What is contribution of components (CoC)?

Contribution of components (CoC) refers to the impact that specific therapies that are part of a broader set of combination treatment are having for the overall outcome. For example, in a combination treatment of drug A and drug B, one may want to know what drug A means for outcomes when added to drug B compared to using drug B alone. The same question might come up for drug B as an add-on compared to drug A alone. Contribution of components is something that regualators or other health authorities may question pharma companies on, especially when trials did not specifically compare monotherapy to combination therapy.