Revo­lu­tion and re­ac­tion in bio­pharm­ing

“The food in­dus­try’s wor­ries that bio­pharmed plants could con­tam­i­nate their prod­ucts are overblown. And in any case, the risk can be mit­i­gated in sev­eral ways, most ob­vi­ously by us­ing non-food plants like to­bacco”

Financial Mirror (Cyprus) - - FRONT PAGE -

Ob­tain­ing medicines from plants is not new. Aspirin was first iso­lated from the bark of the wil­low tree in the eigh­teenth cen­tury. And many other com­mon phar­ma­ceu­ti­cals, in­clud­ing mor­phine, codeine, and the fiber sup­ple­ment Me­ta­mu­cil, are pu­ri­fied from the world’s flora.

More re­cently, sci­en­tists have de­vel­oped tech­niques that take this process a step fur­ther, us­ing ge­netic en­gi­neer­ing to in­duce agri­cul­tural crops to syn­the­sise high-value phar­ma­ceu­ti­cals. Known as “bio­pharm­ing,” the great prom­ise of this tech­nol­ogy emerged about 15 years ago, with clin­i­cal tri­als of vac­cines and drugs pro­duced in bananas, toma­toes, and to­bacco. Un­for­tu­nately, progress has since stalled, ow­ing to the ve­he­ment risk-aver­sion of reg­u­la­tors.

One early ex­am­ple of bio­pharm­ing was the pro­duc­tion by the biotech com­pany Ven­tria Bio­science of rice that con­tained two hu­man pro­teins, lacto­fer­rin and lysozyme. Once grown and har­vested, the rice ker­nel is pro­cessed to ex­tract and pu­rify the pro­teins for use in oral re­hy­dra­tion so­lu­tion for treat­ing di­ar­rhea, which is sur­passed only by res­pi­ra­tory dis­eases as the lead­ing in­fec­tious killer of chil­dren un­der the age of five in de­vel­op­ing coun­tries.

The pro­teins have the same struc­ture and func­tional prop­er­ties as those found in nat­u­ral breast milk, and the process for ex­tract­ing them is anal­o­gous to that used rou­tinely for the pro­duc­tion of ther­a­peu­tic pro­teins from or­gan­isms like bac­te­ria and yeast. Re­search in Peru showed that for­ti­fy­ing an oral-re­hy­dra­tion so­lu­tion with the pro­teins ex­tracted from Ven­tria’s rice sub­stan­tially lessens the du­ra­tion of di­ar­rhea and re­duces the rate of re­cur­rence – a near-mirac­u­lous ad­vance for peo­ple in the de­vel­op­ing world.

But reg­u­la­tors can undo mir­a­cles, and they regularly do. When Ven­tria ap­proached the US Food and Drug Ad­min­is­tra­tion in 2010 for recog­ni­tion that these pro­teins are “gen­er­ally recog­nised as safe” (a reg­u­la­tory term of art), it re­ceived no re­sponse. With­out an endorsement by the FDA, the com­pany was un­will­ing to mar­ket the prod­uct, and so it re­mains un­avail­able, trag­i­cally de­priv­ing chil­dren in de­vel­op­ing coun­tries of a life-sav­ing ther­apy.

Even field test­ing bio­pharmed plants has proved prob­lem­atic. In 2003, the US Depart­ment of Agri­cul­ture an­nounced oner­ous new rules for test­ing crops en­gi­neered to pro­duce phar­ma­ceu­ti­cals. The os­ten­si­ble ob­jec­tive of the reg­u­la­tion is to avoid con­tam­i­nat­ing food sup­plies with drugs, es­pe­cially when ed­i­ble crops are used to pro­duce them. But the food in­dus­try’s wor­ries that bio­pharmed plants could con­tam­i­nate their prod­ucts are overblown. And in any case, the risk can be mit­i­gated in sev­eral ways, most ob­vi­ously by us­ing non-food plants like to­bacco.

In fact, even if bio­pharmed plants were to con­tam­i­nate food crops, the like­li­hood that con­sumers would end up with harm­ful amounts of pre­scrip­tion drugs in their corn flakes, pasta, or tofu is very small. Gene flow is an age-old process that is well un­der­stood by farm­ers, who grow hun­dreds of crops, vir­tu­ally all of which have been ge­net­i­cally im­proved in some way with a va­ri­ety of tech­niques. As a re­sult, they have de­vel­oped metic­u­lous strate­gies for pre­vent­ing pollen cross­con­tam­i­na­tion in the field – when and if it is nec­es­sary for com­mer­cial rea­sons.

Even if some crops were to be­come con­tam­i­nated, the chances that ac­tive drug sub­stances would be present in the fi­nal food prod­uct at suf­fi­cient lev­els to have an ad­verse ef­fect on hu­man health would re­main very small. The bio­pharmed plant would be pooled into a large harvest, where its phar­ma­ceu­ti­cals would be heav­ily di­luted. The ac­tive agent would then need to sur­vive milling and other pro­cess­ing, and then cook­ing, and it would need to be orally ac­tive, which pro­tein drugs most of­ten are not, be­cause they are di­gested in the stom­ach.

The chance of all of this oc­cur­ring is not zero, of course. But, with a com­bi­na­tion of fac­tors – in­clud­ing nat­u­ral se­lec­tion, farm­ers’ pur­suit of their com­mer­cial self-in­ter­est, and li­a­bil­ity con­cerns – mil­i­tat­ing against such a pos­si­bil­ity, the odds are very long, and the im­pact would al­most cer­tainly be very low. When you weigh this against the pos­si­bil­ity of the de­vel­op­ment of the drug in­dus­try’s Next Big Thing or, at the very least, a new method to pro­duce high-value com­pounds at low cost, reg­u­la­tors’ pre­oc­cu­pa­tion with such un­likely events ap­pears to be mis­placed.

Bio­pharm­ing has much to of­fer us. If we are to reap what we can sow, how­ever, we will need rea­son­able, science-based poli­cies from reg­u­la­tors world­wide. Sadly, to bor­row a phrase from the late No­bel lau­re­ate economist Milton Fried­man, that is like wish­ing that our cats could bark.

Newspapers in English

Newspapers from Cyprus

© PressReader. All rights reserved.