Drug com­pa­nies look for less toxic treat­ments for ag­ing HIV pa­tients

▶ As pa­tients age, drug­mak­ers seek less toxic treat­ments ▶ “The drugs came along—and we all started liv­ing”

Bloomberg Businessweek (Asia) - - CONTENTS - Ke­taki Gokhale

Two decades ago, Gus Cairns was cer­tain AIDS would kill him. He’d buried his part­ner and seen count­less friends suc­cumb to the dis­ease. Cairns was con­stantly tired, suf­fered chronic stom­ach bugs, and had lost 35 pounds. In 1993, he re­tired from his work as a ther­a­pist to start pre­par­ing for the in­evitable. But death didn’t come. “We were at the peak of peo­ple dy­ing of AIDS, and then the drugs came along— and we all started liv­ing,” says Cairns, ap­pear­ing fit and vig­or­ous as he sips tea at a cafe near Lon­don’s King’s Cross rail­way sta­tion. “It’s as­tound­ing.”

At age 60, Cairns has be­come the new face of HIV. An­tiretro­vi­ral ther­apy has turned what was once a death sen­tence into a chronic dis­ease, which means more pa­tients are liv­ing into their 60s and even 70s. By 2020, more than 70 per­cent of HIV-pos­i­tive peo­ple in the U.S. will be over 50, ac­cord­ing to the AIDS Com­mu­nity Re­search Ini­tia­tive of Amer­ica.

That’s an un­al­loyed suc­cess, but HIV med­i­ca­tions are typ­i­cally toxic for not only the virus but also the peo­ple who take them. This presents drug­mak­ers with new chal­lenges: mak­ing med­i­ca­tions that sub­due the ill­ness with­out wreak­ing havoc on ag­ing bod­ies and min­i­miz­ing the risk of harm­ful drug in­ter­ac­tions for peo­ple who might have to take their HIV med­i­ca­tions along­side pills for blood pres­sure, cholesterol, or di­a­betes.

Since 1996, HIV has been treated with com­bi­na­tion ther­a­pies, in which three or more drugs at­tack the virus so it has a harder time de­vel­op­ing re­sis­tance. Gilead’s Tru­vada, the pre­ferred ba­sis of com­bi­na­tions, is known for harsh side ef­fects such as kid­ney dam­age and loss of bone den­sity, prob­lems that are typ­i­cally worse for older pa­tients.

Glax­oSmithK­line — the com­pany that cre­ated the first HIV drug, AZT— is work­ing on eas­ier-to-tol­er­ate twodrug com­bi­na­tions. In 2013, it in­tro­duced a treat­ment that’s less toxic than older for­mu­las and that makes it hard for the virus to de­velop re­sis­tance. The drug, Tivicay, is typ­i­cally used with other med­i­ca­tions—often in­clud­ing Tru­vada—and re­searchers say it might be­come the foun­da­tion of sim­pler two-drug reg­i­mens.

The drive to sim­plify treat­ment could af­fect the com­pet­i­tive land­scape. As word of Tivicay spread, Glaxo made small gains in AIDS-drug mar­ket share in 2014, re­vers­ing more than

a decade of losses. UBS says that if Glaxo’s dual reg­i­mens prove ef­fec­tive, the com­pany could cap­ture half the mar­ket by 2023, up from 17 per­cent to­day. Ex­ist­ing treat­ments “have long-term tox­i­c­ity prob­lems,” says Do­minique Limet, chief ex­ec­u­tive of­fi­cer of ViiV, a joint ven­ture of Glaxo, Ja­pan’s Shionogi, and Pfizer that makes HIV treat­ments. Two-drug ther­a­pies, he says, could be less dam­ag­ing to pa­tients and cheaper to ad­min­is­ter.

Gilead got Food and Drug Ad­min­is­tra­tion ap­proval for an up­graded ver­sion of Tru­vada this year that re­places the in­gre­di­ent con­nected to kid­ney and bone prob­lems with a for­mu­la­tion that causes fewer side ef­fects. The com­pany says it’s in­tro­duced two com­bi­na­tion ther­a­pies based on the com­pound and is de­vel­op­ing more. The up­grade will help Gilead off­set lost rev­enue when a key patent for the orig­i­nal Tru­vada ex­pires next year, open­ing the door to low-cost generic ver­sions.

Tivicay be­longs to a group of drugs called in­te­grase in­hibitors that pre­vent the HIV virus from repli­cat­ing in the body. Left unchecked, HIV turns im­mune cells into virus fac­to­ries, us­ing the en­zyme in­te­grase to insert its DNA into healthy cells—but com­pounds like Tivicay block that process. Glaxo, which says the drug can de­crease the virus to un­de­tectable lev­els in 70 per­cent of pa­tients, is test­ing two-drug com­bi­na­tions of Tivicay and other com­pounds. Such ad­vances were once al­most unimag­in­able for pa­tients like Cairns, who re­calls the early days when an­tiretro­vi­ral ther­apy often con­sisted of 20 to 30 pills a day. To­day he takes five pills daily, in a reg­i­men based on Tru­vada, and the virus has been al­most un­de­tectable in his blood for 18 years. “It was a close call,” Cairns says. “The com­bi­na­tion ther­apy got to me just in time.”

Cairns con­tin­ues his work as a ther­a­pist and ed­its a news­let­ter for an HIV group; in his spare time, he tends his gar­den and has re­turned to a great pas­sion of his 20s: singing. He says he’s heard about Tivicay and is in­trigued—it’s got lim­ited side ef­fects, he’d need to take fewer pills, and the virus is slower to de­velop re­sis­tance— but for now, he’s stick­ing with his cur­rent ther­apy, since it’s work­ing. Tivicay “has the sort of pro­file you want for an HIV drug,” Cairns says. “But at the mo­ment I’m fine with what I’ve got.”

The bot­tom line Glaxo is try­ing to de­velop less harm­ful, two-drug treat­ments for HIV, which could threaten the mar­ket lead­er­ship of Gilead’s Tru­vada.

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