Indian pharmaceutical company Ranbaxy has told the World Health Organization (WHO) that it is voluntarily withdrawing seven of its antiretroviral products from the WHO `prequalified` list and conducting new tests on all the drugs following the discovery of `discrepancies` in bioequivalence data on one product provided by a contract research laboratory in India.
Ranbaxy withdrew three products from the list in August following a WHO-mandated inspection of the contract research organisation that carried out antiretroviral studies on behalf of Ranbaxy.
WHO emphasised on Monday that there is no evidence that the products are substandard, but that patients should suspend the use of de-listed medicines and switch to other prequalified products.
WHO also went slightly further in hinting at serious problems with the data that were submitted by generic manufacturers, saying that there were “serious discrepancies between the original results compiled by the contract research organisations and the results presented to WHO."
The WHO prequalification programme reviews data on the bioequivalence of generic copies of branded antiretrovirals. These are largely manufactured by Indian companies, and WHO checks data from studies that are carried out to demonstrate that the generic copies produce equivalent blood levels of the active drug to the originator product, and that the pills contain the right amount of drug.
The programme is intended to provide a checklist of approved products that United Nations agencies and others can buy, safe in the knowledge that they are all of an equivalent standard. The list is also intended to help national governments make decisions about whether to use generic products.
The seven prequalified medicines Ranbaxy is withdrawing are:
- Indinavir 400mg capsule, blister (60, 100).
- Lamivudine 150mg tablet, blister (60, 100).
- Lamivudine/Stavudine 150mg/40mg tablet, Al strip (10), 60 in box.
- Lamivudine/Stavudine 150mg/30mg tablet, Al strip (10), 60 in box.
- Nevirapine 200mg tablet, blister (60, 100).
- Stavudine 30 mg capsule, Al strip (10), 60 in box.
- Zidovudine 300 mg tablet, blister (60, 100).
Ranbaxy’s partner company in South Africa, Thembalami, withdrew four products from the South African market for the same reason in late October. These are:
- Lamivudine 150mg tablets.
- Zidovudine 300mg tablets.
- Nevirapine 200g tablets.
- The combined lamivudine/zidovudine tablets.
The company also withdrew from the tender process to supply antiretroviral products for South Africa’s treatment roll-out programme, leaving one South African and one Indian generic manufacturer in the running.
WHO says that where alternative prequalified products are not available, patients should continue the use of de-listed products, as the risk of withholding treatment is higher than that of providing medicines whose bioequivalence is not proven but which have otherwise been prequalified. A switch to non-prequalified products is not recommended as their quality has not been documented by WHO.