Information technology also plays a key role for CombinatoRx (which is pronounced com-bin-a-TOR-ics, as in the mathematics field that deals with combinations). The company relies on the latest robotic drug-screening technology and software to test several thousand pairs of medicines a day.

At its laboratory here, researchers and robots systematically pair about 2,000 generic drugs with one another, with 2 million different combinations possible. Each is tested on human cells. If a drug pair inhibits the cells’ production of inflammatory proteins, for example, that might be reason to explore whether the combination might work against arthritis.

Mr. Borisy describes it as a “dumb, brute-force, empirical approach” that assumes current knowledge of disease is too limited to predict in advance what combinations might work. The company does, though, give priority to testing pairs it believes have the best chance of working.

Image Credit... Illustration by The New York Times

Eight of the company’s randomly arranged marriages, including drugs for cancer, arthritis and diabetes, have moved into clinical trials — an unusually high number for a company that is only seven years old. Other companies are taking more calculated approaches. Orexigen, in creating its obesity drug Contrave, took a treatment used for drug and alcohol addiction and combined it with an antidepressant sometimes used to help people quit smoking.

Meanwhile, Celator is focusing on drugs that are already used together to treat cancer. But while doctors now generally use the maximum tolerable dose of each drug, Celator says the ratio of the drugs is what matters more. So the company is developing combination products meant to deliver optimal ratios of the drugs to tumors.

Besides being quicker or cheaper to develop than single new drugs, combinations might also be more effective. Scientists have long known that the biochemical pathways involved in disease are complex, with numerous alternate routes. Trying to interfere with disease by blocking a single point can be like trying to keep traffic from reaching downtown Manhattan by closing a single intersection.