply classic immunoassay techniques to antipsychotic drug testing in an attempt to speed up the process. The company has managed to "successfully [patent] out the entire field," Salamone said, and with the help of Janssen Pharmaceuticals has established "significant" intellectual property protection. The Bethlehem, Pennsylvania-based firm has 345 validated patents.
"We hold this unique position in the field," he said.
While Saladax is talking to other major diagnostic companies and hasn't exclusively partnered with Beckman Coulter, Salamone said Saladax chose to work with the firm because it has a significant part of the clinical chemistry analyzer market.
Saladax doesn't have the distribution channels Beckman has and partnering with the company "give[s] us global presence we would never be able to afford on our own," Foster said.
Carol Gustafson, Beckman Coulter's VP of global clinical chemistry product management, said that Saladax's tests meet a "significant unmet need" and can help determine drug tolerance, adherence, and responsiveness. Clinicians in the antipsychotic drug monitoring field "lack timely and useful tools" in this area and have "little quantitative insight" into the effects of drugs on patients, but Saladax's tests can help fix that.
Putting the tests on automated analyzers, such as Beckman Coulter's AU series of instruments, significantly shortens the turnaround time and resources needed to perform the assays, she noted. They require no specialized equipment or training and can be used in a variety of settings, including hospital labs, psychiatric wards, small physician office labs, and reference labs.
Early feedback from users has emphasized how easy the tests are to use and the benefits of fewer steps and the improved turnaround time, Gustafson said. There are also early indications of cost satisfaction, although she declined to specify the prices of tests.
Both firms emphasized the importance of these kinds of tests, with Saladax's Foster noting the negative impact the lack of available testing has had on patients with psychiatric disorders. It's a "game changer" of a field, she said.
"These patients deserve the same care that we would give to any patient that is sick with a different disease," she said. "And today they're not getting it, in terms of lab support."
Saladax's immunoassay format isn't especially unique. Indeed, "this type of assay is used in many different types of tests that are out on the market currently," Salamone said, and the technology isn't new — clinical chemistry analyzers are available in most central and reference laboratories. "It's just like any other chemistry test," Foster added.
Running the tests is simple, Foster noted, requiring only a venous blood draw, some reagents, and an analyzer. And because many patients on antipsychotic drugs already get their blood drawn for other tests, it doesn't necessarily require an extra step, she said.
Once the sample and reagents are loaded onto an automated analyzer, the time to the first result takes about 10 to 15 minutes, and depending on the throughput of the analyzer, hundreds of tests can be run in an hour, Salamone said. The assays use a two-reagent system, where two vials are loaded onto the analyzer — each type of test uses a different set of reagents. On an analyzer like Beckman Coulter's AU 480 analyzer, 80 reagents might be placed at one time, allowing multiple analytes to be measured with a single sample, he said.
One of the two reagents has an antibody that is coupled to nanoparticles, and the other has a multivalent drug conjugate. When those reagents are mixed with the sample, an aggregation of the nanoparticles occurs, followed by a difference in light characteristics of the solution. The amount of aggregation is inversely proportional to the amount of the drug present in the sample, Salamone said.
The immunoassays are "highly quantitative," he noted, allowing clinicians to measure precisely how much of a certain drug is present in a patient's system. By measuring the amount of active medication, a physician can determine whether a patient is at the right dosage level. While "everybody metabolizes a drug differently," the results of the test can help healthcare providers determine whether the levels are appropriate for the patient, Salamone said.
Inaccurate drug levels can be a safety issue — too high of a dose can cause "major toxicity issues" and side effects, while too low a dose won't be as effective, he said. Receiving the results "in a clinically timely manner" means those potential safety issues can be resolved quickly by a healthcare provider, Foster added.
Another key aspect of drug monitoring is the ability to determine a patient's adherence. Approximately 40 percent to 60 percent of patients on antipsychotic drugs are noncompliant, but trying to determine whether low levels of a drug in a patient's system indicate actual noncompliance, ineffectiveness of the drug, or quick metabolization can be a challenge, Salamone said. If a clinician has a quantitative drug level, as is supplied by Saladax's tests, they can determine the reason for that level. When a patient is in the therapeutic range but still not responding, that patient may be resistant to the drug. If they have a lower level than the reference range, they may be metabolizing quickly or not adhering to the dose requirements.
It's "a tool that is invaluable for making a diagnosis," Salamone said. "There are a lot of people that need this type of medication and need to be managed."
For all of Saladax's tests, "the key is speed," he said.
Currently, the firm offers five MyCare Psychiatry tests for six different drugs used to treat disorders like schizophrenia and bipolar: clozapine, risperidone, paliperidone, aripiprazole, olanzapine, and quetiapine. The patent rights to the clozapine, aripiprazole, olanzapine, and quetiapine tests were acquired by Saladax from Janssen in 2018.
The company's MyCare Insite clozapine assay received CE marking in 2019 and de novo clearance from the US Food and Drug Administration in 2020. All five of the assays received Health Canada approval in February 2021 and are available through HLS Therapeutics. The tests have also received approval from China's National Medical Products Administration, Salamone said.
The firm's risperidone and paliperidone joint test has been submitted to the FDA and is pending approval. Getting the approval has been a "challenging" and prolonged process, since the test was submitted in the middle of the COVID-19 pandemic and there have been significant backlogs for clearance of non-COVID-19 tests at the agency, Salamone said.