Doctors Without Borders (MSF) often has a bone to pick with Big Pharma, especially when it comes to the industry's patents on expensive life-extending meds. As part of its latest campaign, the group is urging the South African government to override a patent for AbbVie's ($ABBV) HIV drug, Aluvia, after shortages of the med cropped up in the country.

Back in April, patient numbers began to rise in South Africa, and the North Chicago, IL-based company faced capacity constraints at its European plant, leading to reduced supplies of the drug, Gavin Steel, head of industrywide procurement in South Africa's Department of Health, told Crain's Chicago Business. AbbVie is the country's only supplier of Aluvia (lopinavir/ritonavir), which is used by about 10% of the 3 million patients on treatment, MSF said in a statement.

Steel said that AbbVie has since resolved the issue, with Aluvia supply picking up by mid-July after three additional manufacturing sites were approved. By October, there were no back orders of the med, Crain's reports.

But MSF is still hopping mad about the shortages and wants the South African government to grant a compulsory license on the drug. AbbVie has "consistently undercut prices" on generic versions of other brands, to discourage competition, the group said in a statement.

MSF's Dr. Amir Shroufi

"Since AbbVie has refused to act appropriately to ensure that patients obtain the medicines they need to stay healthy and alive, the South African government should be compelled to take action," Dr. Amir Shroufi, MSF's Deputy Medical Coordinator in South Africa, said in a statement.

AbbVie is not bowing under pressure. The company has a supply plan that meets monthly requirements in South Africa and any unexpected extra demand, spokesman Ahmed Negm told Crain's in an email. AbbVie's patent for the med's compound is set to expire in December 2016, he added.

And while South Africa's Department of Health "has heard the call" from MSF, the agency is treading lightly, Steel said. AbbVie has already addressed the shortages, and South Africa now has three times the required supply of Aluvia on hand. Plus, prices quoted by companies that supply off-patent generic meds are higher than what AbbVie charges for its HIV brand. The government will continue to meet with AbbVie weekly to discuss supply and "continue to ensure that the interventions have been sustained," Steel told Crain's.

This isn't the first time pharma has faced the threat of a compulsory license and it most likely won't be the last. The tactic, while still uncommon, often appears in cash-strapped developing countries pushing for lower-cost meds. In 2012, India granted its first-ever compulsory license to Natco Pharma, forcing Bayer to license its cancer drug Nexavar to the company.

Last month, a U.K. patient group urged the country's health minister to override Roche's ($RHHBY) patents for its pricey breast cancer drug Kadcyla, which would open the door for other companies to manufacture or import cut-price biosimilars.